Anatomy for bsc-1forbsc nurse referrence

Anatomy for bsc nurse

1. Human Anatomy
1
Unit 1 Introductionto Anatomy

2. Introductionto Human Anatomy
Definationof Anatomy
•It is the study of structureof the body parts. i.e.
Shape
Color
Size
Texture
Position
Their relationships to one another
•Gross Anatomy:-dealt with macroscopic structures
•Microscopic Anatomy:-study tissues(Histology) and cells(Cytology)
•Developmental Anatomy:-Development from fertilization to adulthood
Embryology –development from fertilized egg through eighth week in utero
•Pathological Anatomy:-study of structural changes caused by disease
•Radiographic Anatomy:-imaging
Subdivisions of Anatomy

3. I.The human body is divided into nine regions
1.Head
2.Neck
3.Thorax
4.Back
II.There areten systems in human body
1.Integumentarysystem
2.Skeletal system
3.Muscular system
4.Digestive system
5.Respiratory system
6.Urinary system
7.Reproductive system
8.Endocrine system
9.Circulatory system
10.Nervous system
5.Abdomen
6.Pelvis and perineum
7.Upper limbs
8.Lower limbs
•Regional anatomy –dealt with the body structures in one part of the region
(such as the abdomen or leg)
•Systemic anatomy –dealing with the human body systems of the body
•Surfaceanatomy–thestudy of internal structures from the surface
Approaches

4. Levels of Organization
Chemical–atoms combined to form molecules
Cellular–cells are made of molecules
Tissue–consists of similar types of cells
Organ–made up of different types of tissues
Organ system–consists of different organs that work closely
together
Organismal–made up of the organ systems
Subatomic Particles –
electrons, protons, neutrons
Atom–hydrogen atom,
lithium atom
Molecule–water molecule,
glucose molecule
Macromolecule–protein
molecule, DNA molecule
Organelle–mitochondrion,
Golgi apparatus, nucleus
Cell–muscle cell, nerve cell
Tissue –simple squamous
epithelium, loose
connective tissue
Organ–skin, femur, heart,
kidney
Organ System –skeletal
system, digestive system
Organism -human

5. Anatomical Position
•Body erect
•Feet slightly apart
•Palms facing forward
•Thumbs point away from body

6. Body Planes
•Sagittal–divides the body
into right and left parts
•Midsagittalor medial–
sagittalplane that lies on
the midline
•Frontal or coronal–divides
the body into anterior and
posterior parts
•Transverse or horizontal
(cross section) –divides the
body into superior and
inferior parts
•Oblique section–cuts
made diagonally

7. 7
Body Sections

8. Directional Terms
•Superior –toward
the head
•Inferior–away
from the head
•Anterior –toward
the front of the
body
•Posterior–toward
the back of the
body
•Medial –toward
the midline of the
body

9. Directional Terms

10. Directional Terms
•Lateral–away from
the midline
•Intermediate–
between a more
medial and lateral
structure
•Proximal –closer to
the origin of the
body
•Distal–farther from
the origin of the
body
•Superficial –toward
the body surface
•Deep–away from
the body surface

11. Terms of movements
•Flexion: decreasesjoint angle in A-P plane
Special kinds of flexion at ankle joint:
Dorsiflexion: dorsum (top) of foot is elevated
Plantarflexion: bringing foot and toes closer to back of leg
•Extension: increasesjoint angle in A-P plane
•Abduction: body part moved awayfrom midline of the body, in
a lateral direction
•Adduction: body part moved towardthe midline of the body, in
a medial direction
•Rotation: movement of a body part around its own axis
Special kinds of rotation of forearm:
Supination: palm of hand facing anteriorly
Pronation: palm facing posteriorly

12. Terms of movements

13. Terms of movements …
•Circumduction: circular, conelikemovement of a
body segment
•Inversion: movement of the sole of the foot inward
or medially
•Eversion: movement of the sole of the foot outward
or laterally
•Depression: inferior movement of a body part
•Elevation: superior movement of body part
•Protraction: movement of a body part anteriorly, in
a horizontal plane
•Retraction: movement of a body part posteriorly, in
a horizontal plane

