Endo Flashcards
What are hormones
chemical messengers secreted in the blood
How are peptide hormones synthesized
As prohormones that are cleaved to form the active form
How are steroid hormones synthesized
from cholesterol - im a cat meowwww
How are peptide hormones stored
in vesicles (regulatory secretion )
Where does the pituitary gland sit
sella turcica of the sphenoid bone
What happens in the median eminence
is supplied by nerves from the parvocellular neurons in the hypothalamus and is very vascularised and is fenestrated
How do peptide hormone receptors work
bind to cell surface receptors and transduce a signal using secondary messenger signals
How do steroid hormone receptors work
binds to intracellular receptors that changes gene expression directly
How must steroid hormones be transported in the blood
bound to proteins in the blood
What is superior to the pituitary gland
optic chiasm
how are the capillaries described near the median eminence
fenestrated and so is ‘leaky’
What are the 5 types of endocrine cells in the anterior pituitary gland
somatotrophs gonadotrophs lactotrophs corticotrophs thyrotrophs
Describe 3 things about hypothalamic parvocellular neurons
1) short and terminate at the medial eminence
2) releases realeasing/inhibitory factors into the median eminence
3) hypothalamic factors carried by portal circulation to the anterior pituitary gland
Describe the axis starting from the hypothalamus that leads to hormone secretion
1) axonal terminals of neurons from the hypothalamus release releasing factors or inhibtory factors
2) RF and IF enter the portal system and then go into the anterior pituitary gland
3) RF and IF stimulate or inhibit release of hormones from the cells of the anterior pituitary gland
4) anterior pituitary gland releases hormones which leaves the gland via the blood
Which 2 hormones regulate release of growth hormone
1) Growth hormone releasing hormone (GHRH) (releasing factor)
2) somatostatin (inhibitory )
