Cells-and-Tissues and. moinoaidnionjobuibui iubuib

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1. Chapter 3
Cells and Tissues
Lecture Presentation by
Patty Bostwick-Taylor
Florence-Darlington Technical College
Image PowerPoint slides to accompany
Cell Structures and
Their Functions
Chapter 03

2. Part I: Cells
Cells are the structural units of all living things
The human body has 50 to 100 trillion cells
© 2018 Pearson Education, Ltd.

3. Overview of the Cellular Basis of Life
The Cell Theory
1.A cell is the basic structural and functional unit of
living organisms
2.The activity of an organism depends on the collective
activities of its cells
3.According to the principle of complementarity, the
biochemical activities of cells are dictated by their
structure (anatomy) which determines their function
(physiology)
4.Continuity of life has a cellular basis
© 2018 Pearson Education, Ltd.

4. FUNCTIONS OF THE CELL
1.Cell metabolism and energy use – energy
released during metabolism is used for cell
activities, such as the synthesis of new
molecules, muscle contraction, and heat
production, which helps maintain body temp.
2.Synthesis of molecule - cell synthesize various
types of molecules, including proteins, nucleic
acids and lipids.

© 2018 Pearson Education, Ltd.

5. FUNCTIONS OF THE CELL
3. COMMUNICATION – cells produce and receive
chemical and electrical signals that allow them to
communicate with one another.

4. REPRODUCTION & INHERITANCE – each cell
contains a copy of the genetic information of the
individual.
© 2018 Pearson Education, Ltd.

6. Anatomy of a Generalized Cell
In general, a cell has three main regions or parts:
1.Nucleus
2.Cytoplasm
3.Plasma membrane
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7. © 2018 Pearson Education, Ltd.
Figure 3.1a Anatomy of the generalized animal cell nucleus.
Nucleus
Cytoplasm
Plasma
membrane
(a) Generalized animal cell

8. © 2018 Pearson Education, Ltd.
Figure 3.1

9. © 2018 Pearson Education, Ltd.
Table 3.1

10. The Plasma Membrane
Transparent barrier for cell contents
Contains cell contents
Separates cell contents from surrounding
environment
© 2018 Pearson Education, Ltd.

11. The Plasma Membrane
Fluid mosaic model is constructed of:
Two layers of phospholipids arranged ―tail to tail‖
Cholesterol and proteins scattered among the
phospholipids
Sugar groups may be attached to the phospholipids,
forming glycolipids
© 2018 Pearson Education, Ltd.

12. Figure 3.2 Structure of the plasma membrane.
Extracellular fluid
(watery environment)
Glycoprotein Glycolipid
Cholesterol
Sugar group
Polar heads of
phospholipid
molecules
Bimolecular
lipid layer
containing
proteins
Nonpolar tails of
phospholipid
molecules
Channel
Proteins Filaments of
cytoskeleton
Cytoplasm
(watery environment)
© 2018 Pearson Education, Ltd.

13. © 2018 Pearson Education, Ltd.

14. The Plasma Membrane
Phospholipid arrangement in the plasma
membrane
Hydrophilic (―water loving‖) polar ―heads‖ are oriented
on the inner and outer surfaces of the membrane
Hydrophobic (―water fearing‖) nonpolar ―tails‖ form the
center (interior) of the membrane
This interior makes the plasma membrane relatively
impermeable to most water-soluble molecules
© 2018 Pearson Education, Ltd.

15. The Plasma Membrane
Role of proteins
Responsible for specialized membrane functions:
Enzymes
Receptors for hormones or other chemical messengers
Transport as channels or carriers
© 2018 Pearson Education, Ltd.

16. The Plasma Membrane
Role of sugars
Glycoproteins are branched sugars attached to
proteins that abut the extracellular space
Glycocalyx is the fuzzy, sticky, sugar-rich area on the
cell’s surface
© 2018 Pearson Education, Ltd.

17. The Plasma Membrane
Cell membrane junctions
Cells are bound together in three ways:
1.Glycoproteins in the glycocalyx act as an adhesive or
cellular glue
2.Wavy contours of the membranes of adjacent cells fit
together in a tongue-and-groove fashion
3.Special cell membrane junctions are formed, which
vary structurally depending on their roles
© 2018 Pearson Education, Ltd.

18. The Plasma Membrane
Main types of cell junctions
Tight junctions
Impermeable junctions
Bind cells together into leakproof sheets
Plasma membranes fuse like a zipper to prevent
substances from passing through extracellular space
between cells
© 2018 Pearson Education, Ltd.

19. The Plasma Membrane
Main types of cell junctions (continued)
Desmosomes
Anchoring junctions, like rivets, that prevent cells from
being pulled apart as a result of mechanical stress
Created by buttonlike thickenings of adjacent plasma
membranes
© 2018 Pearson Education, Ltd.

20. The Plasma Membrane
Main types of cell junctions (continued)
Gap junctions (communicating junctions)
Allow communication between cells
Hollow cylinders of proteins (connexons) span the width
of the abutting membranes
Molecules can travel directly from one cell to the next
through these channels
© 2018 Pearson Education, Ltd.

21. Figure 3.3 Cell junctions.
Microvilli Tight
(impermeable)
junction
Desmosome
(anchoring
junction)
Plasma
membranes of
adjacent cells
Connexon
Gap
(communicating)
junction
Underlying
basement
membrane
Extracellular
space between
cells
© 2018 Pearson Education, Ltd.

22. Membrane Transport
Solution—homogeneous mixture of two or more
components
Solvent—dissolving medium present in the larger
quantity; the body’s main solvent is water
Solutes—components in smaller quantities within a
solution
© 2018 Pearson Education, Ltd.

23. Membrane Transport
Intracellular fluid
Nucleoplasm and cytosol
Solution containing gases, nutrients, and salts
dissolved in water
Extracellular fluid (interstitial fluid)
Fluid on the exterior of the cell
Contains thousands of ingredients, such as nutrients,
hormones, neurotransmitters, salts, waste products
© 2018 Pearson Education, Ltd.

24. Membrane Transport
The plasma membrane is a selectively permeable
barrier
Some materials can pass through, while others are
excluded
For example:
Nutrients can enter the cell
Undesirable substances are kept out
© 2018 Pearson Education, Ltd.

25. Membrane Transport
Two basic methods of transport
Passive processes: substances are transported across
the membrane without any input from the cell
Active processes: the cell provides the metabolic
energy (ATP) to drive the transport process
© 2018 Pearson Education, Ltd.

26. Membrane Transport
Concentration gradient –the difference in a
concentration of a solute in a solvent between 2
points divided by a distance 2 points.
© 2018 Pearson Education, Ltd.

27. A&P Flix
TM
: Membrane Transport
© 2018 Pearson Education, Ltd.

28. Membrane Transport
Passive processes: diffusion and filtration
Diffusion
Molecule movement is from high concentration to low
concentration, down a concentration gradient
Particles tend to distribute themselves evenly within a
solution
Kinetic energy (energy of motion) causes the molecules
to move about randomly
Size of the molecule and temperature affect the speed
of diffusion
© 2018 Pearson Education, Ltd.

29. © 2018 Pearson Education, Ltd.
Figure 3.9 Diffusion.

30. © 2018 Pearson Education, Ltd.
Figure 3.3

31. Membrane Transport
Molecules will move by diffusion if any of the
following applies:
The molecules are small enough to pass through
the membrane’s pores (channels formed by
membrane proteins)
The molecules are lipid-soluble
The molecules are assisted by a membrane
carrier
© 2018 Pearson Education, Ltd.

32. Membrane Transport
Types of diffusion
Simple diffusion
An unassisted process
Solutes are lipid-soluble or small enough to pass
through membrane pores
© 2018 Pearson Education, Ltd.

33. © 2018 Pearson Education, Ltd.
Figure 3.10a Diffusion through the plasma membrane.
Extracellular fluid
Lipid-
soluble
solutes
Cytoplasm
(a) Simple diffusion
of lipid-soluble
solutes directly
through the
phospholipid
bilayer

34. © 2018 Pearson Education, Ltd.
Figure 3.4

35. Membrane Transport
Types of diffusion (continued)
Osmosis—simple diffusion of water across a
selectively permeable membrane
Highly polar water molecules easily cross the plasma
membrane through aquaporins
Water moves down its concentration gradient
© 2018 Pearson Education, Ltd.

