ANIMAL TISSUES
Outline:
CAVITE STATE UNIVERSITY
Don Severino de las Alas Campus
Indang, Cavite
College of Arts and Sciences
DEPARTMENT OF BIOLOGICAL SCIENCES
ANIMAL TISSUES
Epithelial tissues
Connective tissues
Muscle tissues
Nervous tissues
PREPARED BY: DMBICUA
TISSUES
HISTOLOGY
Study of Tissues
Epithelial tissue
PREPARED BY: DMBICUA
DEFINITION

Tissues- group of similar cells specialized for
the performance of a common function.

Individual
cells
differentiate
during
development to perform special functions as
aggregates

There are 4 major types of animal tissues.

STEM CELLS- undifferentiated cells.
Connective tissue
Muscle tissue
Nervous tissue
PREPARED BY: DMBICUA
Epithelial tissue/ Epithelium
Covering tissue for protection.
Epithelial tissue/ Epithelium
FUNCTIONS
Protection- protects the underlying tissues from- mechanical injury, drying up,
from harmful chemical and infection.
Absorption- Epithelial lining of the intestine absorbs digested food.
Excretion- Epithelial lining of the uriniferous tubules in the kidney helps in
excretion of substances.
Conduction- ciliated epithelium helps in conduction of substances.
Secretion- Lining of the glands secretes substances.
Exoskeleton- Nails, hairs, claws, feathers etc. are formed form the epithelial cells.
Respiration- Lining of the lung brings about exchange of gases.
Sensory function- epithelium of sense organs receive stimuli and convey nerve
impulses.
PREPARED BY: DMBICUA
METABOLISM OF LIPIDS
TYPES OF EPITHELIAL TISSUE
 Simply combine the two manner of classifying
the epithelial tissue.
 First, determine if it has layers then determine
the shape of the cells that makes up the
epithelial tissue. Simply combine the two terms.
Acc. To strata: Simple
Acc. To shape:
Squamous
“simple
squamous”
Acc. To strata:
Stratified
Acc. To shape:
Squamous
“Stratified
squamous”
PREPARED BY: DMBICUA
Simple
squamous
Simple
columnar
Simple
cuboidal
Stratified
cuboidal
Stratified
squamous
Stratified
columnar
Consist of renewable sheets of cells that have specific specializations.
Basement membrane- separates epithelial tissues from underlying adjacent tissues.
Epithelial tissues are classified in two ways, according to shape and according to strata (layers).
Scale-shaped cells
Box/cube-shaped cells
Simple- when the tissue is single-layered.
PREPARED BY: DMBICUA
Column-shaped cells
Stratified- when the tissue has many layers.
Simple squamous epithelium
Stratified squamous epithelium
• Single layer of tightly packed, flattened cells
•
• Location: air sacs of the lungs, kidney glomeruli,
lining of the heart and lymphatic vessels
• Location: lining of esophagus, mouth and
vagina. Keratinized variety lines the skin
• Function: Allows passage of materials by
diffusion and filtration
• Function: protects underlying tissues in areas
subject the abrasion
Consist of many layers of cells
Simple cuboidal epithelium
•
Stratified cuboidal epithelium
Consist of single layer of tightly-packed cube cells
• Location: kidney tubules, ducts and small glands, and surface of ovary
• Function: Secretion and absorption
Simple
Columnar
Epithelium
Light micrograph (LM) showing simple columnar epithelium in the gall bladder.
•
Location: lining of digestive tract, and excretory ducts of some glands. Some columnar cells are
specialized for sensory reception such as in the nose, ears and the taste buds of the tongue.
•
Function: Absorption and enzyme secretion
Trachea epithelium.
Light micrograph (LM) of a vertical section through the pseudostratified columnar epithelium from the trachea
Pseudostratified Ciliated Columnar Epithelium
Location: Lines bronchi, uterine tubes, and some regions of the uterus.
Function: propel mucus or reproductive cells by ciliary action
Transitional Epithelium
•
•
•
•
These cells show great amount of flexibility.
without distention (relaxed), the cells appear cuboidal-shaped
when distended (tense), the cells appear squamous-shaped
impermeable to salts and water
•
•
found in urinary bladder, ureter,
and pelvis of kidney
urine/fluid builds up in these
cavities, the transitional layers
extend to relieve the stress
PREPARED BY: DMBICUA
Connective Tissue
Binding and Supporting
CONNECTIVE TISSUES
Tissues that “connects” the whole body. The binding and supporting tissues that bind and support the body's
other tissues and organs are known as connective tissues.
•
•
•
•
•
Most abundant tissue in the body
They are the most diverse type of tissues in the animal body.
It contains sparsely packed cells scattered throughout an
extracellular matrix.
The matrix consists of fibers in a liquid, jellylike, or solid foundation.
The nature of the extracellular material determines the functional
properties of the various connective tissues.
TYPES OF CONNECTIVE TISSUE FIBERS
•
Collagenous fibers provide
strength and flexibility.
