AS PE Pulmonary Function

Question 0

When the diaphragm contracts and the chest expands during inspiration, does the pressure within the lungs increase or decrease?

Answer 0

Decreases. This allow the lungs to expand and draws air in as it travels from the high pressure of outside to a low pressure inside the lungs.

Question 1

Which two muscles are responsible for inspiration at rest?

Answer 1

Diaphragm and external intercostal muscles

Question 2

Expiration is a passive process at rest, what does this mean?

Answer 2

No energy is required as the relaxation of the diaphragm and external intercostal muscles increases the pressure within the lungs, forcing the air out.

Question 3

Which muscles are responsible for forcing the ribs and downwards and decreasing the size of the thoracic cavity during expiration when we exercise?

Answer 3

Rectus abdominis (Abdominal muscles) and internal intercostal muscles

Question 4

Other than the external intercostal muscles and the diaphragm, which 3 muscles are recruited to aid inspiration during exercise?

Answer 4

Sternocleidomastoid
Scalene muscles
Pectoralis minor

Question 5

Which control centre is responsible for adjusting breathing rate?

Answer 5

Respiratory control centre

Question 6

Which nervous system is responsible for controlling breathing rate?

Answer 6

The autonomic nervous system. It is made up of the sympathetic and parasympathetic nervous systems which speed up and slow down the breathing rate

Question 7

A nervous impulse is sent to the breathing muscles from the RCC for 2 seconds causing them to contract. Which nerve does the impulse get sent through?

Answer 7

Phrenic nerve

Sympathetic nerve

Question 8

Name at least two types of receptors which act on the respiratory control centre

Answer 8

Chemoreceptors - detect CO2
Thermoreceptors - detect temperature
Proprioceptors - detect movement at joints
Baroreceptors - detect blood pressure

Question 9

Is the partial pressure of oxygen higher in the alveolus or higher in the capillary surrounding the alveolus?

Answer 9

Higher in the alveolus. This ensures oxygen diffuses from the alveoli into the capillaries to be transported to the muscles to make energy.

Question 10

Gases always move from areas of high pressure to areas of low pressure. True or false?

Answer 10

True. Until an equilibrium is reached

Question 11

The term used to describe the movement of a gas across a semi permeable membrane is known as d……..

Answer 11

Diffusion

Question 12

Does the rate of diffusion increase, decrease or remain the same as exercise commences?

Answer 12

It increases. This is due to larger concentration gradients.

Question 13

What characteristics of the lungs make them efficient when exchanging gases between the alveoli and the pulmonary capillaries?

Answer 13

Large surface area
Layer of moisture enhances oxygen uptake
Membranes are semi permeable
Capillaries are 1 cell thick - short diffusion pathway
Haemoglobin's affinity for oxygen

Question 14

Does partial pressure of oxygen in the air increase or decrease at altitude?

Answer 14

Decrease

Question 15

Does the pressure gradient between the blood and the tissues decrease at altitude?

Answer 15

Yes as there are less oxygen particles in the same volume of air breathed in at altitude. This results in a decreased movement of oxygen from the blood into the tissues

Question 16

What is the formula HbO2 better known as?

Answer 16

Oxyhaemoglobin

Question 17

At the lungs, approximately how much of the haemoglobin is saturated with oxygen?

Answer 17

97%

Question 18

Tidal volume is the volume of air inspired and expired per breath. True or false?

Answer 18

False. It is the volume of air inspired OR expired in one breath

Question 19

What piece of equipment is used to measure lung volumes?

Answer 19

Spirometer

Question 20

What happens to tidal volume as exercise commences?

Answer 20

It increases

Question 21

What is minute ventilation?

Answer 21

Volume of air inspired or expired per minute. It is tidal volume multiplied by breaths per minute

Question 22

What happens to the inspiratory reserve volume (IRV) and expiratory reserve volume (ERV) during exercise?

Answer 22

They both decrease, enabling tidal volume to increase

Question 23

What are the sternocleidomastoid, scalene muscles and pectoralis minor used for during inspiration when we exercise?

Answer 23

They lift the ribs and sternum further so the thoracic cavity can expand and more air can fill the lungs. Resulting in deeper breathing.

Question 24

When we exercise what happens to the process of inspiration?

Answer 24

The external intercostal muscles and diaphragm contract with more force, three additional muscles are recruited to help increase the volume of the thoracic cavity, this increases the rate and depth of breathing.

Question 25

What happens to the process of expiration when we exercise?

Answer 25

It becomes an active process, the internal intercostal muscles and abdominals contract to pull the ribs down and force expiration to happen. This decreases the time it takes to breathe out

Question 26

Starting with the medulla, how does the brain control breathing at rest?

Answer 26

Inside the medulla is the RCC, it sends an impulse down the phrenic nerve to the diaphragm and external intercostals, they contract for 2 seconds, the impulse stops and they relax for 3 seconds which causes expiration to occur.

Question 27

What is the role of the chemoreceptors?

Answer 27

They are nerve cells which monitor the blood and detect a raise in carbon dioxide levels and a decrease in pH level. They send a nerve impulse to the medulla to increase rate and depth of breathing if CO2 levels are too high.

Question 28

Where are the chemoreceptors found?

Answer 28

In the aortic arch and carotid artery.

Question 29

When would a decrease in oxygen levels cause the rate and depth of breathing to increase?

Answer 29

At altitude as the air pressure is lower.
In smokers who have a decreased surface area of their lungs for diffusion.
In asthmatics as they have a reduced volume of air inspired per breath.

Question 30

What process causes increased levels of CO2 and increases in body temperature?

Answer 30

(Aerobic and anaerobic) Respiration.

Question 31

If the partial pressure of oxygen is 105mmHg in the alveolus and 40mmHg in the blood in the pulmonary capillaries, what happens?

Answer 31

Oxygen travels down the concentration gradient with is created. A high pO2 in the alveolus (104mmHg) and a low pO2 in the capillary (40mmHg) causes oxygen to diffuse across the semi permeable membrane into the capillary.

Question 32

If the partial pressure is 46mmHg in the blood in the pulmonary capillaries and 40mmHg in the alveolus, what happens?

Answer 32

CO2 travels down the concentration gradient with is created. With a high pCO2 in the capillary (46mmHg) and a low pCO2 in the alveolus (40mmHg) carbon dioxide diffuses across the semi permeable membrane from the capillary into the alveolus.

Question 33

Blood and muscle pH increase during exercise, true or false?

Answer 33

False - blood and muscle acidity increases, this decreases the pH

Question 34

What is haemoglobin?

Answer 34

It is a protein found in red blood cells and is responsible for transporting oxygen in the blood.

Question 35

What is myoglobin

Answer 35

It is a protein found in the muscle cells and is used to transport oxygen to the mitochondria. This supplies oxygen required for aerobic respiration.