36. © 2018 Pearson Education, Ltd.
Figure 3.10b Diffusion through the plasma membrane.
Water
molecules
(b) Osmosis,
diffusion of water
through a specific
channel protein
(aquaporin)

37. Membrane Transport
Osmosis—A Closer Look
Isotonic solutions have the same solute and water
concentrations as cells and cause no visible changes
in the cell
Hypertonic solutions contain more solutes than the
cells do; the cells will begin to shrink
Hypotonic solutions contain fewer solutes (more water)
than the cells do; cells will plump
© 2018 Pearson Education, Ltd.

38. © 2018 Pearson Education, Ltd.
A Closer Look 3.1 IV Therapy and Cellular “Tonics.”
(a) RBC in isotonic solution (b) RBC in hypertonic solution (c) RBC in hypotonic solution

39. © 2018 Pearson Education, Ltd.
Figure 3.7

40. Membrane Transport
Types of diffusion (continued)
Facilitated diffusion
Transports lipid-insoluble and large substances
Glucose is transported via facilitated diffusion
Protein membrane channels or protein molecules that
act as carriers are used
© 2018 Pearson Education, Ltd.

41. © 2018 Pearson Education, Ltd.
Figure 3.10cd Diffusion through the plasma membrane.
Small lipid-
insoluble
solutes
Lipid-
insoluble
solutes
Lipid
bilayer
(d) Facilitated diffusion via
protein carrier specific for one
chemical; binding of substrate
causes shape change in
transport protein
(c) Facilitated
diffusion through
a channel protein;
mostly ions,
selected on basis
of size and charge

42. Membrane Transport
Passive processes
Filtration
Water and solutes are forced through a membrane by
fluid, or hydrostatic, pressure
A pressure gradient must exist that pushes solute-
containing fluid (filtrate) from a high-pressure area to a
lower-pressure area
Filtration is critical for the kidneys to work properly
© 2018 Pearson Education, Ltd.

43. Membrane Transport
Active processes
ATP is used to move substances across a membrane
Active processes are used when:
Substances are too large to travel through membrane
channels
The membrane may lack special protein carriers for the
transport of certain substances
Substances may not be lipid-soluble
Substances may have to move against a concentration
gradient
© 2018 Pearson Education, Ltd.

44. Membrane Transport
Active processes (continued)
Active transport and vesicular transport
Active transport
Amino acids, some sugars, and ions are transported by
protein carriers known as solute pumps
ATP energizes solute pumps
In most cases, substances are moved against
concentration (or electrical) gradients
© 2018 Pearson Education, Ltd.

45. Membrane Transport
Active transport example: sodium-potassium
pump
Necessary for nerve impulses
Sodium is transported out of the cell
Potassium is transported into the cell
© 2018 Pearson Education, Ltd.

46. © 2018 Pearson Education, Ltd.
Figure 3.11 Operation of the sodium-potassium pump, a solute pump.
Binding of cytoplasmic Na
+
to the pump protein stimulates
phosphorylation by ATP, which
causes the pump protein to
change its shape.
The shape change expels
Na
+
to the outside. Extracellular
K
+
binds, causing release of the
inorganic phosphate group.
Loss of phosphate restores
the original shape of the pump
protein. K
+
is released to the
cytoplasm, and Na
+
sites are
ready to bind Na
+
again; the
cycle repeats.
Cytoplasm
Extracellular fluid
Na
+
Na
+
K
+
Na
+
Na
+
Na
+
P
i
K
+
Na
+
P
i
ATP
ADP
Na
+
K
+
K
+
Na
+-K
+ pump
1 2 3
2 3 1
Slide 1

47. © 2018 Pearson Education, Ltd.
Figure 3.8

48. © 2018 Pearson Education, Ltd.
Figure 3.9

49. © 2018 Pearson Education, Ltd.
Figure 3.10

50. © 2018 Pearson Education, Ltd.
Figure 3.11 Operation of the sodium-potassium pump, a solute pump.
Binding of cytoplasmic Na
+
to the pump protein stimulates
phosphorylation by ATP, which
causes the pump protein to
change its shape.
Cytoplasm
Extracellular fluid
Na
+
Na
+
P
i
Na
+
ATP
ADP
Na
+-K
+ pump
1
Slide 2
1

51. © 2018 Pearson Education, Ltd.
Figure 3.11 Operation of the sodium-potassium pump, a solute pump.
Binding of cytoplasmic Na
+
to the pump protein stimulates
phosphorylation by ATP, which
causes the pump protein to
change its shape.
The shape change expels
Na
+
to the outside. Extracellular
K
+
binds, causing release of the
inorganic phosphate group.
Cytoplasm
Extracellular fluid
Na
+
Na
+
K
+
Na
+
Na
+
Na
+
P
i
K
+
Na
+
P
i
ATP
ADP
Na
+-K
+ pump
1 2
Slide 3
2 1

52. © 2018 Pearson Education, Ltd.
Figure 3.11 Operation of the sodium-potassium pump, a solute pump.
Binding of cytoplasmic Na
+
to the pump protein stimulates
phosphorylation by ATP, which
causes the pump protein to
change its shape.
The shape change expels
Na
+
to the outside. Extracellular
K
+
binds, causing release of the
inorganic phosphate group.
Loss of phosphate restores
the original shape of the pump
protein. K
+
is released to the
cytoplasm, and Na
+
sites are
ready to bind Na
+
again; the
cycle repeats.
Cytoplasm
Extracellular fluid
Na
+
Na
+
K
+
Na
+
Na
+
Na
+
P
i
K
+
Na
+
P
i
ATP
ADP
Na
+
K
+
K
+
Na
+-K
+ pump
1 2 3
Slide 4
2 3 1

53. Membrane Transport
Active processes (continued)
Vesicular transport: substances are moved across the
membrane ―in bulk‖ without actually crossing the
plasma membrane
Types of vesicular transport
Exocytosis
Endocytosis
Phagocytosis
Pinocytosis
© 2018 Pearson Education, Ltd.

54. Membrane Transport
Exocytosis
Mechanism cells use to actively secrete hormones,
mucus, and other products
Material is carried in a membranous sac called a
vesicle that migrates to and combines with the plasma
membrane
Contents of vesicle are emptied to the outside
Refer to pathway 1 in Figure 3.6
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55. Figure 3.6 Role of the Golgi apparatus in packaging the products of the rough ER.
© 2018 Pearson Education, Ltd.

56. Membrane Transport
Exocytosis (continued)
Exocytosis docking process
Docking proteins on the vesicles recognize plasma
membrane proteins and bind with them
Membranes corkscrew and fuse together
© 2018 Pearson Education, Ltd.

57. © 2018 Pearson Education, Ltd.
Figure 3.12a Exocytosis.
Extracellular
fluid
Plasma
membrane
docking
protein
The membrane-
bound vesicle
migrates to the
plasma membrane.
Vesicle
docking
protein
Molecule
to be
secreted
Cytoplasm
Secretory
vesicle
Fusion pore formed
Fused
docking
proteins
There, docking
proteins on the
vesicle and plasma
membrane bind, the
vesicle and
membrane fuse, and
a pore opens up.
Vesicle contents
are released to the
cell exterior.
(a) The process of exocytosis
1
2
3

58. © 2018 Pearson Education, Ltd.
Figure 3.12b Exocytosis.
(b) Electron micrograph of a
secretory vesicle in
exocytosis (190,000×)

59. Membrane Transport
Endocytosis
Extracellular substances are enclosed (engulfed) in a
membranous vesicle
Vesicle detaches from the plasma membrane and
moves into the cell
Once in the cell, the vesicle typically fuses with a
lysosome
Contents are digested by lysosomal enzymes
In some cases, the vesicle is released by exocytosis
on the opposite side of the cell
© 2018 Pearson Education, Ltd.