•
Elastic fibers stretch and snap
back to their original length.
•
Reticular fibers join connective
tissue to adjacent tissues.
1. LOOSE CONNECTIVE TISSUE
also called areolar connective tissue, contains numerous fibroblasts that produce collagenous and elastic
fibers that wraps and cushions organs.
2. FIBROUS CONNECTIVE TISSUE
Contains large amounts of collagen fibers and few cells or matrix material.
•
Irregularly-arranged fibrous connective tissues
are found in areas of the body where stress occurs
from all directions, such as the dermis of the skin.
•
Regular fibrous connective tissue is found in
tendons and ligaments.
2. FIBROUS CONNECTIVE TISSUE
3. ADIPOSE TISSUE
Consist of adipocytes which contain large fat droplets that push the nuclei close to the plasma
membrane. Accumulation of these cells forms fat; type of a loose connective tissue.
FUNCTION
• Provides padding.
• Acts as an insulator to slow heat loss.
• Serves as a packing or filler material around
structures of the body.
• Provides reserve fuel
3. ADIPOSE TISSUE
Consist of adipocytes which contain large fat droplets that push the nuclei close to the plasma
membrane. Accumulation of these cells forms fat; type of a loose connective tissue.
LOCATION:
• Located under the skin (flanks, buttocks,
breasts)
• Fills bony sockets behind the eyes.
• Surrounds kidneys (adipose capsule)
• Located around heart and abdominal organs.
Hepatic angiomyolipoma (benign liver tumor) showing
epithelioid smooth muscle cells admixed with adipocytes.
3. ADIPOSE TISSUE
Brown adipocytes chief cells of the brown
adipose tissue
Beige adipocytes
- recently discovered type,
found dispersed within
white fat tissue;
sometimes generate heat.
White adipocytes main cells of the
white adipose tissue
3. ADIPOSE TISSUE
• White adipose tissue
• Most common type, provides
insulation, serves as an energy store
for times of starvation or great
exertion
• Forms pads between organs
• Subjected to lipolysis- breaking
down of triacylglycerol into energyrich fatty acids and glycerol
•
•
•
•
•
Brown Adipose Tissue
Found mainly in newborn animals.
Functions for generation of heat and
consumes energy.
Also common in hibernating species
for their survival.
Its color and heat-generating
properties is due to the abundance
of mitochondria.
4. CARTILAGE
Firm and flexible connective
tissues; hard yet flexible tissue
supports structures
Cells called chondrocytes lie within the lacunae, that
are surrounded by a rubbery matrix that chondroblasts
secret.
A. Hyaline cartilages can support and cushion, resists repetitive stress. Found at the end of long bones.
Hyaline cartilage-consist of cells surrounded by intercellular material containing fine collagenous fibers.
Location: forms embryonic skeleton; covers ends of long bones; and forms cartilage of nose, trachea,
and larynx
Function: support and movement
B. Fibrocartilages have tensile strength and able to absorb compressive shock. Found at the vertebral
column; Contains many large, collagenous fibers in its intercellular material. Its cells are fibroblasts.
Location: Intervertebral disks, pubic symphysis, and disks of knee joint.
Function: Absorbs compression shock
C. Elastic Cartilages maintains shape and flexibility. Found at the ear
Consists of fine collagenous fibers and many elastic fibers in its intercellular material.
Location: External ear, epiglottis
Function: maintain a structure's shape while allowing great flexibility
5. BONE / OSSEUS TISSUE
Hard and rigid tissues which forms the bones of our body.
They lie within lacunae but the matrix around them is impregnated with
calcium phosphate and calcium carbonate, making bones hard.
Bone matrix is deposited in concentric layers around osteonic canals
Location: Bones
Function: Supports, protects,
provides lever system for muscles to
act on, stores calcium and fat, and
forms blood cells.
•
Osteon: any of the central
canals and surrounding bony
layers found in compact bone
•
Canaliculus: any of many small
canals or ducts in bone
Diagram of compact bone: (a) this cross-sectional view of compact bone shows several osteons, the basic structural unit of
compact bone. (B) in this micrograph of the osteon, you can see the concentric lamellae around the central canals.
5. BONE / OSSEUS TISSUE
DIAGRAM OF SPONGY BONE: SPONGY BONE IS COMPOSED OF
TRABECULAE THAT CONTAIN THE OSTEOCYTES.
RED MARROW FILLS THE SPACES IN SOME BONES
Osteogenic Cells
Develop into osteoblasts
Osteoblasts
Bone Formation
Active in making bone for growth and remodelling. They deposit bone material into the matrix which will
surround them. Osteoblasts continue to live, but in a reduced metabolic state as osteocytes.
Osteocytes
Maintain mineral concentrations of matrix. Assist in maintenance of the bone.
Osteoclasts
Bone resorption active in breaking down bone for bone remodeling, providing access to calcium stored in
tissues to release it into the blood.
6. BLOOD
One important connective tissue aside from their cellular function of fighting against pathogens and transporting
oxygen. Blood transports oxygen, carbon dioxide, nutrients, wastes, hormones, minerals, vitamins, and other
substances.
