• AUTONOMIC NERVOUS SYSTEM

The autonomic nervous system is the part of the involuntary nervous system that controls the autonomic functions of the body.

It originates from the lower part of the cerebrum of the brain and is connected to the visceral organs of the body.

The autonomic nervous system is divided into 2 parts.

1. Sympathetic nervous system
2. Parasympathetic nervous system

• Sympathetic Nervous System.

The sympathetic nervous system stimulates the body’s fight and flight response, which regulates the body’s involuntary actions.

It is known as thoracolumbar outflow and occurs at the level of the T1-L2 spinal cord.

•Parasympathetic nervous system.

It is found activated in relaxed situations.

This is known as craniosacral outflow. It arises from the sacral segment of the brain and spinal cord.

•Functions of ANS ..

The sympathetic nervous system increases heart rate and force while the parasympathetic nervous system decreases it.

The sympathetic nervous system dilates the pupil while the parasympathetic nervous system constricts it.

The sympathetic nervous system dilates the trachea and bronchi while the parasympathetic nervous system constricts them.

The sympathetic nervous system decreases the secretion of the intestine and its mobility while the parasympathetic nervous system increases it.

The sympathetic nervous system decreases urine secretion while the parasympathetic nervous system increases it.

Sympathetic nervous system decreases gastric secretion and motility while parasympathetic nervous system increases it.

Explain body temperature regulation in humans.

Regulation of heat in the human body means maintaining the balance of heat production and heat loss in the body. Generally, normal body temperature in humans is found to be 36.5 to 37 degrees Celsius. Only if this temperature is kept normal, every function in the body is kept regular and internal homeostasis can be maintained.

The structure that regulates body temperature in humans is the thermoregulatory center located in the hypothalamus. Nerve impulses of temperature are received by the hypothalamus through the thermoreceptors located in the body and the hypothalamus acts accordingly to know the normal body temperature.

Heat production occurs in the body due to metabolic activity, movement of skeletal muscles etc. When this heat is higher than normal in the body, the hypothalamus stimulates the sweat glands to lose excess heat from the body through the action of perspiration and helps to maintain a regular body temperature.

When the body heat is less than normal, sweat gland activity is not observed and the body maintains normal body temperature by preserving heat.
Thus hypothalamus plays an important role in maintaining normal body temperature.