Introduction to the Respiratory System

Question 1

State the functions of the respiratory system

Answer 1

• gas exchange
• acid base balance
• protection from infection
• communication via speech

Question 2

What is meant by ‘gas exchange’?

Answer 2

Acquiring oxygen and removing carbon dioxide ie
oxygen from air -> blood
CO2 from blood -> air

Question 3

Describe the importance of gas exchange

Answer 3

When producing energy oxygen is burned and CO2 is produced => oxygen must be acquired and CO2 removed to allow respiration to continue/maintain homeostasis

Question 4

What is the cardiovascular system responsible for?

Answer 4

• transporting oxygen to tissues

- transporting CO2 away from tissues

Question 5

Describe how the integration of CV and Respiratory systems satisfy the energy demand by working muscles

Answer 5

Resp: Rate and depth of breathing increases
=> speeds up substrate (O2) acquisition
=> speeds up waste (CO2) disposal

CV: heart rate and force contraction increases => speeds up substrate delivery to muscles via blood
=> speeds up waste removal via blood

Question 6

Describe the importance of the integration of the respiratory system and the cardiovascular system

Answer 6

Allows movement of gases between the air and the body’s cells

Question 7

Define external respiration

Answer 7

Occurs in the lungs where oxygen diffuses into the blood and carbon dioxide into the alveolar air to be expelled.

Question 8

Describe the direction of blood flow in the Pulmonary Artery

Answer 8

Blood travels AWAY from the heart

Question 9

Describe the direction of blood flow in the pulmonary vein

Answer 9

Blood travels TOWARDS the heart

Question 10

Describe how pulmonary circulation differs from systemic circulation

Answer 10

Pulmonary circulation is opposite in functions to systemic circulation
PC - delivers CO2 to the lungs and picks up O2
SC - delivers O2 to body tissues

Question 11

Where does gas exchange occur?

Answer 11

The lungs and systemic capillaries

Question 12

Describe the movement of oxygen and carbon dioxide during gas exchange at the lungs

Answer 12

O2 moves from inspired air to blood

CO2 moves from blood to air which is then expired

Question 13

Describe the movement of oxygen and carbon dioxide during gas exchange at the systemic capillaries

Answer 13

O2 moves from blood to cells

CO2 moves from cells to blood

Question 14

Describe how the steady state of gas exchange allows supply to meet the demand

Answer 14

The net volume of O2 exchanged in the lungs per unit of time is equal to the net volume exchanged in the tissues. Same for CO2

Question 15

What does the steady state of gas exchange prevent?

Answer 15

Gas build up in the circulation = would impede gas exchange

Question 16

State the average volumes of O2 and CO2 exchanged per minute

Answer 16

250 ml O2 consumed

200 ml CO2 produced

Question 17

State the average breathing rate for an adult at rest and at maximum exercise

Answer 17

10-20 breaths/min @ rest

40-45 breaths/min @ max exercise

Question 18

State the components of the upper respiratory tract

Answer 18

• mouth
• vocal cords
• nasal cavity
• larynx
• pharynx

Question 19

Describe the components of the lower respiratory tract

Answer 19

• trachea
• bronchi
• lungs

Question 20

Describe the location of the the lower resp tract

Answer 20

• Enclosed in the thorax

- bounded by the ribs, spine and diaphragm

Question 21

Describe the branching of the airways

Answer 21

The trachea branches into two bronchi, one to each lung.

Each bronchus branches 22 more times each terminating in a cluster of alveoli.

Question 22

Describe how the patency of airway is maintained in semi rigid tubes

Answer 22

C-shaped rings of cartilage

Question 23

Describe how the patency of the airways is maintained in tubes with no cartilage

Answer 23

Physical forces in the thorax

Question 24

Describe the structure and function of alveoli

Answer 24

• site of gas exchange
• elastic fibres - recoil
• thin walls
• made up of Type I️ and type II pneumocytes
  
  • Type I️ cover 97% alveolar surface
  • simple squamous epithelium
  • gas exchange
  • Type II are surfactants (reduce surface tension between a two liquids or liquid and gas
  • made up of phospholipids and protein
  • reduces work of breathing

Question 25

Describe the relationship between resistance to air flow and airway diameter

Answer 25

The smaller the airway diameter the greater the resistance to airflow

Question 26

Describe the effects of contraction and relaxation of airway diameter on resistance to air flow

Answer 26

Contraction decreases diameter = increases resistance to air flow

Relaxation increases diameter = decreases resistance to air flow

Question 27

Describe the lining of the respiratory tract

Answer 27

• epithelium (pseudo-stratified, ciliated, columnar)
• glands
• lymph nodes
• blood vessels
• mucous

Question 28

Describe the changes in the lining of respiratory tract in the progression from nose to alveoli

Answer 28

• epithelium becomes more squamous
• cilia lost
• mucous cells lost (before cilia)

Question 29

Describe the structure and function of mucous

Answer 29

• moistens air
• traps particles
• provides large surface are for cilia to act on
• goblet cells
• subepithelial cells

Question 30

Describe systemic circulation

Answer 30

Movement of blood from the heart through the body to provide oxygen to tissues while bringing deoxygenated blood back to the heart

Question 31

Describe pulmonary circulation

Answer 31

Occurs between the heart and the lungs, delivers CO2 to the lungs and picks up O2

Question 32

Define internal respiration

Answer 32

Occurs in tissues where oxygen diffuses into the blood into the tissue and carbon dioxide out of the tissue and into the blood