Human Health +Systems

Question 1

Ingestion/eating

Answer 1

Food is taken in by the body

Question 2

Digestion

Answer 2

Food is broken down

Question 3

Absorption

Answer 3

Digested food passes into the bloodstream

Question 4

Assimilation

Answer 4

Using the food in the cells of the body

Question 5

Elimination

Answer 5

Getting rid of undigested food

Question 6

Physical digestion

Answer 6

Mouth ( teeth) and stomach (churning)

Question 7

Chemical digestion

Answer 7

Uses enzymes to break food down

Question 8

Chemical digestion

Answer 8

Enzymes are chemicals that speed up reactions

Question 9

Enzymes

Answer 9

Involves the use of chemicals to brak down water

Question 10

Enzymes

Answer 10

Are chemicals that speed up reactions without being used up in the reaction

Question 11

Substrate

Answer 11

Enzymes act on a substrate and breaks down into a product

Question 12

Plasma

Answer 12

Liquid part of the blood,pale yellow-mostly water,function:to transport chemicals to the heart
Chemical ( useful): food hormones
Chemical (waste): CO2,salts,urea
Heat:Generated from chemical reactions transported around to maintain 37c

Question 13

Red blood cells

Answer 13

Round,flattened discs,curve inward near centre
Small, no nucleus, formed in bone marrow
Very numerous-approx 5million per drop blood
Function: transport oxygen to cells
Red colour comes from haemoglobinthey contain
Haemoglobin picks up oxygen in the lungs
It later releases it in other parts e.g muscle

Question 14

White blood cells.

Answer 14

Larger then red blood cells
No definition shape- can change shape
They are ade in bone marrow
Some can surround micro-organisms and destroy them

Question 15

Platelets

Answer 15

Smaller than red or white blood
cells
• They are formed in the bone
marrow
• They are formed from larger
cells breaking down into pieces
When a blood vessel is injured, platelets help to form a clot

Question 16

System of tubes +pump

Answer 16

Blood being a fluid, needs tubes in
which to flow
• These tubes are called blood
vessels
• They come in three main types:
– Arteries
– Veins
– Capillaries
• Good blood flow requires the aid of a good pump
• In the human circulatory system this pump is the heart
• In an average lifetime, the heart beats more than 2.5 billion
times, without ever pausing to rest

Question 17

Arteries

Answer 17

Carry blood AWAY from the heart
• Flow of blood is strong and at high pressure
• Artery walls are thick and strong to withstand this
pressure
• Blood is under pressure – forced to move in one direction
• There is no need for valves in arteries to prevent
backwards flow
• All arteries (except pulmonary artery) carry oxygenated blood

Question 18

Veins

Answer 18

• Carry blood BACK to the heart
• Flow of blood is weaker and pressure is low
• Vein walls are thinner and weaker than artery walls
• Pressure is low, so there is a danger of backward flow of
blood, especially when flow direction is against gravity
• Valves in veins at regular intervals, allow blood to flow
forwards, but prevent reverse flow
• All veins (except pulmonary vein) carry deoxygenated blood

Question 19

Capillaries

Answer 19

• These are tiny blood vessels
• There are a huge number of them in the body
• Capillaries are found between arteries and veins
• Capillaries have very thin walls which allow materials t

Question 20

The heart

Answer 20

• Is an organ about the size of a
clenched fist
• Function: pumps blood around
the body
• It pumps blood by contracting
periodically
• Cardiac muscle provides the
contraction
• Unlike regular muscle, cardiac muscle doesn’t tire easily
• Resting heart rate in adults is about 72 bpm(beats per minute)
• In exercise, the heart beats faster, so that the blood can
carry chemicals faster around the body e.g. Oxygen

Question 21

Pulse rates

Answer 21

• Is an organ about the size of a
clenched fist
• Function: pumps blood around
the body
• It pumps blood by contracting
periodically
• Cardiac muscle provides the
contraction
• Unlike regular muscle, cardiac muscle doesn’t tire easily
• Resting heart rate in adults is about 72 bpm(beats per minute)
• In exercise, the heart beats faster, so that the blood can
carry chemicals faster around the body e.g. Oxygen

Question 22

Two blood circuits

Answer 22

• The human circulatory system has
what is known as Double Circulation
• Blood passes through the heart twice
on its journey around the body
• It consists of two circuits:
• 1: Pulmonary Circulation
– Blood leaves the heart
– goes to the lungs to become oxygenated
– returns to the heart
• 2: Systemic Circulation
– Blood leaves the heart
– travels to other parts of the body

Question 23

Structure of the heart

Answer 23

• The heart is split down the
middle into two sides by the
septum
• Each side has an upper
chamber called an atrium
(plural atria)
• Each side also has a lower
chamber called a ventricle.
• This makes a total of 4
chambers
• Valves between the upper
and lower chambers ensure
that blood only flows in one

Question 24

Left versus right

Answer 24

• Heart diagrams are
always shown as if facing
the person
• The left side of the heart
appears on the right of
the diagram, and vice
versa
• The left side of the heart always pumps oxygenated
blood (shown in red), received from the lungs, and pumps it
to the body.
• The right side always pumps deoxygenated blood (shown
in blue), received from the body, and pumps it to the lun

Question 25

Blood vessels of the heart

Answer 25

• The vena cava (veins)
bring blood from the body
into the right atrium.
• The right ventricle pumps
blood into the pulmonary
artery, which leads to the
lungs.
• The pulmonary vein returns blood from the lungs to the
left atrium.
• The left ventricle pumps blood into the aorta (an artery)
which leads to all other parts of the body.
• Both the pulmonary artery and the aorta have valves at the
base to prevent blood flowing back into the heart.