Basics continued (L2)

Question 1

Chemical categories of hormones

Answer 1

Monamines, proteins/peptides, and steroids

Question 2

What are the subsets of monoamines?

Answer 2

Catecholamines and indolamines

Question 3

Half life of monoamines

Answer 3

1-2 minutes

Question 4

Action and method of travel of monoamines

Answer 4

Bind membrane receptors; travel freely in blood

Question 5

From what are catecholamines derived?

Answer 5

Tyrosine

Question 6

Rate limiting step of catecholamine formation

Answer 6

Tyrosine hydroxylase

Question 7

What is special about catecholamines?

Answer 7

They act as both hormones and neurotransmitters

Question 8

First product of tyrosine hydroxylase

Answer 8

L-DOPA

Question 9

Endocrine action of dopamine

Answer 9

Tonic inhibitor of prolactin in the anterior pituitary

Question 10

From where do dopaminergic neurons arise?

Answer 10

In the arcuate nucleus of the hypothalamus (TIDA neurons)

Question 11

Where is dopamine released?

Answer 11

In the hypophyseal capillary bed

Question 12

Norepinephrine requires what type of stimulation?

Answer 12

Sympathetic

Question 13

What enzyme catalyzes the formation of norepinephrine?

Answer 13

Dopamine beta-hydroxylase

Question 14

Through what types of receptors does NE act?

Answer 14

Both alpha and beta-adrenergic receptors

Question 15

What innervates the adrenal glands, and what is formed there?

Answer 15

Splanchnic nerve, epinephrine

Question 16

Chromaffin cells

Answer 16

In the adrenal medulla; homologous to postsympathetic neurons and release hormones into the blood

Question 17

From what are indoleamines derived?

Answer 17

Tryptophan

Question 18

Rate-limiting enzyme of indoleamine formation

Answer 18

Tryptophan hydroxylase

Question 19

What type of hormone is serotonin?

Answer 19

Indoleamine

Question 20

How much of serotonin is involved in the GI system?

Answer 20

95%

Question 21

What is the primary function of serotonin in the GI system?

Answer 21

Causes vasoconstriction and stimulates smooth muscle contraction

Question 22

SSRIs

Answer 22

Increase the amount of serotonin in the synaptic cleft to treat depression and other mental disorders

Question 23

What are the considerations when using SSRIs?

Answer 23

Depression is not well-understood physiologically
May downregulate amount of serotonin produced by negative feedback
May cause insensitivity to the serotonin receptors

Question 24

What happens in the pineal gland?

Answer 24

Serotonin is converted to melatonin

Question 25

Dopa decarboxylase

Answer 25

Decarboxylation reaction from L-dopa to dopamine

Question 26

Inhibitor of DDC

Answer 26

Carbidopa and benzerazide

Question 27

Catecholamine O-methyltransferase

Answer 27

(COMT:) Inactivates and degrades catecholamines

Question 28

COMT inhibitor

Answer 28

Entacapone

Question 29

Monoamine oxidase

Answer 29

Catalyzes deamination of monoamines, resulting in ammonia and aldehyde

Question 30

MAO inhibitors

Answer 30

Increase the amount of dopamine, used to treat depression and other mood disorders

Question 31

Rate-limiting enzyme in melatonin formation

Answer 31

N-acetyltransferase

Question 32

Negative effects of melatonin

Answer 32

Potent inhibitor of reproduction: reduces spermatogenesis and testis size in males

Question 33

How is the pineal gland activated? Explain the steps.

Answer 33

Light enters the brain, information travels through the suprachiasmatic nucleus and through the retinohypothalamic tract

Question 34

Half-life of peptides and proteins

Answer 34

2-120 minutes; longer if bound to a transport protein

Question 35

A large proportion of peptide and protein hormones are from the __

Answer 35

Hypothalamus and pituitary

Question 36

Biosynthetic processing of peptide hormones

Answer 36

Released as preprohormones, signal peptide is cleaved off to give a prohormone, and then copeptides are cleaved to leave the active peptide

Question 37

Half life of steroid hormones

Answer 37

Several minutes to several hours

Question 38

Steroids are manufactured from what?

Answer 38

Common precursor, pregnenolone

Question 39

Steroidogenic acute regulatory protein

Answer 39

(StAR protein) Transfers the cholesterol from the outer to the inner mitochondrial membrane so it can be further processed

Question 40

Cytochrome P450 side chain cleavage enzyme

Answer 40

Also known as desmolase. Cleaves the side chain from cholesterol in the inner mitochondrial membrane to form pregnenolone

Question 41

Primary endocrine disease

Answer 41

Defect at the peripheral organ

Question 42

Secondary endocrine disease

Answer 42

Problem is at the pituitary

Question 43

Tertiary endocrine disease

Answer 43

Problem is at the hypothalamus

Question 44

Long loop feedback

Answer 44

Peripheral gland hormone inhibition of the pituitary or the hypothalamus

Question 45

Short-loop feedback

Answer 45

Inhibition of the pituitary on the hypothalamus

Question 46

Physiologic response-driven negative feedback

Answer 46

There is no feedback from a specific hormone, it's just a physiologic change that alters expression of hormones

Question 47

Primary disease with TRH stimulation test

Answer 47

High basal levels of TSH that spike after TRH stimulation

Question 48

Secondary disease with TRH stimulation test

Answer 48

Flat line that does not change with TRH injection

Question 49

Tertiary disease with TRH stimulation test

Answer 49

TSH levels appear normal throughout test, but may have delayed return to baseline

Question 50

What causes variation in hormone levels? (5)

Answer 50

``` Age Time of day Body weight Sex Diet ```

Question 51

Variations in BNP

Answer 51

Higher in older people, obese people, women | Used to detect CHF or renal failure