14. Regional Terms:
•Axial–head,
neck, and
trunk
•Appendicular
–appendages
or limbs
•Specific
regional
terminology
Figure 1.7a

15. Anatomical Variability
•Humans vary slightly in both external and
internal anatomy
•Over 90% of all anatomical structures match
textbook descriptions, but:
–Nerves or blood vessels may be somewhat
out of place
–Small muscles may be missing
•Extreme anatomical variations are seldom
seen

16. Body Cavities
•Dorsal cavityprotects
the nervous system,
and is divided into two
subdivisions
–Cranial cavity is
within the skull and
encases the brain
–Vertebral cavity runs
within the vertebral
column and encases
the spinal cord
•Ventral cavity houses
the internal organs
(viscera)
−It is divided into two
subdivisions
ThoracicandAbdominopelviccavities

17. Body Cavities
–Pleural cavities–each houses a lung
–Mediastinum–contains the pericardial
cavity, and surrounds the remaining
thoracic organs
–Pericardial cavity–encloses the heart
•Thoracic cavityis subdivided into pleural cavities, the
mediastinum, and the pericardial cavity

18. Body Cavities
•The abdominopelviccavity is separated from the superior thoracic
cavity by the dome-shaped diaphragm
•It is composed of two
subdivisions
–Abdominal cavity–contains
the stomach, intestines,
spleen, liver, and other
organs
–Pelvic cavity–lies within the
pelvis and contains the
bladder, reproductive
organs, and rectum

19. Abdominopelvicquadrants and regions
•Topographical divisions of the abdomen are used to describe the location
of abdominal organs and the associated pain. These are;
A four-quadrantpattern
A nine-regionorganization
•For that purpose, the four quadrants are defined by 2 planes
1.The transversetransumbilicalplane-passing through the umbilicus and the
intervertebral[IV] disc between the L3 and L4 vertebrae
2.The vertical median plane, passing longitudinally through the body
•The nine regions are delineated by 4 planes → 2 sagittal& 2 transverse
The two sagittalplanes are usually the midclavicularplanes
–They pass from the midpoint of the clavicles (approx. 9 cm from the
midline) to the midinguinalpoints, midpoints of the lines joining the
anterior superior iliac spine (ASIS) and the pubic on each side
The two transverse planes are usually
−The transpyloricplane-halfway between the jugular notch and the
symphysispubis (L1 vertebral level)
−The interspinousplane-passes through the ASIS of each side

20. 1.Right upper
2.Left upper
3.Right lower
4.Left lower
Superiorly-right hypochondrium, epigastric, left hypochondrium
Inferiorly-right inguinal (groin), pubic (hypogastric), left inguinal
In the middle -right lumbar (lateral), umbilical, left lumbar (lateral)
Quadrants
Regions
Quadrants Abdominal Regions

21. Topographical divisionsand organs
Nine-regions
Four-quadrants

22. Body membranes
•Mucous Membranes
(mucosa)
•Serous Membranes
(serosa)
•Cutaneous
Membranes (skin)
•Synovial Membranes
Parietal serosalines
internal body walls
Visceral serosacovers
the internal organs
Serous fluidseparates
the serosae

23. Ventral Body Cavity Membranes

24. •The cell is the simplest
structural and
functional unit of life(&
of disease processes) in
all tissues, organs &
organ systems
Cytology-the study of
cell structure & function
Cell
Prokaryotic cells
Eukaryotic cells
•The human body
contains about 100 trillion cells
•All cells are derived from the zygote
It is a single cell formed by fertilization
of an oocytewith a spermatozoon
Zygote →blastomeres→inner cell
massand outer trophoblasticlayer
The inner cell massof the blastomeres
gives rise to all tissue types of the adult

