1.2.6 the respiratory system

Question 1

functions of the respiratory system (5)

Answer 1

1. Brings air from the atmosphere into the lungs
2. Transfer oxygen into the bloodstream
3. Removes carbon dioxide from the blood
4. Expels heat and water vapour in the air breathed out
5. Creates speech as air is breathed out over the voice box (larynx)

Question 2

in a nutshell, the respiratory system…

Answer 2

can be simply put as the system that takes in 02, utilizes it in the body, and removes CO2.

Question 3

Nasal Cavity

Answer 3

The nose is the initial pathway from the air outside the body. Air is warmed and moistened in the nose, to be more readily used by the body’s interior.

Question 4

Pharynx

Answer 4

Section of the throat where the backs of the mouth and nose combine. Food goes to the oesophagus and air goes to the larynx.

Question 5

Larynx

Answer 5

males Adam’s apple. Contains vocal cords that create the voice as air passes through.

Question 6

Trachea

Answer 6

Often referred to as the windpipe. Sits mostly behind the sternum, providing a well-protected medium for the passage of air to the lungs

Question 7

Bronchi

Answer 7

The trachea divides into two bronchi, each bronchus feeds into the lungs.

Question 8

Bronchioles

Answer 8

Each bronchus sub-divides into a series of sub-dividing bronchioles.

Question 9

The alveoli

Answer 9

These are the ’leaves’ of the tree. Microscopic cup-shaped sacs at the ends of the smallest bronchiole. Alveoli are only one cell thick and surrounded by capillaries and are the site for gas exchange.

Question 10

the pleura

Answer 10

each lung is covered in pleura.
the gap between the membrane and each lung is filled with fluid that allows the lung to expand and contract with each breath, with minimal friction between the lung and its surrounding body tissue.

Question 11

the diaphragm

Answer 11

this involuntary or smooth muscle contracts and relaxes to aid breathing.
As the diaphragm moves up and down, the chest cavity decreases and increases in size, causing breathing (inspiration and expiration)
a blow to the diaphragm in sport, causes it to spasm. this is known as being winded.

Question 12

inspiration

Answer 12

The movement of air from the external environment into the lungs (The act of breathing in)

Question 13

mechanics of breathing in

Answer 13

Humans breathe in actively by contracting the intercostal muscles and the diaphragm
When the intercostal muscles contact, the ribs move upwards and outwards and at the same time the diaphragm contracts downwards.
This increases the size of the thoracic cavity and space within the lungs
This causes the pressure within the lungs to decrease to less of that than the air outside.
Gases always move from areas of higher pressure to lower pressure, so it moves into the lungs quickly.

Question 14

expiration

Answer 14

The movement of air out of the lungs into the external environment. (The act of breathing out)

Question 15

mechanics of breathing out

Answer 15

Is passive and occurs in response to the intercostal and diaphragm muscles relaxing
When this happens the ribs drop & the diaphragm adopts its relaxed dome-like shape in the thoracic cavity
The space inside the lungs decreases
Air pressure increases until it exceeds that of the air outside of the body and air is exhaled or expired.

Question 16

Tidal volume (TV)

Answer 16

The amount of air inhaled & exhaled per breath. (during exercise this increases in order to supply more oxygen to the blood and deliver to the working muscles. More oxygen is breathed in each breath.)

Question 17

Respiratory rate (RR)

Answer 17

the number of breaths per minute. (during exercise, this increases due to increased demand for oxygen and need for removal of carbon dioxide)

Question 18

Ventilation (V)

Answer 18

is the amount of air breathed in (inspiration)and out (expiration) for 1 minute V = TV + RR
(during exercise, this increases due to increase in RR and TV)

Question 19

gaseous exchange

Answer 19

THIS IS HOW THE CARDIOVASCULAR SYSTEM AND RESPIRATORY SYSTEM WORK TOGETHER. gases are exchanged through diffusion at the alveoli/capillary interface and at the muscles.

Question 20

diffusion

Answer 20

involves the movement of gas from an area of higher concentration to an area with a lower concentration
(during exercise, diffusion capacity increase to allow greater amounts of oxygen and carbon dioxide to be exchanged)

Question 21

pulmonary diffusion

Answer 21

Pulmonary diffusion is the gaseous exchange that occurs in the lungs. This has two main functions:

• To provide the blood with oxygen before the blood is transported to the muscles and other cells within the body.
• To remove carbon dioxide from the blood returning from the muscles and other cells.

Question 22

movement of gases in pulmonary diffusion

Answer 22

Oxygen moves from the alveoli into the blood and carbon dioxide moves from the blood to the alveoli.
The blood supplying the lungs and alveoli makes up a part of the pulmonary circuit.
The CO2 removed from the blood and transferred to the alveoli is exhaled with each breath.
The O2 rich blood in the capillaries continues flowing back to the heart and that blood is pumped to the rest of the body to provide O2.

Question 23

Exchange of gases at the muscle (cell) site

Answer 23

At the muscle (cell) site, the concentration of gases inside and outside the capillaries is the reverse of those in the lungs.
Oxygen-rich blood is transported to the muscles in response to the increase demand of oxygen for energy production.

Question 24

The respiratory system and physical activity

Answer 24

many changes are undergone during exercise, these changes all revolve around the greater demand for oxygen to be delivered to the working muscles to create energy and the associated removal of wastes.

Question 25

Oxygen deficit

Answer 25

Temporary shortage of oxygen in cells, occurs at the start of exercise, where oxygen demand is are greater than the bodies ability to supply it.

Question 26

Steady-state

Answer 26

the point during exercise where oxygen supply meets the oxygen demand.

Question 27

VO2 max

Answer 27

The maximum amount of oxygen taken up, transported and utilised per minute.

Question 28

EPOC

Answer 28

excess post-exercise oxygen consumption. Another word for oxygen debt.

Question 29

AVO2 difference

Answer 29

Is an indication of the difference between the oxygen levels in the arteries compared to the oxygen levels in the veins.
(during exercise, a-VO2 diff will increase as the muscles extract more oxygen from the blood flowing through them)

Question 30

oxygen uptake during exercise

Answer 30

Increases due to the greater demand for oxygen by the muscles. This increase is linear, but will not increase further than max levels of VO2 max are achieved.

Question 31

brain control over breathing

Answer 31

• breathing is controlled by the respiratory centre located in the brain stem
• constantly monitors o2 and co2 in the bloodstream and adjusts breathing to maintain balance and homeostasis