Heartbeat

Question 1

MYOGENIC:

Answer 1

Heart generates its own beat

Question 2

Contraction is called:

Answer 2

Systole

Question 3

Relaxation is called…

Answer 3

Diastole

Question 4

The atria and ventricles contract at different times during a single beat -

Answer 4

Cardiac cycle

Question 5

Order of contraction is:

Answer 5

Diastole
Atrial systole
Ventricular systole

Question 6

Diastole is:

Answer 6

Heart chambers relax, allowing atria to fill with blood

Question 7

Atrial systole is…

Answer 7

Atria contract forcing blood into ventricles

Question 8

Ventricular systole…

Answer 8

Ventricles contract forcing blood out of the heart to lungs or body

Question 9

SAN sends an electrical impulse through atria - first - systole, then…

Answer 9

Down septum

then from top of ventricular systole

Question 10

Heart rate changes via 2 nervous systems:

Answer 10

Parasympathetic (vagus nerve)

Sympathetic

Question 11

SAN sets heart rate at about…

Answer 11

120bpm (too high, when at rest 60-80bpm)

Question 12

Nerves act as…

Answer 12

Brakes and accelerators.

Question 13

Cause of change in heart rate:

Answer 13

Exercise - more CO2 in blood

Increased acidity - decrease in pH

Question 14

Increase in CO2 is detected by…

Answer 14

Chemoreceptors (found in blood vessels)
Impulses sent to medulla oblongata (situated in cardiac control centre)
Changes to HR via para- and sympathetic nerves

Question 15

Regulation of HR (exercise)

Answer 15

Blood CO2 levels rise (detected by chemoreceptors)
Impulse to medulla
Decreased parasympathetic impulses to SAN lets heart beat faster
Increased sympathetic - heart beats even faster

Question 16

Regulation of HR after exercise:

Answer 16

Blood pressure rise detected by baroreceptors
Sent to medulla
Increased parasympathetic - let’s heart beat slower
Decreased sympathetic - allows HR to slow

Question 17

Mechanoreceptors:

Answer 17

Receptors in muscle fibres tell if heart is contracting or relaxing

Question 18

Controlled by 2 mechanisms:

Answer 18

Neural control

Hormonal control

Question 19

Neural control -CCC

Receives information from…

Answer 19

Sensory receptors - mechanoreceptors
Chemoreceptors

Baroreceptors (blood pressure)

• sense for stretch
• heart and blood vessels
  - increase in blood flow/pressure

Question 20

Hormonal control:

Answer 20

Adrenalin - the anticipatory rise cause adrenaline to be released from adrenal glands into the blood stream

Question 21

Adrenalin prepares body by:

Answer 21

Increasing hr
Strength of ventricular systole
Increases blood glucose levels by stimulating breakdown of glycogen in the liver

Question 22

Adrenalin forms part of the:

Answer 22

Sympathetic nervous system

Question 23

Acetylcholine released by…

Answer 23

Parasympathetic nerves

Causes a decrease in heart rate

Question 24

Chemoreceptors detect acidity causes by CO2 and lactic acid during exercise
Sends message to medulla oblongata
Sends a signal via the sympathetic (accelerating nerve)
Stimulates the…

Answer 24

SAN in the right atrium to contract the heart more forcefully and quickly
Therefore pumping more blood

Question 25

Chemoreceptors detect acidity causes by CO2 and lactic acid during exercise
Sends message to medulla oblongata
Sends a signal via the parasympathetic (decelerating nerve)
Reduces stimulation of the…

Answer 25

SAN in the right atrium to contract the heart less forcefully therefore reducing amount of blood being pumped
Happens gradually