25. •There are ~200 different cell types
•They vary greatly in shape
Squamous
Eg. Alveolar type I cells (lung),
Stellateor starlike
Eg. Some nerve cells
Cuboidal
Eg. Liver cells
Spheroid to ovoid
Eg. Egg cells and fat cells
Discoid(disc-shaped)
Eg. Red blood cells
Columnar
Eg.Those cells lining the intestines
Cell anatomy
Fusiform
Eg. Smooth muscle cells
Fibrous (threadlike shape)
Eg. Skeletal muscle cells

26. •The cell is organized
in to two basic parts:
1.Nucleus(L. Nux=
nut): contains genetic
material, has nuclear
envelope
2.Cytoplasm(Gr.
Kytos=cell +
plasma =thing
formed):Limited by
cell membrane
General cell structure
Cell/Plasma membrane:-
is the outermost component
of the cell, separating
the cytoplasm from its
extracellular environment
Two basic cell types
1. Prokaryotes
✹lack nuclear envelope & memb. organelles
2. Eukaryotes
✹multicellularorganisms with nuclear envelope

28. 1.Cell Membrane or
“plasma membrane”
3-layered outer
boundary of a cell
which maintains
integrity
•Made of lipids and
proteins
Phospholipids,
glycolipids,
cholesterol
Proteins -many
types (eg.
glycoproteins)
•Integral proteins
•Peripheral proteins
Cell structure …

29. Cytoplasm
•Material orarea inside
the cell b/ncell
membrane &nucleus
~ guts of cell
•Contains:
Cytosol:-fluid
component (intra-
cellular fluid)
Organelles:-
metabolocallyactive
micro-cellstructures
suspendedincytosol Cytoskeleton: –structural framework
of the cell which determined the shape
and motility of cells
Inclusions:–minor cytoplasmic
structures which are generally deposits
of carbohydrates, lipids, or pigments
Membranous (eg.
mitochondria) or non-
membranous protein
complexes (eg. ribosomes
& proteasomes)

30. Cytoplasm “organelles”
Organelles
•Internal cell structures ~ perform most cell activities
Organelles have specific structure
Major Organelles
Nucleus
Mitochondria
Ribosomes
Endoplasmic
reticulum (ER)
Golgi complex
(apparatus)
Lysosomes
Peroxisomes
Centrioles

31. Nucleus
•The nucleus is the
controller of the cell.
•It is surrounded by the
nuclear envelope which
controls what substances
may exit/enter the
nucleus.
•It contains DNA and the
nucleolus.
•DNA is termed the “genetic
blueprint” and directs all
protein synthesis.
•The nucleolus makes
ribosomes.

32. Mitochondria
•Elongated double layered organelles
The outer membraneis sieve-like,smooth
Inner membraneis folded to form a series
of long infoldingscalled cristae… ↑↑↑SA
•They are responsible for carrying out
aerobic cellular respiration.
This process forms ATP from the food we
eat and requires oxygen. Hence, named as
the “powerhouses” of the cell
•The number of mitochondria is related to
the cell's energy needs
Eg, cardiac muscle, cells of some kidney
tubules have abundant mitochondria
Whereas cells with a low-energy
metabolism have few mitochondria
* surface area
is increased
Organelles …

33. Ribosomes
•Protein factories ~
protein synthesis
•Composed mostly of r-
RNA & proteins
–Fixed ribosomes~
attached to
Endoplasmic Reticulum
•Involved in Protein
Synthesis
Organelles…
–Free ribosomes~ freely present in cytoplasm
•Produce “proteases” ~ protein-digesting enzymes
–Proteases
»Break down & remove damaged or abnormal proteins
in cytoplasm in to amino acids for future use
Free floating
and fixed

34. Endoplasmic Reticulum ~ ER
•Networkof membranes,
tubes, sheets -cisternae
•Surrounds nucleus ~
connected to nuclear
envelope
•Synthizes~ Proteins,
Lipids, Carbohydrates
•There are 2 types:
•Rough ERhas ribsosomes
attached to it & is involved in
protein synthesis
•Smooth ER which is involves
in the synthesis of lipid
products such as steroid
hormones& carbohydrates
•Rough
•Smooth
Organelles…

