Hormones II

Question 1

Humoral stimuli

Answer 1

Stimuli, like metabolites adn other molecules, that stimulate the release of some hormones through circulation in the blood

Question 2

Neural stimuli

Answer 2

Neurons release a neurotransmitter to synapse with a hormone-producing cell thus stimulating the cell to secrete their hormone.

Question 3

Releasing hormones

Answer 3

A neuropeptied that stimulates hormone secretion from other endocrine cells, usually reserved for hormones from the hypothalamus

Question 4

Hormonal stimuli

Answer 4

When hormones stimulate the secretion of other hormones

Question 5

Tropic hormones

Answer 5

hormones from the anterior pituitary gland, and are examples of hormonal stimuli

Question 6

Hormonal stimuli can be either stimulatory or inhibitory

How does humoral and neuronal stimuli work to inhibit hormone release?

Answer 6

Inhibition of hormones released by humoral stimuli - companion hormone inhibitied by same stimuli

Inhibition of hormone release by neural stimuli - neurons can inhibit targets

Question 7

Inhibiting hormones

Answer 7

Hormonal stimuli that prevent teh secretion of other hormones

Question 8

What are the two mechanisms for maintaining hormone levels in the blood?

Answer 8

Negative feedback > self-limiting system

Positive feedback > self-propogating system

Question 9

Hormone receptors

Answer 9

target cell proteins where hormones can bind to exert their actions

Question 10

Specificity

Answer 10

the tendancy for each tyep of hromone to bidn to one type of receptor, and not to others

Question 11

Desensitization

Answer 11

the response of some target tissues can decrease over time due to cells’ deficiency in nutrients and energy, causing the cell to lose the ability to respond to the hormone.

Question 12

Down-regulation

Answer 12

the number of receptors decreases after exposure to certain hormones, causing desensitization

Question 13

Up-regulation

Answer 13

increase in sensitivity when teh rate of receptor sythesis in the target cells increases, thus increasing the total number of receptor molecules in a cell.

Question 14

Nucelar receptors

Answer 14

bind to lipid-soluble hormones bc they can easily seep through the cell wall

found in the cell nucleus

Question 15

Membrane-bound receptors

Answer 15

bind to water-soluble hormones

Proteins that extend across teh plasma membrane.

Question 16

Was is the action of nucelar receptors?

Answer 16

Lipid soluble hormones stimulate synthesis of new proteins. They bind to DNA to produce a response

Question 17

Hormone-response elements

Answer 17

Fingerlike projection receptors that bind to specific nucleotide sequences in DNA

Question 18

Transcription factor

Answer 18

The combination of the hormone and its receptor which will activate teh transcription of mRNA

Question 19

2 ways membrane bound receptors can activate a response

Answer 19

1) alter the activity of G proteins at inner surface of plasma membrane
2) alter the activity of intracellular enzymes

Question 20

Intracellular mediators

Answer 20

Second messengers system - chemicals produced inside a cell from the membrane-bound hormone that activates cellular processes inside the cell

Question 21

3 ways G proteins can alter the activity of enzymes insdie the cell

Answer 21

1) Activate or inhibit adenylate cyclase - the enzyme that converts ATP to cAMP
2) G proteins scan activate otehr intracellurlar mediators
3) G proteins can open ion channels

Question 22

Which 3 subunit bind to guanine?

Answer 22

alpha
beta
gamma

Question 23

Cyclic Guanine Monophosphate cGMP

Answer 23

an intracellular mediator that is sythesized in response to a hormone binding to a membrane-bound receptor, eventually activating specific enzymes in cytoplasm of a cell

Question 24

Amplification

Answer 24

“an army of molecules” that enable a hormone to produce final products within a few seconds.

when receptors produce thousands of second messengers, which leads to a cascading effect of the hormonal signal