1: Gas exchange

gas exchange

The transfer of gases between an organism and its environment.

lungs

The organ in which gas exchange takes place.

ribs

Bones which surround the lungs to protect them and form the rib cage.

respiratory system

Organ system which replaces oxygen and removes carbon dioxide from the blood.

Label the diagram

nose, trachea, ribcage, muscle, heart, lung, bronchus, bronchiole, alveolus (air sac), rib, diaphragm

trachea

Tube which carries air from the mouth and nose to the lungs.

bronchus

One of the two tubes which carry air into the lungs.

bronchiole

Small tube in the lung.

alveoli

Small air sacs found at the end of each bronchiole where gas exchange takes place with the blood.

breathing

The movement of air in and out of the lungs.

inhale

Breathing in, to take in oxygen.

respiration

* Process that transfers energy in plants and animals
* Glucose reacts with oxygen to make carbon dioxide and water

exhale

Breathing out, to remove carbon dioxide.

condense

The change of state from gas to liquid.

State the step by step process of respiration.

1. Air enters body through mouth and nose.
2. Air moves down trachea (windpipe) - a large tube.
3. Air moves down a bronchus - a smaller tube.
4. Air moves through a bronchiole - a tiny tube.
5. Air moves into alveolus - air sac.
6. Oxygen diffuses into blood.

Which specific features of the alveoli aid gas exchange? ie. their adaptations

* Millions of alveoli
* Create large surface area
* Thin walls - one cell thick
* Gas exchange can occur quickly and easily

Why do we breathe in and out?

* Breathing - movement of air in and out the lungs
* When we breathe, we inhale to take in oxygen
* Oxygen in used in respiration to transfer energy
* Respiration produces carbon dioxide, which must be removed from the body
* When we breathe out, we exhale to remove carbon dioxide

What determines how fast you breathe?

Amount of oxygen required by body cells

How does exercise impact the amount of oxygen your body requires?

* More oxygen required during exercise
* Harder you exercise → faster breathing rate → greater volume of breathing
* Allows you to take in the oxygen you need to respire more
* Transfers more energy to muscle cells

State how much nitrogen, oxygen, carbon dioxide and other gases are present in inhaled air.

* Nitrogen: 78%
* Oxygen: 20.96%
* Carbon dioxide: 0.04%
* Other gases: 1%

State how much nitrogen, oxygen, carbon dioxide and other gases are present in exhaled air.

* Nitrogen: 78%
* Oxygen: 16%
* Carbon dioxide: 4%
* Other gases: 2%

Why does a cold mirror steam up when you breathe on it?

* Water vapour in the air you breathe out condenses on the cold surface