Endocrine System Flashcards
How do water soluble hormones exit the cell, travel through the blood stream, bind to other cells
exit the cell: exocytosis
travel through: freely, without a transport protein
bind to other cells: through a plasma membrane receptor
How do lipid soluble hormones exit the cell, travel through the blood stream, bind to other cells
exit the cell: diffuse across the plasma membrane
travel through: with a transport protein
bind to other cells: diffuse across its plasma membrane and binds to an intracellular receptor
can a hormone act on many different types of cells?
Of course!!!
Epinephrine stimulates liver cells to break down glycogen, smooth muscle cells in walls of blood vessels of skelean muscle to relax (increasing bloodflow), and smooth muscle cells in the walls of blood vessels to the intestines to contract (reducing bloodflow)
What are the 3 things that stimulate the release of hormones?
1) signals from the nervous system (ex both the hypothalamus and adrenal medulla release hormones in response to signals called neurotransmitters)
2) other hormones (ex the anterior pituitary releases its hormones in response to receiving hormones from the hypothalamus)
3) chemical changes in the blood (ex blood ca2+ levels stimulate secretion of a hormone by the parathyroid gland
What is the function of the hypothalamus? The posterior pituitary? The anterior pituitary?
The function of the hypothalamus is to coordinate endocrine signaling. It receives information from the nerves thrugohout the body and initiates appropriate neuroendocrine signals
Posterior pituitary stores and secretes hormones that are made in the hypothalamus. The posterior pituitary has the axons of many neurons whose cell bodies are in the hypothalamus
What releases oxytocin and ADH (anti diurrhetic hormone)
The posterior pituitary releases these hormones but they do not synthesize it
Do the anterior and posterior pituitary come from the same tissues?
They are fused together but come from different tissues
Why does the anterior pituitary and hypothalamus need the portal system between them
BC the anterior pituitary is not an extension of the hypothalamus
How many molecules in our body have iodine
thyroid hormones (t4 and t3) are the only iodine containing
What happens as a result of not having enough thyroid hormone (T4 and T3)
no t3/t4. no inhibition of hypothalamus and AP, so they contrinue to produce TSH which enlarges the thyroid
How do the stimuli encourage release of TRH
They activate neurons that form synapses on TRH synthesizing neurons
the surrounding neurons release neutrotransmitters that activate GPCRs on the TRH synthesizing neurons
how does t3/t4 release help the initial stimulus (cold)? what aboutstress
increased metabolic rate, increases heat
stress (inc heart rate, muscle contractility, inc metabolic rate)
What are the 3 sex hormones
estrogen, androgen, progesterone
Which releasing hormone and which two tropic hormones are involved in the sex hormone pathway? What do they target
releasing hormone: gonadotropin releasing hormone
tropic hormones: follicle stimulating hormone and luteinizing hormone
ovaries and testes
What are the two portions of the adrenal glands?
adrenal cortex (outside)
adrenal medulla (inside)
