The Hypothalamus, Pituitary Glands and Hormones! And not the Sex Pheromone Variety…

The Hypothalamus and the pituitary gland are super important in regulating the hormone release from one other gland in the body.
The Hypothalamus is the link between the Endocrine and Nervous System, It also controls the Pituitary Gland through 9 releasing and inhibiting hormones. Together the Pituitary Gland and the Hypothalamus regulate all aspects of growth, development, metabolism and homeostasis. The Pituitary Gland secretes several hormones that the Hypothalamus generates (synthesises).

For example the Pituitary Gland and the hypothalamus are involved in Thyroid Function.
The Hypothalamus produces TRH  – Thyrotropin releasing Hormones when the thyroid hormone level drops in the body. This causes the secretion of TSH – Thyroid stimulating Hormone from the Pituitary Gland. This causes the Thyroid to produe more T3 and T4 Hormones which raise the level in the blood – The Pituitary Gland will then lower the amount of TSH in the blood.


ADH – Antidiuretic Hormone – Vasopressin

ADH is produced in the Hypothalamus and released in the posterior pituitary (Posterior Lobe/Neurophypophysis) as a response to dehydration.

Antidiuretic Hormone stimulates water reabsorption by the kidneys and arteriolar constriction. General Function is vasopressin – conserving water. ADH (is released) kicks in during dehydration –  decreases urine production and sweating and increases blood pressure as a result of vasoconstriction. ADH is controlled by the osmotic pressure in the blood. And during over hydration ADH is inhibited.

Dehydration:

  1. Hypothalamic osmoreceptors are stimulated by High Blood Osmotic pressure
  2. Osmoreceptors activate the neurosecretory cells that synthesis and release ADH
  3. Nerve impulses free ADH from axon terminals in the Pituitary Gland into the bloodstream
  4. Kidneys retain more water – decreases urine volume, Sweat Glands decrease water loss and Arterioles constrict – increased BP

Overhydration:

  1. Low Blood Osmotic Pressure inhibits hypothalamic osmoreceptors
  2. Then this impacts on the ADH secretion as osmoreceptors are inhibited
  3. Which effects, sweat, urine and blood pressure.
Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s