Endocrine System

what are hormones

regulatory chemicals secreted into extracellular fluid and carried by the bllod

can hormones act at a distance from the source

yes

multicellular animals need hormones to help maintain

homeostasis

hormones act on cells that have ___

receptors for that hormone

what is the endocrine system

organs and tissues that produce hormones

hormones act on cells that have receptors for that hormone - attachment will induce

a cellular response

what are the 3 classes of hormone structure

lipid-derived hormones, amino acid derived hormones, peptide derived hormones

what class of hormones can diffuse across plasma membranes

lipid-derived hormones

what are peptides

chains of amino acids

what are peptide hormones derived from

peptides or full proteins

what type of hormone are testosterone and estradiol (estrogen)

lipid-derived

what is the building block for estradiol and testosterone

cholesterol

can testosterone and estradiol diffuse through membranes

yes

what is estradiol

estrogen

many amino acid derived hormones are

neurotransmitters

what are neurotransmitters

hormones that one nerve cell sends to another nerve cell

what type of hormones are oxytocin, growth hormone, and follicle stimulating hormone

peptide hormones

peptide hormones are ___ than those derived from cholesterol or amino acids

much larger

nervous system controls through what

nerve impulses conducted by axons

endocrine system controls through what

hormones transported in the blood

response time of nervous system

milliseconds

response time of endocrine system

seconds to days

area of effect of nervous system

relatively local, specific effects

nervous system stops when stimulus stops →

adapts quickly

can the endocrine system have widespread general effects

yes

effects of endocrine system are more prolonged →

adapts slowly

hormone levels are primarily controlled through

negative feedback

how does negative feedback occur in the endocrine system

rising levels of a hormone inhibit its further release

humoral stimuli

changes in extracellular fluid or ion levels

hormonal stimuli

hormones released by other endocrine glands

neural stimuli

nervous system stimulation

what is type of feedback is this an example of:

the anterior pituitary stimulates the thyroid gland to release thyroid hormones T3 and T4. Increasing levels of these hormones in the blood results in feedback to the hypothalamus and anterior pituitary to inhibit further signaling to the thyroid gland.

negative feedback

for a hormone to effect a cell that cell must have a

specific receptor

number of receptors can change due to

up regulation, down-regulation

hormone receptors can be found

within the cell or on the plasma membranes

what type of hormones bind to intracellular hormone receptors

lipid-derived hormones

lipid derived hormones first step in effecting the cell

hormone binds to transport protein

at the target cell, lipid derived hormones are released from their carrier protein and pass through the ____

plasma membrane

what does lipophilic mean

cross membrane and bind to intrs-cellular receptor

what is the last step of lipid derived hormones affecting intracellular hormone receptors

the hormone/receptor complex regulates transcription by increasing or decreasing the synthesis of mRNA.

can amino acid derived hormones and peptide hormones pass through the plasma membrane

no

amino acid derived hormones and peptide hormones are

hydrophilic

where do amino acid derived hormones and peptide hormones bind

receptors in the membrane

when hormones bind to plasma membrane receptors they initiate what

a signaling pathway

what is the signaling pathway called

the 2nd messenger system

what does the excretory system do

maintains water balance

what hormone regulates amount of water excreted by kidneys

antidiuretic hormone (ADH)

what does antidiuretic hormone do

regulates amounts of water excreted by the kidneys

ADH regulates amounts of water excreted by kidneys therefore regulating

blood pressure

when is ADH released

when water levels are low in bloodstream

what happens when ADH is released

kidneys release less water and urine output is lowered

what does a diuretic do

increases urine output

what produces aldosterone

adrenal cortex

what is the main regulator of water and electrolytes (Na+ and K+)

aldosterone (steroid hormone)

what does aldosterone promote

reabsorption of water

important pituitary hormones of the reproductive system

follicle stimulating hormone, luteinizing hormone, oxytocin

what does follicle stimulating hormone do

maturation of sperm cells and development of egg cells

what does luteinizing hormone do

production of testosterone in males and surge causes ovulation in females

what does oxytocin do

stimulates uterine contraction during childbirth

what hormone is produced by the testes

testosterone

what hormones are produced by ovaries

estrogen and progesterone

the cells of what organ produce insulin

pancreas

the cells of what organ produce glucagon

pancreas

what does insulin do

lowers blood sugar by increasing cellular uptake and utilization of glucose

deficiency or insensitivity of insulin causes what

diabetes

what is the agonist to insulin

glucagon

what does glucagon do

raises blood sugar by targeting liver to break down glycogen to glucose

what two hormones regulate blood glucose levels

insulin and glucagon

what is basal metabolic rate

calories required by body at rest

regulation of metabolism by ___ hormones

thyroid

basal metabolic rate is determine by what two hormones that are secreted from where

T4 and T3 released from thyroid gland

what causes T4 and T3 to be secreted from the thyroid gland

stimulation by TSH (thyroid stimulating hormone) released from anterior pituitary

hypothyroidism =

low metabolic rate

hyperthyroidism =

high metabolic rate

calcium is regulated by what hormone

PTH

what does PTH do

increase blood calcium

what is the antagonist to PTH

calcitonin

an antagonist has ___ effects on body

opposite

what does calcitonin do

decrease blood calcium

growth and cell regulated are regulated by

growth hormone (GH) from pituitary

what does GH stimulate

growth, cell reproduction, and cell regeneration

hormone for short term stress

epinephrine

where is epinephrine from

adrenal gland

epinephrine =

fight or flight

hormone for long term stress

cortisol

where is cortisol from

adrenal gland

what integrates the endocrine and nervous system

hypothalamus

what does the hypothalamus do

integrates the endocrine and nervous system by synthesizing and secreting regulatory hormones that control endocrine cells in the anterior pituitary

what gland is considered the master gland

the pituitary

what is the pituitary controlled by

the hypothalamus

where is the pituitary

hanging by a stalk from the hypothalamus

what two parts does the pituitary consist of

the anterior and posterior pituitary

is the anterior pituitary a part of the brain

no

how does the anterior pituitary function

hypothalamus releases neurohormones into anterior pituitary, causing the anterior pituitary to release tropic hormones that then work on other endocrine glands

is the posterior pituitary a part of the brain

no

what does the posterior pituitary release

ADH and oxytocin

anterior pituitary release and produce ____ hormones

a LOT of

does the posterior pituitary produce hormones

no two hormones are produced in the hypothalamus and stored in special cells in the posterior pituitary

where are the adrenal glands located

on top of the kidneys