20.3 endocrine

Question 1

what is the function of negative feedback loops?

Answer 1

prevent over-activity of hormone system

Question 2

Where can feedback regulation of hormones occur?

Answer 2

1. gene transcription
2. gene translation
3. hormone processing
4. hormone release

Question 3

Stages of development and seasonal changes are able to influence the hormone release?

Answer 3

yes

Question 4

Where are cell receptors located?

Answer 4

surface of PM, cytoplasm, nucleus

Question 5

What factors can influence down regulation of receptors?

Answer 5

1. inactivate intracellular protein molecules
2. sequester receptors
3. inactivate receptors
4. lysosome destruction of receptor
5. reduce production

Question 6

What can cause up regulation of receptors?

Answer 6

1. hormone increases production of the receptor via intracellular signaling
2. improve reaction rate, to make receptor more available

Question 7

What receptor is generally used by neurotransmitters?

Answer 7

1. ion-channel-linked

Question 8

What is a leptin receptor?

Answer 8

JAK-STAT pathway, enzyme linked hormone receptor

Question 9

Which hormones are intracellular signalers?

Answer 9

1. adrenal and steroidal
2. thyroid
3. retinoid
4. vitamin D

Question 10

What are the different classes of hormones?

Answer 10

1. polypeptide and protein
2. steroids
3. amine

Question 11

What are unique features of polypeptide hormones?

Answer 11

1. stored as prohormones in secretory vesicles until needed

2. releases involves cAMP and exocytosis

Question 12

What are unique features about steroid hormones?

Answer 12

1. cholesterol derivatives
2. lipid soluble, diffuse across membranes
3. stored as cholesterol esters until needed

Question 13

What are unique features about amine hormones?

Answer 13

1. tyrosine derivative
2. form adrenal medullary and thyroid hormone
3. form catecholamines in the adrenal medulla
4. thyroid hormones form in thyroid glandular cells

Question 14

What is the role of PLC in signal transduction?

Answer 14

cleaves PiP2 into DAG and IP3 which release calcium and activate PKC

Question 15

How many Ca ions are required to activate the calcineurin-calmodulin system?

Answer 15

3-4 bind with calmodulin to initiate multiple effects

Question 16

Which hormones act directly on DNA?

Answer 16

steroid ( do not last long) thyroid (have long lasting effect)
* process is longer than the PM receptor binding

Question 17

Which of the hormones that act on DNA bind inside the nucleus?

Answer 17

thyroid hormones

Question 18

Which of the hormones that act on DNA bind in the cytoplasm?

Answer 18

steroid hormones

Question 19

What cells types are located in the anterior pituitary gland (adenohypophysis)?

Answer 19

1. somatotropes
2. corticotropes
3. thyrotropes
4. gonadotropes
5. lactotropes

Question 20

What hormones are released from the adenohypophysis?

Answer 20

1. HGF
2. adrenocorticothyroid hormone
3. thyroid stimulating hormone
4. LH and FSH
5. prolactin

Question 21

What hormones are secreted from the magnocellular neurons of the supraoptic nuclei?

Answer 21

ADH

Question 22

What hormones is secreted from the paraventricular nuclei of the magnocellular neurons from the posterior pituitary?

Answer 22

oxytocin: cause uterus contraction and milk secretion

Question 23

What major system controls the anterior pituitary gland?

Answer 23

hypothalamus via the hypothalamic releasing and inhibitory hormones

Question 24

Where are hormones from the hypothalamus ultimately secreted?

Answer 24

into the hypothalamic-hypophyseal portal system

Question 25

How does growth hormone increase growth?

Answer 25

1. increase protein deposition of chondrocytic and osteogenic cells 2. increases reproduction of chondrocytic/osteogenic cells 3. convert condrocyte into osteocyte 4. stimulate osteoblast

Question 26

How does growth hormone affect the protein synthesis?

Answer 26

1. increase amino acid transport to cytoplasm 2. increas RNA translation 3. increase transcription 4. reduce protein catabolism

Question 27

What is the effect of growth hormone on fatty acids?

Answer 27

1. release FA from adipose | 2. increase FA conversion to acetyl-CoA

Question 28

How does growth hormone reduce the glucose utilization?

Answer 28

1. reduce glucose uptake in skeletal muscle and fat 2. increase liver glucose production 3. increase insulin secretion 4. growth hormone can stimulate formation of diabetes

Question 29

What effect does growth hormone have on the liver?

Answer 29

1. forms somatomedins - affect bones growth - called insulin-like growth factor

Question 30

What is the most important somatomedin?

Answer 30

somatomedin C or insulin like growth factor-1

Question 31

What factors will stimulate secretion of growth hormone?

Answer 31

1. starvation (protein deficiency) 2. hypoglycemia 3. Ghrelin 4. first 2 hr of deep sleep