lecture 26 - pituitary, hypothalamus & growth hormone Flashcards
Where is the pituitary gland located?
At the base of the brain, attached to the hypothalamus.
How is the pituitary gland stimulated to produce hormones?
Activated by the hypothalamus by neural and hormonal imput.
What are the 2 key parts of the pituitary gland?
Anterior lobe and Posterior lobe
How is the posterior lobe of the pituitary connected to the hypothalamus?
By neurons, which have their cell bodies in the hypothalamus, and axon terminals in the posterior lobe
Where are posterior pituitary hormones made?
In the cell body of neurons that connect the hypothalamus to the posterior lobe
Where are posterior pituitary hormones stored?
At the axon endings of the neurons that connect the hypothalamus and posterior pituitary.
What type of hormone are posterior pituitary hormones, and in what medium are they soluble?
Peptide hormones (water soluble)
What are the hormones released by the posterior pituitary?
(ADH) Antidiuretic hormone, oxytocin
What is the rate of the release of posterior pituitary hormones dependent on?
The rate of action potentials fired by the hypothalamus.
What is ADH (hormone)?
Antidiuretic hormone
What is the function of ADH?
Antidiuretic - stimulates the kidneys to reabsorb and conserve water, rather than releasing it as urine
What hormone acts on the kidneys, causing them to reabsorb water?
ADH - antidiuretic hormone
What are the key functions of oxytocin?
Stimulate the contraction of uterine muscles during childbirth and stimulate the milk ejection reflex during breast feeding
How is the anterior pituitary connect to the hypothalamus?
Via a portal vessel network
How does the hypothalamus signal to the anterior pituitary?
Via releasing hormones, released from neurosecretory neurons in the hypothalamus and transported via portal vessels to the anterior lobe.