35. Smooth Endoplasmic Reticulum ~ SER
•NOattached ribosomes~ smooth surface
•NO protein synthesis, only lipid
& carbohydrates synthesis
–Phospholipids
–Cholesterol
–Steroid Hormones(androgen &
estrogen)
–Glycerides(especially triglycerides)
–Glycogen (for storage in liver)
Rough Endoplasmic Reticulum ~RER
•Ribosomeson outer surface ~ rough
•Protein production
•Contains “transport vesicles” ~ shipping vessels
For protein movement to Golgi Apparatus
Organelles…

36. Golgi Apparatus ~ Golgi Complex
•Receivesproteins, lipids , CHO from ER
Via “Transport Vesicles”
•Stores proteins for future secretions
•Secretes stored materials & waste
Via“Golgi~ SecretoryVesicles” ~ exocytosis
»Hormones
»Enzymes
•Replenishes cell membrane ~ phospholipid
vesicles, glycoprotein vesicles
•Release specialized lysosome“vesicles”
•This organelle consists of tubular
channels which function to assemble,
and check proteins coming from the
rough ER
Organelles…

37. Lysosomes
•Lysosomescontain powerful
digestive enzymes which
break apart anything that
gets inside it
•They are important in
protection(splitting
bacteria) as well as, old
organelles
•Lysosomesare able to
release the end products for
reusein the cell
•It is important that the
lysosomedoesn’t rupture or
the enzymes would digest
the cell
Organelles…

38. Peroxisomes
Structure
•Small, single
membrane enclosed
spheres
Function
•Breakdown hydrogen
peroxide (toxic to
cells)
•Catalase-enzyme
that catalyzes
breakdown
Organelles…

39. Organelles…
Centrioles
–Cylinder shapped
–2 centrioles in most cells
–Involved in celldivision~
mitosis
–Associated with
separation of DNA
strands
–NOcentriolesin:
•RBC’s
•Neurons -nerve cells
•Skeletal & cardiac
muscle cells
–These cells incapable of dividing
–These are derived from “stemcells”

40. Major Organelles

41. Major Organelles

42. Cytoskeleton
•The cytoskeleton
functions as the
“muscles and bones
“of the cell.
•It consists of:
1.Microfilaments:
are actinfilaments
which help the cell
to move (muscle
contraction)
2.Intermediate
Filaments: which
prevent the cell from
being pulled apart
3.Microtubules: function in
Maintaining the cell shape
Transport of organelles and vesicles
Movmentof the cell particularly
important in ciliaand flagella

43. Cell extensions
Cilia ~ “globular” protein forms cilia
•Hair like extensions of cell membrane
•Beat rhythmically ~ move substances,
fluids, secretions across cell surfaces
•Found in respiratory & reproductive tracts
–Trachea ~ coughing ~ removes debris
–FillopianTubes ~ move egg from ovary
Microvilli
•Small projections of cell membrane ~look like cilia
•Very prominent on digestive tractcells
•Increase surface area for absorption of nutrients
Flagella(flagellum is the singular) –more longer than cilium
•Flagellaare cellular projections which help the cell to move
Found on sperm cells and helps them to swim to fertilize the egg

44. Tissues
•The human body contains about 100 trillion cells
•However, no one cell can carry out all the necessary
bodily functions by itself
So, cells aggregate and form tissues
TissueCollection of cells with a similar structure and
function
•The study of tissues is known as histology
•There are 4 primary tissue types in the human body:
1.Epithelial (covering/lining)
2.Connective (support)
3.Muscle (movement)
4.Nervous (control)
•These tissues differ in the typesand functionsof their
cells, and the products of those cells and the relative
distributionof the two

