Physio & Biochem

Question 1

What are the main components of bone matrix?

Answer 1

Type 1 (&5) collagen and Ca10(PO4)6(OH)2 (Hydroxyapatite)

Question 2

What is the normal yearly rate of remodeling?

Answer 2

5-10%

Question 3

What is the scientific name of vitamin D3?

Answer 3

Cholecalciferol

Question 4

What is the inheritance pattern of ehlers-danlos syndrome?

Answer 4

Autosomal dominant

Question 5

What is the activated form of vitamin D3 called?

Answer 5

Calcitriol

Question 6

What is the function if Subunits 1-6 in voltage gated channels?

Answer 6

S1-S4 sense the voltage
S5 & S6 are the pore

Question 7

Resting membrane potential of muscles and neurons

Answer 7

-90 & -70 respectively

Question 8

Length of action potential in muscles

Answer 8

2-5ms

Question 9

What are the small clefts found in the muscular side of the motor end plate called?

Answer 9

Sub-neural cleft

Question 10

What is the socket for the neural terminal in the muscle called?

Answer 10

Synaptic gutter/trough

Question 11

How many ACh are needed to activate thr ACh receptors in the muscle?

Answer 11

2; on the a-subunits

Question 12

How much is MEPP?

Answer 12

0.4 mv (100 released causes action potential)

Question 13

What is quantal theory?

Answer 13

Small quantas of Ach are released randomly at rest producing a MEPP

Question 14

What does the triad of reticulum former by?

Answer 14

A T-tubule with 2 terminal cisternae of ssrcoplasmic reticulum

Question 15

What is the function of tropomodulin?

Answer 15

Modulates the size of actin at the exposed end (-/pointed)

Question 16

What is the function of CapZ

Answer 16

Caps the barbed end of actin at the Z band

Question 17

List the names of the 3 troponin proteins and their functions

Answer 17

Troponin I : attach to actin
Troponin T : attach to tropomyosin
Troponin C : attach to calcium

Question 18

What is the function of Titin?

Answer 18

Acts as a base for myosin to wrap around and also has an elastic part attaching myosin to the Z-disk

Question 19

What is the function of Nebulin?

Answer 19

Sets up the length of actin and gives it a ground to wrap around

Question 20

What is the function of a-actinin?

Answer 20

Attaches actin to z-disk

Question 21

What is Fenn effect?

Answer 21

More contractile force needs more ATP

Question 22

What causes rigor mortis?

Answer 22

Lack of ATP keeping cross bridges stuck on actin

Question 23

What is the difference between isometric and isotonic contraction?

Answer 23

Isometric= constant length with increasing tension
Isotonic= Change in length but constant tension

Question 24

What is G-actin?

Answer 24

The monomer of F-actin

Question 25

Give an example of a type 2 muscle fiber with small motor units

Answer 25

Eye, face and hand

Question 26

Give an example of a type 1 muscle fiber with big motor units

Answer 26

Posture muscles

Question 27

What causes muscles to have passive tension?

Answer 27

Connective tissue (fascia)

Question 28

What is the difference in EMG between curare and botulinum toxin?

Answer 28

Botulinum causes less depolarization

Question 29

What are dense bodies?

Answer 29

Proteins stimulating calcium channels that stimulate ACh production

Question 30

What 4 steps of muscle contraction require ATP?

Answer 30

Na/K pump (Rest) Ach production (end plate) SERCA depolarization (of RyR) Power stroke (of myosin)