QS Study

The nervous system and the endocrine system control and coordinate body functions by allocation in a sole partnership. The body functions are coordinated by chemical messengers, by interplaying of several types of the communication system including –

  1. Neural: Neurotransmitter released at synaptic junctions act locally to control cell and act locally across synaptic cleft on a postsynaptic cell.
  2. Endocrine: Hormones that influence the function of cells at another location in the body. Endocrine hormones are released by glands or specialized cells into the circulating blood and influence the function of cells at another location in the body.
  3. Neuroendocrine: Neurohormones that reach the circulating blood and influence the function of cells at another location in the body.
  4. Paracrine: The cells secrete substances that diffuse into ECF and affect neighboring cells. They are secreted by cells into the extracellular fluid and affect neighboring cells of a different type.
  5. Antocrine: The cells secrete substances that affect the function of the same cell by binding to the cell surface receptor. They are secreted by cells into the extracellular fluid and affect the function of the same cells that produced them by binding to cell surface receptors.

Fig: Body Functions Coordination

It is noted worthing that in various part of the body, the same chemical messenger can function as a neurotransmitter, a paracrine mediator, neural hormone and a hormone.

  • Neural hormone = hormone secreted by neurons into the blood.
  • Hormone = Secreted by glandular cells into the blood.