8

Question 1

How many chambers

Answer 1

4

Question 2

Which way does blood flow

Answer 2

One direction

Question 3

Arterial blood flows…

Answer 3

Away from heart

Question 4

Venous blood flows…

Answer 4

Towards the heart

Question 5

The hearts pump the ____ amount - are in _____

Answer 5

The hearts pump the same amount - are in series
- two pumps in series working together

Question 6

Answer 6

Question 7

Contraction of heart

Answer 7

• pressure of contraction shuts AV valve
• pressure drops and valves flop open for passive filling
• valves keep it unidirectional
• right and left pumps contract simultaneously
• atria contract first… ventricles contract second
• valves open and close to direct blood

Question 8

What do AV valves do?

Answer 8

• control flow between the atria and ventricles
• tricapsid and bicapsid

Question 9

What do the aortic and pulmonary valves do?

Answer 9

• control flow from the ventricles out to the circulatory vessels

Question 10

Blood movement through the heart is gated by…

Answer 10

….valves

Question 11

Answer 11

Question 12

Valves open and close to…

Answer 12

.. direct blood

Question 13

Structure of muscle in heart

Answer 13

• sarcomere is key contractile element
• actin = thin

Question 14

Cellular mechanism of cardiac contraction

Answer 14

• Ca2+ levels go up, and more Ca2+ is released from the SR
• myosin binds to actin to form cross-bridges
• myosin pulls on actin to shorten the sarcomere and generate force
• every myocyte activated during each heart beat
• so how can we increase force of contraction ??

Question 15

How many myocytes are activated each heart beat?

Answer 15

All of them- everyone is recruited

Question 16

How to increase the force of cardiac contraction

Answer 16

• every cardiomyocyte is activated during each heart beat
• extent of X-bridges formed not maximised at rest
  
  • increase cytosolic Ca2+ level
  • increase number of cross-bridges formed
  • increase force of contraction

(Don’t activate more fibres like skeletal - all are already activated so we increase the calcium)

Question 17

Cellular mechanism of cardiac relaxation

Answer 17

• decrease in cytosolic Ca2+ levels - Ca2+ pumped back into the SR
• cross bridges release when ATP binds to myosin
• reduction is force means the heart can relax
• all cardiac myocyres relax each beat

REQUIRES ATP

Question 18

Diastole

Answer 18

• relaxation
• falling pressure

Question 19

Systole

Answer 19

• contraction
• rising pressure

Question 20

Cardiac cycle

Answer 20

Question 21

Main phases of the cardiac cycle

Answer 21

-lubb sound is the AV valve closing
- isovolumetric ventricular = contraction and building pressure but not ejecting (systole)
- ventricular ejection - pulse - Dupp sound of closing semilunar
- myosin heads release - relaxation - isovolumetic ventricular relaxation
- pressure falls in ventricle and valve opens

Answer 22

• pressure up in systole
• down in diastole

Question 23

Features of a blood pressure trace

Answer 23

• pulsatile change in pressure in the major arteries linked to ejection of blood
• periods of systole (rising pressure) and diastole (falling pressure)
• diastole is typically longer then systole
• systemic arterial pressure is much higher then the pulmonary arterial pressure - need more pressure as its going further

Question 24

Feautres of blood pressure trace

Answer 24

• systolic pressure is the highest point on the trace
• diastolic pressure is the lowerst point on the trace
• pulse pressure is the difference between the highest and lowest points
• mean pressure is the average across the full cycle - pulled down by diastolic pressure - about a third of the pulse pressure
• hypertension is high blood pressure, while hypotension is low blood pressure

Question 25

What is the systolic pressure

Answer 25

• systolic pressure is the highest point on the trace

Question 26

What is diastolic pressure

Answer 26

• diastolic pressure is the lowerst point on the trace

Question 27

What is pulse pressure

Answer 27

• pulse pressure is the difference between the highest and lowest points

Question 28

What is mean pressure

Answer 28

• mean pressure is the average across the full cycle - pulled down by diastolic pressure - about a third of the pulse pressure

Question 29

What is hypertension and what is hypotension

Answer 29

• hypertension is high blood pressure, while hypotension is low blood pressure

Question 30

The heart is two pumps in _____ moving blood through the ______ (right pump) and systemic (left pump) circuits

Answer 30

The heart is two pumps in Series moving blood through the pulmonary (right pump) and systemic (left lump) circuits

Question 31

What can be used to determine systolic and diastolic pressure in the arteries ?

Answer 31

Blood pressure trace

Question 32

Cellular contraction is initiated by ____________ and the __________, relaxation requires_____

Answer 32

Cellular contraction is initiated by an increase in cytosolic Ca2+ levels and the formation of cross-bridges; reaction requires the reversal of these events

Question 33

The cardiac system is defined by the _________ and the _______ of the Chem ambers of the ______ which work in concert to _______ pressure and _____ the bloood into the _____

Answer 33

The cardiac cycle is defined by the contraction (systole) and relaxation (diastole) of the chambers of the heart which work in concert to build pressure and eject the blood into the vessels

Question 34

What can be used to determine systolic and diastolic pressure in the arteries ?

Answer 34

A blood pressure trace