Adrenal Medulla

Question 1

dopamine enters _______ and is converted to norepinephrine by _______

Answer 1

the granules

dopamine B-hydroxylase

Question 2

Catecholamine effect on pupils?

Answer 2

dilation

Question 3

Catecholamine effect on alertness?

Answer 3

increased

Question 4

What is the rate limiting step of catecholamine synthesis

Answer 4

tyrosine hydroxylase converting tyrosine to DOPA

Question 5

Catecholamine effect on GI activity?

Answer 5

decreased

Question 6

synthesis of catecholamines occurs in the ____ cells

Answer 6

chormaffin

Question 7

What are the two main enzymes of catecholamine degradation?

Answer 7

1. monoamine oxidase (MAO)

2. Catechol-O-methyltransferase (COMT)

Question 8

What is the only cause of HYPERfunction of adrenomedullary catecholamine synthesis

Answer 8

pheochromocytoma

Question 9

monoamine oxidase (MAO) converts norepinephrine into __________ and is then excreted in the urine as __________

Answer 9

MHPG - 3-methoxy-4-hydroxyphenylglycol

VMA - 3-methoxy-4-hydroxymandelic acid

Question 10

Pheochromocytoma produces catecholamines ___x more than normal

Answer 10

20

Question 11

tyrosine hydroxylase converts ______ to _______

which part of the cell?

Answer 11

tyrosine to DOPA

cytosol

Question 12

Which enzyme predominantly degrades epinephrine?

Answer 12

Catechol-O-methyltransferase (COMT)

Question 13

Chronic stress activates which enzyme in the pathway of catecholamine synthesis

HOW

Answer 13

tyrosine hydroxylase

increased expression and concentration

(acute stress = activity of TH)

Question 14

Catechol-O-methyltransferase (COMT) degrades which catecholamine?

Answer 14

epinephrine

Question 15

Catecholamine effect on bronchioles?

Answer 15

dilation

Question 16

phenylethanolamine-N-methyltransferase “PNMT” is regulated by:

Answer 16

cortisol

Question 17

storage of catecholamines:

\_\_\_% = norepinephrine 
\_\_\_% = epinephrine

Answer 17

15% epinephrine

85% norepinephrine

Question 18

half life of catecholamine

Answer 18

~2 min

Question 19

What converts DOPA to dopamine?

Answer 19

amino acid decarboxylase

Question 20

monoamine oxidase (MAO) degrades which catecholamine?

Answer 20

norepinephrine

Question 21

Which enzyme predominantly degrades norepinephrine?

Answer 21

monoamine oxidase (MAO)

Question 22

clinical manifestations of pheochromocytoma

What age is it usually found/diagnosed?

Answer 22

1. hypertension
2. rapid pulse
3. chest pain
4. sweating
5. headache
6. hyperglycemia***
7. fatigue

40’s/50’s

Question 23

What can be measured in the urine that serves as an index of SNS activity or pathology

Answer 23

VMA - 3-methoxy-4-hydroxymandelic acid

Question 24

MOST of the norepinephrine made in the granules is ______________

SOME of the norepinephrine made in the granules is ______________

Answer 24

MOST = converted to epinephrine in the cytosol

SOME = stored in granules

Question 25

phenylethanolamine-N-methyltransferase "PNMT" converts _________ to ________ which part of the cell?

Answer 25

norepinephrine to epinephrine cytosol

Question 26

Where do you find Catechol-O-methyltransferase (COMT)

Answer 26

heart, liver, kidney

Question 27

Acute stress activates which enzyme in the pathway of catecholamine synthesis HOW

Answer 27

tyrosine hydroxylase *ACTIVITY* (chronic stress = increased expression and concentration of TH)

Question 28

What enzyme converts tyrosine to DOPA

Answer 28

tyrosine hydroxylase

Question 29

Catechol-O-methyltransferase (COMT) converts epinephrine into __________ and is then excreted in the urine as __________

Answer 29

MHPG - 3-methoxy-4-hydroxyphenylglycol | VMA - 3-methoxy-4-hydroxymandelic acid

Question 30

catecholamine effects on the cardiovascular system

Answer 30

1. increased cardiac contractility 2. increased heart rate 3. increased conduction 4. increased blood pressure 5. increased arteriolar vasoconstriction in the renal, splanchnic and cutaneous bed

Question 31

amino acid decarboxylase converts _____ to _____ which part of the cell?

Answer 31

DOPA to dopamine cytosol of the cell

Question 32

What is the only cause of HYPOfunction of adrenomedullary catecholamine synthesis

Answer 32

post-adrenalectomy surgery

Question 33

dopamine B-hydroxylase converts _____ to _____ which part of the cell?

Answer 33

dopamine to norepinephrine granules

Question 34

epinephrine mobilizes fuels of stress by:

Answer 34

1. increased glycogenolysis 2. inhibition of glycogen synthesis 3. increased gluconeogenesis 4. inhibition of insulin secretion 5. increased glucagon secretion 6. increased lipolysis

Question 35

What is pheochromocytoma? | How can it be detected?

Answer 35

catecholamine-secreting tumor | VMA (3-methoxy-4-hydroxymandelic acid) in the urine

Question 36

what enzyme converts norepinephrine to epinephrine

Answer 36

phenylethanolamine-N-methyltransferase | "PNMT"

Question 37

Secretion of catecholamines occurs during which events (5)

Answer 37

1. fight-or-flight 2. hypotension 3. shock 4. heart failure 5. hypoglycemia

Question 38

What is the precursor molecule for all catecholamines

Answer 38

tyrosine

Question 39

catecholamine effects: fast/slow ? short-acting/ long lasting?

Answer 39

fast | short-lived

Question 40

Why does epinephrine mobilize fuels in times of stress?

Answer 40

to sustain glucose production for use by the CNS

Question 41

cortisol regulates which enzyme in catecholamine synthesis?

Answer 41

phenylethanolamine-N-methyltransferase | "PNMT"

Question 42

Where do you find monoamine oxidase (MAO)

Answer 42

neuronal cytoplasm