45. Epithelial Tissue
•It’s found all over the place!
Covers the surface of the body
Lines the body cavities
Forms the external and internal linings of
most organs
Constitutes the bulk of most glands
•Functions
1. Protection 4. Absorption
2. Secretion 5. Filtration
3. Sensory reception
•Composed almost entirely of sheetsof close-
packed cells & very little extracellular material
•Epithelia can be divided into two main groups
according to their structure and function:
1.Covering (lining) epithelia
2.Glandular epithelia

46. •Epithelia are classified based on the numberof cell layers present
and the shapeof the cells in the apical layer.
•If there is only one layer of cells, the epithelium is simple.
•If there is more than one layer, the epithelium is stratified.
•There are 3 cell shapes:
Epithelia …
•Layers+ shape = 6types:
1.Simple squamous
2.Simple cuboidal
3.Simple columnar
4.Stratified squamous
5.Stratified cuboidal
6.Stratified columnar
•There are actually 2
othersthat are special –
Transitionalepithelium
Pseudostratifiedcolumnar
Epithelia Types
1.Squamous= flat, scale-like
2.Cuboidal= cube-shaped
3.Columnar= column-shaped

47. Simple Squamous Epithelium
•Locations:
–Air sacs (alveoli) of
lungs
–Glomerularcapsules of
kidneys
–Lining of heart and all
blood vessels
•Here it’s called the
endothelium
–Serous membranes
–External lining of
visceral organs
•Here it’s called the
mesothelium

48. Simple Squamous Epithelium
Functions:
•Thinness allows material to
rapidly diffuse or be
transported through the
epithelial layer
Example
•Gases diffuse across the thin
air sac epithelium in the lungs
Blood traveling to the lungs is
high in CO
2and low in O
2.
After gas exchange in the
lungs, the blood leaving is
high in O
2and low in CO
2
•Blood is filtered through the
epithelium of the kidney capillaries
This begins the process of removing waste products
from the blood and modifying its ionic content
•Secretion of a
lubricating fluid by
the epithelium
making up the
serous membranes

49. Simple Cuboidal Epithelium
Locations:
•Liver
•Pancreas
•Thyroid, salivary, and most others
•Most kidney tubules
•Bronchioles
Functions:
•Absorption
Kidney tubules
–Microvillioften
present to
increase the
surface area
•Secretion
Kidney tubules
Liver
Pancreas
Cross-section of the thyroid gland
Cross-section of
a kidney tubule
A longitudinal
section of a
kidney tubule
Thyroid, salivary, and
most other glands

50. Simple Columnar Epithelium
•Microscopic Appearance:
–Single layer of tall, narrow cells.
–Oval or sausage-shaped nuclei, vertically-oriented,
usually located in the basal half of the cell.
–Microvilli occasionally present.
–Cilia occasionally present.
•Cilia are hair-like extensions of the cell membrane that
can move and sweep material across the cell surface
–Goblet cells often interspersed.
•Secrete a lubricating mucus
•Locations:
–Inner lining of
stomach, intestines,
and rectum.
–Inner lining of
gallbladder
–Inner lining of
uterus and uterine
tubes
Simple columnar epithelium lining the
lumen of the gallbladder.

51. Simple Columnar Epithelium …
•Functions:
–Absorption and secretion
•Columnar cells in small intestine
have microvilli to increase the
available surface area for the
absorption of nutrients.
–Secretion of mucus.
•Lots of goblet cells in the large intestine
so as to lubricate it
and ease the
passage of feces.
–Movement of egg
and embryo in
uterine tube.
•Hence the
presence of cilia.

