Lecture 34: The Pituitary Gland & Hypothalamus Flashcards
What is the neurohypophysis?
The posterior lobe of the hypothalamus.
What is the adenohypophysis?
The anterior lobe of the hypothalamus.
Where is the pituitary gland located?
at the base of the brain, attached to the hypothalamus.
When activated by ________ input, the hypothalamus stimulates the _______ ______ to secrete hormone.
When activated by NEURAL input, the hypothalamus stimulates the PITUITARY GLAND to secrete hormone.
Which part of the pituitary gland is connected to the neural network?
The posterior lobe.
Describe the movement of posterior pituitary gland hormones. (production and storage)
Made in the hypothalamus (cell body), travels down the axon and stored at axon endings until required.
What 2 hormones are released into the blood from the posterior pituitary gland?
Antidiuretic hormone (ADH) and oxytocin (peptide!)
What does antidiuretic hormone do?
stimulate the kidneys to reabsorb water (the kidneys conserve water when the body dehydrates).
What does oxytocin do?
Stimulate the contraction of uterine muscles during childbirth (+ive fdbck)
Stimulates milk release in breast feeding (reflex)
How does the hypothalamus connect with the anterior lobe of the pituitary gland?
Blood vessels (capillaries) - releasing and inhibiting hormones.
How are hormones produced in the anterior lobe of the pituitary gland?
Hormone binds to receptor on membrane of SPECIFIC cell type and SPECIFIC PEPTIDE hormone is released.
What is GH?
Growth hormone
How does GH work?
It stimulates the liver to produce growth factors, stimulates protein synthesis in muscle, increases BGL (by liver g synthesis and inhibition of cellular g uptake),
and increases fat breakdown.
When is most GH secreted?
While sleeping, and as a child (esp. puberty)
What does hyposecretion and hypersecretion of GH result in?
Hyposecretion: Dwarfism
Hypersecretion: Gigantism
