Anatomy and Physiology Nervous System Note

·         Nervous System 
Nervous System:
     It's consist of two Anatomic divisions
I.                 The central nervous system 

 

A) Brain and Spinal cord
: They are enclosed by Skull and vertebral column respectively.
II.            The Peripheral nervous system
A) CRANIAL NERVE: It carries impulse to and from the brain
 
B) SPINAL NERVE. It carries Impulse to and from the spinal Cord.
      The Central Nervous System:
 The brain and Spinal cord are protected by bony and membranous covering:
 Meninges are:
* Dura Mater (outer and tough Layer)
*Arachnoid Mater (Middle and delicate layer)
* Pia-mater (Innermost layer and very delicate firmly attached to a brain).
  Cerebraspinal Fluid: (0.5ml /min Produce) 750ml/day
Normally clear, colorless and odorless fluid.
- It fills in the ventricles of brain Sub arachnoid Spaces of the brain and the Spinal Cord.
 - Produces Ependymal cells (choroid plexus)

 
 
It's composed of Water, Small amount of Protein, oxygen and carbon dioxide.
Electrolytes: Sodium, potassium, chloride and glucose.
 Functions
 Protect, Lubricates the brain.
Provides nutrients, removed waste
Adults 90-150 ml
Newborn 10- 60 ml.

 

The brain   (1-4 kg)
 Brain is divided into 3 Major area-
 a) Cerebrum
b) Cerebellum
c) Brain stem
 

 1) The cerebrum (cerebrum): corpus callosum
*largest part of the brain)
* It is divided into right and left hemispheres
* Cerebral hemispheres receive information and control the opposite half of the body.
*Each hemisphere can be divided into 4 Lobes
a) Frontal lobe: Behavior, Learning, Speech, Creative thinking. Personality, emotional response and memory
* The posterior part of the frontal lobe controls the motor function in the opposite side (speech).
b) Parietal lobe: (sensation)
It receive sensory impulse from the skin, muscle, joints and tendons of the opposite side of the body. < Pain, temperature, pressure, touch, awareness of muscular movement >
c) Temporal lobe:Smell, hearing
d) Occipital lobe: Vision
 
The diencephalon: connect cerebrum and midbrain.


 
A)       Thalamus:
Two oval structure made up of gray matter at the base of cerebrum.
Function:
·         Relay motor and sensory signal to the cerebral cortex.
 
B)       Hypothalamus:
·         *Small in size.
·        * Weigh=7 gram
·        * Situated below thalamus and above posterior pituitary gland.
Function: Homeostasis
·        * Hunger/appetite balance
·         *Body temperature
·         *Sexual behavior
     *Satiety (being completely full stomach).