Mammalian tissues

types of mammalian tissues

1. BIO
231(Cell biology & Histology)
The study of
Mammalian tissues
Emphasizing on structure and function
DEPARTMENT OF BIOLOGICAL SCIENCES
FEDERAL UNIVERSITY DUTSIN-MA
BY RUQAYYA ADAM

2. Introduction
•
Tissue
is a group cells which work together to
perform particular functions .
•
The branch of biology that deals with the study
of detailed structure, chemical composition and
function of tissue is known as
histology
coined
by
Mayer

3. TYPES OF MAMMALIAN TISSUE
•
Epithelial tissue
•
Connective tissue
•
Muscle tissue
•
Nervous tissue

4. EPITHELIAL TISSUE
•
Epithelial tissue forms the outer lining of
body surfaces
and
cavities
as well as form glands
•
The cells of the tissues are
tightly connected
to each other via
cellular junctions
•
It
is non vascular
( has no blood vessels) and are dependent
upon the underlying connective tissue for nutrients
•
It is found on the
edges of organs
, hence has two distinct
surfaces.
•
The
apical surface/layer
is exposed to the body cavity or
exterior
•
The
basal surface/layer
is adjacent to the underlying tissue
•
It functions in protecting the internal organs fro
m mechanical
injury, invasive microbes and fluid loss

5. TYPES OF EPITHELIAL TISSUE
•
Epithelial tissues are classified based on the
shape
of the cells
composing the tissue;
•
squamous (flattened and thin),
•
cuboidal (boxy),
•
columnar (Rectangular).
•
and by the
number
of cell layers present in the tissue;
•
simpleepithelium.
•
Stratifiedepithelium
•
The combination of cell shape and number of cell la
yers is
used to classify epithelial tissue into;

6. Inner walls of blood vessels
& alveoli of lung
Kidney tubules and duct of
glands
Location
Location
Location
GIT and female reproductive tract
Mouth and oesophagus

7. Simple epithelium
•
Simple squamous epithelium
: it appears as thin scales. The
nuclei appears flat, horizontal, and elliptical. I
t’s found lining
the
inner wall of blood vessels
(providing smooth surface that
reduces friction as blood passes through) and
the small air
sacs(alveoli) of the lung.
•
Simple cuboidal epithelium:
it appears as
box-like cells
, having
a
round nucleus
that is generally located near the center of the
cell. It’s involved in secretion and absorptions of
molecules.
These epithelia are observed in the lining of
the kidney tubules
and in the
ducts of glands
.

8. Simple epithelium contd.
•
Simple columnar epithelium
, the nucleus is elongated and
located in the basal end of the cells. Its primary
function is
absorption (of nutrients) and secretion of molecule
s. It forms a
majority of the
digestive tract
and some parts of the
female
reproductive tract
.
•
Ciliated columnar epithelium
is composed of simple columnar
epithelial cells with
cilia on their apical surfaces.
These
epithelial cells are found in the
lining of the fallopian tubes
where the assist in the passage of egg, and
parts of the
respiratory system,
where the beating of the cilia helps remove
particulate matter.

9. Stratified epithelium
•
Stratified squamous epithelium;
consists of multiple layers with
squamous cells at the apical surface whereas the ba
sal layer
contains
either columnar or cuboidal cells
. Its primary function
is
protection from abrasion,
found in areas like
mouth and
oesophagus
•
The apical layer may be covered with layer of
dead keratin
filled
cells.
The skin is an example of a keratinized, stratified

squamous epithelium.
Alternatively, the lining of the
mouth/oral cavity
is an example of an
unkeratinized, stratified
squamous epithelium.
•
Stratified cuboidal epithelium
and
stratified columnar
epithelium
can also be found in certain glands (sweat glands,
mammary glands, and salivary glands), but are relat
ively rare in
the human body.

10. •
Pseudo stratified columnar epithelium
•
it appears to be stratified but instead consists of a single
layer of irregularly shaped and differently sized columnar
cells.
•
Pseudostratifiedcolumnar epithelium is found in the
respiratory tract, where some of these cells have ci
lia
.

11. CONNECTIVE TISSUE
•
Connective tissue ranges from vascular to avascula
r
•
These tissues are hard as a bone or has fluid like
structure as of
blood.
•
Cells called
Fibroblasts are found in all types of connective tissue
and are scattered in a
matrix
. This matrix is called
intercellular
matrix or extracellular matrix.
•
The
matrix
consists of
fibers and ground substance (solid,
semisolid, viscous)
. The most abundant
fiber
in connective tissues is
a tough
protein
called
collagen
•
Location
; it is present between different tissue and organs
.
•
functions :
•
It supports and connects (binds) other tissues
•
Transporting fluids and other dissolved materials
•
Protecting organs
•
Storing energy
•
Defending the body from micro organisms

12. TYPES OF CONNECTIVE TISSUE
•
Areolar (loose) connective tissue.
•
Adipose tissue (fat).
•
Dense irregular connective tissue.
•
Dense regular connective tissue.
•
Cartilage (gristle).
•
Bone (osseous tissue).
•
Blood

