(i) Connective tissue develops from the mesoderm and is distributed widely in the body.
Component: All connective tissues consists of three main components.
a. Fibres
b. Ground substance
c. Cells
Fibres provide support and are of three types collagen, elastic and reticular fibres.
Connective tissues are classified into
I Loose connective tissue
II Dense connective tissue
III Specialized connective tissue

Divisions of nervous system
1. Central Nervous System (CNS)
2. Peripheral Nervous System (PNS)
3. Autonomic Nervous System (ANS)
(i) CNS consists of brain and spinal cord
(ii) PNS consists of cranial nerves and spinal nerves
(iii) ANS consists of sympathetic and parasympathetic nervous systems
(iv) CNS consists of 10 paired cranial nerves and 10 paired spinal nerves

(v) controls visceral involuntary activities.
(vi) Brain lies in cranial cavity.
(vii) Brain and spinal cord are covered by two meninges.
(viii) Such two meninges are an outer piamater and an inner duramater
(ix) Brain is divisible into
(i) Fore brain (Prosencephalon).
(ii) Mid brain (Mesencephalon).
(iii) Hind brain (Rhombencephalon).
(i) Fore brain:
(i) It is the anterior most and largest part consisting of a paired olfactory lobes, cerebral hemispheres and a diencephalon.
(ii) Anterior part of the olfactory lobe is narrow and free but is fused posteriorly
(iii) Olfactory lobes aid in the sense of smell.
(iv) The cavity of olfactory lobes is called as ventricle.
(v) Cerebral hemispheres (telencephalon) are the largest part of fore brain.
(ii) Mid brain:
(i) It includes two large, oval shaped optic lobes having cavities and are called as optic ventricles.
(iii) Hind brain:
(i) It consists of the cerebellum and medulla oblongata.
(ii) Cerebellum balances the body in movements and maintains posture of the body.
(iii) Cerebellum is narrow, thin transverse band followed by medulla oblongata.
(iv) Medulla oblongata passes out through the foramen magnum then it continues as spinal cord.
(v) The spinal cord passes through the vertebral column.