60. © 2018 Pearson Education, Ltd.
Figure 3.13a Events and types of endocytosis.
Extracellular
fluid Cytoplasm
Vesicle
forms and fuses
with lysosome
for digestion.
Vesicle
Plasma
membrane
Lysosome
Release of
contents to
cytosol
Transport to plasma
membrane and exocytosis
of vesicle contents
Detached vesicle
Ingested
substance
Pit
Membranes and receptors
(if present) recycled to
plasma membrane
(a) Endocytosis (pinocytosis)
1
2
3
2A
2B
Slide 1

61. © 2018 Pearson Education, Ltd.
Figure 3.13a Events and types of endocytosis.
Extracellular
fluid
Vesicle
forms and fuses
with lysosome
for digestion.
Plasma
membrane
(a) Endocytosis (pinocytosis)
1
Slide 2

62. © 2018 Pearson Education, Ltd.
Figure 3.13a Events and types of endocytosis.
Extracellular
fluid Cytoplasm
Vesicle
forms and fuses
with lysosome
for digestion.
Vesicle
Plasma
membrane
Lysosome
(a) Endocytosis (pinocytosis)
1
Transport to plasma
membrane and exocytosis
of vesicle contents
2
Slide 3
Detached vesicle

63. © 2018 Pearson Education, Ltd.
Figure 3.13a Events and types of endocytosis.
Extracellular
fluid Cytoplasm
Vesicle
forms and fuses
with lysosome
for digestion.
Vesicle
Plasma
membrane
Lysosome
(a) Endocytosis (pinocytosis)
1
Transport to plasma
membrane and exocytosis
of vesicle contents
2
Slide 4
Release of
contents to
cytosol
2A
Detached vesicle

64. © 2018 Pearson Education, Ltd.
Figure 3.13a Events and types of endocytosis.
Extracellular
fluid Cytoplasm
Vesicle
forms and fuses
with lysosome
for digestion.
Vesicle
Plasma
membrane
Lysosome
Release of
contents to
cytosol
(a) Endocytosis (pinocytosis)
1
2A
2B
Transport to plasma
membrane and exocytosis
of vesicle contents
2
Slide 5
Detached vesicle

65. © 2018 Pearson Education, Ltd.
Figure 3.13a Events and types of endocytosis.
Extracellular
fluid Cytoplasm
Vesicle
forms and fuses
with lysosome
for digestion.
Vesicle
Plasma
membrane
Lysosome
Release of
contents to
cytosol
Detached vesicle
Ingested
substance
Pit
Membranes and receptors
(if present) recycled to
plasma membrane
(a) Endocytosis (pinocytosis)
1
3
2A
2B
Transport to plasma
membrane and exocytosis
of vesicle contents
2
Slide 6

66. Membrane Transport
Types of endocytosis
1.Phagocytosis—―cell eating‖
Cell engulfs large particles such as bacteria or dead
body cells
Pseudopods are cytoplasmic extensions that separate
substances (such as bacteria or dead body cells) from
external environment
Phagocytosis is a protective mechanism, not a means
of getting nutrients
© 2018 Pearson Education, Ltd.

67. © 2018 Pearson Education, Ltd.
Figure 3.13b Events and types of endocytosis.
Extracellular
fluid
Cytoplasm
Bacterium
or other
particle
Pseudopod
(b) Phagocytosis

68. Membrane Transport
Types of endocytosis (continued)
2.Pinocytosis—―cell drinking‖
Cell ―gulps‖ droplets of extracellular fluid containing
dissolved proteins or fats
Plasma membrane forms a pit, and edges fuse around
droplet of fluid
Routine activity for most cells, such as those involved in
absorption (small intestine)
© 2018 Pearson Education, Ltd.

69. © 2018 Pearson Education, Ltd.
Figure 3.13a Events and types of endocytosis.
Extracellular
fluid Cytoplasm
Vesicle
forms and fuses
with lysosome
for digestion.
Vesicle
Plasma
membrane
Lysosome
Release of
contents to
cytosol
Transport to plasma
membrane and exocytosis
of vesicle contents
Detached vesicle
Ingested
substance
Pit
Membranes and receptors
(if present) recycled to
plasma membrane
(a) Endocytosis (pinocytosis)
1
2
3
2A
2B

70. Membrane Transport
Types of endocytosis (continued)
3.Receptor-mediated endocytosis
Method for taking up specific target molecules
Receptor proteins on the membrane surface bind
only certain substances
Highly selective process of taking in substances
such as enzymes, some hormones, cholesterol,
and iron
© 2018 Pearson Education, Ltd.

71. © 2018 Pearson Education, Ltd.
Figure 3.13c Events and types of endocytosis.
Membrane
receptor
Target molecule
(c) Receptor-mediated
endocytosis

72. The Nucleus
Control center of the cell
Contains genetic material known as
deoxyribonucleic acid, or DNA
DNA is needed for building proteins
DNA is necessary for cell reproduction
Three regions:
1.Nuclear envelope (membrane)
2.Nucleolus
3.Chromatin
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73. Figure 3.1b Anatomy of the generalized animal cell nucleus.
Nuclear envelope
Chromatin
Nucleolus
Nuclear
pores
(b) Nucleus
Nucleus
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74. The Nucleus
Nuclear envelope (membrane)
Consists of a double membrane that bounds the
nucleus
Contains nuclear pores that allow for exchange of
material with the rest of the cell
Encloses the jellylike fluid called the nucleoplasm
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75. The Nucleus
Nucleolus
Nucleus contains one or more dark-staining nucleoli
Sites of ribosome assembly
Ribosomes migrate into the cytoplasm through nuclear
pores to serve as the site of protein synthesis
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76. The Nucleus
Chromatin
Composed of DNA wound around histones (proteins)
Scattered throughout the nucleus and present when
the cell is not dividing
Condenses to form dense, rodlike bodies called
chromosomes when the cell divides
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77. The Cytoplasm
The cellular material outside the nucleus and
inside the plasma membrane
Site of most cellular activities
Includes cytosol, inclusions, and organelles
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78. The Cytoplasm
Three major component of the cytoplasm
1.Cytosol: Fluid that suspends other elements and
contains nutrients and electrolytes
2.Inclusions: Chemical substances, such as stored
nutrients or cell products, that float in the cytosol
3.Organelles: Metabolic machinery of the cell that
perform functions for the cell
Many are membrane-bound, allowing for
compartmentalization of their functions
© 2018 Pearson Education, Ltd.

79. Figure 3.4 Structure of the generalized cell.
Chromatin
Nucleolus
Smooth endoplasmic
reticulum
Cytosol
Lysosome
Mitochondrion
Nuclear envelope
Nucleus
Plasma
membrane
Centrioles
Rough
endoplasmic
reticulum
Ribosomes
Golgi apparatus
Microtubule
Intermediate
filaments
Secretion being released
from cell by exocytosis
Peroxisome
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80. The Cytoplasm
Mitochondria
―Powerhouses‖ of the cell
Mitochondrial wall consists of a double membrane with
cristae on the inner membrane
Carry out reactions in which oxygen is used to break
down food into ATP molecules
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81. The Cytoplasm
Ribosomes
Made of protein and ribosomal RNA
Sites of protein synthesis in the cell
Found at two locations:
Free in the cytoplasm
As part of the rough endoplasmic reticulum
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82. The Cytoplasm
Endoplasmic reticulum (ER)
Fluid-filled tunnels (or canals) that carry substances
within the cell
Continuous with the nuclear membrane
Two types:
Rough ER
Smooth ER
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83. The Cytoplasm
Endoplasmic reticulum (ER) (continued)
Rough endoplasmic reticulum
Studded with ribosomes
Synthesizes proteins
Transport vesicles move proteins within cell
Abundant in cells that make and export proteins
© 2018 Pearson Education, Ltd.

84. © 2018 Pearson Education, Ltd.
Figure 3.5 Synthesis and export of a protein by the rough ER.
Ribosome
mRNA
Rough ER
As the protein is synthesized on the ribosome,
it migrates into the rough ER tunnel system.
In the tunnel, the protein folds into its
functional shape. Short sugar chains may be
attached to the protein (forming a glycoprotein).
The protein is packaged in a tiny
membranous sac called a transport vesicle.
The transport vesicle buds from the rough ER
and travels to the Golgi apparatus for further
processing.
Protein
Transport
vesicle buds off
Protein inside
transport vesicle
1
2
3
4
1
2
3
4
Slide 1

85. © 2018 Pearson Education, Ltd.
Figure 3.5 Synthesis and export of a protein by the rough ER.
Ribosome
mRNA
Rough ER
As the protein is synthesized on the ribosome,
it migrates into the rough ER tunnel system.
Protein
1
Slide 2
1

86. © 2018 Pearson Education, Ltd.
Figure 3.5 Synthesis and export of a protein by the rough ER.
Ribosome
mRNA
Rough ER
As the protein is synthesized on the ribosome,
it migrates into the rough ER tunnel system.
In the tunnel, the protein folds into its
functional shape. Short sugar chains may be
attached to the protein (forming a glycoprotein).
Protein
1
2
Slide 3
1
2

87. © 2018 Pearson Education, Ltd.
Figure 3.5 Synthesis and export of a protein by the rough ER.
Ribosome
mRNA
Rough ER
As the protein is synthesized on the ribosome,
it migrates into the rough ER tunnel system.
In the tunnel, the protein folds into its
functional shape. Short sugar chains may be
attached to the protein (forming a glycoprotein).
The protein is packaged in a tiny
membranous sac called a transport vesicle.
Protein
1
2
3
Transport
vesicle buds off
Slide 4
1
2
3

88. © 2018 Pearson Education, Ltd.
Figure 3.5 Synthesis and export of a protein by the rough ER.
Ribosome
mRNA
Rough ER
As the protein is synthesized on the ribosome,
it migrates into the rough ER tunnel system.
In the tunnel, the protein folds into its
functional shape. Short sugar chains may be
attached to the protein (forming a glycoprotein).
The protein is packaged in a tiny
membranous sac called a transport vesicle.
The transport vesicle buds from the rough ER
and travels to the Golgi apparatus for further
processing.
Protein
Transport
vesicle buds off
Protein inside
transport vesicle
1
2
3
4
Slide 5
1
2
3
4

89. The Cytoplasm
Endoplasmic reticulum (ER) (continued)
Smooth endoplasmic reticulum
Lacks ribosomes
Functions in lipid metabolism
Detoxification of drugs and pesticides
© 2018 Pearson Education, Ltd.

