Cells and Tissues in Anaphy and Physiology

Cells

1. Cellular Basis
of Life

2. 1600s: Robert Hooke discovered cells;
named them after rooms in a
monastery
The Cell1
The Cell Theory
A cell is the basic structural and
functional unit of living organisms
The activity of an organism depends
on the collective activities of its cells.
The activities of cells are dictated by
their structure (anatomy), which
determines function (physiology).
Cells come from cells.
1
2
3
4

3. Anatomy of the Cell1

4. All cells have three main regions or
parts—a plasma membrane, a
nucleus, and the cytoplasm
Anatomy of the Cell1
The Nucleus
•“headquarters,” or the control
Center of the cell
* Has three recognizable regions:
nuclear envelope, nucleolus, and
chromatin

5. Anatomy of the Cell1
The Plasma Membrane
The flexible plasma membrane is a
fragile, transparent barrier that
contains the cell contents and
separates them from the surrounding
environment
The Fluid Mosaic Model
Hydrophilic heads
Hydrophobic tails

6. Anatomy of the Cell1
The flexible plasma membrane is a
fragile, transparent barrier that
contains the cell contents and
separates them from the surrounding
environment
The Fluid Mosaic Model
Hydrophilic heads
Hydrophobic tails

7. Anatomy of the Cell1
Cell membrane junctions
Tight junctions - encircle the cells
and bind them together into leakproof
sheets.
Desmosomes - anchoring
junctions scattered like rivets along the
sides of adjacent cells.
Gap junctions - communicating
junctions, function mainly to allow
communication.

8. Anatomy of the Cell1
The Cytoplasm
the cellular material outside the
nucleus and inside the plasma
membrane
Has three major components: cytosol,
inclusions, and organelles
Cytosol - semitransparent fluid that
suspends the other elements.
Inclusions - chemical substances that
may or may not be present, depending
on the specific cell type.
Organelles – are specialized cellular
compartments specialized to carry out
a specific function

9. Anatomy of the Cell1
Mitochondria
The powerhouse of the cell
Produces ATP

10. Anatomy of the Cell1
Ribosomes
Sites of protein synthesis

11. Anatomy of the Cell1
Endoplasmic reticulum
Rough and Smooth ER; network of
channels for carrying substances

12. Anatomy of the Cell1
Endoplasmic reticulum

13. Anatomy of the Cell1
Golgi apparatus
Principal “traffic director” for cellular
proteins.
modify, package, and ship proteins

14. Anatomy of the Cell1
Golgi apparatus

15. Anatomy of the Cell1
Lysosomes
membranous “bags” containing
powerful digestive enzymes; cellular
stomachs

16. Anatomy of the Cell1
Cytoskeleton
An elaborate network of protein
structures extends throughout the
cytoplasm.
Acts as a cell’s “bones
and muscles”

17. Anatomy of the Cell1
Cilia and Flagella
Cilia. whiplike cellular extensions that
move substances along the cell
surface.
Flagella. Longer than cilia; formed by
centrioles

18. Anatomy of the Cell1
Microvilli
tiny, fingerlike extensions of the
plasma membrane that project from an
exposed cell surface

19. Cell Diversity2
Cells that connect body parts
Fibroblasts
Erythrocytes
Cells that cover and line body
organs
Epithelial cells

20. Cell Diversity2
Cells that move organs and
body parts
Skeletal, cardiac, and smooth
muscle cells
Cells that store nutrients
Fat cells/adipocytes

21. Cell Diversity2
Cells that fight diseases
WBCs e.g., macropahage
Cells that gather information
and control body functions
Fat cells/adipocytes

22. Cell Diversity2
Cells for reproduction
Oocyte & sperm

23. 3
Solution – homogenous mixture of two
or more components
Solvent – substance present in
largest amount
Solute – substances present in
smaller amounts
Cell Physiology
Membrane Transport

24. 3
Intracellular fluid – collectively, the
nucleoplasm and the cytosol; solution
containing small amounts of gases
(oxygen and carbon dioxide), nutrients,
and salts, dissolved in water
Extracellular/interstitial fluid – the
fluid that continuously bathes the
exterior of cells
Cell Physiology
Membrane Transport

25. 3
Selective permeability – means that a
barrier allows some substances to pass
through it while excluding others.
Small inorganic solutes, e.g., O2, CO2,
and H2O, penetrate the lipid bilayer
readily, as do solutes with high lipid
solubility.
Ions and polar organic solutes,
such as sugars and amino acids,
require special transporters to
enter or leave the cell.
Cell Physiology
Membrane Transport

