2 - Exercise physiology

Question 1

List the principle structures of the ventilatory system

Answer 1

• Nose
• Mouth
• Pharynx
• Larynx
• Trachea
• Bronchi
• Bronchioles
• Lungs
• Alveoli

Question 2

Explain the pathway of oxygen

Answer 2

1) Oxygen rich air in breathed in through conducting airways (nasal and oral passage) and larger airways (trachea and bronchi). No gas exchange takes place here but the air is warmed, moistened and filtered by the lining of the airways.
2) Airways branch into smaller bronchioles and then into smaller air sacs called alveoli.
3) Gaseous exchange takes place here, the lungs are ideally designed for gaseous exchange

Question 3

What pressure does air travel from to pressure

Answer 3

Air will flow from areas of HIGH PRESSURE LOW PRESSURE

Question 4

Outline the functions of conducting airways

Answer 4

• Low resistance pathway of air
• Defense against chemicals and other harmful substances that are inhaled
• Warming and moistening the air

Question 5

Functions of the nose, Pharynx and Larynx :

Answer 5

Nose:Humidifies the air entering and filters particles (thanks to the Vibrissae).

Pharynx:Air then passes through the 3 parts of the pharynx which offers a low resistance path for airflow into the larynx and then finally into the trachea.

Larynx:In addition to its function as the ‘voice box’ it also protects the trachea from invasion of foods and fluids.

Question 6

Explain the mechanics of breathing in the lungs

Answer 6

• Inhalation -

Air: Air moves inwards

Pressure: Decreases

Volume: Increases

Diaphragm: Contracts and flattens

Intercostal muscles: contract

Chest cavity: Move up and outwards

• Exhalation -

Air: Air moves outwards

Pressure: Increases

Volume: Decreases

Diaphragm: Relaxes and recoils

Intercostal muscles: relax

Chest cavity: Moves down and inwards

Question 7

The mechanics of breathing during exercise effects

Answer 7

• Increase in heart rate
• rate and depth of breathing increase
• Lowers pH in the blood
• Rate and depth of breathing increase due to detection of increased CO2 levels by chemoreceptors

Question 8

Pulmonary ventilation (breathing)

Answer 8

inflow and outflow of air between the lungs and atmosphere

Question 9

Total lung capacity

Answer 9

Volume of air in lungs after maximum inhalation

Question 10

Vital capacity

Answer 10

Maximum volume of air exhaled after maximum inhalation

Question 11

Tidal volume

Answer 11

Volume of air breathed in and out in one breath

Question 12

Expiratory reserve volume

Answer 12

Additional volume of air in excess of tidal volume that can be forcefully exhaled

Question 13

Inspiratory reserve volume

Answer 13

Additional volume of air in excess of tidal volume that can be forcefully inhaled

Question 14

Residual volume

Answer 14

Volume of air still contained in the lungs after maximum exhalation

Question 15

Minute ventilation

and calculation

Answer 15

Volume of air breathed out in one minute

Minute ventilation = Tidal volume x breaths per minute

Question 16

What system is breathing controlled by and where does it report to?

Answer 16

Breathing is controlled by the nervous system, all reports to the medulla oblongata …

Question 17

The nervous control and chemical control of the ventilation system

Answer 17

Nervous:

• Stretch receptors – Prevent over-inflation of the lungs, once stretching too much they send signals to the respiratory Centre in the medulla oblongata to reduce inflation
• Proprioceptors – Detect increase in movement
• Chemoreceptors –Detect increase in blood acidity
• Baroreceptors – Detect increase in blood pressure

Chemical:

Ventilation increases as a direct result of increases in blood acidity levels (lowers PH) due to increased carbon dioxide content of blood detected by the respiratory center. This results in an increase in rate and depth of breathing.

Question 18

Hemoglobin

Answer 18

is a protein that allows oxygen to bind to a red blood cell. One Hemoglobin can hold up to 4 oxygens. These atoms diffuse into the tissue to let them receive oxygen. It returns CO2 back to the lungs.