90. The Cytoplasm
Golgi apparatus
Appears as a stack of flattened membranes
associated with tiny vesicles
Modifies and packages proteins arriving from the
rough ER via transport vesicles
Produces different types of packages
Secretory vesicles (pathway 1)
In-house proteins and lipids (pathway 2)
Lysosomes (pathway 3)
© 2018 Pearson Education, Ltd.

91. © 2018 Pearson Education, Ltd.
Figure 3.6 Role of the Golgi apparatus in packaging the products of the rough ER.
Rough ER Tunnels Proteins in tunnels
Membrane
Transport
vesicle
Lysosome fuses with
ingested substances.
Golgi vesicle containing
digestive enzymes
becomes a lysosome.
Pathway 3
Golgi
apparatus
Pathway 1
Golgi vesicle containing
proteins to be secreted
becomes a secretory
vesicle.
Pathway 2
Secretory vesicles
Proteins
Secretion by
exocytosis
Golgi vesicle containing
membrane components
fuses with the plasma
membrane and is
incorporated into it.
Plasma membrane
Extracellular fluid

92. The Cytoplasm
Lysosomes
Membranous ―bags‖ that contain digestive enzymes
Enzymes can digest worn-out or nonusable cell
structures
House phagocytes that dispose of bacteria and cell
debris
© 2018 Pearson Education, Ltd.

93. The Cytoplasm
Peroxisomes
Membranous sacs of oxidase enzymes
Detoxify harmful substances such as alcohol and
formaldehyde
Break down free radicals (highly reactive chemicals)
Free radicals are converted to hydrogen peroxide and
then to water
Replicate by pinching in half or budding from the ER
© 2018 Pearson Education, Ltd.

94. The Cytoplasm
Cytoskeleton
Network of protein structures that extend throughout
the cytoplasm
Provides the cell with an internal framework that
determines cell shape, supports organelles, and
provides the machinery for intracellular transport
Three different types of elements form the
cytoskeleton:
1.Microfilaments (largest)
2.Intermediate filaments
3.Microtubules (smallest)
© 2018 Pearson Education, Ltd.

95. © 2018 Pearson Education, Ltd.
Figure 3.7 Cytoskeletal elements support the cell and help to generate movement.
(a) Microfilaments
Actin subunit
7 nm
(b) Intermediate filaments
Fibrous subunits
10 nm
(c) Microtubules
Tubulin subunits
25 nm
Microfilaments form the blue
batlike network.
Intermediate filaments form
the purple network surrounding
the pink nucleus.
Microtubules appear as gold
networks surrounding the cells’
pink nuclei.

96. The Cytoplasm
Centrioles
Rod-shaped bodies made of nine triplets of
microtubules
Generate microtubules
Direct the formation of mitotic spindle during cell
division
© 2018 Pearson Education, Ltd.

97. © 2018 Pearson Education, Ltd.
Table 3.1 Parts of the Cell: Structure and Function (1 of 5)

98. © 2018 Pearson Education, Ltd.
Table 3.1 Parts of the Cell: Structure and Function (2 of 5)

99. © 2018 Pearson Education, Ltd.
Table 3.1 Parts of the Cell: Structure and Function (3 of 5)

100. © 2018 Pearson Education, Ltd.
Table 3.1 Parts of the Cell: Structure and Function (4 of 5)

101. © 2018 Pearson Education, Ltd.
Table 3.1 Parts of the Cell: Structure and Function (5 of 5)

102. Cell Extensions
Surface extensions found in some cells
Cilia move materials across the cell surface
Located in the respiratory system to move mucus
Flagella propel the cell
The only flagellated cell in the human body is sperm
Microvilli are tiny, fingerlike extensions of the plasma
membrane
Increase surface area for absorption
© 2018 Pearson Education, Ltd.

103. © 2018 Pearson Education, Ltd.
Figure 3.8g Cell diversity.
Nucleus
Sperm
(g) Cell of reproduction
Flagellum

104. Cell Diversity
The human body houses over 200 different cell
types
Cells vary in size, shape, and function
Cells vary in length from 1/12,000 of an inch to over
1 yard (nerve cells)
Cell shape reflects its specialized function
© 2018 Pearson Education, Ltd.

105. Cell Diversity
Cells that connect body parts
Fibroblast
Secretes cable-like fibers
Erythrocyte (red blood cell)
Carries oxygen in the bloodstream
© 2018 Pearson Education, Ltd.

106. © 2018 Pearson Education, Ltd.
Figure 3.8a Cell diversity.
Fibroblasts
Secreted
fibers
Rough ER and
Golgi apparatus
No organelles
Nucleus
Erythrocytes
(a) Cells that connect body parts

107. Cell Diversity
Cells that cover and line body organs
Epithelial cell
Packs together in sheets
Intermediate fibers resist tearing during rubbing or
pulling
© 2018 Pearson Education, Ltd.

108. © 2018 Pearson Education, Ltd.
Figure 3.8b Cell diversity.
Epithelial
cells
Nucleus
Intermediate
filaments
(b) Cells that cover and line body organs

109. Cell Diversity
Cells that move organs and body parts
Skeletal muscle and smooth muscle cells
Contractile filaments allow cells to shorten forcefully
© 2018 Pearson Education, Ltd.

110. © 2018 Pearson Education, Ltd.
Figure 3.8c Cell diversity.
Skeletal
muscle cell
Contractile
filaments
Nuclei
Smooth
muscle cells
(c) Cells that move organs and body parts

111. Cell Diversity
Cell that stores nutrients
Fat cells
Lipid droplets stored in cytoplasm
© 2018 Pearson Education, Ltd.

112. © 2018 Pearson Education, Ltd.
Figure 3.8d Cell diversity.
Fat cell Lipid droplet
Nucleus
(d) Cell that stores nutrients

113. Cell Diversity
Cell that fights disease
White blood cells, such as the macrophage (a
phagocytic cell)
Digests infectious microorganisms
© 2018 Pearson Education, Ltd.

114. © 2018 Pearson Education, Ltd.
Figure 3.8e Cell diversity.
Lysosomes
Macrophage
Pseudopods
(e) Cell that fights disease

115. Cell Diversity
Cell that gathers information and controls body
functions
Nerve cell (neuron)
Receives and transmits messages to other body
structures
© 2018 Pearson Education, Ltd.

116. © 2018 Pearson Education, Ltd.
Figure 3.8f Cell diversity.
Processes
Rough ER
Nerve cell
Nucleus
(f) Cell that gathers information and
controls body functions

117. Cell Diversity
Cells of reproduction
Oocyte (female)
Largest cell in the body
Divides to become an embryo upon fertilization
Sperm (male)
Built for swimming to the egg for fertilization
Flagellum acts as a motile whip
© 2018 Pearson Education, Ltd.

118. © 2018 Pearson Education, Ltd.
Figure 3.8g Cell diversity.
Nucleus
Sperm
(g) Cell of reproduction
Flagellum

119. Cell Physiology
Cells have the ability to:
Metabolize
Digest food
Dispose of wastes
Reproduce
Grow
Move
Respond to a stimulus
© 2018 Pearson Education, Ltd.

