Acute Responses To Exercise.

Question 1

Acute responses of the cardiovascular system.

Answer 1

In creased cardiac output, blood pressure, venous return. Redistribution of blood flow

Question 2

acute responses of the Muscular system

Answer 2

Increased A-vo2 difference
Increased body temperature
Increased motor unit recruitment
Increased lactate 
Decrease in energy substrates
Increase in blood flow.

Question 3

Ventilation. During exercise it is 15-30 times greater than at rest

Answer 3

V= tidal volume X respiratory rate. It is a measure of the volume of oxygen being inspired and the volume of waste products removed. An increase in ventilation during exercise indicates that more oxygen is being inspired in a minute. Allowing oxygen supply to meet oxygen demand. Tidal volume reaches its max capacity during sub maximal exercise any other increase in tidal volume is due to an increase in respiratory rate. Ventilation increases until exercise is stopped.

Question 4

Diffusion

Answer 4

The movement of oxygen molecules from high concentration to low concentration to allow the transport of oxygen and waste products. air comes in via the lungs through to the alveoli and the capillaries where it is then transferred into the blood stream and in reverse for removal of co2

Question 5

Diffusion during exercise

Answer 5

Diffusion increases during exercise to meet oxygen demand. The capillaries expand to provide more surface area and more diffusion

Question 6

Cardiac output

Answer 6

Q= stroke volume X heart rate. The total blood pumped out in a minute it increases with stroke volume and heart rate during exercise to meet oxygen demand. Stroke volume reaches capacity during submaximal exercise any further increase is a result of increasing heart rate.

Question 7

Trained and untrained cardiac output

Answer 7

Through training, athletes are able to increase stroke volume and as result heart rate is lowered. A lower heart rate is required to meet oxygen demand due to the volume of oxygen per stroke volume. This is the opposite in untrained people. At rest cardiac output is the same or slightly lower between trained and untrained athletes

Question 8

Blood pressure

Answer 8

An increase in cardiac output results in an increase in blood pressure. During exercise arteries vasodilate to allow more blood through.

Question 9

Diastolic blood pressure

Answer 9

The blood pressure in the arteries when the heart relaxes

Question 10

Systolic blood pressure

Answer 10

The blood pressure created in the arteries as blood is pumped through them

Question 11

Venous return

Answer 11

During exercise the blood returning back to the heart is increased by 3 mechanisms.

1. Muscle pump- the muscle contracts to squeeze the veins and ensure pressure remains.
2. respiratory pump- diaphragm creates abdominal pressure to ensure blood is emptied toward the heart.
3. Vasoconstriction- constriction of veins to ensure continual pressure towards the heart.

Question 12

Redistribution of blood flow

Answer 12

During exercise blood is directed away from the spleen kidneys and intestines and increases towards the working skeletal muscles, heart. Blood flow increases to the skin to cool it but at max exercise this step is bypassed.

Question 13

Arterio venous oxygen difference

Answer 13

The difference in oxygen levels within the arteries and veins. When capillaries expand more blood is allowed and more diffusion takes place, therefore More oxygen is extracted by the muscles from the blood and so the difference in levels increases. The higher the avo2 the better as it indicates more oxygen units are going to the muscles.

Question 14

Acute responses of the respiratory system

Answer 14

Increase in ventilation, diffusion

Question 15

Increase in blood flow

Answer 15

A muscular response. Skeletal capillaries dilate to allow more oxygenated blood through to the skeletal muscles and increase surface area for diffusion.

Question 16

Decrease in energy substrates.

Answer 16

As exercise is completed energy stores will decrease as they are used up to create energy. During aerobic activities, glycogen decreases quickly as the primary source of fuel. During anaerobic activity ATP and PC stores will decrease as the primary fuels source.

Question 17

Increase in body temperature

Answer 17

Muscular response. As the rate and number of energy producing reactions occur in the muscles body heat increases. During sub maximal exercise blood is cooled through thermoregulation. At maximal intensity this step is skipped as demand is extreme.

Question 18

Increase in motor unit recruitment

Answer 18

As exercise increases, more force is required by muscles and so more motor units need to be activated. Number of motor unit’s is determined by the speed and intensity of activity and so more motor units are required during maximal intensity than sub maximal.

Question 19

Increase in lactate

Answer 19

Lactate is required to move but during exercise it increases rapidly. When muscles are full of lactate they become fatigued an unable to move. Oxygen is required to reduce lactate levels. During exercise lactate increase = increase in oxygen demand. During submaximal activity lactate reaches a steady state once oxygen supply meets oxygen demand. During high intensity activity a steady state is not reached. Lactate levels rise until the Maximal intensity event is over.