Active 45

what is a hormone

chemical messenger made by one part of body that travels to another to instruct cells

Why does a hormone elicit a response only with target cells

Receiving cells have receptors that only accept correct hormone

The body has two long-distance regulating systems. Which involves chemical signals by hormones?

endocrine system

Two major communication and control systems

Nervous

Endocrine

. Explain the difference between an endocrine gland and an exocrine gland.

endo=release hormone into bloodstream

exo=release hormone through ducts

endocrine gland example

thyroid gland releases thyroid hormone

exocrine gland example

salivary gland release saliva into mouth

how do hormones act

long distance chemical signal that travels through blood to target cell

hormone example

insulin, lowers blood glucose

how do local regulators act

short distance signals that influence nearby cell

local regulator example

histamine helps cause inflammation

how do

neurotransmitters act

very short distance signal released by neurons across a synapse

neurotransmitters example

acetylcholine signals muscle contraction

how do

pheromones act

chemical signal released outside the body to influence another individual of same species

pheromones example

ant pheromones marks a trail

what is this

endocrine signaling,

gland releases hormones into blood stream, travel long distance, affect target cell anywhere in the body

what is this

paracrine signaling

cell releases chemical signals that alter nearby cells

what is this

autocrine signaling

cell releases a signal that acts upon itself (secreting cell is target cell)

what is this

synaptic signaling

neuron releases neurotransmitters across a synapse to a target cell, like another neuron, muscle cell, or gland cell

what is this

neuroendocrine signaling

neurohormones diffuse into bloodstream and trigger responses in target cell anywhere in body

Where are the receptors for lipidsoluble hormones found

inside target cell, within cytoplasm or nucleus

Where are the receptors for the water-soluble proteins found?

cell surface / plasma membrane

can lipid / water soluble hormones cross membrane

yes / no

method of secretion for water soluble hormones

exocytosis

Method of secretion for lipid soluble hormones

diffuse across cell membrane

Method of travel in bloodstream for water soluble hormones

travel freely dissolved in plasma

Method of travel in bloodstream for lipid soluble hormones

inside cell: cytoplasm or nucleus

water soluble examples

insulin glucagon epinephrine

lipid soluble example

testosterone estrogen cortisol

location of receptors for lipid hormone

inside cell, in cytoplasm or nucleus

location of receptors for water soluble hormone

embedded on cell membrane

What endocrine gland secretes epinephrine?

adrenal medulla

two intracellular responses in the liver to epinephrine

break down glycogen to glucose and stop glycogen formation

-allows glucose to enter blood stream faster, stops glyocgen from being stored

define + what is happening

epinephrine (adrenaline) is a hormone released during short term stress

define + whats happening

g protein coupled receptor, accepts epinephrine then changes its shape to activate g protein

define+whats happening

gtp binds to g protein and activates

gdp=off

activated part of g protein seperates and actives adenylyl cyclase

adenylyl cyclase converts ATP to cAMP,

cAMP activates protein kinase a, causing break down of glycogen and prevent creation of glycogen

define + whats happening

Estradiol, lipid soluble steroid hormone can diffuse through membrane because it is made of phospholipids

define + whats happening

estradiol binds to estradiol receptor, forming a hormone-receptor complex

define + whats happening + why important

hormone receptor complex enters nucleus, containing cell dna, important as steroid hormones directly affect gene expression

hormone receptor complex binds to a specific region of dna, activating a gene

altered gene makes mRNA through transcription, then mrna exits nucleus into ribosomes then into cytoplasm

how can one hormone have several different effects

different target cells have different receptors

Explain how the local regulator nitric oxide (NOO) is affected by Viagra, a drug used to treat male erectile dysfunction.

horny=release NO, NO goes into nearby smooth muscle and activates enzyme cGMP, cgmp relaxes it, allowing more blood to penis, PDE5 breaks cGMP, ending signal, viagra inhibits pde5

how does prostaglandin contribute fo menstrual cramps

when period, uterine lining breaks down and releases prostaglandin, they signal smooth muscle of uterus to contract so body can push out menstrual lining and blood, contractions temporarily reduce oxy to uterine muscle, causing pain

what occurs in a negative feed back loop

body detect change, responds by reversing change to return to homeostasis

Hormone insulin is secreted by

beta cells of pancreas

Hormone insulin acts by

lowering blood glucose, causing body cells to uptake glucose + liver muscles to store glucose as glycogen

glucagon is secreted by

alpha cells of pancreas

glucagon works by

causing liver to break down glycogen into glucose and release glucose into the blood, raising blood glucose

when glucose is too high

b-pancreas release insulin

body cells take up more glucose

liver stores glucose as glycogen

blood glucose decreases to homeostasis

when glucose is too low

a-pancreas release glucagon

liver breaks down glycogen

glucose is released into blood

blood glucose level increases to homeostasis

What occurs in diabetes mellitus?

glucose is too high because either doesnt make enough insulin or doesnt respond properly to insulin

Which type of diabetes is correlated with obesity?

2

define

hypothalamus, region of brain linking nervous to endocrine,

define

anterior pituatary, front part of pituatary gland, makes and releases its own hormons but is controlled by releasing hormones from hypothalamus

define

posterior pituatary, rear end of pituitary gland, stores and releases hormones made by hypothalamus

what does posterior pituitary mainly produce

adh / oxytocin

what does anterior pituitary mainly produce

prolactin

gh

endorphins

How is oxytocin an example of a hormone that is under positive regulation?

during birth, stretching of cervix sends signal to hypothalamus to signal posterior pituitary to release oxytocin, oxy travels to blood in uterus and causes uterine muscles to contract

8. What two hormones are antagonistic controllers of blood calcium levels?

pth / calcitonin

29. How does parathyroid hormone (PTH) raise blood calcium? (three ways

stimulate calcium release from bone

stimulate reabsorption in kidney

stimulate calcium absorption in intestine by activating vitamin d

. Why are glucocorticoids effective in treating arthritis? What is the problem with their long-term use?

they reduce inflammation, but

bone loss

high blood sugar

weight gain

what kind of hormone if associated with receptors and nuclear extracts of cells

lipid soluble steroid hormone

two endocrine disruptor examples

bpa

ddt

how do endocrine disruptors work

mimic a hormone, producing similar effects even when body doesnt instruct it

block a hormone, binds to receptor but doesnt activate, preventing real one from influencing

disrupt hormone level