P1 - Cardiovascular and respiratory systems

Question 1

What are the stages of the cardiac cycle? (diastole, atrial systole, ventricular systole) how long does it take each?

Answer 1

Diastole, as the atria and ventricles relax they expand drawing blood into the atria, av valves open and sl valves close (0.4secs)

Atrial systole, the atria contract, forcing remaining blood into the ventricles (0.1secs)

Ventricular systole, the ventricles contract, increasing blood pressure closing the AV valves to prevent backflow. SL valves forced open as blood is ejected from the ventricles into the aorta and pulmonary artery
(0.3secs)

Question 2

what is the conduction system process? (heart)

Answer 2

An electrical impulse is sent from the SA node. It travels through the atria walls causing them to contract.

The AV node collects it and delays it for 0.1seconds to allow for the atria to finish contracting. then releases the impulse to the bundle of his.

Bundle of his then splits into two.

The bundle branches then carry the impulse to the base of each ventricle

Purkyne fibres, these distribute them through the ventricle walls allowing them to contract

Once complete the atria and ventricles relax allowing blood to fill in the heart

Question 3

What is heart rate? equation?

what is stroke volume?

what is cardiac output? equation and unit?

Answer 3

heart rate is the number of times the heart beats per minute. 220 - age
Stroke volume is the volume of blood ejected from the heart (left ventricle) per beat
Cardiac output is the volume of blood ejected form the heart per min ( HR X SV) = Q

Question 4

what is resting HR, SV, Q for an untrained person?

for a trained person? AT REST

Answer 4

70 - 72 bpm, 70ml , 5l/min

50bpm. 100ml , 5 l/min

Question 5

What is sub maximal exercise?

what is maximal exercise?

Answer 5

sub maximal exercise is at low to moderate intensity within a performers aerobic capacity
Maximal exercise is at a high intensity above a performers aerobic capacity which will take a performer to exhaustion

Question 6

Explain how HR is effected from start to finish of exercise where steady state is met? (sub maximal exercise)

Answer 6

An initial anticipatory rise in HR prior to exercise due to the release of the hormone adrenaline
There is then a rapid increase in HR at the start to increase blood flow and oxygen delivery in line with exercise intensity .
A steady state HR throughout the sustained intensity exercise as oxygen and waste removal demands are met.
an initial rapid decrease in heart rate as recovery is entered and the action of muscle pump is reduced
Then there is a more gradual decrease in HR to resting levels

Question 7

How is HR effected during maximal exercise?

Answer 7

steep rise in HR
shallower rise in HR
till exhaustion, so then rapid decrease, then much slower decrease in HR

Question 8

How does stroke volume respond to exercise? (sub maximal)

What happens as maximal intensity approaches why?

Answer 8

Stroke volume increases proportional to exercise intensity until a plateau is reached at approximately 40 - 60% of working capacity
Increased venous return form muscle pump, etc etc
A greater increase in blood returning to the heart means a greater stretch on the ventricular walls. This greater stretch means a stronger contraction is needed but time is needed to maximise this effect. so increased HR does not allow enough time for the ventricles to completely fill with blood in the diastole phase

Question 9

How does cardiac output respond to exercise?

Answer 9

cardiac output increases proportionally to exercise intensity and plateau’s during maximal exercise. There is then a rapid decrease followed by a slower decrease to resting levels

Question 10

what is the SV, Q for a untrained and trained athlete at maximal intensity?

Answer 10

100-120ml 20-30l/min

160- 200ml 30 - 40 l/min

Question 11

What is the CCC?

what does ANS stand for?

Answer 11

Cardiac control centre, receives information from the sensory nerves and sends direction through motor nerves to change HR
Autonomic nervous system, control

Question 12

What are the three sources of information that determine the action of the CCC?

Answer 12

Neural, intrinsic control, hormonal control

Question 13

what are the 3 receptors? (neural control)

Answer 13

Chemoreceptors located in the muscles, aorta inform the CCC of chemical changes in the blood stream, such as increased levels of CO2 and lactic acid.
Proprioceptors located in the muscles, tendons and joints inform the CCC of motor activity
Baroreceptors located in the blood vessel walls inform the CCC of increased blood pressure

Question 14

what is intrinsic control (in terms of sending info to the CCC) ?

Answer 14

Temperature changes will affect the viscosity of the blood and speed of nerve impulse transmission
Venous return changes will affect the stretch in the ventricle walls, force of ventricular contraction and therefore stroke volume

Question 15

What is hormonal control? (CCC)

Answer 15

Adrenaline is released form the adrenal glands increasing the force of ventricular contraction and increasing the speed of electrical activity through the heart therefore HR.

Question 16

What does the CCC do start from finish?

Answer 16

Located in the medulla oblongata, the CCC receives information from the sensory nerves (neural, intrinsic and hormonal control). Based on the information provided the CCC will either increase or decrease the stimulation of the SA node.

Question 17

What does the CCC do to stimulate the SA node if an increase in HR is needed? what nerve?
What does the CCC do if a decrease in HR is required?
what nerve?

Answer 17

The sympathetic nervous system is actioned (accelerator nerve) releasing adrenaline and sending stimulation to the SA node increasing HR and force of contraction
The parasympathetic nervous system is actioned to inhibit the effects of adrenaline etc via the vagus nerve, lowering HR

Question 18

What kind of blood do arteries and arterioles transport? What kind of blood do veins and venules transport?

