Page 12 - Health & Physical edu- 8

Medulla Oblongata: Medulla oblongata lies between pons varoli and spinal cord.
It regulates the involuntary functions of the body. The main functions of this part
of the brain are to control heartbeat, respiration, blood pressure, swallo wing ,
salivation, sneezing against pinching, heating, etc. are the examples of reflex actions.

Spinal Cord: Spinal cord begins from medulla oblongata. The white soft cord like
part that runs along the dorsal side of the body within the vertebral column to the

coccygeal bone is referred to as spinal cord. It sends the sensations to the brain and
also controls reflex actions. Thirty one pairs of spinal nerves emerge from this cord.
These nerves control the functions of internal and external organs.

B. Peripheral Nervous System

In peripheral nervous system, twelve cranial nerves and thirty one spinal nerves
work collectively. The cranial nerves generate from the brain and the spinal nerves
generate from the spinal cord. They are spread around various organs of the body.
They communicate the sensations to the brain or spinal cords from various organs

and vice versa.

C. Autonomic Nervous System

A number of actions take place in our body, which are beyond our control. Such
actions are regulated by autonomic nervous system. This system can be divided
into two types as sympathetic and para-sympathetic nervous system. The functions
of sympathetic and para-sympathetic nervous system are opposite to each other.

The sympathetic nervous system makes the pupils smaller, increases the heartbeat,
slows down the digestive system, decreases the amount of urine, and slows the
functions of endocrine glands. The para-sympathetic functions just opposite to the
actions mentioned above.

Reproductive System

The process of collective functions of the organs responsible for reproduction is
known as reproductive system. It includes both male and female reproductive
systems. Both these systems produce gamete, a special type of cell. The male

reproduction cell is known as sperm and female reproduction cell is known as ova.
Within human reproductive system, the male and female reproductive systems are
separately described as below.

8 Health & Physical Education, Class-8