Endo Lec 5

Question 1

parathyroid glands look like

Answer 1

small pearls

Question 2

chief cells of parathyroid gland secrete

Answer 2

parathyroid hormone(PTH)

Question 3

conc of free Ca++ is __ in the ECF than ICF

Answer 3

greater

Question 4

PTH increases ___ and decreases ___ in ___

Answer 4

• [Ca++]
• [phosphate]
• in ECF

Question 5

conc of bound Ca++ is __ in the ECF than ICF

Answer 5

lower

Question 6

parathyroid regulates __ Ca++ in __

Answer 6

• free

- ECF

Question 7

Calcitonin is a __ that

Answer 7

hormone that plays a role in regulating the level of calcium in your blood by decreasing it.

Question 8

importance of calcium

Answer 8

• Structural role (bone, teeth)
• Blood coagulation
• Intracellular messenger
• Regulation of excitability

Question 9

importance of phosphate

Answer 9

• Structural role
• Metabolism (ATP, nucleic acids)
• Buffer (maintaining pH balance)

Question 10

source – hormone – target ? source= parathyroid gland

Answer 10

hormone: PTH
target: bone (kidneys and GIT indirectly)

Question 11

source – hormone – target ? source= kidneys

Answer 11

hormone: active vitamin D
target: GIT

Question 12

source – hormone – target ? source= thyroid gland (parafollicular cells)

Answer 12

hormone: calcitonin
target: kidneys (bone and GIT indirectly)

Question 13

bone (3 components)

Answer 13

• organic framework.matrix, osteoid (1/3 total weight)
• inorganic salts (2/3 total weight)
• bone cells

Question 14

organic framework.matrix, osteoid (components)

Answer 14

-collagen type 1

Question 15

inorganic salts (components)

Answer 15

• calcium phosphate

- hydroxyapatite

Question 16

bone cells (type)

Answer 16

• osteoblasts
• osteocytes
• osteoclasts

Question 17

osteoblasts

Answer 17

synthesize bone matrix and coordinate the mineralization of the skeleton
addition of Ca++ to bone

Question 18

osteocytes

Answer 18

cell in mature bone tissue, maintain bone (has dendrites that connects osteoblasts)

Question 19

osteoclasts

Answer 19

cells that degrade bone to initiate normal bone remodeling

release Ca++ from bone

Question 20

hormonal control of Ca++ balance

Answer 20

↓ plasma Ca++
↑ parathyroid hormone secretion
kidneys: ↑ Ca++ reabsorption , ↑active Vit-D (↑Ca++absorption in intestine)

Question 21

vitamin D3 also

Answer 21

cholecalciferol

Question 22

active vit. D other names

Answer 22

• calcitriol

- 1,25 (OH)2 cholecalciferol

Question 23

synthesis of active vitamin D3

Answer 23

vitamin D3 (cholecalciferol) --> (in liver) 25-OH cholecalciferol--->
(in kidneys by 1-hydroxylase) calcitriol (active vit. D)

Question 24

PTH influence of 1-hydroxylase

Answer 24

PTH (+) stimulates activity of 1-hydroxylase

Question 25

absorption of Ca++

Answer 25

1. in the presence of vitamin D, ca++ channels, open on the luminal side of duodenal cells
2. Ca++ forms complex with calbindin andmoves to basolateral side
3. Active transport of Ca++ on basolateral cell through Ca++ ATPase

Question 26

vitamin D regulated proteins as transcription factor

Answer 26

Epithelial calcium channel (ECaC)
Calbindin protein
Basolateral calcium pump

Question 27

deficiency of active Vit D

Answer 27

rickets (soft spot on baby head, bony necklace, curved bones, big lumpy joints, bowed legs)

Question 28

hormones favoring bone formation (6)

Answer 28

1. Insulin
2. Growth hormone
3. Insulin like growth factor-1
4. Estrogen
5. Testosterone
6. Calcitonin

Question 29

hormones favouring bone reabsorption (3)

Answer 29

1. PTH (chronic elevation)
2. Cortisol
3. Thyroid hormones (T3 and T4)

Question 30

low calcium disease

Answer 30

tetany