Question 19

Oxyhemoglobin

Answer 19

A bright red substance formed by the combination of hemoglobin with oxygen.

Question 20

What percentage of oxygen in the blood is transported by hemoglobin as oxyhemoglobin within red blood cells

Answer 20

98.5%

Question 21

Homeostasis

Answer 21

Maintenance of a constant internal environment.

Gas exchange

Question 22

Gas exchange

Answer 22

The transfer of oxygen and carbon dioxide between the systems

is the delivery ofoxygenfrom the lungs to the bloodstream, and the elimination of carbon dioxide from the bloodstream to the lungs. It occurs in the lungs between the alveoli and a network of tiny blood vessels called capillaries, which are located in the walls of the alveoli.

Question 23

Gas exchange in the lungs takes place due to another passive process known as diffusion.

What pressure of air will gas move from to what pressure of air?

Answer 23

Gas will move along a gradient from HIGH LOW

Question 24

Explain the process of gaseous exchange

Answer 24

1. Air enters through the nose and mouth
2. Air travels down the trachea (has cartilage rings for structure)
3. Travels through the bronchi to the Bronchiole and into the alveoli
4. Oxygen flows into the alveoli and diffuses into the one cell thick capillary into the blood which when oxygen combines with hemoglobin in the red blood cells to create oxyhemoglobin
5. While this occurs deoxygenated blood diffuses out of the capillary into the alveoli where it is exhaled out of the body as a waste product.

• Alveoli creates a pressure gradient
• Air diffuses from high to low

Question 25

Adaptations for gaseous exchange:

Answer 25

- Walls of alveoli are one cell thick - Huge surface area allows a greater uptake of oxygen - Supplied by a dense capillary network

Question 26

State the components of blood

Answer 26

* Plasma – Transports nutrients * Red blood cells – Transport oxygen around the body and bine with hemoglobin * White blood cells – Involved in the immune function, protecting body against infection * Platelets – Help to clot blood when there’s an injury

Question 27

What is another name for red and white blood cells?

Answer 27

leucocytes - white blood cells erythrocytes - red blood cells

Question 28

Blood three main functions:

Answer 28

- Transportation - Regulation - Protection

Question 29

Myogenic contraction.

Answer 29

Meaning the heart makes itself contract. The cardiac cycle does not require nerve simulation like other muscle contractions.

Question 30

Name the 4 chambers of the heart and the 4 values in order

Answer 30

``` 4 chambers: • Right atrium • Right ventricle • Left atrium • Left ventricle ``` ``` 4 values: • Tricuspid value • Pulmonary value • Mitral value • Aortic value ```

Question 31

The pathway of blood way through the heart

Answer 31

``` Process. • Superior vena cava • Right atrium • Tricuspid valve • Right ventricle • Pulmonary valve • Pulmonary artery • Lungs (deoxygenated gets oxygenated) • Pulmonary veins • Left atrium • Mitral valve • Left ventricle • Aortic valve • Aorta ```

Question 32

Autonomic nervous system

Answer 32

Autonomic nervous system – Control involuntary bodily functions. It is made from the sympathetic and parasympathetic nervous systems. The sympathetic system stimulates the heart to beat faster. The parasympathetic system returns the heart to its resting rate. Sympathetic nervous system – Sympathetic system stimulates the heart to beat faster; due to multiple factors. During exercise, 3 receptors are stimulated; proprioceptors, baroreceptors, chemoreceptors.  = heart goes FASTER Parasympathetic nervous system When exercise stops, the receptors pick up decreases in co2 levels, blood pressure and muscle movement; hence impulses are sent to the cardiac control centre (medulla oblongata). An impulse is sent to the parasympathetic nervous system which stimulates the SA node and heart rate decreases. Hormonal Control • Adrenaline and noradrenaline are stress hormones • Released by adrenal glands • Exercise causes stress induced adrenaline response which results in: • Stimulation of SA node, which results in increased speed and force of contraction. • Increase in blood pressure due to constriction of blood vessels. • Increase in blood glucose levels (glucose is used by muscles for energy)

