1
What structures make up the gas exchange system in humans?
Cartilage rings
Trachea
Bronchi
Larynx
Intercostal
Muscles
Alveoli
Diaphragm
Ribs
Bronchioles
Trachea: Moves air from outside the body to inside the lungs. Also called the windpipe
Cartilage rings: C-shaped rings that hold open the trachea.
Bronchi: The trachea splits into two bronchi, that lead into each lung.
Bronchioles: The bronchi split into many smaller tubes that take air throughout the lungs.
Ribs: Bones that protect the lungs from damage.
Alveoli: At the ends of the bronchioles, where gas exchange takes place.
Intercostal muscles: The muscle between the ribs.
MHS Year 10 Science - BIOLOGY 2025
How does air, containing oxygen, get into and out of the lungs?
Breathing in: Diaphragm contracts and moves down, intercostal muscles contract
and move ribs up and out = more space in the chest = air moves in.
Breathing out: Diaphragm relaxes and moves up, intercostal muscles relax and
move ribs down and in = less space in the chest = air moves out.
Carbon dioxide needs to be breathed out as it is toxic and will kill cells.
Oxygen needs to be breathed in as it is needed by all cells to release energy from food (respiration)
What structures make up the human circulatory system?
The heart has 4 chambers, two atrium at the top and 2 ventricle at the bottom.
There is a left and right side of the heart. The left side has thicker muscle than the right as it pumps blood a greater distance than the right side. The septum is the muscle between the two sides.
There are 3 types of blood vessels. Arteries take blood away from the heart, veins that take blood towards the heart and very thin capillaries join the arteries and veins.
Blood is made of a liquid called plasma and blood cells. There are three types of blood cells, red blood cells (carry oxygen) white blood cells (prevent disease) and platelets (form blood clots).
5
What does the heart look like?
Aorta
Right Vent
sorrenated
3
Where does oxygen get into the blood?
Air containing lots of oxygen is breathed in. The air travels down the trachea, bronchi, bronchioles to the alveoli.
Gas exchange takes place in the alveoli. Oxygen is needed by all cells for respiration. Oxygen moves from the air in the alveoli into the blood in the capillaries surrounding the alveoli.
Carbon dioxide is made during respiration and is toxic. It is removed from the blood as it travels past the alveoli. It is removed from the body when we breathe out
Updated 4d ago