The Respiratory System 1.2

Question 1

Define respiration

Answer 1

The taking in of oxygen and the removal of carbon dioxide

Question 2

What does respiration include?

Answer 2

• Ventilation- getting air into and out of the lungs
• External respiration- gaseous exchange between the lungs and the blood
• Transport of gases
• Internal respiration- exchange of gases between the blood in the capillaries and the body cells
• Cellular respiration

Question 3

What is the order of the passage of air?

Answer 3

Nose/mouth
Larynx
Trachea
Bronchi
Bronchioles
Alveoli

(nearly lobbed the ball brilliantly again)

Question 4

Define diffusion

Answer 4

The movement of gas molecules from an area of high concentration to an area of low concentration

Question 5

Define gaseous exchange

Answer 5

Movement of oxygen from the air into the blood and carbon dioxide from the blood into the air

Question 6

What are the 3 properties of the alveoli that help during gaseous exchange?

Answer 6

B-Big surface area
O-One cell thick
G- Good blood supply

Question 7

When inspiring what muscles are used at rest and when exercising?

Answer 7

Inspiration
Muscles used during breathing at rest:
* Diaphragm
* External intercostals

Muscles used during exercise:
Diaphragm
External intercostals
Sternocleidomastoid
Scalenes
Pectoralis major

Question 8

When expiring what muscles are used at rest and when exercising?

Answer 8

Expiration
Muscles used during breathing at rest:
* Diaphragm
* External intercostals

Muscles used during exercise:
* Internal intercostals
* Abdominals

Question 9

What is tidal volume?

Answer 9

Volume of air breathed in or out per breath

Question 10

What is your inspiratory reserve volume?

Answer 10

Volume of air that can be forcibly inspired after a normal breath

Question 11

What is your expiratory reserve volume?

Answer 11

Volume of air that can be forcibly expired after a normal breath

Question 12

What is your residual volume?

Answer 12

The amount of air that remains in the lungs after maximal expiration

Question 13

Explain gaseous exchange at the alveoli

Answer 13

The partial pressure of oxygen (po2) in the alveoli (100mmHg) is higher than the partial pressure of oxygen in the capillary blood vessles (40mmHg)

This is because oxygen has been removed by the working muscles so its concentration in the blood is lower & therefore so is its partial pressure

The bigger the concentration/diffusion gradient the faster diffusion will be

Oxygen will diffuse from the alveoli into the blood until the pressure is equal in both

Question 14

What are the two diffusion pathways of oxygen and carbon dioxide?

Answer 14

Diffusion pathway of oxygen:
Alveoli- Blood- Muscles

Diffusion pathway of carbon dioxide:
Muscles- Blood- Alveoli

(opposites)

Question 15

Explain gaseous exchange at the muscles.

Answer 15

In the capillary membranes surrounding the muscle the partial pressure of oxygen is 40mmHg and it is 100mmHg in the blood

Diffusion occurs until equilibrium is reached

Conversley the partial pressure of carbon dioxide in the blood (40mmHg) is lower than in the tissues (46mmHg) so again diffusion occurs & CO2 moves into the blood to be transported to the lungs

Question 16

What are the 3 factors involved in the reguation of pulmonary ventilation?

Answer 16

Neural control
Chemical control
Hormonal control

Question 17

What is neural control and chemical control?

Answer 17

Neural control involves the brain and the nervous system
Chemical control is concerned with blood acidity

• When blood acidity is high the brain is informed and it sends impulses through the nervous system to increase breathing

Question 18

What is pulmanory ventilation?

Answer 18

• Pulmonary ventilation is breathing

The nervous system controls this automatically through two systems: The sympathetic and parasympathetic

Question 19

What do the sympathetic and parasympathetic nervous system do?

Answer 19

Sympathetic- Prepares body for exercise so it will increase breathing rate

Parasympathetic- Lower breathing rate, heart rate

The respiratory system in the medulla oblongata of the brain controls the rate and depth of breathing and uses both neural and chemical control

Question 20

What does the inspiratory centre do?

Answer 20

Sends out nerve impluses via the phrenic nerve to the inspiratory muscles (diaphragm& intercostals) to cause them to contract
impulse lasts for approx 2 seconds and then the impulses stop and passive expiration occurs due to the elastic recoil of the lungs

Question 21

What other factors affect neural control of breathing?

Answer 21

Mechanical factors- Proprioceptors are sensory receptors located in the joints and muscles that provide feedback to the respiratory centre to increase breathing during exercise

Baroreceptors- a decrease in blod pressure detected by baroreceptors in the aorta & cartoid arteries results in an increase in breathing rate

Stretch receptors- During exercise lungs stretched more
Stretch receptors prevent over inflation of the lungs by sending impulses to the expiratory centre & then down the intercostal nerve to the expiratory muscles so that expiration occurs

Question 22

What is the order of neural/chemical control for inspiration?

Answer 22

Receptors- Medulla- Phrenic Nerve- Diaphragm & External Intercostals

Question 23

# #

What is the order of neural/chemical control for expiration?

Answer 23

Receptors- Medulla- Intercostal nerve- Abdominals & internal intercostals

Question 24

What is adrenaline?

Answer 24

The hormone that increases breathing rate in preparation for exercise

Question 25

How do adrenaline & exercise correlate?

Answer 25

Just before we start exercise the brain sends impulses to the renal glands which respond and pump adrenaline into the blood in anticipation of the increased need for oxygen & carbon dioxide exchange
As a result breathing rate increases in preparation for exercise and the demand to take in more oxygen and remove more carbon dioxide

Question 26

What effects can smoking have on the respiratory system?

Answer 26

Cause irritation of the trachea and bronchi

Reduces lung function & increases breathlessness caused by the swelling & narrowing of the lungs airways

Damages cell lining the trachea bronchi & bronchioles- these tiny cells have cillia on their surface which help to push mucus out of the lungs- when they are damaged excess mucus builds up in the lung passages leading to a smokers cough to try & get rid of the mucus

Damages alveoli as their walls break down & join together forming larger air spaces than normal reducing efficiency of gaseous exchange which also increases risk of COPD

Question 27

What are the impacts of smoking on performance?

Answer 27

Decreases supply of O2 to muscles
Decreases efficiency of respiratory system
Impairs performance
Reduces respiratory health

Question 28

What is minute ventilation?

Answer 28

The volume of air inhaled or exhaled from the lungs per minute

Question 29

What is COPD?

Answer 29

Chronic obstructive pulmonary disease
A chronic and debilitating disease & the name for a collection of diseases such as emphysema

It is a long term progressive disease of the lungs that causes shortness of breath

Question 30

The respiratory centre has two main areas, what are they?

Answer 30

Inspiratory centre- Responsible for inspiration and expiration
Expiratory centre- Stimulates the expiratory muscles during exercise