1.2/1.3 The hormonal, neural and chemical regulation of responses during physical activity and sport

Question 1

what is the sympathetic nervous system

Answer 1

part of the ANS and can activate an increase in HR

Question 2

what is the parasympathetic nervous system

Answer 2

part of the ANS and can activate a decrease in HR

Question 3

what is myogenic

Answer 3

The heart’s ability to create its own contraction

Question 4

what do chemoreceptors detect

Answer 4

change in CO2, lactic acid/blood acidity

Question 5

what do baroreceptors detect

Answer 5

change in blood pressure

Question 6

what do proprioceptors detect

Answer 6

change in muscle movement

Question 7

what is the medulla oblongata

Answer 7

the part of the brain that regulates processes that keep us alive such as breathing and heart rate

Question 8

what is the sinoatrial node

Answer 8

a small mass of cardiac muscle found in the wall of the right atrium that generates the heartbeat. it is more commonly called at the pacemaker.

Question 9

what is the atrioventricular node

Answer 9

This node relays the impulse between the upper and lower sections of the heart

Question 10

what is the Bundle of His

Answer 10

A collection of heart muscle cells that transmit electrical impulses from the AVN via the bundle branches to the ventricles

Question 11

what are the Purkinje Fibres

Answer 11

Muscle fibres at conduct impulses in the walls of the ventricles.

Question 12

what is the process of vascular shunting

Answer 12

• increase in CO2 and lactic acid detected by the chemoreceptors
• the chemoreceptors stimulate the Vasomotor centre
• the Vasomotor signals for a redistribution of blood flow
• VC + VD occur and the precapillary sphincters adjust blood flow into the capillaries

Question 13

what is the Vasomotor Control Centre

Answer 13

located in the medulla oblongata and is responsible for central regulation of blood flow. It receives impulses from chemoreceptors and controls the width of precapillary sphincters

Question 14

what is the cardiac conduction system

Answer 14

• SAN receives nerve impulses from the brain
• This sends electrical impulses across the atria causing atrial systole and forcing blood into ventricle
• AVN gathers electrical impulses and holds them for 0.1s so the atria can fully contract
• Then the impulses get sent down the Bundle of His in the septum
• then into the Purkinje fibres which causes the ventricles to contract and push the blood up and out into the blood vessels

Question 15

sympathetic vs parasympathetic systems

Answer 15

The sympathetic system can speed up the cardiac impulses given out by the cardiac conduction system, whereas the parasympathetic system can decrease these impulses and heart rate.
Both of these control mechanisms are controlled by the medulla oblongata in the brain.

Question 16

characteristics of the ANS

Answer 16

Question 17

3 different ways the heart rate is controlled

Answer 17

neural control, hormonal control, intrinsic control

Question 18

characteristics of neural control

Answer 18

chemoreceptors, baroreceptors and proprioceptors all detect changes and send impulses to the medulla oblongata where the cardiac control centre and respiratory centre are.

Question 19

how does the cardiac control centre contribute to neural control during exercise

Answer 19

sends an impulse down the cardiac accelerator nerve to the SAN node - increase frequency of impulses
When heart rate speeds up the SAN node sends impulses across atria more often

Question 20

how does the cardiac control centre contribute to neural control after exercise

Answer 20

cardiac centre sends impulses down the Vagus nerve to tell the SAN node to send less frequent impulses

Question 21

what is the Vagus nerve

Answer 21

control the parasympathetic system so decreases nerve impulses

Question 22

what is the cardiac accelerator nerve

Answer 22

controls the sympathetic system so increases nerve impulses

Question 23

what is hormonal control

Answer 23

releases adrenaline to the SAN node to increase nerve impulses - anticipatory rise

Question 24

what is intrinsic control

Answer 24

the heart detects changes of temperature and contractility so stroke volume and cardiac output increase