120. Cell Division
Cell life cycle is a series of changes the cell
experiences from the time it is formed until it
divides
Cell life cycle has two major periods
1.Interphase (metabolic phase)
Cell grows and carries on metabolic processes
Longer phase of the cell cycle
2.Cell division
Cell reproduces itself
© 2018 Pearson Education, Ltd.

121. Cell Division
Preparations: DNA Replication
Genetic material is duplicated and readies a cell for
division into two cells
Occurs toward the end of interphase
© 2018 Pearson Education, Ltd.

122. © 2018 Pearson Education, Ltd.

123. Cell Division
Process of DNA replication
DNA uncoils into two nucleotide chains, and each side
serves as a template
Nucleotides are complementary
Adenine (A) always bonds with thymine (T)
Guanine (G) always bonds with cytosine (C)
For example, TACTGC bonds with new nucleotides in
the order ATGACG
© 2018 Pearson Education, Ltd.

124. © 2018 Pearson Education, Ltd.
Figure 3.14 Replication of the DNA molecule at the end of interphase.
KEY:
Adenine
Thymine
Cytosine
Guanine
Old
(template)
strand
Newly
synthesized
strand
New
strand
forming
DNA of one sister chromatid
Old (template)
strand

125. Protein Synthesis
DNA serves as a blueprint for making proteins
GENE EXPRESSION
Gene: DNA segment that carries a blueprint for
building one protein or polypeptide chain
Proteins have many functions
Fibrous (structural) proteins are the building materials
for cells
Globular (functional) proteins can act as enzymes
(biological catalysts)
© 2018 Pearson Education, Ltd.

126. Protein Synthesis
DNA information is coded into a sequence of
bases
GENE –a sequence of nucleotides that provides
a chemical set of instructions for making a
specific protein
A sequence of three bases (triplet) codes for an
amino acid
For example, a DNA sequence of AAA specifies
the amino acid phenylalanine
© 2018 Pearson Education, Ltd.

127. Protein Synthesis
The role of DNA
Most ribosomes, the manufacturing sites of proteins,
are located in the cytoplasm
DNA never leaves the nucleus in interphase cells
DNA requires a decoder and a messenger to carry
instructions to build proteins to ribosomes
Both the decoder and messenger functions are carried
out by RNA (ribonucleic acid)
© 2018 Pearson Education, Ltd.

128. Protein Synthesis
How does RNA differ from DNA?
RNA is single-stranded
RNA contains ribose sugar instead of deoxyribose
RNA contains uracil (U) base instead of thymine (T)
© 2018 Pearson Education, Ltd.

129. Protein Synthesis
Three varieties of RNA
Transfer RNA (tRNA): Transfers appropriate amino
acids to the ribosome for building the protein
Ribosomal RNA (rRNA): Helps form the ribosomes
where proteins are built
Messenger RNA (mRNA): Carries the instructions for
building a protein from the nucleus to the ribosome
© 2018 Pearson Education, Ltd.

130. Protein Synthesis
Protein synthesis involves two major phases:
Transcription
Translation
We will detail these two phases next
© 2018 Pearson Education, Ltd.

131. Protein Synthesis
Transcription
Transfer of information from DNA’s base sequence to
the complementary base sequence of mRNA
DNA is the template for transcription; mRNA is the
product
Each DNA triplet corresponds to an mRNA codon
If DNA sequence is AAT-CGT-TCG, then the mRNA
corresponding codons are UUA-GCA-AGC
© 2018 Pearson Education, Ltd.

132. Figure 3.23

133. © 2018 Pearson Education, Ltd.
Figure 3.16a Protein synthesis (1 of 2).
Nucleus
(site of transcription)
DNA
gene
Cytoplasm
(site of translation)
mRNA specifying
one polypeptide is
made from a gene on
the DNA template by an
enzyme (not shown).
mRNA
Nuclear pore
Nuclear membrane Correct amino
acid attached to
each type of
tRNA by an
enzyme
Amino
acids
mRNA leaves nucleus
and attaches to ribosome,
and translation begins.
Synthetase
enzyme
1
2

134. Protein Synthesis
Translation
Base sequence of nucleic acid is translated to an
amino acid sequence; amino acids are the building
blocks of proteins
Occurs in the cytoplasm and involves three major
varieties of RNA
© 2018 Pearson Education, Ltd.

135. Protein Synthesis
Translation (continued)
Step 2: mRNA leaves nucleus and attaches to
ribosome, and translation begins
Step 3: incoming tRNA recognizes a complementary
mRNA codon calling for its amino acid by temporarily
binding its anticodon to the codon
© 2018 Pearson Education, Ltd.

136. Figure 3.24

137. © 2018 Pearson Education, Ltd.
Figure 3.16 Protein synthesis.
Nucleus
(site of transcription)
DNA
gene
Cytoplasm
(site of translation)
mRNA specifying
one polypeptide is
made from a gene on
the DNA template by an
enzyme (not shown).
mRNA
Nuclear pore
Nuclear membrane Correct amino
acid attached to
each type of
tRNA by an
enzyme
Amino
acids
mRNA leaves nucleus
and attaches to ribosome,
and translation begins.
Synthetase
enzyme
As the ribosome moves
along the mRNA, a new amino
acid is added to the growing
protein chain.
Growing
polypeptide
chain
tRNA “head”
bearing anticodon
Incoming tRNA
recognizes a complementary
mRNA codon calling for its
amino acid by temporarily
binding its anticodon to the
codon.
Peptide bond
Released tRNA
reenters the cytoplasmic
pool, ready to be recharged
with a new amino acid.
Large ribosomal subunit
Codon
Portion of
mRNA already
translated
Direction of ribosome
reading; ribosome
moves the mRNA strand
along sequentially
as each codon is read.
Small ribosomal subunit
IIe
Met
Gly
Ser
Ala
Phe
1
2
4
5
Slide 1
3

138. © 2018 Pearson Education, Ltd.
Figure 3.16 Protein synthesis (1 of 2).
Nucleus
(site of transcription)
DNA
gene
Cytoplasm
(site of translation)
mRNA specifying
one polypeptide is
made from a gene on
the DNA template by an
enzyme (not shown).
mRNA
Nuclear pore
Nuclear membrane Correct amino
acid attached to
each type of
tRNA by an
enzyme
Amino
acids
Synthetase
enzyme
1
Slide 2

139. © 2018 Pearson Education, Ltd.
Figure 3.16 Protein synthesis (1 of 2).
mRNA leaves
nucleus and attaches to
ribosome, and
translation begins.
2
Nucleus
(site of transcription)
DNA
gene
Cytoplasm
(site of translation)
mRNA specifying
one polypeptide is
made from a gene on
the DNA template by an
enzyme (not shown).
mRNA
Nuclear pore
Nuclear membrane Correct amino
acid attached to
each type of
tRNA by an
enzyme
Amino
acids
Synthetase
enzyme
Slide 3
1

140. © 2018 Pearson Education, Ltd.
Figure 3.16 Protein synthesis (2 of 2).
Incoming tRNA
recognizes a complementary
mRNA codon calling for its
amino acid by temporarily
binding its anticodon to the
codon.
tRNA “head”
bearing anticodon
Large ribosomal subunit
Codon
Portion of
mRNA already
translated
Direction of ribosome
reading; ribosome
moves the mRNA strand
along sequentially
as each codon is read.
Small ribosomal subunit
IIe 3
Slide 4

141. Protein Synthesis
Translation (continued)
Step 4: as the ribosome moves along the mRNA, a new
amino acid is added to the growing protein chain
Step 5: released tRNA reenters the cytoplasmic pool,
ready to be recharged with a new amino acid
© 2018 Pearson Education, Ltd.