Erythrocyte
RED BLOOD CELLS.
Most abundant blood formed element, responsible for transporting
oxygen to body tissues.
Mammalian erythrocytes lose their nuclei and mitochondria when
they are released from the bone marrow where they are made.
Fish, amphibian, and avian red blood cells maintain their nuclei and
mitochondria throughout the cell’s life.
Leukocytes
WHITE BLOOD CELLS
Involved in defending the body
against pathogens and foreign
bodies
• Neutrophils- phagocytic cells that participate in one of the early
lines of defense against pathogens,
• Eosinophils and basophils- help in facilitating inflammatory
response
• Monocytes- give rise to phagocytic macrophages which facilitates
in disposal of dead and damaged cells in the body
• Lymphocytes- determines the specificity of response. account
for immunologic “memory,” a rapid, vigorous response to 2nd
encounter with the same antigen.
PREPARED BY: DMBICUA
Thrombocytes
PLATELETS
Cytoplasmic fragments of a cell in the bone marrow which
participate in the stages leading up to coagulation of the blood.
Blood clots are formed in response to injury/trauma of a blood
vessel. The four basic steps to coagulation are:
1. Platelets are activated by the exposed collagen
2. Platelet factors are released
3. More platelets are attracted by the platelet factors
4. Platelets come together to form a plug
FIGURE 40.5BA
Connective Tissue
Loose connective tissue
Blood
Collagenous fiber
Plasma
120 m
55 m
White
blood cells
Elastic fiber
Red blood cells
Cartilage
Fibrous connective tissue
30 m
100 m
Chondrocytes
Chondroitin sulfate
Bone
Adipose tissue
700 m
Central
canal
Osteon
Fat droplets
150 m
Nuclei
MUSCLE TISSUE
Movement
Muscle Tissue
MUSCLE TISSUES
•
Skeletal muscle
Nuclei
Tissues that functions for
movement.
•
Muscle
fiber
Muscle tissue consists of long
cells called muscle fibers,
Sarcomere
100 m
which contract in response to
nerve signals
•
There are movements that can
Smooth muscle
Cardiac muscle
be controlled and there are not.
•
This is due to the different
types of muscle tissues.
Nucleus
Muscle fibers 25 m
Nucleus Intercalated disk
50 m
1. CARDIAC MUSCLE CELLS
Consist of branched straited cells, each containing a single nucleus and specialized cell junctions called
intercalated disks that allow ions to move quickly from cell to cell.
Location: walls of the heart
Function: As the walls of the heart contract, cardiac muscle
propels blood into the circulation; involuntary control
2. SKELETAL MUSCLE
Composed of striated muscle fibers that are long and cylindrical and contain many peripheral nuclei; makes
body movement possible in vertebrates
Location: In skeletal muscles attached to bones
Function: Voluntary movement
3. SMOOTH MUSCLE
formed of spindle-shaped cells, each containing a single centrally located nucleus. Cells are arranged closely
to form sheets. These are not striated.
Location: mostly in the walls of hollow organs
Function: moves substances or objects along internal
passageways, involuntary body activities
PREPARED BY: DMBICUA
Muscle
Tissue
TYPES
OF MUSCLE
TISSUES
Skeletal muscle
Nuclei
Muscle
fiber
Cardiac muscle tissue- consist of
branched straited cells, each containing a
single nucleus and specialized cell junctions
called intercalated disks that allow ions to
move quickly from cell to cell.
 Location: walls of the heart
 Function: As the walls of the heart
contract, cardiac muscle propels blood
into the circulation; involuntary control
Sarcomere
100 m
Skeletal muscle tissues- Skeletal muscle tissuecomposed of striated muscle fibers that are long and
cylindrical and contain many peripheral nuclei; makes body
movement possible in vertebrates
Location: In skeletal muscles attached
Smooth muscle
to bones
Function: Voluntary movement
Smooth muscle- formed of spindleshaped cells, each containing a single
centrally located nucleus. Cells are arranged
closely to form sheets. These are not
striated.
Nucleus
Muscle fibers
25 m
 Location: mostly in the walls of hollow organs
 Function: moves substances or objects along internal passageways,
involuntary control
PREPARED BY: DMBICUA
Cardiac muscle
Nucleus
Intercalated disk
50 m
NERVOUS TISSUE
Control
NERVOUS TISSUE
▪ Controls the body as they generally function to
transmit electrical signals.
▪ They make up the nervous system of most animals.
▪ It senses stimuli and transmits signals throughout
the animal
Location: Brain, spinal cord and nerves
Function: Transmit electrical signals from sensory
receptors to the spinal cord or brain, and from the
spinal cord or brain to effectors
Nervous tissue contains:
Neurons, or nerve cells, that transmit nerve (electrical)
impulses. Neurons do not undergo mitosis due to lack
of centrioles.
Glial cells, or glia, that help nourish, insulate, and
replenish neurons.
ANIMAL TISSUES