Respiratory System

Question 0

Name each part of respiratory system and function

Answer 0

Nasal cavity: filters, warms and moistens air before lungs
Pharynx: air from nasal cavity goes through here
Epiglottis: closes off trachea so food doesn’t enter lungs
Larynx: produces voice
Bronchi: two branch from trachea/ divides into more bronchus
Bronchioles:fine tubes- alveoli at end
Alveoli: tiny sacs of air- exchange of O2 & CO2
Intercostal muscles: muscles between ribs- move rib cage
Diaphragm: muscle that separates chest from abdomen

Question 1

Main components of respiratory system

Answer 1

Airways
Lungs
Diaphragm

Question 2

Describe inspiration/inhalation

Answer 2

Diaphragm contracts
Intercostal muscles contract- pull rib cage up
Volume increases
Low pressure
Air goes into lungs to equalise pressure
More O2 / Less CO2

Question 3

Describe expiration (exhalation)

Answer 3

Diaphragm relaxes
Intercostal muscles relax
Volume decreases
Higher pressure
Air out of lungs to equalise pressure
Less O2 / More CO2 / more H2O

Question 4

Describe gas exchange

Answer 4

• blood that surrounds alveoli- brought to lungs by pulm. Arteries.
• this blood comes into capillaries around alveoli that has low conc. of O2
• O2 dissolves in moisture in inside of alveoli- diffuses through membrane- through walls of capillaries and into blood
• blood that arrives at capillaries of alveoli- high conc. of CO2
• CO2 diffuses out of blood, into air in alveolus
• expired air contains less O2 & more CO2

Question 5

Why are lungs suited to gas exchange - 5 reasons

Answer 5

• alveoli gives large internal S.A- large amount s of gas exchange
• alveoli is supplied with blood- maintains diff. in conc. grad. of O2 & CO2 in blood and air in lungs
• walls of alveoli thin- gases don’t have to travel fair in and out of blood
• positioned deep in body so-
  - prevent evaporation of fluid
  - covered by moisture- gases can diffuse in and out
• constant change in air in alveoli- diff. in conc. of O2 & CO2 in air and blood