biochemistry

Question 1

whats a sarcomere

Answer 1

contractile unit in muscle

Question 2

what are Z lines

Answer 2

neighbouring parallel lines that make up the sarcomere

Question 3

whats an M line

Answer 3

line at the centre of the sarcomere where myosin myofilaments bind

Question 4

whats the A band

Answer 4

the length of a myosin myofilament within a sarcomere

Question 5

whats the H band

Answer 5

area adjacent to M-line, only thick filaments

Question 6

whats the I band

Answer 6

adjacent to z line, thin filaments only
this shortens during contraction

Question 7

how is Ca2+ removed from cells

Answer 7

pumped back into sarcoplasmiv reticulum via SERCA
moves out via NCX antiporter

Question 8

stroke volume =

Answer 8

EDV - ESV

Question 9

ejection fraction =

Answer 9

SV / EDV

Question 10

blood pressure

Answer 10

CO X peripheral vascular resistance

Question 11

mean arterial pressure =

Answer 11

diastolic BP + (1/3 pulse pressure)

Question 12

chronotropy

Answer 12

affecting heart rate

Question 13

dronotropy

Answer 13

affecting speed of conduction

Question 14

inotropy

Answer 14

affecting force of contraction

Question 15

what increases contractility

Answer 15

calcium
SNS - noradrenaline, adrenaline
increased body temp
increased T3 and T4

Question 16

what decreases contractility

Answer 16

PNS - acetylcholine
low calcium levels
hyperkalemia

Question 17

frank starlings law

Answer 17

higher the EDV, higher the SV

Question 18

which of these will cause a decrease in left ventricular oxygen demand?
- increased afterload
- increased preload
- decrease in ventricular wall tension
- increase in blood viscosity

Answer 18

decrease in ventricular wall tension