B3: Cardiac cycle

Question 1

what is cardiac hypertrophy?

Answer 1

where the heart muscle gets bigger due to stress on the heart(exercise)

Question 2

What is the cardiac cycle?

Answer 2

-process of filling with blood, followed by contraction
-heart pumps when atria and ventricles work together
-heart is myogenic-has its own electrical impulse

Question 3

whats meant by myogenic?

Answer 3

-it has the ability to contract reflexively without nervous stimulation due to an electrical impulse

Question 4

whats meant by diastole?

Answer 4

-relaxing phase of the heart chambers
-(filling phase)
-0.5s

Question 5

whats meant by systole?

Answer 5

-contraction phase of heart chambers
-(ejecting phase)
-0.3s

Question 6

What is blood pressure?

Answer 6

the pressure of blood against the walls of the chambers

Question 7

whats diastolic and systolic pressure?

Answer 7

diastolic-pressure against chamber walls whilst in filling phase
systolic-pressure against chamber walls whilst in ejection phase

Question 8

explain the Diastolic phase

Answer 8

-atria and ventricles are relaxed
-atrioventricular valves remain shut to prevent blood flow from atria to ventricles.
-ALTHOUGH:
-when pressure builds in the atria the AV valves are forced open -> blood passively passes through bc AV valves aren’t that strong.

Question 9

what parts is the systolic phase?

Answer 9

-is split into 2 parts
-atrial systole
-ventricular systole

Question 10

atrial systole?

Answer 10

-atria contracts
-AV valves open and push blood into ventricles
-semi-lunar valves remain shut
l

Question 11

ventricular systole?

Answer 11

-AV valves are forced shut to prevent backflow
-Ventricles contract
-semi-lunar valves are forced open as blood flows to pulmonary artery and aorta

Question 12

whats the sinoatrial node?

Answer 12

the hearts pacemaker

Question 13

wheres the sinoatrial node located?

Answer 13

-walls of the right atrium

Question 14

what does the sinoatrial node do?

Answer 14

-sends an impulse from the right atrium through wall of the atria to allow them to contract- forcing blood into the ventricles

Question 15

where is the atrioventricular node located?

Answer 15

in the centre of the heart- between the atria and ventricles

Question 16

what does the atrioventricular node do?

Answer 16

-acts a gate to slow down the signals from the SAN
-by slowing it down the atria can contract before the ventricles so they will be relaxed and ready to receive blood

Question 17

Whats the Bundle of his?

Answer 17

specialist heart muscle cells-responsible for transporting electrical impulses from the AVN

Question 18

Where is the bundle of his located?

Answer 18

-found in the walls of the ventricles and in septum

Question 19

where are the purkinje fibres?

Answer 19

-located at the end of the bundle of his

Question 20

what are the purkinje fibres?

Answer 20

-thin filaments which allow the ventricles contract at regular intervals
-causes blood to be pushed out of the heart, either to the lungs or working muscles

Question 21

abbreviation to remember the order of the cardiac cycle?

Answer 21

Sally-> Sinoatrial node
Always-> Atrial systole
Aims-> Atrioventricular node
Balls-> Bundle of his
Past-> Purkinje fibres
Vicky-> Ventricular systole