Exam 4

Question 1

Function of parathyroid hormone

Answer 1

Acts on kidneys (renal tubules) to increase reabsorption and decrease excretion of Ca2+

Question 2

Function of antidiuretic hormone

Answer 2

Aka arginine vasopressin
Released from posterior pituitary gland in response to increase in ECF osmolarity/decreased blood volume (dehydration)
Acts on kidneys to increase water and Na+ reabosorption

Question 3

What inhibits the secretion of antidiuretic hormone?

Answer 3

Alcohol

Question 4

Function of renin

Answer 4

Enzyme released by kidneys in response to decreased blood pressure
Cuts small peptide off the end of angiotensinogen
Ultimate result after cascade: decreases excretion of Na+ and water, increases reabsorption, and increases excretion of K+, increase in blood pressure

Question 5

Function of angiotensinogen

Answer 5

After a peptide is cut off by renin, becomes angiotensin I

Made in liver

Question 6

Function of angiotensin I

Answer 6

Once it reaches the lungs, it is converted to angiotensin II

Question 7

Function of angiotensin II

Answer 7

Vasoconstrictor
Causes release of aldosterone from adrenal glands
Causes release of antidiuretic hormone

Question 8

Function of aldosterone

Answer 8

Hormone
Acts on renal tubules to increase Na+ reabsorption and K+ excretion (water follows Na+)
= increased blood volume = increased blood pressure
Also increases K+ uptake into cells

Question 9

Roles of Na+ in the body

Answer 9

Maintaining water and electrolyte balance
Aids in nutrient absorption
Neural and muscular function

Question 10

What cation circulates in blood with 50% of the total being bound to albumin?

Answer 10

Ca+

Question 11

Symptoms of Na+ deficiency

Answer 11

Vomiting, diarrhea, heavy sweating, muscle cramps, mental apathy, loss of appetite

Question 12

Symptoms of Na+ toxicity

Answer 12

Edema, hypertension

Question 13

Functions of Cl-

Answer 13

Maintaining fluid and electrolyte balance
HCl production (stomach)

Question 14

Symptoms of Cl- deficiency

Answer 14

Heavy sweating, diarrhea, vomiting (same as Na+)

Question 15

Functions of K+

Answer 15

Fluid and electrolyte balance
Nerve and muscle function
Growth

Question 16

Function of epinephrine

Answer 16

Might be important after exercise to prevent hypokalemia (low blood K+)

Question 17

Function of insulin

Answer 17

Increases K+ uptake after eating

Question 18

Symptoms of K+ deficiency

Answer 18

Hypokalemia
Diarrhea, vomiting, severe dehydration
Associated with use of diuretics (like alcohol), steroids, laxatives
Muscle weakness, paralysis, confusion, cardiac arrhythmias
May cause hypertension

Question 19

Symptoms of K+ toxicity

Answer 19

Hyperkalemia
Occurs with overuse of supplements
Muscle weakness, vomiting, severe heart failure

Question 20

What are the trace minerals?

Answer 20

Cr, Mn, Fe, Cu, Zn, Mo, Se, I

Question 21

Which is the ferrous form of iron?

Answer 21

Fe2+

Question 22

Which is the ferric form of iron?

Answer 22

Fe3+ (THREEsomes make me sICk

Question 23

Function of hemosiderin?

Answer 23

Storage protein for iron
Mainly used in liver and when there is excess
Marker for toxicity

Question 24

Which form of iron is in heme?

Answer 24

Ferrous (2+)

Question 25

What makes up hemoglobin?

Answer 25

4 heme groups + 4 protein subunits

Question 26

What is the function of myoglobin and where does it act?

Answer 26

Muscles | Releases oxygen for ATP production and muscle contraction

Question 27

What makes up a heme group?

Answer 27

A protoporphyrin ring (nitrogen containing) with ferrous (2+) iron and oxygen

Question 28

What is a cytochrome?

Answer 28

Cytochromes are, membrane-bound hemeproteins containing heme groups and are primarily responsible for the generation of ATP via electron transport chain

Question 29

What does the body do if it does not need iron?

Answer 29

It is not absorbed, and therefore excreted with the sloughing off of intestinal cells

Question 30

What does the body do if it needs iron?

Answer 30

Ferritin releases iron to ferroportin to be transported out of the mucosal cell, it is oxidised, then taken by trasferrin to blood

Question 31

What is the function of hepcidin?

Answer 31

Released by liver in response to adequate storage of iron Decreases the absorption of iron Pulls ferroportin away from the basolateral membrane

Question 32

How does iron regulate the expression of genes that are involved in its own metabolism?

Answer 32

When present, a 4Fe-4S complex will bind to IRP1, blocking it from attaching to the IRE on the mRNA that codes for the transferrin receptor and ferritin, and unbound IRP2 protein is targeted for destruction by the proteosome = nuclease digestion of transferrin receptor mRNA, and expression of ferritin When absent, the complex does not bind to the IRP and then it can bind to the IRE = expression of transferrin receptor protein and not of ferritin

Question 33

Functions of zinc

Answer 33

VERSATILE | cofactor for metalloenzymes and DNA binding proteins