endocrine 5 - parathyroid

Question 1

where is parathormone PTH release

Answer 1

chief cells of the parathyroid gland

Question 2

where is calcitonin relreased

Answer 2

parafollicular cells of thyroid (between thyroid follicles)

Question 3

what do the chief cells of the parathyroid gland release

Answer 3

parathormone

Question 4

what does PTH do to [calcium] in the ECF

Answer 4

increase

Question 5

what does PTH do to [phosphate] in the ECF

Answer 5

decrease

Question 6

is there more free ionized calcium in the ECF or ICF

Answer 6

more ECF (extracellularly)

Question 7

how many kg of calcium is in our body

Answer 7

1kg

Question 8

what % of calcium is in our bones

Answer 8

99%

Question 9

what % of calcium is in other tissues than bones

Answer 9

1%

Question 10

how many mg of calcium is free

Answer 10

500mg

Question 11

what is resorption

Answer 11

bone breakdown into blood

Question 12

what does calcitonin do to bones

Answer 12

reduces calcium levels in the blood to increase it in bone

Question 13

what does PTH do to bones

Answer 13

increases calcium levels in the blood to decreases it in bone

Question 14

what are 4 roles of calcium

Answer 14

structural
blood coagulation
intracellular messenger
regulation of excitability

Question 15

what are 3 roles of phosphate

Answer 15

structural
metabolism (ATP, nucleic acids)
buffer (maintain pH balance)

Question 16

when do you use phosphate as a buffer

Answer 16

when you deplete CO2 as a buffer

Question 17

where is PTH released

Answer 17

parathyroid gland

Question 18

where is calcitonin released

Answer 18

thyroid gland (parafollicular cells)

Question 19

where is active vitamin D released

Answer 19

kidneys

Question 20

what is the target of PTH

Answer 20

bone (kidney and GIT indirectly)

Question 21

what is the target of active vitamin D

Answer 21

GI tract

Question 22

what is the target of calcitonin

Answer 22

kidneys (bone and GIT indirectly)

Question 23

what is the role of osteoblasts

Answer 23

bone deposition by adding Ca2+

Question 24

what is the role of osteoclasts

Answer 24

bone resorption, release of Ca2+ from bone

Question 25

what are the 3 catogories of structures in bone and their relative weights

Answer 25

organic stuff (1/3), inorganic salts(2/3), bone cells(negligible)

Question 26

what is the organic framework for bone

Answer 26

collagen type 1

Question 27

what is in the inorganic salt of bone

Answer 27

calcium phosphoate and hydroxyapatite

Question 28

what are the bone cells

Answer 28

osteoblasts osteocytes oseoclasts

Question 29

how are osteocytes made

Answer 29

they are osteoblasts that are in the bone that they made (mature osteoblasts)

Question 30

what do osteoclasts look like

Answer 30

multi nucleated with ruffled borders, large, like a macrophage)

Question 31

what do osteoclasts release to dissolve bone

Answer 31

enzymes and H+

Question 32

when/why do osteoclasts start the cycle

Answer 32

with ruffled borders or slight damage/ rough edges

Question 33

what do osteoblasts do once osteoclasts do resorption of the bone

Answer 33

they lay done and secrete proteins like collagen and osteoid

Question 34

what is osteoid

Answer 34

the organic framework matrix of bone

Question 35

what signals vitamin D release

Answer 35

raised plasma parathyroid hormone PTH

Question 36

what happens with raised vitamin D

Answer 36

more calcium absorption into blood from the intestines

Question 37

what happens to PTH with low calcium

Answer 37

raise levels of secretion

Question 38

what kind of solubility is vitamine D

Answer 38

lipid soluble

Question 39

how does PTH increase active Vit D

Answer 39

increases 1alphaHydroxylase

Question 40

what does 1alphaHydroxylase do

Answer 40

adds OH to activate vitamin D

Question 41

what does calbindin do

Answer 41

moves Ca from the luminal to the basolateral side

Question 42

what is calbindin

Answer 42

protein that binds to Ca++ to allow its transportx

Question 43

what are the 3 vitamin D regulated froteins

Answer 43

ECaC (lets Ca++ into cell) calbindin protein basolateral calcium pump

Question 44

what kind of hormone is PTH

Answer 44

peptide

Question 45

what kind of hormone is calcitonin

Answer 45

peptide

Question 46

what does PTH do to blood phosphate

Answer 46

decrease (let it out in urine)

Question 47

what does Vit D do to blood phosphate

Answer 47

increase

Question 48

what does calcitonin do to blood phosphate

Answer 48

decrease

Question 49

what causes secretion of PTH

Answer 49

decreased blood Ca++

Question 50

what causes secretion of Vit D

Answer 50

PTH

Question 51

what causes secretion of calcitonin

Answer 51

increased blood Ca++

Question 52

what does PTH do to bone

Answer 52

increase resorption

Question 53

what does Vit D do to bone

Answer 53

increase resorption by working with PTH

Question 54

what does PTH do to kidney

Answer 54

increase reabsorption of Ca++ | decrease reabsorption of phosphate

Question 55

what does Vit D do to kidney

Answer 55

increase reabsorption of Ca++ and phosphate

Question 56

what does Vit D do to GIT

Answer 56

increase reabsorption of Ca++ and phosphate (major)

Question 57

what does PTH do to GIT

Answer 57

increase reabsorption of Ca++ and phosphate (indirect via Vit D)

Question 58

what causes rickets

Answer 58

deficiency of Vit D in children

Question 59

what causes osteomalacia

Answer 59

deficiency of Vit D in adults

Question 60

what is osteomalacia

Answer 60

softening of the bones, typically through a deficiency of vitamin D in adults

Question 61

what causes tetany

Answer 61

low calcium

Question 62

what happens with low plasma calcium

Answer 62

increases nerve and muscle excitability via opening of Na+ channels

Question 63

what would happen without parathyroid hormone

Answer 63

you die