Hypothalamus, pituitary and growth hormone Flashcards
What are the two parts of the pituitary gland
Anterior and posterior lobe
How is the hypothalamus and the pituitary gland related
Hypothalamus controls the secretion of pituitary hormones
What do pituitary hormones do
Some stimulate target cells and some stimulate the secretion of hormones by other endocrine glands
Describe the posterior lobes secretion mechanism
Connected to hypothalamus by neurons and secretes hormone into blood.
Posterior pituitary hormones made in neuron cell body in hypothalamus and stored in axon endings.
What can affect the rate of secretion from the posterior pituitary lobe
Change in frequency of AP release. If increased hormone release will be increased
What hormone does the PPL release
Antidiuretic hormone (ADH) - Stimulates kidney to reabsorb water OR
Oxytocin - Stimulates contraction of uterine muscles and stimulates lactation
Both made in the hypothalamus and stored in PPL.
Describe the anterior lobes secretion mechanism
Connect to hypothalamus by blood vessels. Stimulates or inhibits release of stored hormones in APL cells using receptors
What hormones does the APL secrete
Peptides - prolactin and growth hormone (GH) and Thyroid Stimulating Hormone (TSH)
What are the direct effects of growth hormone (GH)
Muscles - Stimulates protein synthesis (Long term). Inhibits cellular uptake of glucose (Short)
Liver - Stimulates glucose synthesis (short)
Fat - Increases triglyceride breakdown in adipose tissue (short)
What are the indirect effects of growth hormone (GH)
Promotes bone, muscle and tissue growth - release of somatomedin (promotes cell division)
What are the overall short and long term effects of GH
Long-term - Growth
Short-term - Metabolism
When are GH secretions the highest
During sleep
During puberty
Be able to understand the negative feedback loop of GH
Look at loop
