Science 9A2 Test - Human Health and Work

Skeleton

The supporting structure of an organism. Functions: support (to stay upright), protection of organs, movement (attached to muscles)

Joint

Structure where two bones are linked together. Most allow different parts of the skeleton to move. Different types allow different movement.

Tendon

Tissue that attaches bones to muscles

Ligament

Tissue that connects two bones

Vein

Blood vessels that carry blood towards the heart. They have thin walls and are closer to the surface of the skin

Artery

Blood vessels that carry blood away from the heart. They have thick walls because blood pressure is higher

Capillary

Tiny blood vessels where gas exchange takes place

Valve

Structures that only allow blood to flow in one direction

Trachea

The windpipe. Air passes through here from the mouth

Bronchi

The trachea divides into bronchi which carry air into the lungs

Bronchiole

The bronchi divides into smaller tubes in the lungs called bronchioles

Muscles

They work by contracting, in pairs that pull the opposite direction of each other (antagonistic pairs)

Vena Cava

Returns deoxygenated blood from body

Septum

Separates two sides of the heart

Pulmonary Artery

Carries deoxygenated blood to lungs

Aorta

Carries oxygenated blood towards the rest of the body

Pulmonary Vein

Carries oxygenated blood from lungs to heart

Blood circulation

Lungs, pulmonary vein, bicuspid valve, left ventricle, aorta, rest of body, vena cava, right atrium, tricuspid valve, septum, right ventricle, pulmonary artery, lungs

Diaphragm

Contracts, increases air pressure in the chest cavity, causing air to fill lungs

Intercostal muscles

Contract to pull ribs up and out, increasing chest volume, air fills lungs

Alveoli

Air sacs adapted to make gas exchange in lungs efficient. They have thin, moist walls with lots of capillaries. Oxygen diffuses into the bloodstream and carbon dioxide out

Pressure

the measure of force applied perpendicular to the surface of an object per unit area.

Pressure formula

P=F/A

Work

Whenever a force moves an object e.g lifting a bag. Measured in joules

Work formula

Work done=force*distance (measured in J

Permanent magnet

A magnet made from magnetic materials

Induced magnet

Becomes a magnet when placed in a magnetic field

Magnetic field

the area around a magnet where a magnetic force acts on another magnet or magnetic material. Points from north to south.

Electromagnet

A temporary magnet where the magnetic field is produced by an electric current

Magnetic elements

Iron, nickel, cobalt

Hooke's Law

F=Ke (F applied force in N, K is the spring constant in N/m, e is extension is m)

Effects of smoking

Smoking damages the cilia, leading to a buildup of mucus and smoker’s cough, damages the walls of alveoli so they join together, decreasing the efficiency of gas exchange. Smoking also increases the risk of lung cancer and other respiratory diseases.