17.7- Hypothalamus and pituitary glands. Flashcards
What is the posterior pituitary gland made of?
Neurons- 1/4 the mass of the total pituitary gland.
What is the anterior pituitary gland made of?
Hormone producing cells.
Supra-optic nucleus
Part of the hypothalamus superior to the optic chiasm.
Paraventricular nucleus
Part of the hypothalamus located adjacent to the third ventricle.
Portal vessel
Vessel located between two capillary beds.
Primary plexus
Vary porous capillary network associated with the hypothalamus.
Secondary plexus
The plexus associated with the anterior pituitary gland.
Hypophyseal portal vein
The vein that connects the primary plexus to the secondary plexus.
What two hormones doe the posterior pituitary store?
Oxytocin and anti-diuretic hormone.
But these are both synthesized in the hypothalamus.
What hormone does the supraoptic nucleus form?
Antidiuretic hormone
What hormone does the paraventricular nucleus form?
Oxytocin
How are antidiuretic hormone and oxytocin moved from the hypothalamus to the posterior pituitary?
Fast axon transport inside vesicles.
What are target cells of ADH?
Kidneys, and the thirst center. In high doses ADH causes vasoconstriction, which it is also called vasopressin.
What does oxytocin do in males?
Initiates the moment of sperm through the reproductive tracts.
Regulatory hormone
The hormone that is released from the hypothalamus into the primary plexus which moves it to the anterior pituitary gland and causes the release of the hormones held there into general circulation.
What are the two types of regulatory hormones?
Releasing and inhibiting hormones.
What are the hormones of the anterior pituitary?
What do they do?
Thyroid stimulating hormone- causes the thyroid to release thyroid hormone, which established the body’s metabolic rate.
Prolactin- mammillary gland growth and breast milk production. Also made by mails, but to unknown effect.
Follicle stimulating hormone and luteinizing hormone- These are called gonadotropins-
In women: act on ovaries control development of oocytes and their follicles (spherical structure that holds them), ovulation, and release of estrogen and progesterone.
In men: regulates production of sperm and release of testosterone.
Adrenocorticotropic hormone- stimulates the adrenal cortex to secrete glucocorticoids- increase blood levels of nutrient molecules- glucose, glycerol, fatty acids, and amino acids.
Growth hormone- stimulates the liver to release Insulin Like Growth Factor 1 and 2. GF and IGF’s function synergistically to stimulate cell growth and cell division (especial in the skeleton and the muscle).
What re the half lives of GH and IGF?
GH- 6 hours
IGF- 20 hours because protected by carriers.
