Hypothalamus Functions

 Functions of hypothalamus.
Answer:

1. Secretion of hormones:

• Anterior pituitary hormones.
  • Hypothalamus secretes releasing hormones and inhibitory hormones.
  • These hormones are transported to the anterior pituitary by the hypothalamo-hypophyseal portal blood vessels.
• Posterior pituitary hormones.
  • These hormones are secreted by supraoptic and paraventricular nuclei of hypothalamus.
  • Transported by axonic flow through the fibers of hypothalamohypophyseal tract to posterior pituitary.

Read And Learn More: BDS Previous Examination Question And Answers

2. Control of adrenal gland:

• Corticotropic releasing hormone is secreted which regulates adrenal cortex.
• Hypothalamic nuclei send impulses to adrenal medulla and cause release of catecholamines.

3. Regulation of automomic nervous system (ANS):

• Stimulation of the anterior hypothalamus causes parasympathetic response.
• Stimulation of the anterior hypothalamus causes parasymptathetic response.
• Stimulation of lateral areas of the hypothalamus produces sympathetic response.

4. Regulation of heart rate and blood pressure:

• Posterior and lateral nuclei – increases heart rate and BP.
• Preoptic nucleus – decreases heart rate and BP.

5. Regulation of body temperature:

• Heat loss center is present in anterior hypothalamus.
• Heat gain center is present in posterior hypothalamus.

6. Control of Hunger and feeding:

1. Satiety center is located in venteromedial nuclei.
   • Its stimulation causes total loss of appatite.
2. Feeding center is located in lateral nucleus
   • Its stimulation increases food intake.

7. Regulation of water balance:

• Osmoreceptors are located in lateral preoptic area.
• When ECF volume decreases, these receptors stimulates thirst center and initiates drinking.
• When ECF volume decreases, supraoptic nucleus causes release of ADH.
• This, in turn, causes retention of water.

8. Control of Waking – Sleep cycle:

• Stimulation of anterior hypothalamus leads to sleep.
• Stimulation of mamillary body of posterior hypothalamus causes wakefulness.

9. Control of Emotional behaviour:

• Stimulation of ventromedial nucleus pleases the persons.
• Stimulation of posterior and lateral nuclei leads to pain, fear, etc.

10. Regulation of sexual function:

• Hypothalamus secretes gonadotropin releasing hormones which regulates sexual functions.

11. Regulation of response to smell:

• Posterior hypothalamus responses to olfactory stimuli.

12. Role in circadian rhythm:

• The supraoptic and anterior nuclei of hypothalamus is responsible for circadian rhythm.