142. © 2018 Pearson Education, Ltd.
Figure 3.16 Protein synthesis (2 of 2).
Growing
polypeptide
chain
Incoming tRNA
recognizes a complementary
mRNA codon calling for its
amino acid by temporarily
binding its anticodon to the
codon.
tRNA “head”
bearing anticodon
Peptide bond
Large ribosomal subunit
Codon
Portion of
mRNA already
translated
Direction of ribosome
reading; ribosome
moves the mRNA strand
along sequentially
as each codon is read.
Small ribosomal subunit
IIe
Met
Gly
Ser
Ala
Phe
Slide 5
As the ribosome moves along
the mRNA, a new amino acid is
added to the growing protein
chain.
3
4

143. © 2018 Pearson Education, Ltd.
Figure 3.16 Protein synthesis (2 of 2).
As the ribosome moves along
the mRNA, a new amino acid is
added to the growing protein
chain.
Growing
polypeptide
chain
Incoming tRNA
recognizes a complementary
mRNA codon calling for its
amino acid by temporarily
binding its anticodon to the
codon.
tRNA “head”
bearing anticodon
Peptide bond
Released tRNA
reenters the cytoplasmic
pool, ready to be recharged
with a new amino acid.
Large ribosomal subunit
Codon
Portion of
mRNA already
translated
Direction of ribosome
reading; ribosome
moves the mRNA strand
along sequentially
as each codon is read.
Small ribosomal subunit
IIe
Met
Gly
Ser
Ala
Phe
5
Slide 6
3
4

144. © 2018 Pearson Education, Ltd.
Figure 3.16 Protein synthesis. Slide 7
Nucleus
(site of transcription)
DNA
gene
Cytoplasm
(site of translation)
mRNA specifying
one polypeptide is
made from a gene on
the DNA template by an
enzyme (not shown).
mRNA
Nuclear pore
Nuclear membrane Correct amino
acid attached to
each type of
tRNA by an
enzyme
Amino
acids
mRNA leaves nucleus
and attaches to ribosome,
and translation begins.
Synthetase
enzyme
As the ribosome moves
along the mRNA, a new amino
acid is added to the growing
protein chain.
Growing
polypeptide
chain
tRNA “head”
bearing anticodon
Incoming tRNA
recognizes a complementary
mRNA codon calling for its
amino acid by temporarily
binding its anticodon to the
codon.
Peptide bond
Released tRNA
reenters the cytoplasmic
pool, ready to be recharged
with a new amino acid.
Large ribosomal subunit
Codon
Portion of
mRNA already
translated
Direction of ribosome
reading; ribosome
moves the mRNA strand
along sequentially
as each codon is read.
Small ribosomal subunit
IIe
Met
Gly
Ser
Ala
Phe
1
2
4
5
3

145. Cell Cycle
Interphase – non-dividing phase


Cell division
© 2018 Pearson Education, Ltd.

146. Figure 3.25

147. Cell Division
Events of cell division
Mitosis—division of the nucleus
Results in the formation of two daughter nuclei
Cytokinesis—division of the cytoplasm
Begins when mitosis is near completion
Results in the formation of two daughter cells
© 2018 Pearson Education, Ltd.

148. A&P Flix™: Mitosis
© 2018 Pearson Education, Ltd.

149. Cell Division
Events of mitosis: prophase
Chromatin coils into chromosomes; identical strands
called chromatids are held together by a centromere
Centrioles direct the assembly of a mitotic spindle
Nuclear envelope and nucleoli have broken down
© 2018 Pearson Education, Ltd.

150. Cell Division
Events of mitosis: metaphase
Chromosomes are aligned in the center of the cell on
the metaphase plate (center of the spindle midway
between the centrioles)
Straight line of chromosomes is now seen
© 2018 Pearson Education, Ltd.

151. Cell Division
Events of mitosis: anaphase
Centromere splits
Chromatids move slowly apart and toward the
opposite ends of the cell
Anaphase is over when the chromosomes stop moving
© 2018 Pearson Education, Ltd.

152. Cell Division
Events of mitosis: telophase
Reverse of prophase
Chromosomes uncoil to become chromatin
Spindles break down and disappear
Nuclear envelope re-forms around chromatin
Nucleoli appear in each of the daughter nuclei
© 2018 Pearson Education, Ltd.

153. Cell Division
Cytokinesis
Division of the cytoplasm
Begins during late anaphase and completes during
telophase
A cleavage furrow (contractile ring of microfilaments)
forms to pinch the cells into two parts
Two daughter cells exist
© 2018 Pearson Education, Ltd.

154. Cell Division
In most cases, mitosis and cytokinesis occur
together
In some cases, the cytoplasm is not divided
Binucleate or multinucleate cells result
Common in the liver and skeletal muscle
© 2018 Pearson Education, Ltd.

155. © 2018 Pearson Education, Ltd.
Figure 3.15 Stages of mitosis.
Centrioles Chromatin Centrioles Spindle
microtubules
Centromere
Forming
mitotic
spindle
Centromere
Plasma
membrane
Interphase
Nuclear
envelope
Nucleolus
Chromosome,
consisting of two
sister chromatids
Early prophase
Fragments of
nuclear envelope
Late prophase
Nucleolus
forming
Metaphase
plate
Cleavage
furrow
Mitotic
spindle
Metaphase
Sister
chromatids
Daughter
chromosomes
Anaphase
Nuclear
envelope
forming
Telophase and cytokinesis
Slide 1

156. © 2018 Pearson Education, Ltd.
Figure 3.15 Stages of mitosis (1 of 6).
Centrioles Chromatin
Plasma
membrane
Interphase
Nuclear
envelope
Nucleolus
Slide 2

157. © 2018 Pearson Education, Ltd.
Figure 3.15 Stages of mitosis (2 of 6).
Centrioles
Forming
mitotic
spindle
Chromosome,
consisting of two
sister chromatids
Early prophase
Centromere
Slide 3

158. © 2018 Pearson Education, Ltd.
Figure 3.15 Stages of mitosis (3 of 6).
Spindle
microtubules
Centromere
Fragments of
nuclear envelope
Late prophase
Slide 4

159. © 2018 Pearson Education, Ltd.
Figure 3.15 Stages of mitosis (4 of 6).
Metaphase
plate
Mitotic
spindle
Metaphase
Sister
chromatids
Slide 5

160. © 2018 Pearson Education, Ltd.
Figure 3.15 Stages of mitosis (5 of 6).
Daughter
chromosomes
Anaphase
Slide 6

161. © 2018 Pearson Education, Ltd.
Figure 3.15 Stages of mitosis (6 of 6).
Nucleolus
forming
Cleavage
furrow
Nuclear
envelope
forming
Telophase and cytokinesis
Slide 7

162. © 2018 Pearson Education, Ltd.

163. Part II: Body Tissues
Tissues
Groups of cells with similar structure and function
Four primary types:
1.Epithelial tissue (epithelium)
2.Connective tissue
3.Muscle tissue
4.Nervous tissue
© 2018 Pearson Education, Ltd.

164. Epithelial Tissue
Locations:
Body coverings
Body linings
Glandular tissue
Functions:
Protection
Absorption
Filtration
Secretion
© 2018 Pearson Education, Ltd.

165. Epithelial Tissue
Hallmarks of epithelial tissues:
Cover and line body surfaces
Often form sheets with one free surface, the apical
surface, and an anchored surface, the basement
membrane
Avascular (no blood supply)
Regenerate easily if well nourished
© 2018 Pearson Education, Ltd.

166. Epithelial Tissue
Classification of epithelia
Number of cell layers
Simple—one layer
Stratified—more than one layer
Shape of cells
Squamous—flattened, like fish scales
Cuboidal—cube-shaped, like dice
Columnar—shaped like columns
© 2018 Pearson Education, Ltd.

167. © 2018 Pearson Education, Ltd.
Figure 3.17a Classification and functions of epithelia.
Apical surface
Basal
surface
Simple
Apical surface
Basal
surface Stratified
(a) Classification based on number
of cell layers

168. © 2018 Pearson Education, Ltd.
Figure 3.17b Classification and functions of epithelia.
Squamous
Cuboidal
Columnar
(b) Classification based on
cell shape

169. © 2018 Pearson Education, Ltd.
Figure 3.17c Classification and functions of epithelia.
Number of layers
Cell shape
Squamous
One layer: simple epithelial
tissues
Diffusion and filtration Secretion in
serous membranes
Secretion and absorption; ciliated types
propel mucus or reproductive cells
Secretion and absorption; ciliated types
propel mucus or reproductive cells
More than one layer: stratified
epithelial tissues
Protection
Cuboidal
Columnar
Protection; these tissue types are rare
in humans
Transitional
(c) Function of epithelial tissue related to tissue type
Protection; stretching to accommodate
distension of urinary structures
No simple transitional epithelium exists

170. Epithelial Tissue
Simple epithelia
Functions in absorption, secretion, and filtration
Very thin (so not suited for protection)
© 2018 Pearson Education, Ltd.

171. Epithelial Tissue
Simple squamous epithelium
Single layer of flat cells
Locations—usually forms membranes
Lines air sacs of the lungs
Forms walls of capillaries
Forms serous membranes (serosae) that line and cover
organs in ventral cavity
Functions in diffusion, filtration, or secretion in
membranes
© 2018 Pearson Education, Ltd.

