Veterinary Physiology-III

INTER-RELATIONSHIP BETWEEN ENDOCRINE AND NERVOUS SYSTEM

• The nervous system controls homeostasis through nerve impulses that trigger the release of neurotransmitters whose effect results in either excitation or inhibition of other neurons, muscle fibres, or glands. The endocrine system releases hormones into blood stream that travels to the target organ where it alters the physiological activity.
• In nervous system, a sensory receptor senses the change and sends action potentials by its afferent sensory neuron to the integration center in the brain or spinal cord. The efferent path is the motor neuron that takes action potentials to the effectors (muscle or glands) for the response of contraction or secretion.
• In the endocrine system, the gland/ the cells may act as the receptors and the integration centres which are often influenced by neural and other inputs. The response is either to change the rate of an enzymatic reaction, to control the transport of certain molecules across cell membranes, or to control gene expression and thus make new proteins.

Nervous system	Endocrine system
Nervous system regulates the activities of muscles and glands via electrical impulses transported through neurons	Endocrine System regulates the body’s metabolic activity via hormones that are transported in the blood
Reflexes of the nervous system are more specific because nerves regulate specific target cells	Hormones can control multiple organs and systems
Nervous system uses both electrical (action potentials) and chemical (neurotransmitters) signals	Endocrine system uses only chemical signals (hormones)
Neural control is fast; its effects are short-lived	Hormonal control is comparatively slower; generally its effects are prolonged
Stimulus intensity in the nervous system is represented by the frequency and amplitude of action potentials.	Stimulus intensity in the endocrine system is determined by the amount and duration of hormone(s) released.