52. Pseudostratified Columnar Epithelium
•Microscopic Appearance:
–Looks multi-layered, but it’s NOT!
•All cells touch the basement membrane.
•In stratified epithelia, only the bottom cell
layer touches the basement membrane.
–Cells are of varying heights which gives the
appearance of stratification. Nuclei are at
several levels.
–Often has goblet cells interspersed.
–Cells often have cilia.
•Locations:
–Respiratory tract
from nasal cavity
to bronchi.
Ciliated Goblet
cells
–Portions of male
reproductive
tract
Non-ciliated

53. The cilia successfully sweep the pathogens up and
away!
Pseudostratified Columnar Epithelium …
•Functions:
–In the respiratory tract there are lots of mucus-secreting
goblet cells.
–The mucus traps dust and bacteria
–Cilia “sweep” the bacteria-laden mucus up the respiratory
tract towards the pharynx where it can be swallowed.
–Smoking paralyzes cilia –smokers have to cough violently
to expel their mucus. Then they die!
The mucosal cells lining the trachea have released a
flood of mucus, trapping the pathogens! Now what?

54. Stratified Squamous
Epithelium
•Microscopic Appearance:
–Multiple cell layers with
cells becoming flatter and
flatter toward surface.
–In keratinizedstratified
squamous epithelium, the
apical layers are layers of
dead cells lacking nuclei
and packed with the tough
protein keratin.
–Nonkeratinizedstratified
squamous epithelium lacks
the layers of dead cells at
the surface.
This is keratinized stratified squamous
epithelium from the sole of the foot. It
extends the length of the blue line on the
left. Notice the multiple layers of clear,
dead, enucleated cells.

55. Stratified Squamous Epithelium
•Location of
keratinized version:
–Epidermis. Palms
and soles of feet are
typically heavily
keratinized.
•Locations of non-
keratinized version:
–Lining of oral cavity
and surface of
tongue
–Lining of esophagus
–Lining of vagina and
anal canal
keratinized stratified
squamousepithelium
Non-keratinized
stratified squamous
epithelium

56. Stratified Squamous Epithelium
•Functions:
–Protection!
–Keratinized version (a.k.a. dry
epithelium) protects against
mechanical abrasion, water
loss, and pathogen entry.
•Keratin is very strong,
waterproof, and is
bacteriostatic (prevents
bacteria from reproducing).
–Non-keratinized version (a.k.a.,
wet epithelium) also protects
from mechanical abrasion.
•Eating food, swallowing,
sexual intercourse, birth,
defecation.

57. Stratified Cuboidal Epithelium
•Microscopic Appearance:
–2 or more layers of cells.
–Surface layers are square or round (cuboidal).
•Locations:
–Some sweat gland ducts.
–Ovarian follicle
•Cells that surround the developing egg
An oocyte (egg
cell) surrounded
by stratified
cuboidal
epithelium.
The oocyte is
circled in blue
•Functions:
–Contributes to
sweat secretion.
–Secretion of
ovarian
hormones (e.g.,
estrogens)

58. Stratified Columnar
Epithelium
•Microscopic Appearance:
–2 or more layers of cells.
–Surface cells tall and narrow with
basally located nuclei.
•Locations:
–Rare.
–Small portions of anal canal, pharynx,
epiglottis, and male urethra.
–Sometimes seen in large ducts of
sweat and salivary glands.
•Functions:
–Often seen where 2 other tissue types
meet
–Structural integrity of gland ducts

59. Transitional Epithelium
•Microscopic Appearance:
–Somewhat resembles stratified squamous
epithelium, but the surface cells are rounded
and often bulge above surface (dome-shaped)
–Typically 5-6 cell layers thick when relaxed and
2-3 cell layers thick when stretched
–Cells may be flatter and thinner when stretched
–Some cells are binucleate, i.e., have 2 nuclei
•Locations:
–lining the urinary tract
–Found in part of the kidney, the ureters
•Functions:
–Stretches to allow filling of the urinary
tract
–Originally called “transitional” because it
was thought to be an intermediate b/n
stratified squamousand strat. columnar
This isn’t true but the name has persisted

60. Epithelia Types

61. Glands
•A gland is a cell or an organ that secretes
substances for use inside or outside the body
•Glands are composed of epithelial tissue
•Glands are broadly classified as:
ThyroidGland:
An endocrine
gland
Stomach: Both an
exocrine and an
endocrine gland
1.Endocrine
2.Exocrine
Liver: An
exocrine
gland

62. Glands

63. Endocrine Glands
•Endo = within
•Do not secrete material
into ducts
•Secrete chemical signals
called hormones into the
bloodstream where they
travel through the body
and affect other cells
•Examples include:
–Thyroid, thymus, testes,
ovaries, pituitary, pineal,
adrenal, etc.

