Question

Receptor	osmoreceptor
Control Center	hypothalamus
Effector	Post pituitary
Target Tissue	kidney

Describe the flow of information in this homeostatic mechanism by correctly matching the names of the receptors, control center, effector, and target tissue: posterior pituitary, kidney, hypothalamus, osmoreceptor.

1. Is this a negative feedback, positive feedback, or feedforward mechanism, AND how does activation of this mechanism relate to water balance in the ECF?

Answer 1

This is a homeostasis loop for osmoregulation. This is a negative feedback loop.

Osmorrceptor : receptor

Hypothalamus : control centre

Posterior pituitary : effector

Kidney : target tissue

When the water content of ECF reduces the osmoreceptors are activated. These osmoreceptors sends sensory signals to the hypothalamus. Hypothalamus acts as a control centre and integrates the sensory information and stimulates posterior pituitary to release ADH. ADH acts on renal tubules of the kidney to cause water retention. This increases the water content of ECF and maintains osmotic balance of body.