2. OBJECTIVE
Nervous system and its functions.
Components and contents of the nervous system.
What is nervous tissue and it is functions?
Structures of nervous tissue and there function.
Divisions of nervous system.
Plexuses.
Nervous system diseases.
Medicines that affect neurotransmitters.
5. NERVOUS SYSTEM AND ITS FUNCTIOS
• The nervous system is the major controlling ,
regulation , and communicating system in the body.
It is the center of all mental activity including
thought, learning, and memory.
• Together with the endocrine system, the nervous
system is responsible for regulation and maintaining
homeostasis.
• Through its receptors, the nervous system keeps us
in touch with our environment, both external and
internal.
6. COMPONENTS AND CONTENTS OF THE NERVOUS
SYSTEM
• Like other systems in the body, the nervous system
is composed of organs, principally the brain, spinal
cord, nerves, and ganglia.
• These, in turn, consist of various tissues, including
nerve, blood, and connective tissue.
• Together these carry out the complex activities of
the nervous system.
8. WHAT IS NERVOUS TISSUE
AND IT IS FUNCTIONS ?
o Nervous or the nerve tissue is the main tissue of our
nervous system.
o Nervous tissue is found in the brain, spinal cord, and
nerves.
o It is responsible for coordinating and controlling many
activities, it stimulates muscle contraction, creates an
awareness of the environment, and plays a major role in
emotions, memory, and reasoning.
o To do all these things, cells in nervous tissue need to be
able to communicate with each other by way of
electrical nerve impulses.
11. STRUCTURES OF NERVOUS TISSUE AND THERE
FUNCTION
1. It is made of nerve cells or neurons there are
about 86 billion cells in the brain, they are star shape
with spherical nucleus, all of them consist of :
o An axon; axons are long stem-like projections
emerging out of the cell, responsible for
communicating with other cells called the Target
cells, thereby passing impulses.
o Cell body; it is the main part which contains the
nucleus, cytoplasm and cell organelles.
12. o Dendrite; is a highly branched processes, responsible for
receiving information from other neurons and synapses
[specialized point of contact]. Information of other neurons is
providing by dendrites to connect with its cell body.
Information in a neuron is unidirectional as it passes through
neurons from dendrites, across the cell body down to the
axon.
2. Neuroglia cells; which helps transmit nerve impulses
and also provides nutrients to neurons and support its.
3. Neurotransmitters; are chemical messenger in the
body. Their job is to transmit signals nerve cell to target cells.
These target cells may be in muscles, glands, or other nerves.
The beat-known neurotransmitters are Acetylcholine,
Dopamine, Endorphins, Adrenaline and Gaba.
18. DIVISONS OF NERVOUS SYSTEM :
1. CENTRAL NERVOUS SYSTEM(CNS): composed of:
Brain; cerebrum, cerebellum & brain stem.
Spinal cord
2. PERIPHERAL NERNOUS SYSTEM(PNS): it is
components of the nervous system. The primary function
of it is to connect the limbs and organs to the central
nervous system, it acts primarily as link between the brain
and spinal cord at the rest of the body. Unlike the (CNS),
(PNS) is not protected by spine, skull, or blood-brain
barrier, leaving it vulnerable to toxins and mechanical
injury. It is composed of:
19. Cranial nerves: are 12 pairs of nerves arise mostly
from brain and distributed(through skull foramina)
into the head & neck (except vagus n. (tenth cranial
n.) which also supplies thorax & abdomen).
Spinal nerves: are 31pair that leave the spinal
cord passing through intervertebral foramina in the
vertebral column.
They are named according to region of vertebra: 8
cervical, 12 thoracic, 5 lumbar, 5 sacral & a coccygeal.
PNS is divided into:
Somatic nervous system; controls voluntary
activity.
20. Autonomic nervous system (ANS); is concerned
with innervations of involuntary structures such as
heart, smooth muscles & glands in the body. IT is
distributed throughout CNS & PNS
ANS is divided into :
1. Sympathetic: effected fibers are located in gray
matter of the spinal cord from T1 (first thoracic) to
L2 (second lumbar) segment (thoraco-lumbar).
2. Parasympathetic: effect fibers are located in
brain (3, 7, 9 & 10 cranial nerves), and sacral
segments (S2,3,4) of spinal cord, so called (cranio-
sacral).
23. PLEXUSES
Nerve bundles forming a plexus are also located throughout your body. There are two
major groups o nerves plexuses, also there are five distinct plexuses in each major
groups of nerves. They are named based on the location or function of the plexus.
1. Spinal plexus : include:
Cervical plexus: arise from C1_C5
Brachial plexus: arise from C5_T1
Lumber plexus: arise from L1_L4
Sacral plexus: arise from L4_S4
Coccygeal plexus: arise from S4, S5, Co
2. Autonomic plexus : include:
Cardic plexus
Pulmonary plexus
Celica (solar) plexus
Superior & Inferior mesenteric
Hypogastric & Renal plexuses
24. NERVOUS SYSTEM DISEASES
Alzheimer’s disease: affects on brain function,
memory and behaviour.
Cerebral palsy: affects the nervous system,
muscle controls, movement and coordination.
While the cause is often unknown.
Parkinson’s disease: results from damage to
the nerve cells into the brain, which impacts the
smooth control of muscles and movement.
Sciatica: causes pain in the back and legs.
25. MEDICINES THAT AFFECT NEUROTRANSMITTERS
Medicines can affect neurotransmitters in three ways:
Excitatory neurotransmitters encourage a target cell to
take action; like Selective Serotonin Re-uptake Inhibitors
are a type of antidepressant.
Inhibitory neurotransmitters decrease the chances of the
target cell taking action (relaxation effect); like
Benzodiazepines for individuals who are suffering from
insomnia & anxiety.
Modulatory neurotransmitters can send messages to many
neurons at the same time, they also communicate with
other neurotransmitters; like Dopamine & Serotonin.
![o Dendrite; is a highly branched processes, responsible for
receiving information from other neurons and synapses
[specialized point of contact]. Information of other neurons is
providing by dendrites to connect with its cell body.
Information in a neuron is unidirectional as it passes through
neurons from dendrites, across the cell body down to the
axon.
2. Neuroglia cells; which helps transmit nerve impulses
and also provides nutrients to neurons and support its.
3. Neurotransmitters; are chemical messenger in the
body. Their job is to transmit signals nerve cell to target cells.
These target cells may be in muscles, glands, or other nerves.
The beat-known neurotransmitters are Acetylcholine,
Dopamine, Endorphins, Adrenaline and Gaba.](https://image.slidesharecdn.com/seminar5-250624170954-3aaa69a2/85/seminar5-pptx-Seminar-on-Nervous-system-and-something-12-320.jpg)
