Nervous System made easy

Today we will talk about the nervous system. Remember that nervous system is a very important and essential part of every human body.

So nervous system and endocrine system control the functions of the body.

• The nervous system is divided into central and peripheral nervous system.
• The nervous system contains specialized cells, that function to recieve sensory stimuli and transmit them to effector organs, whether musclular or glandular.
• The nervous system of higher species have the ability to store sensory information recieved during past experiences.

Central and Peripheral Nervous System:

• Central Nervous System (CNS) = Brain + Spinal cord.
• Peripheral NervousSystem (PNS) = Cranial and Spinal nerves and their associated ganglia.
• Both brain and spinal cord are covered by meninges and are suspended in the Cerebrospinal Fluid (CSF).

CNS:

•  composed of neurons supported by specialized tissue called neuroglia.
• Long processes of a nerve cell are axons or nerve fibers.
• Interior of the CNS has: a) Grey Matter b) White Matter.

a) Gray Matter:

Nerve cells embedded in neuroglia.

b) White Matter: 

Nerve fibers embedded in neuroglia.

White colour due to presence of lipid material in the myelin sheaths of many of the nerve fibers.

PNS:

• Cranial and spinal nerves, consisting of bundles nerve fibers or axons, conduct information to and from the CNS.
• The nerve although covered by fibrous sheaths are still unprotected and easily damaged during trauma.

ANS:

• Part of nervous system the innervates the involuntary structures such as heart, smoot muscle and glands within the body.
• distributed through out the CNS and PNS.
• Two parts of ANS:

1. Symapthetic: prepares the body for emergenncy.
2. Parasympathetic: conserving and restoring energy.

Note: both sympathetic and parasympathetic have afferent and efferent nerve fibers.