Endocrine Lecture Flashcards
Describe the difference between endocrine and exocrine glands?
endocrine: do not have a duct to the surface of the skin or lumen of organ (except goblet cells) and secrete hormones to the blood stream
exocrine: have ducts to the surface
Exocrine and endocrine function of the pancreas
exocrine: pancreatic juices
endocrine: insulin and glucagon production
Exocrine and endocrine function of the testes
exocrine: sperm
endocrine: testosterone
Exocrine and endocrine function of the ovaries
exocrine: ova
endocrine: estrogen and progesterone
which type of hormone is water soluble?
amino-acid based hormones
which type of hormone is lipid soluble?
steroid hormones
What are three examples of amino acid based hormones
amines, peptides, and proteins
what are two examples of steroid hormones
gonadal and adrenocortical hormones
What are steroid hormones made from?
cholesterol
How do intracellular hormone receptors work?
Lipid soluble hormones + thyroid hormones enter the cell and bind to intracellular receptor and form hormone-receptor complex. Complex binds to DNA which starts transcription of target gene to create protein that alters cell activity
how do cell membrane receptors work?
-Water soluble hormone binds to receptor and activates G protein
-G protein activates adenlyl cyclase
-adenlyl cyclase catalyzes the conversion of ATP to cAMP.
-cAMP activates protein kinases
-protein hydrolyzes ATP to ADP
-free phosphate phosphorylates proteins, activating them
-proteins change cellular activity
what is the first messenger in the membrane receptor cascade?
the hormone
what is the second messenger in the membrane receptor cascade?
cyclic AMP (cAMP)
How are hormone levels regulated in the blood?
negative feedback
What are the three stimuli that stimulate hormone release?
humoral, neural, and hormonal
define humoral stimuli
extracellular concentration of solutes, too high or low
define neural stimuli
direct neural communication to glands
define hormonal stimuli
gland stimulated by another hormone
name for the anterior pituitary
adenohypophysis (glandular tissue)
name for the posterior pituitary
neurohypophysis (axons and axon terminals of the neurons of the hypothalumus)
what is the main function of the neurohypophysis
storing and secreting hormones made by the hypothalamus. released by action potentials
What hormones are made by the supraoptic nucleus and the paraventricular nucleus of the hypothalamus?
supraoptic=antidiuretic hormone
paraventricular= oxytocin
what method regulates oxytocin levels?
positive feedback
