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?
-maternal behavior was more rewarding than cocaine
- moms who had contained preferred their pups
What do endocrine systems consist of? what is the singling molecule called?
endocrine systems consist of cells that secrete long-distance signaling molecules (hormones) into the blood
How do nervous and endocrine systems tend to differ?
the nervous system is faster and short term, more voluntary control
endocrine system is slower and longer term, less voluntary control
Describe the study that is considered the first study in endocrinology. What hormone
was involved in this study? What gland released that hormone?
1849 study on chickens
conclusion: chemical from gonads flows through the body to affect male development
gland: gonads
hormone: 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?
chemical messengers that are released into the blood stream and act on distant target cells
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?
Pancreas releases glucagon
Glucose is low (stimulus)–>Pancreas releases glucagon cell (endocrine cell)–>goes into the blood vessel–>act on liver (target cell)–>glucose becomes available (response)
What is the endocrine system?
consists of all hormone-secreting cells
can hormones access the entire body
yes
why do hormones only affect certain cells?
hormones bind to target cells (it is only a target cell if the hormone fits the receptor)
where are hormone receptors located?
plasma membrane or inside of the cell
what are the three major classes of hormones? how do they differ with respect to later and lipid solubility? how does this relate to the way in which they are stored, and interreact with receptors, and their effects on cells?
The way in which hormones interact with target cells depends on the class of hormones
1. Amines
2. Proteins/Peptides
3. Steroids
Amines and proteins/peptides are water soluble and lipid insoluble
Stored: in vesicles, secreted through exocytosis
Act of MEMBRANE receptors
Activate signal transduction pathways (rapid, cytoplasmic response, sometimes gene transcription ex. glucagon)
Steroids are water insoluble and lipid soluble
Not stored, made on demand: transported through blood by transport proteins
Act on INTRACELLULAR receptors
Receptor-hormone complex forms (enters the nucleus and results in gene transcription, slow sometimes rapid effects ex. testosterone
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?
-amines and proteins/peptides: bind to receptors in the plasma membrane
-travel through blood not lipids
-steroids: bind to receptors in the cytoplasm or nucleus
-travel through lipids not blood
What effects are induced when receptors are activated by lipid- and water-soluble
hormones? Which class of hormones tends to induce rapid effects? Which tends to
induce slower effects?
What structure is key for the brain to interact with the endocrine system? What are
neurosecretory cells?
hypothalamus: contains the pituitary gland made up of the posterior pituitary and anterior pituitary
neurosecretory cells: neurons that release chemicals (hormones) into the bloodstream
What is different about how the anterior versus the posterior parts of the pituitary gland connect to the brain?
posterior: directly connected to the brain
anterior: connected to brain by vessels
