3. Central Nervous System
oIt consist of brain and spinal cord.
oBoth brain and spinal cord are in hollow shaped.
oBoth are protected in three ways;
1. Cranium.
2. Meninges.
3. Cerebrospinal Fluid (CSF)
4. These three parts are further divided into there sub parts.
Brain can be divided into Forebrain,
Midbrain, and Hindbrain.
Brain
5.
6. Forebrain
Fore brain is divided into three functional parts which are as
follows;
1.Thalamus:
It carries sensory information to limbic system and cerebrum.
2.Limbic System:
It works together to produce our most basic primitive emotions,
drives and behaviors. Limbic system is divided into;
a. Hypothalamus
b. Amygdala
c. Hippocampus
3.Cerebrum:
It is largest part of brain and it is divided into two halves;
i. Left Cerebral hemisphere.
ii. Right Cerebral hemisphere.
7. Mid Brain:
Mid brain is reduced in humans, and it contains auditory relay center
and center that controls reflex movements of eyes. Midbrain
contains reticular formation, which is a relay center connecting
hindbrain with the forebrain. Reticular formation is very important
in screening the input information, before they reach higher brain
centers.
8. Hind Brain
Hind brain includes the medulla, pons and cerebellum.
Medulla:
Medulla controls several automatic functions, such as breathing,
heart rate, blood pressure and swallowing.
Pons:
Pons located above medulla appears to influence transitions between
sleep and wakefulness, and the rate and pattern of breathing.
Cerebellum:
The cerebellum is important in coordinating the movements of the
body. It is engaged in the complex activity of flight.
12. Peripheral Nervous System
It consist of two neurons;
1. Sensory Neurons:
It carry signals to the CNS from sensory organs.
2. Motor Neurons:
It carry signals from the CNS that control the activities of
muscles and glands. Motor neuron consist of;
a. Somatic Nervous System. (controls voluntary movements)
b. Autonomic Nervous System. (controls involuntary responses)
Autonomic Nervous System is further divided into;
a. Sympathetic Division.
b. Parasympathetic Division.