64. Exocrine Glands
•Exo= outside and crine= secrete
•Typically secrete material into ducts
that lead to the body surface or to one
of the cavities that is continuous with
the body surface, i.e., digestive,
reproductive, respiratory tract.
•Can be multicellular or unicellular.
–Multicellular:
•Pancreas, stomach, sweat glands,
salivary glands, mammary glands,
sebaceous glands, etc.
–Unicellular:
•Goblet cells.
The parotid gland (a
salivary gland)
Goblet Cell

65. Exocrine Gland Structure
•Exocrine glands are either:
–Simpleif their ducts do not
branch
–Compoundif their ducts do
branch
•Exocrine glands are further
classified by the shape of their
secretory portionas:
–Tubularif the secretory portion is
the same diameter as the duct
–Alveolarif the secretory portion
is like a round ball
–Tubuloalveolarif it’s a
combination of the 2
Simple
Compoun
d

67. •Most abundant, widely distributed, and histologically variable of the 4
primary tissue types.
•Consists of cells that are typically widely separated by lots of
extracellular material –referred to as the extracellular matrix.
•Most cells are not in contact with each other but are distributed
throughout the extracellular matrix.
Connective Tissue

68. Functions of
Connective Tissue
1.Binding of organs
2.Support
3.Physical protection
4.Immune protection
5.Movement
6.Storage
7.Heat production
8.Transport

69. 1.Fibrous connective
tissue (a.k.a. connective
tissue proper)
2.Supporting connective
tissue
3.Fluid connective tissue
Categories of CT
Blood
Bone
Loose Connective
Tissue

70. Fibrous Connective Tissue
•Most diverse type of CT
•Contain extremely conspicuous fibers –hence the name, fibrous
connective tissue
•The illustration below shows a 3-D model of some typical CT fibers, typically
made of multiple strong filamentous proteins twisted about one another.
•Fibrous CT consists of cells, fibers, and ground substance
•Of these 3, which you do suppose is typically NOT that abundant?

71. Cells of Fibrous CT:
1.Fibroblasts
–Fibro = fat, blast = making
–Large, flat cells with tapered ends;
produce fibers and ground substance.
–Inactive ones are known as fibrocytes.
2.Macrophages
–Macro= large, phage = eating
–Large phagocytic cells that wander
through connective tissue, where they
engulf and destroy bacteria, other
foreign particles, and dead or dying
cells of our own body.
–They activate the immune system
when they encounter foreign matter
called antigens.
–Derived from white blood cells known
as monocytes.

72. Cells of Fibrous CT
3.Leukocytes
–Leuko= white, cyte= cell
–White blood cells that crawl out of
the bloodstream and spend the
majority of their time in the CT.
–Many are phagocytesthat wander in
search of pathogens.
4.Plasma Cells
–Certain white blood cells differentiate
into plasma cells when they detect
foreign agents.
–Plasma cells produce and secrete
antibodies(proteins that bind to
foreign molecules (antigens)
Thus inactivating them or marking
them for future destruction.

73. Cells of Fibrous CT
5.Mast Cells
–Often found in CT adjacent to
blood vessels.
–Secrete a chemical called
heparinwhich is an anti-
coagulantand a chemical called
histaminewhich is a vasodilator.
6.Adipocytes
–Adipo = fat
–Appear in small clusters in some
fibroconnective tissues.
–If they dominate an area, we call
that area adipose tissue.
–Contain huge droplets of lipids
for storage.