13. Areolar (loose) connective tissue
•
Fibers are loosely arranged with a wide
variety of cell types, highly vascularized,
viscous ground substance
•
Homogenous, transparent, gelatinous
matrix
•
Location:
Under all epithelia; outer
coverings of blood vessels, nerves,
esophagus, between muscles
•
Function
;
•
Nourishes and cushions epithelia,
defense against infection, binds tissue
together,
•
And secretes
heparin
(anticoagulant)
and
histamine
(causes inflammation
reaction)
Areolar tissue

14. Adipose tissue (fat).
•
Large fat-filled
adipocytes
and scanty extracellular matrix.
•
Location:
Beneath skin; around kidneys, heart, and eyes;
breast; abdominal membranes
•
Function:
Stores energy, conserves body heat, cushions and
protects many organs, fills space, shapes body
•

15. Dense irregular connective tissue
•
Densely spaced, randomly arranged fibers
and fibroblasts. Highly vascularized
•
Location:
Dermis of skin, around liver,
spleen, and other organs
•
Function
: Toughness; protects organs from
injury; provides protective capsules
(covering) around many organs

16. Dense regular connective tissue
.
•
Densely spaced, parallel collagen fibers
and fibroblasts. Reducibly vascularized
•
Location
: Tendons and Ligaments
•
Function:
Binds bones
together(ligaments) and attaches
muscle to bone(tendons); transfers
force from muscle to bone

18. Cartilage (gristle
)
•
Cartilage is made up of highly specialized cells
called
chondrocytes and chondroblasts
( chondrorefers to
cartilage),
•
and other extracellular material which forms the ca
rtilage
matrix which is semi solid
•
Location:
External ear, larynx, rings around trachea, joint
surfaces and growth zones of bones, between ribs
•
Function:
Eases joint movements; resists compression at
joints; holds airway open; shapes outer ear; moves
vocal
cords; forerunner of fetal skeleton; growth zone of
children's
bones

20. Bone (osseous tissue).
•
Widely spaced cells called
osteocytes
in lacunae; much of
matrix in concentric onion like layers; hard minera
lized matrix.
•
Location:
Skeleton
•
Function:
Physically supports body, provides movement,
encloses and protects soft organs, stores and relea
ses calcium
and phosphorus

21. Bone (Osseous tissue)

22. Blood (Fluid connective tissue)
•
Erythrocytes (RBC), leukocytes (WBC), and Thrombocy
tes
(platelets )
•
Location:
Circulates in cardiovascular system
•
Function:
Transports nutrients, gases, wastes, hormones,

23. MUSCLE TISSUE
•
It is characterized by properties that allow moveme
nt.
•
Muscle cells respond to a stimulus and are contract
ile
•
Muscles are made up of highly specialized
thin and elongated
cells called
muscle fibres
•
The muscle fibrescontains specialized cytoplasm cal
led
sarcoplasm
that contain network of the membrane called
sarcoplasmic reticulum
.
•
The
muscle fibres
may be bounded by the cell membrane
called
sarcolemma.
•
Each muscle fibremay contain
numerous longitudinal fibrils
called
myofibrils
•
Muscle tissue is classified into three types accord
ing to
structure and function:
•
Skeletal,cardiac, and smooth

25. Skeletal muscle
•
Structure:
Long cylindrical fiber, striated, many peripherally

located nuclei
•
is arranged in bundles surrounded by connective tis
sue.
•
Location
: Attached to bones and around entry & exit sites o
f
body (e.g., mouth, anus)
•
Function:
Voluntary movement (its contraction makes possible
locomotion, facial expressions, posture,), produces
heat,
protects organs

26. Cardiac Muscle
•
Structure:
Short, branched (Y-Shaped), striated, single central
nucleus
•
Location
: Heart
•
Function
: Contracts to pump blood through the heart by
alternate contraction and relaxation

27. Smooth Muscle
•
Short, spindle-shaped, not striated, single nucleus
in each
fiber and centrally located
•
Location
;Walls of major organs and passageways
•
Function;
Involuntary movement, moves food along the GIT,
involuntary control of respiration, moves secretion
s, regulates
flow of blood in arteries by contraction

28. NERVOUS TISSUE
•
Nervous tissue is the main tissue component of the
two parts
of the nervous system;
the brain and spinal cord of the
central nervous system (CNS),
and
•
the branching
peripheral nerves of the peripheral nervous
system (PNS),
which regulates and controls bodily functions
and activity.
•
It’s characterized as being
excitable and capable of sending
and
receiving electrochemical signals that provide the
body
with information
.
•
Two main classes of cells make up nervous tissue:
the
neuron
and
neuroglia

29. Neuron
•
Neurons secrete chemical substances(neurotrnsmitter
s)
which are responsible for stimulating other neurons
as a
result of a stimuli
•
The cell body
is the enlarged portion of the neurons that
contains the nucleus. It is the “
nutritional centre
” of the
neuron where macromolecules are produced.
•
Dendrites
(from the Greek
dendron= tree branch
) are thin,
branched processes or structure that extend from th
e
cytoplasm of the cell body. Dendrites provide a
receptive
area
that transmits electrical impulses to the cell body
.
•
The axon
is a longer process that
conducts impulses away
from the cell body.

30. Neuron

31. Neuroglia
•
The neuroglia are a diverse class of cells that pro
vide
developmental, physiological, and metabolic support
for
neurons.
•
They are responsible for maintaining homeostatic co
ntrol and
immune surveillance in the
nervous system
.