sport science topic 2

Question 1

List the principal structures
of the ventilatory system

Answer 1

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

Question 2

outline the functions of the
conducting airways.

Answer 2

• low resistance pathway for airflow
• defense against chemicals and other
  harmful substances that are inhaled
• warming and moistening the air.

Question 3

Give the definition of pulmonary ventilation

Answer 3

inflow and outflow of
the air between the atmosphere and the lungs (also
called breathing)

Question 4

Give the definition of TLC and VC

Answer 4

Total lung capacity: volume of air in the lungs after
a maximum inhalation.
Vital capacity: maximum volume of air that can be
exhaled after a maximum inhalation

Question 5

Explain the mechanics of
ventilation in the human
lungs

Answer 5

Air flows because of pressure differences between the atmosphere and gases inside the lungs.
During inhalation the intercostal muscles (between the ribs) and diaphragm contract to expand the chest cavity.
The diaphragm flattens and moves downwards and the intercostal muscles move the rib cage upwards and out. - This increases the space for the lungs.
This increase in size decreases the internal air pressure and so air from the outside (at a now higher pressure than inside the thorax) rushes into the lungs to equalize the pressures. When we exhale the diaphragm and intercostal muscles relax and return to their resting positions. This reduces the size of the thoracic cavity, thereby increasing the pressure and forcing air out of the lungs.

Question 6

Describe nervous and
chemical control of
ventilation during exercise

Answer 6

ventilation increases as a direct result of
increases in blood acidity levels (low pH) due to
increased carbon dioxide content of the blood
detected by the respiratory center. This results in
an increase in the rate and depth of ventilation.
Neural control of ventilation includes lung
stretch receptors, muscle proprioceptors and
chemoreceptors.
The role of H+
ions and reference to partial
the pressure of oxygen is not required

Question 7

Outline the role of
hemoglobin in oxygen
transportation

Answer 7

Most (98.5%) of oxygen in the blood is transported
by hemoglobin as oxyhemoglobin within red
blood cells

Question 8

Explain the process of
gaseous exchange at the
alveoli

Answer 8

1)Gases diffuse across the alveoli membrane and the blood capillaries
2)membrane 1 cell thick-> allows gases to move quickly/easily
3)gases move from a high to low partial pressure along a centration gradient
4)o2 higher partial pressure in air in alveoli compared to blood
5)co2 higher partial pressure in blood compared to air.

Question 9

State the composition of
blood

Answer 9

Blood is composed of cells (erythrocytes,
leucocytes and platelets) and plasma. Blood is also
the transport vehicle for electrolytes, proteins,
gases, nutrients, waste products and hormones

Question 10

Distinguish between the
functions of erythrocytes,
leucocytes and platelets

Answer 10

erythrocytes: Make up 40-45% of the blood volume known as hematocrit. Contain an oxygen-carrying pigment called haemoglobin, which gives blood its red color.

leucocytes: White blood cells <1% of blood volume, primarily involved in immune fuction and protecting body from infection. They do this by ingesting foreign microbes in a process called phagocytosis.

platelets: <1% of blood volume. Assist in the provess of repair following an injurt

Question 11

Describe the anatomy of the
heart with reference to the
heart chambers, valves and
major blood vessels

Answer 11

4 chambers..
Right atrium
Right ventricle
Left atrium
Left ventricle

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 12

Describe the anatomy of the
heart with reference to the
heart chambers, valves and
major blood vessels

Answer 12

4 chambers..
Right atrium
Right ventricle
Left atrium
Left ventricle

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 13

Outline the relationship
between the pulmonary and
systemic circulation

Answer 13

Pulmonary circulation: is the portion of the cardiovascular system that carries oxygen-depleted blood away from the heart and to the lungs and then returns it, oxygenated, back to the heart.

Systematic circulation: is the portion of the cardiovascular system that carries the oxygenated blood away from the heart and delivers it to the body. It also carries the deoxygenated blood after use back to the heart to be re-oxygenated.

Question 14

Describe the relationship
between heart rate, cardiac
output and stroke volume at
rest and during exercise

Answer 14

cardiac output = stroke volume x heart rate

Stroke volume
increases according to how you exercise because your body needs more oxygen and nourishment, which are both received from the blood.
increases depending on the type of physical activity you are doing and your training level.
during an upright physical activity like jogging, stroke volume increases from about 50 mL at rest to 120 mL at maximal exercise intensity.
In a trained Olympic runner, stroke volume can increase from 80 mL at rest to 200 mL during maximal exercise intensity as the heart pumps more efficiently.

Cardiac Output
because stroke volume increases, cardiac output increases simultaneously with the increase in heart rate, and the body beings to work harder

Question 15

Analyse cardiac output,
stroke volume and heart
rate data for different
populations at rest and
during exercise

Answer 15

• males
• females
• trained
• untrained
• young
• old

Question 16

Explain cardiovascular drift

Answer 16

An increase of body temperature results in a lower venous return to the heart, a small decrease in blood volume from sweating. A reduction in stroke volume causes the heart rate to increase to maintain cardiac output.

Blood viscosity, if the blood is thinker and more viscous, it makes it more difficult to be returned back (up gravity) to the heart to pick up more oxygen.

Question 17

Define the terms systolic and
diastolic blood pressure

Answer 17

systolic blood pressure: the force exerted by the blood on the arterial walls during ventricular contraction
diastolic blood pressure: the force exerted by the blood on the arterial walls during ventricular relaxation

Question 18

Discuss how systolic and
diastolic blood pressure
respond to dynamic and
static exercise

Answer 18

Why does Systolic blood pressure increase?
-Volume of blood + contraction rate a larger amount of blood is being pumped through the arteries with each contraction;

Why does Diastolic blood pressure increase?
-The pressure on the arterial walls is increased even during relaxation
-The vasoconstriction creates an increase in pressure
-Muscles squeeze the veins to promote venous return, by doing so increases pressure
-During static exercise, breathing is more constricted, there is less oxygen and more carbon dioxide, the heart must work harder to pump the blood it does have to supply the muscles with sufficient oxygen to continue the static exercise

Dynamic Exercise
Why does Systolic blood pressure increase at a lower rate?
-the breathing frequency is much higher than in static exercise, therefore the pressure is not as high as during static exercise

Why does Diastolic blood pressure remain the same?
-muscles are moving constantly, no added pressure on constant contraction
-you are constantly breathing, which allows carbon dioxide to be quickly expelled
-arteries are dilated as vasodilation is occurring

Question 19

Describe the cardiovascular
adaptations resulting from
endurance exercise training

Answer 19

Heart Adaptation
- The myocardium (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 20

Explain maximal oxygen
consumption

Answer 20

Fitness can be measured by the volume of oxygen you can consume while exercising at your maximum capacity. VO2 max is the maximum amount of oxygen in milliliters, one can use in one minute per kilogram of body weight. Those who are ‘fitter’ have higher VO2 max values and can exercise more intensely than those who are not as well conditioned.