172. © 2018 Pearson Education, Ltd.
Figure 3.18a Types of epithelia and examples of common locations in the body.
Air sacs of
lungs
Nucleus of
squamous
epithelial cell
Nuclei of
squamous
epithelial
cells
Basement
membrane
(a) Diagram: Simple squamous
Photomicrograph: Simple squamous
epithelium forming part of the alveolar
(air sac) walls (275×).

173. Epithelial Tissue
Simple cuboidal epithelium
Single layer of cubelike cells
Locations
Common in glands and their ducts
Forms walls of kidney tubules
Covers the surface of ovaries
Functions in secretion and absorption; ciliated types
propel mucus or reproductive cells
© 2018 Pearson Education, Ltd.

174. © 2018 Pearson Education, Ltd.
Figure 3.18b Types of epithelia and examples of common locations in the body.
Nucleus of
simple
cuboidal
epithelial
cell
Basement
membrane
Simple
cuboidal
epithelial
cells
Basement
membrane
Connective
tissue
Photomicrograph: Simple cuboidal
epithelium in kidney tubules (250×). (b) Diagram: Simple cuboidal

175. Epithelial Tissue
Simple columnar epithelium
Single layer of tall cells
Goblet cells secrete mucus
Locations
Lining of the digestive tract from stomach to anus
Mucous membranes (mucosae) line body cavities
opening to the exterior
Functions in secretion and absorption; ciliated types
propel mucus or reproductive cells
© 2018 Pearson Education, Ltd.

176. © 2018 Pearson Education, Ltd.
Figure 3.18c Types of epithelia and examples of common locations in the body.
Nuclei of simple
columnar epithelial cells
tend to line up
Mucus of a
goblet cell
Simple columnar
epithelial cell
Basement
membrane
Basement
membrane
(c) Diagram: Simple columnar
Photomicrograph: Simple columnar
epithelium of the small intestine (575×).

177. Epithelial Tissue
Pseudostratified columnar epithelium
All cells rest on a basement membrane
Single layer, but some cells are shorter than others
giving a false (pseudo) impression of stratification
Location: respiratory tract, where it is ciliated and
known as pseudostratified ciliated columnar epithelium
Functions in absorption or secretion
© 2018 Pearson Education, Ltd.

178. © 2018 Pearson Education, Ltd.
Figure 3.18d Types of epithelia and examples of common locations in the body.
Pseudo-
stratified
epithelial
layer
Basement
membrane
Nuclei of
pseudostratified
cells do not line up
(d) Diagram: Pseudostratified (ciliated)
columnar
Cilia
Pseudostratified
epithelial layer
Basement
membrane
Connective tissue
Photomicrograph: Pseudostratified
ciliated columnar epithelium lining
the human trachea (560×).

179. Epithelial Tissue
Stratified epithelia
Consist of two or more cell layers
Function primarily in protection
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180. Epithelial Tissue
Stratified squamous epithelium
Most common stratified epithelium
Named for cells present at the free (apical) surface,
which are squamous
Functions as a protective covering where friction is
common
Locations—lining of the:
Skin (outer portion)
Mouth
Esophagus
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181. © 2018 Pearson Education, Ltd.
Figure 3.18e Types of epithelia and examples of common locations in the body.
Nuclei
Stratified
squamous
epithelium
Stratified
squamous
epithelium
Basement
membrane
Connective
tissue
Basement
membrane
Photomicrograph: Stratified
squamous epithelium lining of
the esophagus (140×).
(e) Diagram: Stratified squamous

182. Epithelial Tissue
Stratified cuboidal epithelium—two layers of
cuboidal cells; functions in protection
Stratified columnar epithelium—surface cells are
columnar, and cells underneath vary in size and
shape; functions in protection
Stratified cuboidal and columnar
Rare in human body
Found mainly in ducts of large glands
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183. Epithelial Tissue
Transitional epithelium
Composed of modified stratified squamous epithelium
Shape of cells depends upon the amount of stretching
Functions in stretching and the ability to return to
normal shape
Location: lining of urinary system organs
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184. © 2018 Pearson Education, Ltd.
Figure 3.18f Types of epithelia and examples of common locations in the body.
Basement
membrane
Transi-
tional
epithelium
Basement
membrane
Transitional
epithelium
Connective
tissue
Photomicrograph: Transitional epithelium lining of
the bladder, relaxed state (270×); surface rounded cells
flatten and elongate when the bladder fills with urine. (f) Diagram: Transitional

185. Epithelial Tissue
Glandular epithelia
One or more cells responsible for secreting a particular
product
Secretions contain protein molecules in an aqueous
(water-based) fluid
Secretion is an active process
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186. Epithelial Tissue
Two major gland types develop from epithelial
sheets
Endocrine glands
Ductless; secretions (hormones) diffuse into blood
vessels
Examples include thyroid, adrenals, and pituitary
Exocrine glands
Secretions empty through ducts to the epithelial surface
Include sweat and oil glands, liver, and pancreas (both
internal and external)
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187. Connective Tissue
Found everywhere in the body to connect body
parts
Includes the most abundant and widely
distributed tissues
Functions
Protection
Support
Binding
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188. Connective Tissue
Characteristics of connective tissue
Variations in blood supply
Some tissue types are well vascularized
Some have a poor blood supply or are avascular
Extracellular matrix
Nonliving material that surrounds living cells
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189. Connective Tissue
Two main elements of the extracellular matrix
1.Ground substance—mostly water, along with
adhesion proteins and polysaccharide molecules
2.Fibers
Collagen (white) fibers
Elastic (yellow) fibers
Reticular fibers (a type of collagen)
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190. Connective Tissue
Types of connective tissue from most rigid to
softest, or most fluid:
Bone
Cartilage
Dense connective tissue
Loose connective tissue
Blood
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191. Connective Tissue
Bone (osseous tissue)
Composed of:
Osteocytes (bone cells) sitting in lacunae (cavities)
Hard matrix of calcium salts
Large numbers of collagen fibers
Functions to protect and support the body
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192. © 2018 Pearson Education, Ltd.
Figure 3.19a Connective tissues and their common body locations.
Osteocytes
(bone cells)
in lacunae
Central canal
Lacunae
(a) Diagram: Bone Photomicrograph: Cross-sectional view
of bone (165×).

193. Connective Tissue
Cartilage
Less hard and more flexible than bone
Found in only a few places in the body
Chondrocyte (cartilage cell) is the major cell type
Types
Hyaline cartilage
Fibrocartilage
Elastic cartilage
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194. Connective Tissue
Hyaline cartilage
Most widespread type of cartilage
Abundant collagen fibers hidden by a glassy, rubbery
matrix
Locations
Trachea
Attaches ribs to the breastbone
Covers ends of long bones
Entire fetal skeleton prior to birth
Epiphyseal (growth) plates in long bones
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195. © 2018 Pearson Education, Ltd.
Figure 3.19b Connective tissues and their common body locations.
Chondrocyte
(cartilage cell)
Chondrocyte
in lacuna
Lacunae
(b) Diagram: Hyaline cartilage
Matrix
Photomicrograph: Hyaline cartilage
from the trachea (400×).

196. Connective Tissue
Elastic cartilage (not pictured)
Provides elasticity
Location: supports the external ear
Fibrocartilage
Highly compressible
Location: forms cushionlike discs between vertebrae of
the spinal column
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197. © 2018 Pearson Education, Ltd.
Figure 3.19c Connective tissues and their common body locations.
Chondrocytes
in lacunae
Chondro-
cytes in
lacunae
Collagen
fibers
(c) Diagram: Fibrocartilage
Collagen fiber
Photomicrograph: Fibrocartilage of an
intervertebral disc (150×).

198. Connective Tissue
Dense connective tissue (dense fibrous tissue)
Main matrix element is collagen fiber
Fibroblasts are cells that make fibers
Locations
Tendons—attach skeletal muscle to bone
Ligaments—attach bone to bone at joints and are more
elastic than tendons
Dermis—lower layers of the skin
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199. © 2018 Pearson Education, Ltd.
Figure 3.19d Connective tissues and their common body locations.
Ligament
Tendon
Collagen
fibers
Collagen
fibers
Nuclei of
fibroblasts
Nuclei of
fibroblasts
(d) Diagram: Dense fibrous Photomicrograph: Dense fibrous connective
tissue from a tendon (475×).

