Unit 2: Cardio-respiratory Exercise Physiology

Question 1

List the principal structures of the ventilatory system:

Answer 1

1) Nose
2) Mouth
3) Pharynx
4) Larynx
5) Trachea
6) Bronchi
7) Bronchioles
8) Lungs
9) Alveoli

Question 2

Outline the functions of the conducting airways:

Answer 2

Everything except the alveoli:
1) Low resistance pathway for airflow
2) Defence against chemicals and other substances or pathogens (Cilliated cells + Mucus + White blood cells)
3) Warming and moistening the air

Question 3

Where and how does low resistance pathway for airflow take place?

Answer 3

• The structural design of the conducting airways (wide diameter) minimizes resistance to airflow.
• Bronchi and bronchioles can adjust their diameter ensuring a balanced and effective airflow during rest and physical activity.

Question 4

Where and how does defence against chemicals and other harmful substances occur?

Answer 4

• Nose and throat where cilia filter the air and trap particles that are present and stop them from entering the lungs and causing infection

Question 5

Where and how does warming and moistening of air occur?

Answer 5

• As it passes through the conducting airways: Air reaches the lungs at an optimal temperature for gas exchange preventing thermal shock to the respiratory tissues
• Air is saturated with water vapor in the conducting airways, maintaining mucosal health and facilitating efficient gas exchange.

Question 6

Define Pulmonary Ventilation

Answer 6

Inflow and outflow of air between the atmosphere and the lungs (breathing)

Question 7

Define the term “Total Lung Capacity”

Answer 7

Volume of air in the lungs after a maximum inhalation
TLC = Vital Capacity + Residual Volume

Question 8

Define the term Vital Capacity:

Answer 8

Maximum volume of air that can be exhaled after maximum inhalation
VC = Tidal Volume + Expiratory reserve volume + Inspiratory Reserve Volume

Question 9

Define the term tidal volume

Answer 9

Volume of air breathed in and out in any one breath

Question 10

Define the term expiratory reserve volume

Answer 10

Volume of air in excess of tidal volume that can be exhaled forcibly

Question 11

Define the term inspiratory reserve volume

Answer 11

Additional inspired air over and above tidal volume

Question 12

Define the term residual volume

Answer 12

Volume of air still contained in the lungs after a maximal exhalation

Question 13

Explain the mechanics of ventilation during inhalation in the human lungs:

Answer 13

1) Diaphragm contracts and moves downward (thoracic cavity vertical space increases)
2) External intercostal muscles contract (raising the ribs and expanding the chest cavity)
3) Contraction creates a negative pressure diferential (Intrathoracic pressure decreases. Atmospheric pressure tuns higher than intrathoracic pressure)
4) Air moves into the lungs until intrathoracic and atmospheric pressures equilibrate.

Question 14

Explain the mechanics of breathing during expiration in the human lungs

Answer 14

1) Diaphragm relaxes and moves up
2) Internal intercostal muscles do the same by pulling the ribs downward and inward
3) Interthoracic volume decraces
4) Interthoracic pressure increases (Atmospheric pressure is lower than Interthoracic pressure)
5) Air flows out of the lungs

Question 15

Mechanics of ventilation during exercise

Answer 15

1) Frequency of inhalation and explanation increases
2) Volume of air moves and increases
3) Accesory muscles such as pectoral is and external intercostal muscles are used for inhalation
4) Accesory muscles such as rectus abdominals and obliques are used for exhalation

Question 16

Describe the nervous and chemical control of ventilation during exercise

Answer 16

1) PH and BP decrease (detected by chemoreceptors and broreceptors)
2) Lungs stretch, detected by stretch receptors
3) Information is taken to the medulla oblongata, and the breathing and heart rate center
4) A signal passes through the spinal cord and the sympathetic nerve stimulates and increases heart rate and breathing rate (Because diaphragm contracts and expands faster)
5) Adrenal glands secrete adrenaline which increases HR and Breathing Rate whenever one feels strong emotions

Question 17

Outline the role of hemoglobin in oxygen transportation

Answer 17

98.5% of oxygen in the blood is transported by hemoglobin as oxyhemoglobin within the red blood cells
1) Protein that allows oxygen to bind to a red blood cell.
2) Contains a central Iron ion which can hold up to 4 oxygen atoms per heme.
3) Oxygen atoms are then diffused into the tissues once they reach their target.
4) While they are diffusing they are also picking back up CO2 & returning it back to lungs so you can exhale it into the atmosphere

Question 18

Explain the process of gaseous exchange at the alveoli

Answer 18

1) Blood arrives at the alveoli with a High Partial Pressure (HPP) of CO2 and a Low partial pressure (LPP) of O2 (Inside the RBC)
2) Inhaled air has a HPP of O2 and a LPP of CO2
3) O2 moves from the alveoli into the RBC and CO2 from the capillary into the alveoli by diffusion
4) CO2 is eliminated w/ exhaled air, and the blood leaves the alveoli with a HPP of O2, and a LPP of CO2