endocrine system Flashcards
Know the results of brain scans on virgin compared to mother rats. What brain areas
were activated in virgin rats when presented with cocaine? What about maternal rats?
Instead of cocaine what activated reward brain regions in mother rats?
virgin rats: large activation in prefrontal cortex and nucleus accumbus
mother rats: some activation in same two structure and significantly more activation when they saw their pups
What do endocrine systems consist of? What is the signaling molecule called?
cells that secrete long distance signaling molecules into the blood
called hormones
How do nervous and endocrine systems tend to differ?
the nervous system tends to send shorter signals that are more rapid and voluntary than the endocrine system
Describe the study that is considered the first study in endocrinology. What hormone was involved in this study? What gland released that hormone?
removing testes from young roosters and seeing the effects,
discovered testosterone
What is a hormone? What hormone was released from the pancreas in the example from class? What causes it to be released? Where does the hormone go? What does it
do?
hormones are chemical messengers released into bloodstream that act on different target cells
the pancreas releases glucogen when glucose is low, which enters the blood stream and acts on liver to produce more glucose
What is the endocrine system? What are some organs and glands that release hormones? Know that blood vessels surround endocrine glands
consists of all hormone-secreting cells, acess to all body like pancreas, stomach overies testes, the glands
Why do hormones only affect certain cells?
b/c they have specific receptors for that hormone
Where are hormone receptors located?
located on or inside target cells
1. cell surface receptors:locate don outside of cell and usually used for peptide
2.Intracellular receptors located inside the cell, either in cytoplasm or nucleus and usually used for steroid hormones
What are the 3 major classes of hormones? How do they differ with respect to water and lipid solubility? How does this relate to the way in which they are stored, and interact with receptors, and their effects on cells?
- amines
- peptide proteins
- steroids
amines and peptide proteins are water soluble, lipid insoluble
sterioids are lipid soluble, water insoluble
add the effects and stuff to your notebard
How are water- and lipid-soluble hormones stored and released (e.g., glucagon and testosterone, respectively)? How do they travel through the bloodstream? Where are
their receptors located?
water soluble are released through vesicles, and travel through blood, receptors on plasma membrane
lipid soluble not stored, made on demand, travel through lipids not blood and have transport vesicles to if they need to do through blood
receptors located in cytoplasm and nucleus
Which class of hormones tends to induce rapid effects? Which tends to
induce slower effects?
water soluble have rapid effects
lipid soluble have slower effects
What structure is key for the brain to interact with the endocrine system? What are neurosecretory cells?
Hypothalamus and pituitary gland
neurosecretory cells are cells that release hormones into blood vessels
What is different about how the anterior versus the posterior parts of the pituitary gland connect to the brain?
pituitary gland divided into two parts– anterior and posterior
anterior gland receives signals from hypothalamus via the portal, posterior does not
anterior connected to brain via blood vessels
posterior directly connected to brain
What two peptide hormones are released from the posterior pituitary gland? What do they do?
ADH: acts on kidney to reduce water loss in urine
oxytocin: stimulates uterin contractions at birth, promotes bonding
Why do only women who are about to give birth respond to the hormone oxytocin (or Pitocin)?
that’s when their oxytocin receptors are most available
Milk ejection is a unique example of what?
positive feedback
What effects does oxytocin have as a neurotransmitter?
promotes bonding between mother and child and mated pairs
Where are receptors for ADH?
kidney, blood vessels, brain
What interferes with ADH? (5)
- dehydration
2, alcohol
3.certain medications - diabetes
- damage to hypothalamus or pituitary gland
What are “releasing hormones”? Portal veins?
releasing hormones: hormones produced by hypothalamus that stimulate other hormones
What are tropic and non-tropic hormone effects?
tropic effects: regulate the function of other endocrine glands
non-tropic effects: directly stimulate target cells to stimulate effects
Describe what leads to release of thyroid hormones from the thyroid gland. How is this process tightly controlled (i.e., explain negative feedback)?
The hypothalamus releases TRH in which the anterior pituitary gland and thyroid gland have receptors for.
anterior: releases TSH
thyroid: releases T3 and T4
increases levels of thyroid hormone lead hypothalamus to stop produces TRH
Where are receptors for TRH and TSH?
anterior pituitary gland
thyroid gland
What is the function of thyroid hormones?
T3 an T4 increase cellular metabolism
can warm you up