200. Connective Tissue
Loose connective tissue
Softer, have more cells and fewer fibers than other
connective tissues (except blood)
Types
Areolar
Adipose
Reticular
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201. Connective Tissue
Areolar connective tissue
Most widely distributed connective tissue
Soft, pliable tissue like ―cobwebs‖
Functions as a universal packing tissue and ―glue‖ to
hold organs in place
Layer of areolar tissue called lamina propria underlies
all membranes
All fiber types form a loose network
Can soak up excess fluid (causes edema)
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202. © 2018 Pearson Education, Ltd.
Figure 3.19e Connective tissues and their common body locations.
Mucosal
epithelium
Lamina
propria
Elastic
fibers
Collagen
fibers
Elastic
fibers of
matrix
Fibroblast
nuclei
Nuclei of
fibroblasts
Collagen
fibers
(e) Diagram: Areolar Photomicrograph: Areolar connective tissue, a
soft packaging tissue of the body (270×).

203. Connective Tissue
Adipose connective tissue
An areolar tissue in which adipose (fat) cells dominate
Functions
Insulates the body
Protects some organs
Serves as a site of fuel storage
Locations
Subcutaneous tissue beneath the skin
Protects organs, such as the kidneys
Fat ―depots‖ include hips, breasts, and belly
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204. © 2018 Pearson Education, Ltd.
Figure 3.19f Connective tissues and their common body locations.
Nuclei of
fat cells
Vacuole
containing
fat droplet
Nuclei of
fat cells
Vacuole
containing
fat droplet
(f) Diagram: Adipose Photomicrograph: Adipose tissue from the
subcutaneous layer beneath the skin (570×).

205. Connective Tissue
Reticular connective tissue
Delicate network of interwoven fibers with reticular
cells (like fibroblasts)
Forms stroma (internal framework) of organs
Locations
Lymph nodes
Spleen
Bone marrow
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206. © 2018 Pearson Education, Ltd.
Figure 3.19g Connective tissues and their common body locations.
Spleen
Reticular
cell
Blood
cell
Reticular
fibers
(g) Diagram: Reticular
White blood cell
(lymphocyte)
Reticular fibers
Photomicrograph: Dark-staining network
of reticular connective tissue (400×).

207. Connective Tissue
Blood (vascular tissue)
Blood cells surrounded by fluid matrix known as blood
plasma
Soluble fibers are visible only during clotting
Functions as the transport vehicle for the
cardiovascular system, carrying:
Nutrients
Wastes
Respiratory gases
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208. © 2018 Pearson Education, Ltd.
Figure 3.19h Connective tissues and their common body locations.
Blood cells
in capillary Plasma (fluid
matrix)
Neutrophil
(white blood
cell)
White
blood cell
Red
blood cells
Red blood
cells
Monocyte
(white blood
cell)
(h) Diagram: Blood Photomicrograph: Smear of human blood (1290×)

209. Muscle Tissue
Function is to contract, or shorten, to produce
movement
Three types of muscle tissue
1.Skeletal
2.Cardiac
3.Smooth
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210. Muscle Tissue
Skeletal muscle tissue
Packaged by connective tissue sheets into skeletal
muscles, which are attached to the skeleton and pull
on bones or skin
Voluntarily (consciously) controlled
Produces gross body movements or facial expressions
Characteristics of skeletal muscle cells
Striations (stripes)
Multinucleate (more than one nucleus)
Long, cylindrical shape
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211. © 2018 Pearson Education, Ltd.
Figure 3.20a Types of muscle tissue and their common locations in the body.
(a) Diagram: Skeletal muscle Photomicrograph: Skeletal muscle (195×).
Striations
Multiple nuclei
per fiber
Part of muscle
fiber

212. Muscle Tissue
Cardiac muscle tissue
Involuntarily controlled
Found only in the heart
Pumps blood through blood vessels
Characteristics of cardiac muscle cells
Striations
One nucleus per cell
Short, branching cells
Intercalated discs contain gap junctions to connect cells
together
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213. © 2018 Pearson Education, Ltd.
Figure 3.20b Types of muscle tissue and their common locations in the body.
Intercalated
discs
Nucleus
(b) Diagram: Cardiac muscle Photomicrograph: Cardiac muscle (475×).

214. Muscle Tissue
Smooth (visceral) muscle tissue
Involuntarily controlled
Found in walls of hollow organs such as stomach,
uterus, and blood vessels
Peristalsis, a wavelike activity, is a typical activity
Characteristics of smooth muscle cells
No visible striations
One nucleus per cell
Spindle-shaped cells
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215. © 2018 Pearson Education, Ltd.
Figure 3.20c Types of muscle tissue and their common locations in the body.
Nuclei
Smooth
muscle cell
(c) Diagram: Smooth muscle Photomicrograph: Sheet of smooth muscle (360×).

216. Nervous Tissue
Function is to receive and conduct
electrochemical impulses to and from body parts
Irritability
Conductivity
Composed of neurons and nerve support cells
Support cells called neuroglia insulate, protect, and
support neurons
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217. © 2018 Pearson Education, Ltd.
Figure 3.21 Nervous tissue.
Brain
Spinal
cord
Nuclei of
neuroglia
(supporting
cells)
Cell body
of neuron
Neuron
processes
Diagram: Nervous tissue
Nuclei of
neuroglia
(supporting
cells)
Cell body
of neuron
Neuron
processes
Photomicrograph: Neurons (320×)

218. Summary of Tissues
Figure 3.22 summarizes the tissue types and
functions in the body
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219. © 2018 Pearson Education, Ltd.
Figure 3.22 Summary of the major functions, characteristics, and body locations of the four tissue types: epithelial, connective, muscle, and
nervous tissues.
Nervous tissue: Internal communication and control
Hallmarks: irritable, conductive
• Brain, spinal cord, and nerves
Muscle tissue: Contracts to cause movement
Hallmarks: irritable, contractile
• Muscles attached to bones (skeletal)
• Muscles of heart wall (cardiac)
• Muscles of walls of hollow organs (smooth)
Epithelial tissue: Forms boundaries between different
environments, protects, secretes, absorbs, filters
Hallmarks: one free (apical) surface, avascular
• Lining of GI tract and other hollow organs
• Skin surface (epidermis)
Connective tissue: Supports, protects, binds
other tissues together
Hallmarks: extracellular matrix, varying vascularity
• Cartilage
• Bones
• Tendons
• Fat and other soft padding tissue

220. Tissue Repair (Wound Healing)
Tissue repair (wound healing) occurs in two ways:
1.Regeneration
Replacement of destroyed tissue by the same kind of
cells
2.Fibrosis
Repair by dense (fibrous) connective tissue (scar
tissue)
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221. Tissue Repair (Wound Healing)
Whether regeneration or fibrosis occurs depends
on:
1.Type of tissue damaged
2.Severity of the injury
Clean cuts (incisions) heal more successfully
than ragged tears of the tissue
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222. Tissue Repair (Wound Healing)
Events of tissue repair
Inflammation sets the stage
Capillaries become very permeable
Clotting proteins migrate into the area from the
bloodstream
A clot walls off the injured area
Granulation tissue forms
Growth of new capillaries
Phagocytes dispose of blood clot and fibroblasts
Rebuild collagen fibers
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223. Tissue Repair (Wound Healing)
Events of tissue repair (continued)
Regeneration and fibrosis effect permanent repair
Scab detaches
Whether scar is visible or invisible depends on severity
of wound
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224. Tissue Repair (Wound Healing)
Tissues that regenerate easily
Epithelial tissue (skin and mucous membranes)
Fibrous connective tissues and bone
Tissues that regenerate poorly
Skeletal muscle
Tissues that are replaced largely with scar tissue
Cardiac muscle
Nervous tissue within the brain and spinal cord
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225. Developmental Aspects of Cells and Tissues
Growth through cell division continues through
puberty
Cell populations exposed to friction (such as
epithelium) replace lost cells throughout life
Connective tissue remains mitotic and forms
repair (scar) tissue
With some exceptions, muscle tissue becomes
amitotic by the end of puberty
Nervous tissue becomes amitotic shortly after
birth
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226. Developmental Aspects of Cells and Tissues
Injury can severely handicap amitotic tissues
The cause of aging is unknown, but chemical and
physical insults, as well as genetic programming,
have been proposed as possible causes
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227. Developmental Aspects of Cells and Tissues
Neoplasms, both benign and cancerous,
represent abnormal cell masses in which normal
controls on cell division are not working
Hyperplasia (increase in size) of a tissue or organ
may occur when tissue is strongly stimulated or
irritated
Atrophy (decrease in size) of a tissue or organ
occurs when the organ is no longer stimulated
normally
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