endocrine Flashcards
what are hormones?
are chemical messengers that are secreted from one cell, travel through the bloodstream and affect another cell in another part of the body.
- Used for homeostatic.
examples of the endocrine system at work.
Nutrient uptake
- Every time you eat your endocrine system are working to ensure your glucose is stable
Growth
- When to grow and how long, how much
Stress.
- Can’t have too much stress.
endocrine communication loop.
stimulus - hormone release into the blood - hormone binds to a receptor in a distant cell - distant cell responds to stimulus.
example- Stress (before an exam) -> adrenaline -> adernaine binds to specific heart cells -> in those heart cells it increases heartbeat
organs of the endocrine.
hypothalamus, pituitary gland, thyroid gland, adrenal glands, pancreas, pineal gland and parathyroid glands.
What are hormones made of?
Amino acids or cholesterol.
You eat building blocks for hormones. (eggs 26g proteins, 740mg cholesterol)
what makes a hormone know what to bind to?
Hormones ONLY bind to receptors specifically designed to receive it.
The receptors are only expressed in specific areas in the body. (square only goes to square)
what happens to hormones after use.
- It is removed, broken down and recycled.
- OR excreted in swear or urine.
what are pregnancy tests looking for?
detecting human chorionic gonadotrophin (hCG) in the urine.
how do lipid soluble hormones travel?
bound to carrier protein.
how do water-soluble hormones travel?
unbound/soluble.
chemical classification of water soluble hormones
some amines (catecholamines) , peptides and proteins.
chemical classification of lipid soluble hormones?
some amines (thyroid hormones) and steroids (cholesterol based).
receptors of water soluble hormones.
cell membrane. only bind to the outside of the cell.
receptors of lipid-soluble hormones.
intracellular. because the cell wall is made of lipids.
Action mechanism.
Water soluble
– activation of 2nd messengers to amplify hormone response. Remain outside the cell and the thing inside the cell to do the job.
Internal part amplifies the inside one.
Can make the response faster and bigger.
Action mechanism
Fat soluble
once it binds to the intrecellular receptor this enters the nucleas. to cause alteration of gene transcription (to make new proteins).
response time for lipid soluble hormones.
slow - hours to days.
response time for water soluble hormones.
fast.
what does the pituitary gland do?
master gland, all things that are important for survival. Connected to the brain through blood vessels and neurons
Posterior pituitary
Hypothalamus to posterior pituitary = axon connection
Posterior pituitary hormones made in hypothalamus
…travel down axons
…then stored in axon terminals
Action potentials cause hormone release from the nerve endings from posterior pituitary.
Anterior pituitary
Hypothalamus to anterior pituitary = blood vessel connection.
Releasing/inhibiting hormones made in hypothalamus
…travel in blood
…to affect anterior pituitary cells
…to release or inhibit release of anterior pituitary hormones
Two tired system.
posterior
- Oxytocin
- Anti-diuretic hormone neurons
Release of OXT and ADH from pos pituitary