Question 33

The intrinsic regulation of the heart:

Answer 33

1. The peacemaker sends an impulse through the walls of the atria (left and right sides) to a group of specialized cells called atrioventricular (AV) node 2. The rapid conduction of the impulse causes the muscles in the walls of the atria to contract simultaneously. 3. Pressure increases in the atria and forcing blood through the atria, though he AV valves into the ventricles. 4. The AV valves close 5. There is a brief delay, the impulse is then conducted rapidly via a group of specialized cells called the Bundle of His. 6. These cells rapidly conduct the impulse along the very fast conducting Purkinje fibers that spread the impulse along the ventricle walls. 7. The impulse now causes the fibers in the ventricle walls to contract simultaneously, increasing the pressure in the ventricles and forcing blood up and out through the main arteries leaving the heart. 8. The semi-lunar valves are the openings into the main arteries now close 9. While the ventricles relax the cycle has already started again with the atria filling with blood returning to the heart ahead of the peacemaker firing.

Question 34

Pulmonary circulation | Systemic circulation

Answer 34

1) Pulmonary circulation – delivers deoxygenated blood from the Right side of the heart to the lungs for oxygenation ad then back to the Left side of the heart. 2) Systemic circulation – delivers the oxygenated blood from the left side of the heart to the other tissues of the body where oxygen is used up

Question 35

Cardiac output and formula

Answer 35

Cardiac output – The amount of blood the heart pumps through the circulatory system in a minute.  cardiac output = stroke volume x heart rate

Question 36

Stoke volume

Answer 36

is the volume of blood in millilitres ejected from the each ventricle due to the contraction of the heart muscle

Question 37

Explain cardiovascular drift

Answer 37

A gradual slow rise in heart rate when exercise is performed at a constant rate over a prolonged period in a hot environment. An increase of body temperature results in a lower venous return to the heart, a small decrease in blood volume from sweating. Leads to decrease in stroke volume Leads to increase to maintain cardiac output. Water loss via sweating Increase in blood viscosity

Question 38

Systolic blood pressure

Answer 38

Systolic blood pressure – Force exerted by the blood on the arterial walls during ventricular contraction.

Question 39

Diastolic blood pressure

Answer 39

Diastolic blood pressure - Force exerted by the blood on the arterial walls during ventricular relaxation.

Question 40

Static exercise

Answer 40

Static exercise – Positions in which you hold for a period of time

Question 41

Dynamic exercise

Answer 41

Dynamic exercise – Controlled movements

Question 42

Compare the distribution of blood at rest and at exercise

Answer 42

At rest: The most blood goes to the Liver, kidneys and muscles During exercise: The most blood goes to the muscles by a lot while all the rest remain low

Question 43

Cardiovascular adaptions resulting from endurance exercise training

Answer 43

Heart Adaptation - The muscular tissue of the heart increases in thickness - The left ventricles internal dimensions increase Stroke Volume - The increase in size of the heart enables the left ventricle to stretch more and thus fill with more blood. - The increase in muscle wall thickness also increases the contractility resulting in increased stroke volume at rest and during exercise, increasing blood supply to the body Resting Heart Rate - As the stroke volume increases the cardiac output can remain constant, therefore enabling the resting heart rate to be lower. Cardiac Output - Cardiac output increases exponentially during maximal exercise, because of increases stroke volume. - This results in a greater oxygen supply, waste removal and hence improved endurance performance. Muscular Adaptations - increased capillarization of the trained muscles. - improvements in the vasculature efficiency Blood  - resting blood pressure decreases as a result of improved cardiovascular factors. - increase in blood plasma - red blood cell volume and haemoglobin

Question 44

VO2 Max

Answer 44

Is the maximum amount of oxygen in millimeters you can use in one minute.Those who are fitter have a higher VO2 max.