Hormone Synthesis, Regulation, and Receptors

Question 1

What system works in concert with the nervous system to maintain homestasis?

Answer 1

endocrine system

Question 2

What system regulates growth, development, reproduction, blood pressure, ion concentrations, behavior, and aging?

Answer 2

endocrine system

Question 3

Most hormones are synthesized and secreted by what?

Answer 3

glands

Question 4

What hormones are not synthesized or secreted by glands?

Answer 4

GIT hormones secreted by clusters of endocrine cells and some made in hypothalamus, placenta, kidney

Question 5

What are the endocrine glands?

Answer 5

• thyroid gland
• parathyroid gland
• hypothalamus
• pituitary gland
• kidney
• adrenal gland
• ovary and testis
• pancreas

Question 6

What are common characteristics of endocrine cells and neurons?

Answer 6

• both secrete substances into blood
• some molecules are both neurotransmitters and hormones
• mechanism of action for hormones and neurotransmitters require a specific receptor
• similar processes of exocytosis of granules and synaptic vessels
• both systems may respond to the same stimuli

Question 7

What are the messengers of the endocrine system?

Answer 7

hormones

Question 8

Where is the release of messengers for the endocrine system?

Answer 8

distant to cell of influence

Question 9

Are the target cells specific or wide spread for the endocrine system?

Answer 9

wide spread

Question 10

What is the speed of the endocrine system reaction (fast or slow)?

Answer 10

slow

Question 11

What is the duration of the endocrine system reaction (short or long)?

Answer 11

long

Question 12

What is the mode for messenger transport in the endocrine system?

Answer 12

blood borne

Question 13

What is homeostasis?

Answer 13

ability of body to maintain a stable interval environment despite changes in external conditions

Question 14

Dynamic equilibrium occurs constantly. Explain.

Answer 14

As changes occur, body works to maintain uniform conditions

Question 15

What are the three mechanisms involved to restore and maintain homeostasis?

Answer 15

• receptor
• control center
• effector

Question 16

Homestasis uses what type of feedback?

Answer 16

negative feedback loops

Question 17

Describe a negative feedback loop.

Answer 17

Stimulus triggers sensor which relays to control center and produces effector response. The effector response works on the same stimulus to inhibit or stimulate it.

Question 18

Positive feedback does not result in homeostasis. Why?

Answer 18

It amplifies change in variable – bloood clotting, parturition

Question 19

What pathways can alter homeostasis?

Answer 19

• nutrition
• toxins
• psychological
• physical
• genetic
• medical

Question 20

What are the four hormone signaling pathways?

Answer 20

• endocrine/telecrine
• neurocrine
• autocrine
• paracrine

Question 21

Describe the endocrine signaling pathway.

Answer 21

• Cell A secretes hormone
• hormone travels through blood to Cell B
• hormone produces effect on Cell B

Question 22

Decsribe the neurocrine signaling pathway.

Answer 22

• Hormone secreted by brain
• Hormone travels through blood to target
• Hormones produces effect on target cell

Question 23

Describe the paracrine signaling pathway.

Answer 23

• hormone secreted by cell A
• hormone travels to neighboring cell B (NOT THROUGH BLOOD)
• Hormone produces effect on cell B

Question 24

Describe the autocrine signaling pathway.

Answer 24

Cell A produces hormone, and that hormone produces effects on cell A

Question 25

What are the hormone classifications?

Answer 25

- peptides and proteins - steroids - amines - eicosanoids

Question 26

What classification of hormone is derived from amino acids?

Answer 26

peptides/proteins

Question 27

Give examples of peptide/protein hormones.

Answer 27

- insulin - growth factors - growth hormone - parathyroid hormone - thyroid-stimulating hormone - antidiuretic hormone

Question 28

The structure of different peptide hormones may be very similar to each other and may only differ by a side chain, which allows them to do what?

Answer 28

allows similar hormones to act on multiple receptors

Question 29

What are the steps in the synthesis of peptide and protein hormones?

Answer 29

- mRNA is transcribed and travels to cytoplasm - message is translated on ribosome - product is preprohormone -- now transferred to endoplasmic reticulum - signal peptide degraded in endoplasmic reticulum -- results in prohormone, now transferred to Golgi - when endocrine cell is stimulated, granule contents released

Question 30

Catecholamines are synthesized using what amino acid?

Answer 30

tyrosine

Question 31

Thyroid hormones are synthesized from what?

Answer 31

tyrosine and iodide

Question 32

Thyroid hormones are stored where and as what?

Answer 32

stored in follicle as thyroglobulin

Question 33

Steroid hormones are synthesized from what?

Answer 33

cholesterol

Question 34

Prostaglandins are synthesized from what?

Answer 34

arachidonic acid

Question 35

What mechanisms are used for regulation of hormone secretion?

Answer 35

- neural mechanisms - feedback mechanisms

Question 36

What is the more common mechanism for regulation of hormone secretion?

Answer 36

feedback mechanisms

Question 37

Describe negative feedback via a hormone.

Answer 37

When hormone levels are judged to be adequate or high, further secretion is inhibited

Question 38

Describe negative feedback via a substrate.

Answer 38

When hormone/substrate levels are judged to be inadequate or low, secretion of hormone is stimulated

Question 39

Which feedback type is uncommon?

Answer 39

positive feedback

Question 40

Describe positive feedback.

Answer 40

A feature of hormone action causes MORE secretion of hormone