2. Muscular
Tissue:-D

3. Tissues are groups of cells that are
similar in structure and function.
* Epithelium * Muscle
Coverings Movement
Linings of surfaces
* Connective * Nervous
Support Control
Bone, ligaments, fat Brain, nerves, spinal
cord

4. •Muscle – a Latin word for “little
mouse”
•Muscle is the primary tissue in the
•Heart (cardiac MT)
•Walls of hollow organs (Smooth
MT)
•Skeletal muscle
•Makes up nearly half the body’s
mass

5. Functions of muscle tissue
Contractility
Long cells shorten and generate pulling
force
Excitability
Electrical nerve impulse stimulates the
muscle cell to contract
Extensibility
Can be stretched back to its original length
by contraction of an opposing muscle
Elasticity
Can recoil after being stretched

6. Location Function Appearance Control
striated, multi-
Skeletal movement, nucleated
skeleton voluntary
heat, posture (eccentric), fibers
parallel
Cardiac heart
pump blood striated, one
involuntary
continuously central nucleus
Peristalsis,
Visceral G.I. tract,
blood
uterus, eye, no striations, one
(smooth pressure, involuntary
blood central nucleus
pupil size,
muscle) vessels
erects hairs

11. Nervous
Tissue:-D

12. •Nervous tissue comprises the nervous system.
•Nervous tissue includes:
•Nerve cells:
•Neurons.
•Supportive cells:
•Schwann cells in peripheral nervous system (P.N.S)
•Glial cells in central nervous system (C.N.S)
•Nerve fibers.
•Nerve endings:
•Receptors or sensory nerve endings.
•Effectors or motor nerve endings.

13. The neuron is the structural and functional unit of the
nervous system.
•The neuron has 2 highly developed physiologic
properties:
•Irritability, is the capacity to generate nerve
impulses in response to various stimuli.
•Conductivity, is the ability to transmit the
impulses along the processes of the neuron.

14. Fine structure of neuron
•The cell body of the neuron contains:
•Central euchromatic vesicular nucleus (open-face nucleus).
•Perinuclear very well developed Golgi Complex.
•Mitochondria (are found throughout the neuron i.e. in cell body and its
processes).
•Rough Endoplasmic reticulum (rER) is present only in cell body and dendrites
and not present in the axon or axon hillock. RER appears as clumps of
basophilic material called Nissl granules.
•Neurofibrils (are distributed throughout the neuron and appear by light
microscope).
•Microtubules are found all over the neuron.
•Inclusions found in nerve cells include:
•a) fat droplets
•b) pigments as lipofuscin, melanin
•c) glycogen present only in embryonic neurons, but in adult neurons it is absent
because it depends on oxidative metabolism. Therefore nervous system is
vulnerable (sensitive) to anoxia.
•N.B.:
•Centrioles are not found in mature neurons, so they are incapable of cell
division.

15. Processes of the
neuron: They are
the axon and the
dendrites.

16. •The axon (axis cylinder):
•It is the efferent process of the neuron which carries the impulse away
from the cell body.
•It originate from the cell body by a conical portion called “axon
hillock”.
•It is a single, thin, long process with uniform size.
•It gives some collateral branches and many terminal branches.
•It is surrounded with a membrane called axolemma and its cytoplasm
is called axoplasm.
•It contains mitochondria, microtubules and neurofibrils.
•It does not contain Nissl granules.
•As the axon is devoid of rER, it depends on the proteins synthesized in
the cell body which is conveyed by the aid of the movements of
microtubules throughout the axon by a process called axoplasmic
transport.
•The Dendrites:
•They are the afferent processes of the neuron which carry the impulse
to the neuron.
•They are multiple, short, thick processes and their thickness
decreases towards its end.
•They have many branches with spines.
•They contain mitochondria, microtubules and neurofibrils.
•They contain Nissl granules.

18. Types of the neurons: are classified according to
number of processes into:
•Pseudo-unipolar neurons: which have single process, then
divides into axon and dendrite. They are present in dorsal
root ganglion (also called spinal ganglion or sensory ganglion).
•Bipolar neurons: they are spindle-shaped with 2 processes;
one axon and one dendrite. They are present in areas of
special sensations as: retina, olfactory mucosa and inner ear.
•Multipolar neurons: they have several processes, the nerve
cell body takes several shapes as follows:
•Pyramidal cells: as in cerebral cortex.
•Purkinje (flask-shaped) cells; as in cerebellar cortex.
•Stellate cells: as in
•Gray matter of spinal cord (anterior horn cells).
•Autonomic ganglia.

20. Types of nerve fibers:
•In CNS, all the fibers have no neurilemma
sheath and may be:
•Non-myelinated (naked): as in grey matter.
•Myelinated: as in white matter.
•In PNS, all the fibers (except the nerve endings)
have neurilemma sheath and may be:
•Non-myelinated: as post-ganglionic sympathetic
fibers.
•Myelinated: as all the peripheral nerves.

21. Schwan cells (neurolemmal cells)
•These cells surround the axons of peripheral nerves. They look
like tubes which envelop the axon. They have peripheral oval
nucleus and basophilic cytoplasm.
• Whether the nerve fiber is myelinated or not, it is related to
Schwann cells.
•If the axon is myelinated, one Schwann cell is related to
each axon.
•In non-myelinated axons, one Schwann cell is related to
several axons.
•Functions of Schwann cells:
•They have a protective and a metabolic role for the axons.
•They act as an insulator for the nerve impulse.
•They are essential for regeneration of injured peripheral
neurons.
•They form myelin sheath which is important because:
•It insulates the nerve impulse.
•It increases the conduction velocity of the axon.

23. Ganglia
Ganglia are either:
•Autonomic ganglia (sympathetic & parasympathetic)
•Spinal (sensory) ganglia.

24. Satellite Cells: form a layer around ganglion cells
and separate them from blood capillaries. It helps
metabolic exchange between ganglion cells and
blood.

25. Spinal (sensory) ganglion Autonomic Ganglion
Surrounded by thick connective tissue  Surrounded by thin connective tissue
capsule. capsule.
Cells are round or oval (pseudo-  Cells are stellate (multipolar)
unipolar)
Cells are arranged in groups  Cells are scattered
Cells are not of same size  Of equal small size
Few number of cells  Large number of cells
Cells with central nuclei  Cells with peripheral nuclei
Myelinated nerve fibres separate the  Unmyelinated nerve fibres separate the
groups of cells cells
Cells are surrounded by many satellite  Few satellite cells
cells
No synapse between neurons  Has synapses between neurons

26. Neuroglia
•Neuroglial cells are the supporting cells within the CNS. They
have a function similar to Schwann cells in PNS. They have many
types:
•Astrocytes: these cells support the neurons. They are either
fibrous or protoplasmic.
•Fibrous astrocytes: With long processes which branch
infrequently. They are found in white matter. They have
euchromatic nuclei and a vascular pedicle, i.e. one process
ends on a small blood vessel. Their cytoplasm contains
neuroglial fibers.
•Protoplasmic astrocytes: With short processes. They are
found in gray matter. Their cytoplasm is rich in cytoplasmic
granules called gliosomes which are considered as lysosomes.

27. Oligodendrocytes: Microglial cells:
With few processes, (dark) – Small in size with few
nuclei, and contain many processes and elongated
microtubules. It is dark nucleus. Function:
responsible for myelin phagocytosis.
formation in CNS by
sending processes to
several axons.

30. THANK YOU MAM ALMOND :-D