74. Fibers in Fibrous Connective Tissue:
1.Collagenous Fibers
2.Reticular Fibers
3.Elastic Fibers
Collagen Fibers as seen
with a scanning electron
microscope

75. Collagenous Fibers
•Interwoven strands of the protein
collagen.
–The most abundant protein in the
human body.
•Thick fibers with great tensile
strength–i.e., it’s tough to pull them
apart.
•In fresh tissue, they have a white
appearance, so they are sometimes
called white fibers.
•In stained slides, they are often pink
and they usually appear quite wavy.
•Tendons, ligaments, and the deep
layer of the skin (the dermis) are
made primarily of collagenous fibers.
Close-up of a
single fiber
Multiple fibers
arranged in the
extracellular
matrix

76. Reticular Fibers
•A thinner collagen
fiber coated with
glycoproteins.
–Stained black in the
adjacent micrograph
of the liver.
•These fibers can
branch extensively
and form networks
or frameworks for
certain organs.

77. Elastic Fibers
•Made primarily of a
protein called elastin,
whose coiled structure
allows it to stretch and
snap back like a rubber
band.
•Account for the ability of
the lungs, arteries, and
skinto spring back after
they are stretched.
•Fresh elastic fibers are
yellowishand thus often
called yellow fibers.
In this slide, “A” is an elastic fiber
–“B” is collagenous Fiber

78. Ground Substance
•Gelatinous material that occupies the space between
the cells and the fibers in connective tissues.
Imagine some lime Jell-o
that a not-so-bright chef
decided to make with
carrots and grapes. The
carrots are like fibers, the
grapes like cells, and the
Jell-o itself is the ground
substance/

79. Types of Fibrous Connective Tissue
•2 types based on the relative
abundance of fibers.
–Loose Connective Tissue
•Lots of ground substance and
cells. Fewer fibers.
•Leaves lots of empty space in
tissue sections.
•Eg,. Adipose and Aerolartissues
–Dense Connective Tissue
•Fibersoccupy the most space.
•Much lower number of cells
and less ground substance.
•Appears closely packed in
tissue sections.
•Eg,. Regular -tendons,
ligaments
•Irregular–dermis of skin, joint
capsule etc

80. Adipose Tissue
•Locations:
–Subcutaneous fat beneath
skin
–Breast
–Heart surface.
–Cushioning organs
•Kidneys
•Eyes
•Functions:
–Energy storage
–Thermal insulation
–Shock absorption
–Protective cushioning for
some organs

81. Types of Dense CT
1.Dense regular
2.Dense irregular
1
2

82. Dense Regular CT
•Microscopic
Appearance:
–Densely packed,
parallel, often wavy
collagenous fibers.
–Slender fibroblast nuclei
compressed between
bundles of collagenous
fibers.
–Scanty open space (little
ground substance)
–Scarcity of blood
vessels.

83. Dense Regular Connective Tissue
Locations:
–Tendons.
–Ligaments.
NOTE the waviness of the fibers.
Functions:
–Ligaments bind bone
tightly to other
bones. Resist stress.
–Tendons attach
skeletal muscles to
bone and transfer
muscular tension to
bones.

84. Dense Irregular CT
•Microscopic Appearance:
–Densely packed, collagenous fibers
running in random directions.
Compare this to dense regular CT.
–Scanty open space (ground
substance).
–Few visible cells.
–Scarcity of blood vessels.
•Locations:
–Deeper portion of dermis
of skin.
–Capsulesaround visceral
organs such as the liver,
spleen, and kidneys.
–Fibrous sheaths around
cartilages and bones.
•Functions:
–Provides a durable, hard to tear
structure that can withstand
stresses placed in unpredictable
directions.

85. Supporting Connective Tissue
•They provide the majority of the
structural support of the body
•2 types:
–Cartilage
–Bone
1
2
* Will be seen with the
skeletal system
Fluid connective tissue
–Blood
–Lymph
*Will be seen with the
circulatory system
3.Muscle Tissue
4.Nervous Tissue
*Will be seen with the Muscular
and Nervoussystemsrespectively