The Cardiac System

Question 1

Sympathetic nervous system

Answer 1

• increased HR by releasing adrenaline
• adrenaline increases the strength of ventricular contraction
• increased metabolic activity increases the release of CO2 which is detected by chemoreceptors and informs the sympathetic centre to flush ou the excess CO2

Question 2

Parasympathetic system

Answer 2

• Releases acetylcholine which slows the spread of impulses throughout the heart .
• lowers HR

Question 3

sympathetic nerves (fight or flight)

Answer 3

• dilate pupils
• inhibit salivation
• inhibit stomachs activity
• inhibit bladder and intestine function

Question 4

Parasympathetic nerves (rest and digest)

Answer 4

• Constrict pupils
• stimulate stomachs activity
• stimulate intestine activity
• inhibit release of glucose and stimulate gallbladder

Question 5

What is the cardiac control centre stimulated by?

Answer 5

Chemoreceptors- senses the increase in CO2- increases HR

Baroreceptors- senses blood pressure -decreases HR

Proprioceptors-senses and increase in joint and muscle movement-stimulated higher HR

Question 6

Diastole

Answer 6

The term used to describe the relaxation phase of the cardiac cycle.
The heart ventricle are reloaded and fill with blood

Question 7

Systole

Answer 7

The term used to describe the contraction phase of the cardiac cycle - the ventricles contract and pump blood tho the arteries

( right ventricle to the pulmonary artery and lungs, left ventricle to the aorta and the body)

Question 8

Stroke Volume

Answer 8

The volume of blood that leaves the heart in each contraction

Question 9

health

Answer 9

A state of complete physical, emotional and social well being and not merely the absence of disease and infirmity

Question 10

Fitness

Answer 10

The ability to meet and cope with the demands of the environment

Question 11

Physical activity

Answer 11

Being active and taking part in exercise - can directly benefit your physical health and wellbeing

Question 12

Anticipatory rise

Answer 12

Slight increase of heart rate usually before activity starts due to the expectation of the exercise.

Question 13

cardiac output

Answer 13

The amount of blood the heart pumps out in 1 min. Measures in litres per minute (L/M)

Question 14

Name the parts of the heart

Answer 14

• left and right ventricle, left and right atrium
• tricuspid valve
• bicuspid valve
• chordae tendinae
• interventricular septum
• semi lunar valve

Question 15

sate the order electrical impulse travels through the heart

Answer 15

• SAN
  (0. 1 seconds delay)
• atrial systole
• Av node
• bundle of His
• bundle branches
• purkinje fibres
• ventricular systole

Question 16

Myogenic

Answer 16

Creates its own electrical impulses e.g. the heart

Question 17

Vascular shunt mechanism

Answer 17

The redistribution of blood through vasoconstriction and vasodilation

Question 18

Myoglobin

Answer 18

Main function to transport oxygen from the muscle cell membrane to the mitochondria
Serves as an extra reserve of oxygen to help exercising muscle maintain activity for longer

Question 19

Venous return

• def
• 6 mechanisms

Answer 19

• the return of blood to the right side of the heart via vena cava
  1 - skeletal muscle pump
  2 - the respiratory pump
  3 - pocket valves
  4 - smooth muscle walls of veins
  5 - gravity
  6 - the suction pump action of the heart, pressure gradient , negative pressure in the right atrium

Question 20

What is the Bohr shift

Answer 20

When and increase in blood carbon dioxide and a decrease in PH results in a reduction of the affinity of haemoglobin for oxygen.

Question 21

What is cardio vascular drift

Answer 21

Cardiovascular drift occurs during prolonged exercise and is the result of an increasing heart rate and decreasing stroke volume. Cardiovascular drift results from a decrease in blood volume and sympathetic nervous system triggered increase in heart rate.

Question 22

Stages of cardiovascular drift (8)

Answer 22

• cardiovascular drift occurs 10 mins into exercise and in a hot environment
• HR increases
• stroke volume decreases
• fluid is lost in sweat
• this reduces plasma volume
• this reduces venous return
• cardiac output increases Due to higher energy demands

Question 23

Arterio venous difference

Answer 23

The difference between the oxygen content of the arteriolar blood arriving at the muscles and venous blood leaving the muscles.

Question 24

At rest arterio venous difference is low because…

Answer 24

Not much oxygen is required in the muscles

Question 25

Training can increase arterio venous difference because…

Answer 25

Trained performers can extract more oxygen from the blood

Question 26

Name mechanisms of venous return

Answer 26

• gravity
• skeletal pumps
• pocket valves
• the respiratory pump.

Question 27

What is starlings law

Answer 27

Starling’s Law states that the greater venous return, the greater stroke volume is. As venous return increases the walls of the ventricles are stretched further. Results in a more powerful contraction. Increases the amount of blood pumped around the body during exercise.

Question 28

Medulla oblongata

Answer 28

• The most important part of the brain
• regulates processes that keep us alive
  E.g. breathing, HR

Question 29

What receptor detects an increase in CO2 in the blood

Answer 29

Chemoreceptors

Question 30

What receptor detects blood pressure

Answer 30

Baroreceptors

- and therefore decrease HR

Question 31

What receptor monitors joint movement

Answer 31

Proprioceptors

Question 32

What happens to the oxyhemoglobin curve during exercise (Bohr shift)

Answer 32

It shifts to the right