26. Cell Physiology
3
Passive processes: substances are
transported without any energy input
1. Diffusion – movement of particles
away from more concentrated areas to
areas where they less concentrated
Simple diffusion – unassisted diffusion
through plasma membrane
Membrane Transport

27. Osmosis – diffusion of water through
selectively permeable membrane
Aquaporin – water pores
Tonicity - ability of a solution to change
the size and shape of cells by altering the
amount of water they contain
Isotonic - solutions having the same solute and
water concentrations as cells do.
Hypertonic - solutions that contain more solutes,
or dissolved substances, than there are inside the
cells
Hypotonic - solutions with fewer solutes than the
cell does

28. 3
Facilitated diffusion –provides
passage for substances that are both
lipid-insoluble and too large to pass
through the membrane pores, or
charged
Cell Physiology
Membrane Transport

29. Cell Physiology3

30. Cell Physiology3
Filtration – water and solutes are
forced through a membrane (or
capillary wall) by fluid, or hydrostatic,
pressure.

31. Cell Physiology3
Active processes
cell uses ATP to move substances
across the membrane
Active transport – processes require
protein carriers that interact specifically
and reversibly with the substances to be
transported

32. Cell Physiology3
Vesicular transport
Uses ATP to fuse or separate
membrane vesicles and the cell
membrane
Exocytosis – secretion of molecules by
the fusion of vesicles with the plasma
membrane
Endocytosis – cell takes in molecules
and particulate matter by forming new
vesicles from the plasma membrane

33. Cell Physiology3
Vesicular transport
Uses ATP to fuse or separate
membrane vesicles and the cell
membrane
Exocytosis – secretion of molecules by
the fusion of vesicles with the plasma
membrane
Endocytosis – cell takes in molecules
and particulate matter by forming new
vesicles from the plasma membrane

34. Cell Division3
Cell Cycle
series of changes a cell goes through
from the time it is formed until it
divides.
Interphase – cell growth
Cell division – the cell reproduces
itself.
DNA Replication – The DNA molecule
(the genetic material) is duplicated

35. Cell Division3
Events of Cell Division
Mitosis – the process of dividing a nucleus into two daughter nuclei with exactly
the same genes as the “mother” nucleus
Prophase – chromatin threads coil
and shorten so that the barlike
chromosomes become visible
under a microscope
Metaphase – chromosomes line
up at the metaphase
plate
Anaphase – the
centromeres that have held the
chromatids together
split.

36. Cell Division3
Events of Cell Division
Telophase –
chromosomes at
opposite ends of the cell
uncoil to become
threadlike chromatin
again. The spindle breaks
down and disappears, a
nuclear envelope
forms around each
chromatin mass, and
nucleoli appear in each of
the daughter nuclei.
Cytokinesis – or the division of the
cytoplasm

37. Protein Synthesis4
Genes – defined as a DNA
segment that carries the information for
building one protein.
Transcription – the transfer
of information from the sequence of
bases in a DNA gene into the
complementary sequence of
mRNA
Translation – the
language of nucleic acids (base
sequence) is “translated” into the
language of proteins

38. Body Tissues5
Epithelial tissue
is the lining, covering, and glandular
tissue of the body
Epithelial functions include protection,
absorption, filtration, and secretion.
Hallmarks of epithelium
1.Fit closely together;
2.Polarity (an apical surface & basal
surface)
3.Anchored to basement membrane
4.Avascular (no blood supply)
5.Regenerate easily
Classification of epithelia
Based on number of cell layer Based on cell shape

39. Glandular Epithelium
gland -consists of one or more cells that
make and secrete a particular product.

40. Body Tissues5
Connective tissue
Connects body parts.
Perform many functions, but they are
primarily involved in protecting,
supporting, cushioning, and insulating
other body tissues.
Hallmarks of epithelium
1.Variation in blood supply
2.Have ECM
ECM = ground substance + fibers
Ground substance – water + cell
adhesion proteins + polysaccharide
molecules
Types of connective tissue

41. Body Tissues5
Muscle tissue
are highly specialized to contract, or
shorten, which generates the force
required to produce movement
Types of muscle tissue

42. Body Tissues5
Nervous Tissue
- cells in the body responsible for
transmitting electrical signals through
the nervous system
Neurons/Nerve cell