Nervous System
1) An organ system in the human body which carries massages and makes us feel and react to things and situation is called nervous system.
2) Nervous system consists of neurons and tissues.
3)
The nervous system is divided in
to two parts.
a) The central nervous system b) The
peripheral nervous system
The central nervous system (CNS)
The central nervous system (CNS) also divides two parts.
1) Brain 2) Spinal cord
1) Brain:
The brain of an adult human being weights about three pound
and has more than 100 billion neurons.
1) The human brain is enclosed in a bony case
called the cranium (کھوپڑی).
2) The brain is protected by three
layers of connective tissues called meninges.
3) Between the layers of meninges is a fluid.
The fluid protects the brain.
4) The brain itself has three
main parts called
1) Fore brain 2) Mid Brain 3) Hind brain
Forebrain:
5) Forebrain
consists of three parts
1) Cerebrum 2) Thalamus 3) Hypothalamus
6) Cerebrum is the top
most and the larger part of the brain. And divide in left
and right cerebral hemispheres.
7) The right cerebral hemispheres
control movement and activities of the left
side.
8) The left cerebral hemispheres
control activities of the right side.
9) Forebrain is part
of the brain that interprets signals from your body and forms responses such as
hunger, thirst, emotion, pain
and also responsible for intelligence thinking and judgments
etc.
10) Inside the cerebrum, there is a small structure
called thalamus. It acts as a processing center
between the body and the cerebrum.
11) At the base of the thalamus is the Hypothalamus which regulates body temperature hunger and thirst.
Mid brain:
12) Mid
brain is the central part of brain.
13) Its basic function is to transfer
information and impulses between forebrain
and hind brain.
14) Mid brain is associated with vision,
hearing, sleep/wake and temperature
regulation.
15) The midbrain also controls some reflexes
such as changing the size of the pupil to control
the amount of light entering the eye.
Hindbrain:
16) Hindbrain
consists of cerebellum, Pons and medulla
oblongata.
17) Cerebellum is the
part of the brain that coordinates body movements. Its helps the body
balances.
18) Pons
regulated breathing and passes signals between the brain
and spinal cords.
19) The
medulla oblongata connects the brain to the spinal cords.
20) Medulla
oblongata controls basic life functions such as heart
beat, blood pressure, vomiting etc.
2) Spinal Cord:
The
vertebral column consists of vertebrae and spinal cord.
The spinal cord is a rope like bundle of neurons.
1) All
signals that go to the body or come to the brain, pass
through the spinal cords.
2) When spinal cords are damaged
messages cannot move between the brain and the rest of the
body these results in paralysis.
2) The peripheral Nervous system (PNS)
The Peripheral Nervous system (PNS) is the collection of
nerves that connects the central nervous system
(CNS) to all your organ systems.
1) The PNS uses sensory
neurons to detect stimuli from inside and outside of your body and it
uses motor neurons to carry signals from the CNS to other parts of the body and
stimulated your muscles or other target organs.
2) The PNS includes 12 pairs
of cranial nerves those which branch out from the brain and go to
many places in head such as ear, eyes, and face
etc.
3) 31 pairs of spinal
nerves which branch out from the spinal cord.
4) In short the PNS is made up of a sensory
system and motor system.
5) The system of sensory nerves collects
information from the body and its surroundings.
6) Motor nerves are responsible for producing
voluntary responses and involuntary response.
Neuron
Neuron is the smallest
structural and functional unit of nervous system.
1) Neuron consists of two parts 1)
Cell body 2) Axon
2) The cell body is thicker region
of the neuron containing the nucleus and most of the cytoplasm.
3) Axon is a
long projection that carries impulses away from the cell body.
4) Neuron has a single axon.
5) The thread like projections on
the cell body called dendrites.
6) Fatty substance covering the axon from myelin
sheath.
7) Neurons are of three types.
8) Sensory
neurons: they
carry nerve impulses (stimulus) from receptors to CNS.
9) Motor
neurons: these
neurons take impulses away from CNS to effectors.
10)Associative neurons: Nerve cells found in CNS that link sensory and
motor neurons. They are responsible for analyzing the massage and issuing
order.
11) The
collection of neuron cell bodies is called gray matter because of
its dark gray color.
12) The collection
of axons is called white matter because the myelin
sheath on the axons gives them white appearance.
13) In the
brain the gray matter is on the outside and the white
matter is on the inside.
14) The
special organs, tissues or cells, which detect stimuli, are called receptors.
15) An
immediate and involuntary response to a stimulus is called reflex action.
16) People blink about 15
times per minute. During the 16 hours when you are awake,
you blink approximately 14,400 times each day.
Excretion and Excretory system:
1) The system that helps to eliminate waste
materials from the body is called excretory system.
2) The process of removing the waste product from
the body is known as excretion.
3) Excretory system removes non solid wastes
through sweat, urine and exhalation. It
also helps to maintain stability in the body.
4) The main organs of this system
are the skin, lungs, kidney,
ureter, urinary bladder, and urethral, etc.
5) The structural and functional unit of
kidney is called nephron.
6) The kidneys are organ that remove wastes by
filtering and cleaning the blood to produce urine. This urine
moves through ureters, is collected in the bladder and excreted by the urethra.
7) Kidney is divided in three regions.
8) 1) Renal
cortex is the outer most regions.
9) 2) Renal
medulla is the middle region.
10) 3) Renal pelvis is the inner area where urine is drained.
Role of kidneys:
1) The kidneys are among the main
organs responsible for maintaining fluid and chemical
balances in your body within the limits that support life.
2) One
quarter of your blood supply passes through your
kidney every minute.
3) The most common kidney problems
are kidney stone, high blood pressure, and diabetes.
4) Excretory
organs of human body are called kidneys.
5) The brain of adult human
weights between 1300 and 1400 gm..
6) The brain of cat weight about 30
gm.
7) The weight of dogs about 70
gm.
8) The brain of a dolphin about 1600
gm.
9) The weight of elephant is about 6000
gm.
10) Homeostasis is the
regulation of water, minerals and salts within the body.
11) First artificial
kidney was developed by Abel, Rountee, and turner
in 1913.
12) The cleaning of patient blood artificially with the help of a machine is called dialysis.N
Sensory neurons carry messages towards……..
a) Muscles
b) Muscles and glands
c) Sense organs
d) Brain and spinal card
The part of neuron which receives messages are
a) Cell bodies
b) Dendrites
c) Axon
d) Nuclei
Accumulation of salts in kidneys results in…...
a) Diabetes
b) Hypertension
c) Kidney stone
d) cancer
Medium sized stones are removed by………....
a) Dialysis
b) Lithotripsy
c) Excretion
d) Laser
How can we save life of a person whose kidneys have stop working?
DM-P-2 --- Date not confirm
a) by medicines
b) by motivation
c) by nephron transplantation
d) by kidney transplantation