Answer 18

Oxygenated blood

Deoxygenated blood

Question 19

what is Vasodilation?
what is vasoconstriction?
what is venoconstrict and venodilate?

Answer 19

Vasodilate is the widening of arties, arterioles
Vasoconstriction is the narrowing of arties, arterioles
The same as vaso dilate and constrict but in the veins and venules

Question 20

What is venous return mechanism?

Why does venous return need to increase during exercise?

Answer 20

Venous return is the return of blood to the heart through the venules and veins back to the right atrium largely against gravity.
To increase stroke volume and therefore cardiac output.

Question 21

What are the venous return mechanisms explained?

Answer 21

Pocket valves. Are one way valves located in the veins which prevent the backflow of blood.

Smooth muscle, Is the layer of smooth muscle in the vein walls which venoconstricts to increase pressure and aid the movement of blood.

Gravity, blood from the upper body above the heart is helped to return to the heart via gravity

Muscle pump, is when during exercise skeletal muscle contract compressing the veins located between them squeezing the blood back to the heart.

Respiratory pump, is when during inspiration and expiration, a pressure difference between the thoracic and abdominal cavity is created, squeezing the blood back to the heart.

Question 22

what is blood pooling? how is it caused and how do you prevent it post exercise?

Answer 22

Blood pooling is an accumulation of blood in the veins due to a lack of venous return. Prevented by an active recovery as this low intensity exercise helps maintain respiratory and muscular pump to aid venous return.

Question 23

What is the vascular shunt mechanism?

Answer 23

The vascular shunt mechanism is the redistribution of blood form one area of the body to another.

Question 24

What are the pre capillary sphincters?

Answer 24

Arterioles lead to pre capillary sphincters which controls the blood flow to capillary beds

Question 25

During exercise what do the pre capillary sphincters do?

Answer 25

They dilate maximising blood flow to the capillary beds located by the muscles to maximise gaseous exchange,
And the pre capillary sphincters leading to the organs constrict.

Question 26

During exercise what do the arterioles do? (re distribution of blood)

Answer 26

They vasoconstrict the blood to the organs and vasodilate the blood to the muscles so as much blood can go the muscles as possible to meet oxygen demand

Question 27

What does VCC stand for? and what is it?

What is vasomotor tone?

Answer 27

Vasomotor control centre is in the medulla oblongata of the brain. The VCC controls the vascular shunt mechanism. Responsible for controlling cardiac output distribution (blood redistribution)
Vasomotor tone is the partial state of smooth muscle constriction in the atrial walls.

Question 28

What does the VCC receive information from? (what receptors?)

Answer 28

Chemoreceptors regarding chemical changes such c02 and lactic acid rising during exercise.
Baroreceptors regarding pressure changes on the arterial walls

Question 29

What does the VCC then do when sensory information is gathered? (to do with when body starts exercise)
what nerves do what?

Answer 29

Increases sympathetic stimulation via accelerator nerve to vasoconstrict arterioles and pre capillary sphincters to limit blood flow to an area such as muscles at rest.
Or decrease sympathetic stimulation via vagus nerve to vasodilate arterioles and pre capillary sphincter’s to increase blood flow to an area such as muscles during exercise

Question 30

How much blood is redistributed to the working muscles at maximal intensity?

Answer 30

88%

Question 31

What is gaseous exchange?

Answer 31

the movement of oxygen form the alveoli into the blood stream and c02 from the blood stream into alveoli

Question 32

How is oxygen transported?

Answer 32

Carried with haemoglobin in the red blood cells to make oxyhaemoglobin and carried through plasma

Question 33

How is c02 transported?

Answer 33

Dissolved in water, Carried with haemoglobin to make carbaminohaemoglobin or dissolved in plasma

Question 34

What is tidal volume?

Answer 34

The volume of air inspired or expired per breath

Question 35

What is breathing frequency, tidal volume and minute ventilation of a untrained person at rest? trained?

during maximal intensity?

Answer 35

12 - 15 breaths 500ml for tidal volume 6 - 7.5l/min for minute ventilation

11 - 12 breaths 500ml TV 5.5 - 6l.min VE

40 - 50 breaths 2.5-3l 100- 150l/min

50 - 60 3-3.5l 160 - 210l/min

Question 36

What is minute ventilation and equation?

Answer 36

TV x F = VE

tidal volume times breathing frequency = minuet ventilation

Question 37

How does breathing rate respond to exercise? what about steady state sub maximal?

Answer 37

Breathing rate increases in proportion to the intensity of exercise until we approach maximum of about 50-60breaths per minute.
Breathing rate can plateau during steady state as oxygen demand is met.

Question 38

How is tidal volume respond to exercise?

Answer 38

Tidal volume increases initially proportionally to exercise intensity at submaximal intensities. Although tidal volume reaches a plateau during maximal intensity because increased breathing rate does not allow the strecthed walls of the heart enough time to compeltly fill up with blood

Question 39

How does minute ventilation respond to exercise and recovery?

Answer 39

During sub maximal intensity there will be a plateau as this represents when oxygen demand is met.
As we do maximal exercise VE continues to increase as exercise intensity continues to increases there is a growing demand for oxygen. Increases until exhaustion where it suddenly decreases then slowly decreases.