The document provides an overview of the nervous system, detailing its functions, components like the CNS, PNS, and ANS, and the roles of neurons and neurotransmitters. It describes the structure of the brain, spinal cord, and their protective membranes, as well as the functions of cerebrospinal fluid. Additionally, it explains reflex actions and the differences between somatic and autonomic nervous systems.

1. Independent work
Student: Janibekova J.
Teacher: Khalilova K.

3.  Functions of nervous system
 Types of nervous system
 Difference between CNS & ANS
 Neuron
 CNS
 Brain
 Spinal cord
 PNS
 ANS
 Disorders of NS
 References

4. 1. Communication and coordination
 Adapt and respond to changes from both
inside and outside the body
2. Site of reasoning- your brain

5. Neuron- basic
structural unit of the
nervous system
Dendrites- carry
impulses towards
the cell
 Axon-carry
impulses away from
the cell
Myelin sheath

6.  Nerves are made of many nerve cells
 Afferent-sensory nerves-- carry message to
brain
 Efferent-motor neurons-- carry message
from brain to muscle
 Intercalated neuron- these are found
between sensory & motor neurons and form
links in the pathways of nerves
 Synapse:-the point at which the nerve impulse
passes from one to another is called synapse.

7.  Various chemicals(Neurohumoral) known as
“Transmitters” are secreted in the synapse &
are involved in the transmission of information
across the synapse.
 Important neurohumoral or chemical transmitters
are:-
i)Acetylcholine
ii)Adrenaline
iii)Noradrenaline
 Since they transmit nerve impulses, they are
called as transmitters.

8. cell body
axon
myelin sheath
dendrites nerve endings
nucleus
neurotransmitter
vesicle
synaptic cleft
receptor

9. 1. Brain
A. Mass of nerve tissue
B. Protected by
membranes & the
cranium or skull
C. Cerebrum/ forebrain -
largest part of brain.
Responsible for
reasoning, thought,
memory, speech,
sensation, etc.
 Further divided into
lobes; occipital,
parietal, temporal and
frontal

10. D. Cerebellum/Hind brain -
responsible for muscle
coordination
E. Midbrain
Responsible for:
 conducting impulses
between brain parts
 certain eye reflexes
F. Brain stem/medulla
oblongata- most basic
functions; respiration,
swallowing, blood pressure.
Lower part (medulla oblongata)
is continuous with spinal cord

11. G. Pons
Responsible for:
 conducting messages to other parts of the
brain
 Reflex actions such as chewing, production of
saliva

12. 2. Spinal cord-
 Goes down back of
body from Medulla
Oblongata
 Surrounded and
protected by
vertebrae
 Responsible for
reflex actions
 Carries sensory and
motor messages

13. 3. Meninges
 Consists of 3 membranes
 Covers and protects the brain and spinal cord
Three Membranes
 Dura mater
 thick, tough outer layer
 Arachnoid membrane
 middle delicate web like layer
 Pia mater
 inner most layer with blood vessels to nourish the
nerves

14. 4. Ventricles
 Four hallow spaces located in the middle of the brain.
 Connected to each other
 Filled with fluid called cerebrospinal fluid
1.Right & left lateral ventricles
2.third ventricle
3.fourth ventricle
Function-To produce CSF
Cerebrospinal Fluid
 Circulates continuously
 Serves as shock absorber to protect brain and spinal cord
 Carries nutrients to parts of brain and spinal cord
 helps remove metabolic products & wastes
 after circulation, absorbed into the blood vessels of the dura
mater.

15. Composition of CSF
 It is clear, Slightly alkaline fluid with a specific gravity of
1.005 & consists of :- Water, amino acids, glucose,
mineral salts and urea, creatinine in small amounts .
 The normal hydrostatic pressure of CSF is about 130 mm
of water (10 mm of Hg).
Functions of CSF
 It supports & protects the delicate structures of brain and
spinal cord.
 It maintains uniform pressure around these delicate
structures.
 It acts as a cushion and shock absorber for the brain &
spinal cord.
 It keeps the brain & spinal cord moist as there may be an
interchange of substances between the fluid & nerve cells.

16. Functions of spinal cord
 It is the means of connection between peripheral organs & the brain.
 Reflex action- is the automatic motor response given by the
spinal cord to the sensory stimulus without involving brain
in action. Most of reflex actions are protective in nature. are the part of
defense mechanism of the body.
Simple reflex arc has the following components
 A sensory neuron
 Connector neuron
 Motor neuron
Important reflex actions are
 The quick closing of an eyelid, if the eye is touched or when something
threatens to touch it.
 The sudden withdrawal of the hand if the fingers touch something hot.
 The quick recovery of the balance of the body to prevent falling after a
slip.
 A sudden coughing attack, if a crumb is inhaled.

17.  Somatic system
 12 pairs cranial nerves
arising from Brain
 31 pairs spinal nerves
arising from spinal cord.
 Autonomic
 Sympathetic
 Fight or flight
 Parasympathetic

18. Sympathetic Nervous
System
Parasympathetic
Nervous System
Increases heart rate Decrease heart rate
Increase respiratory rate Decrease respiratory rate
Increase Blood Pressure Decrease Blood Pressure
Decrease digestive system
activity
Increase digestive system
activity

19. We use the modal verb “Can” to express
that we know how to do something.
The negative form is “can’t” or “cannot”
(more formal).
“Can” and “can’t” are always followed by a
verb in the infinitive.

21. we
Yes, you can.
I

23. We also use can /can’t to
ask for and give permission.

24. And we use “can” to ask
somebody to do something!
Can you …….., please?