Unit 3 (AOS2 outcome 2) physiological responses to PA- Chapter 4

Question 0

What is ventilation?

Answer 0

Ventilation refers to how much air is breathed in and out in one minute

During exercise, how much air we breath increases significantly, becoming 15-30 times greater than at rest (4-15 litres)

Question 1

What mechanisms in the respiratory system are responsible for the acute responses to exercise?

Answer 1

Ventilation and diffusion

Question 2

What is tidal volume (TV)?

Answer 2

Tidal volume refers to how much air is inspired or expired in one breath

Question 3

What is respiratory rate (RR)?

Answer 3

The number of breaths taken in one minute

Question 4

What is a Plateau?

Answer 4

To reach a period or level where no change is observed

Question 5

What is Ventilatory threshold?

Answer 5

The point where ventilation increases at a non-linear rate

Question 6

What is the respiratory system responsible for?

Answer 6

The delivery of oxygen to, and removal of carbon dioxide from, the cells of the body

Question 7

What is diffusion?

Answer 7

The movement of molecules from an area of higher concentration to one of lower concentration

Question 8

How do we find the value of ventilation?

Answer 8

Tidal volume (TV) (how much air is inspired or expired in one breath) X respiratory rate (RR) (number of breaths taken in one minute)

Question 9

What does the circulatory system do?

Answer 9

It delivers a greater amount of oxygen and energy substrates to the working muscles in order to meet the increasing energy demands of the activity

Question 10

What is stroke volume (SV)?

Answer 10

The amount of blood ejected by the left ventricle per beat

Question 11

What is hear rate (HR)?

Answer 11

The number of times the heart beats in one minute

Question 12

What is cardiac output (Q)?

Answer 12

The amount of blood pumped out of the heart in one minute

Question 13

How do we find the value of cardiac output (Q)?

Answer 13

Hear rate (HR) (beats per minute) X stroke volume (SV) (litres per beat)

Heart rate X stroke volume

Question 14

What happens to blood pressure during exercise?

Answer 14

During exercise the increase in cardiac output results in an increase in blood pressure.

Question 15

What is systolic blood pressure?

Answer 15

Pressure in the arteries following contraction of ventricles as blood is pumped out of the heart

Question 16

What is diastolic blood pressure?

Answer 16

Pressure in the arteries when the heart relaxes and ventricles fill with blood

Question 17

What do strengthening exercises result in?

Answer 17

A greater increase in systolic and diastolic blood pressure, but changes in cardiac output and heart rate are less

Question 18

What is venous return?

Answer 18

Venous return is the rate of blood flow back to the heart. (It can limit cardiac output)

As the heart can eject only as much blood as it has in its ventricles, it is important for an increase in cardiac output to be accompanied by an increase in venous return.

Question 19

Venous return is increased during exercise by three mechanisms:
1- the muscle pump

Answer 19

The muscle pump is a result of the mechanical pumping action causing pressure on the veins by the surrounding muscles.

• This squashes the veins forcing the blood to flow through them toward the heart.
• The valves in the vein stop the blood from flowing backwards.

Question 20

Venous return is increased during exercise by three mechanisms:
2- respiratory pump:

Answer 20

The respiratory pump uses a similar mechanical action to assist venous return.
-During inspiration the diaphragm increases abdominal pressure, and the veins in the thorax and abdomen are emptied toward the heart.

Question 21

Venous return is increased during exercise by three mechanisms:
3- venoconstriction:

Answer 21

Venoconstriction is a reflex controlled the CNS. It reduces the capacity of the venous system, forcing blood to be pushed toward the heart.

Question 22

What happens to blood volume in aerobic exercise?

Answer 22

It decreases

Question 23

What happens regarding Increased blood flow in exercise?

Answer 23

Blood is directed away from non-essential organs (spleen, liver, kidneys, stomach) to the working muscles

Question 24

Increased blood flow: skeletal capillaries open up and serve three main purposes

Answer 24

1- allow for increases in total muscle blood flow 2- deliver large blood volume with minimal increase in blood flow velocity 3- increase the surface area to increase diffusion rates ~it allows greater delivery if oxygen to meet metabolic demands of energy

Question 25

Redistribution of blood flow: Vasoconstriction occurs in the arteriolar supplying the inactive areas of the body

Answer 25

Vasoconstriction is a decrease in the diameter of a blood vessel, resulting in a decrease in blood flow to the area supplied by the blood vessel

Question 26

Redistribution of blood flow: Vasodilation occurs in the arterioles supplying the working muscles

Answer 26

Vasodilation is an increase in the diameter of the blood vessel, resulting in an increase in blood flow to the area supplied by the blood vessel

Question 27

What is Oxygen consumption (VO2).

Answer 27

Oxygen consumption is the volume of oxygen that can be taken up and used by the body. As intensity of exercise increases so does oxygen consumption.

Question 28

What is arteriovenous oxygen difference (a-vo2 diff)

Answer 28

The difference in oxygen concentration in arterioles compared with venuoles

Question 29

What need to happen when exercise begins?

Answer 29

The muscular contractions responsible for movement need to increase

Question 30

What are the mechanisms responsible for the acute responses to exercise in the respiratory system?

Answer 30

``` ~Oxygen consumption ~a-VO2 difference ~cardiac output ~venous return ~blood pressure ~ redistribution of blood flow ```

Question 31

What is a Motor unit recruitment?

Answer 31

A motor neuron and the muscle fibres it stimulates (the central nervous system communicating with the muscles to control muscular contractions)

Question 32

How will a motor unit contract?

Answer 32

A motor unit will contract maximally or not at all, depending on the strength of the stimulus (this is the all or nothing principle). Increasing the frequency of the messages will also increase the force produced in the muscle.

Question 33

What are energy substrates?

Answer 33

Energy substrates include 1- Adenosine triphosphate (ATP) 2- Adenosine diphosphate (ADP) 3- Phosphocreatine (PC)

Question 34

What is Adenosine triphosphate (ATP)?

Answer 34

A chemical compound made up of adenosine and 3 phosphate molecules

Question 35

what is Adenosine diphosphate (ADP)?

Answer 35

A chemical compound made up of adenosine and 2 phosphate molecules

Question 36

What is Phosphocreatine (PC)?

Answer 36

A chemical fuel (also called creatine phosphate or CP) consisting of a bound phosphate and creatine molecule

Question 37

What is the immediate source of energy for all muscular contractions?

Answer 37

ATP

Question 38

What is used to produce ATP?

Answer 38

Glycogen is used in both anaerobic and aerobic respiration

Question 39

What is the result of exercise?

Answer 39

- decrease in all fuel levels within the muscle - ATP, PC, intramuscular triglyceride concentration and muscle glycogen levels decrease - glycogen content decreases more rapidly with endurance activities compared to high-intensity sprint activities

Question 40

Lactate

Answer 40

As exercise starts, large amounts of lactate are released from the muscle due to anaerobic production of ATP

Question 41

What is lactate inflection point (LIP)?

Answer 41

The exercise intensity beyond which lactate production exceeds removal causing it to build up, sometimes referred to as lactate threshold

Question 42

What happens to Body temperature when we exercise?

Answer 42

As we convert chemical energy (fuel) into chemical energy (movement) heat is created as a by product. Heat production is increased and so is body temperature. At high intensities blood vessels vasoconstrict

Question 43

What is Steady state?

Answer 43

When oxygen supply = oxygen demand

Question 44

What mechanisms are responsible for the acute responses to exercise in the muscular system?

Answer 44

~Temperature ~motor recruitment ~energy substrates ~lactate

Question 45

What is steady state?

Answer 45

When oxygen consumption = oxygen demand