“Nervous and hormonal systems together

Solution:

Both nervous system and hormonal (or endocrine) system are involved in control, regulation and coordination of body parts. Nervous system is

connected to receptors of all senses. Information obtained from sensory organs is passed rapidly to CNS for interpretation.

On the basis of interpretation, a message is sent to effector organ or organs (muscles, glands, etc.). The rate of information or impulse transfer is

very high, some 100m/sec. Every action and activity is well coordinated as the information is sent to all the regions required for that action. The

action can be voluntary (under the will) or involuntary. Passage of food in the alimentary canal is due to an involuntary movement of alimentary

canal called peristalsis. Picking up food and placing it inside the mouth is a voluntary movement. Both these movements are highly coordinated by

nervous system.

Nervous system is also connected with the functioning of endocrine or hormonal system. The endocrine system functions at the biochemical level

while nervous system functions at the physical and physiological level. For their functioning endocrine glands pour their secretion into blood which

transports them to all parts of the body. Target cells have receptors for picking up the hormones and working as per hormonal stimulus. There is a

feedback system which determines the requirement of hormones and the activity of endocrine glands. Other stimuli are also involved for

coordinated functioning. Presence of food in the stomach stimulates its wall to secrete hormone gastrin. Gastrin stimulates gastric glands to pour

gastric juice over the food. As the partially digested food passes into duodenum, the latter forms hormone secretin which induces passage of bile

and pancreatic juice into duodenum.

Joint working of both the systems is observed during an emergency. Both sympathetic nervous system and adrenal glands prepare the body for

meeting the emergency. There is higher rate of heart beat, more blood supply to cardiac and skeletal muscles and higher rate of breathing for

quicker oxygenation of blood.