Structure + Function Of Respiratory System

Question 1

Nasal cavity

Answer 1

Filters dust. Air is warmed and moistened.

Question 2

Pharynx

Answer 2

Throat
Small tube approx 10-13cm
Muscular pharynx wall
Passageway for food and air

Question 3

Epiglottis

Answer 3

Small flap of cartilage
Closes the top of trachea when u swallow
Ensures food and drink pass into stomach not lungs

Question 4

Larynx
Voice box

Answer 4

Rigid walls of muscle and cartilage
Contains vocal cords
Connects pharynx to trachea

Question 5

Trachea

Answer 5

12cm long. 2cm diameter
Contains rings of cartilage to prevent it from collapsing.
Connects larynx and bronchus providing air to and from lungs

Question 6

Bronchi

Answer 6

Carry air to lungs
Extension of trachea split into left and right

Question 7

Bronchioles

Answer 7

1mm diameter
Do not contain cartilage
Small airways that extend from bronchi and connect them to alveoli

Question 8

Alveoli

Answer 8

Gaseous exchange
Huge SA
Surrounded by dense network of capillaries
1 cell thick

Question 9

Lungs

Answer 9

Organ that allows oxygen to be drawn into the body

Question 10

Diaphragm

Answer 10

Flat muscle beneath lungs
Involved in inspiration and expiration

Question 11

Thoracic cavity

Answer 11

Chamber in chest protected by ribs and sternum

Question 12

Internal intercostal muscles

Answer 12

Lie inside ribcage
Draw ribs down and in

Question 13

External intercostal muscles

Answer 13

Lie outside ribcage
Draw ribs up and out

Question 14

Inhalation

Answer 14

External intercostal muscles contract, diaphragm flattens
Internal intercostal muscles relax so ribs go up
Ribs pulled up and out
Increases thoracic volume - expansion of lungs
Reduces pressure in lungs
Air sucked in

Question 15

Exhalation

Answer 15

Diaphragm and external intercostal muscles relax, internal intercostal muscles contract to lower ribs down and in
Decreases area of thoracic cavity
Increases pressure in lungs
Air forced out

Question 16

Characteristics of alveoli

Answer 16

One cell thick - short diffusion pathway
Large SA - more diffusion
Narrow diameter - slow passage of RBCs

Question 17

Diffusion

Answer 17

Movement of molecules from area of high concentration to area of low concentration

Question 18

Concentration gradient increases…

Answer 18

When exercising
More diffusion as higher intensity

Question 19

Gaseous exchange process

Answer 19

O2 diffuses from alveoli to capillaries through partially permeable wall
O2 attached to haemoglobin in RBCs to be carried to working muscles
CO2 diffuses from blood to alveoli where it can then go through respiratory system to be breathed out