Human Health And Systems

Question 1

Ingestion

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 blood stream

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) stomach(churning)

Question 7

Chemical digestion

Answer 7

Uses enzymes to break down food
Enzymes act on a substrate and breaks it down into a product
Enzymes are chemicals that speed up reactions without being used in a the reaction
Substrate=starch,enzyme=amylase (saliva) turns into sugar

Question 8

Plasma

Answer 8

Liquid part of the blood
Pale yellow-mostly water
Function:to transport chemicals and heat
Chemicals(useful):food,hormones
Chemicals:(waste): co2,salts,urea
Heat:generated from chemical reactions,transported around to maintain 37oC
Also carries the red blood cells,white blood cells,and platelets

Question 9

Red blood cells

Answer 9

• 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 haemoglobin
they contain.
• Haemoglobin picks up oxygen in the
lungs
• It later releases it in other parts - e.g.
muscle

Question 10

White blood cells

Answer 10

• Larger than Red Blood Cells
but fewer in number
• No definite shape – shape
can change
• They are also made in the
bone marrow
• Function : to fight infection
• Some can surround micro-organisms and destroy them
• Others produce proteins called antibodies
• Antibodies help to destroy micro-organisms such as
bacteria

Question 11

Platelets

Answer 11

• Smaller than red or white blood
cells
• They are formed in the bone
marrow
• They are formed from larger
cells breaking down into pieces
• Function: help to form blood
clots
• When a blood vessel is injured, platelets help to form a clot
• Clotting prevents loss of blood, and prevents micro-
organisms getting in
• Clots are temporary barriers while repair and healing is
taking place

Question 12

System of Tubes + Pump

Answer 12

• 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 13

Arteries

Answer 13

• 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 14

Veins

Answer 14

• 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 15

Capillaries

Answer 15

• 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 to
pass in and out with the surrounding cells and tissue.

Question 16

The heart

Answer 16

• 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 17

Pulse rates

Answer 17

• When the heart contracts, it
squeezes blood into the arteries
under pressure.
• As blood flows down the arteries,
surges of pressure can be felt where
the arteries are close to the surface
• Areas where it can be felt are:
– At the wrist
– Inner arm near elbow joint
– At the sides of the neck
• A surge of blood felt at these locations is called a pulse
• The pulse rate is at the same pace as the heart rate

Question 18

Two blood circuits

Answer 18

• 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
– returns to the heart

Question 19

Structure of the heart

Answer 19

• 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
direction

Question 20

Left versus Right

Answer 20

• 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 lungs

Question 21

Blood Vessels of The Heart

Answer 21

• 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.

Question 22

Ingredients for energy

Answer 22

• We’ve learned in
digestion that food is
absorbed into our
bloodstream and
carried around to all
the cells in our body!
• The process that
releases energy from
this food is
RESPIRATION.

Question 23

Respiration is the release of
energy from food.

Answer 23

• The equation for respiration in words is:
• Glucose + Oxygen Carbon dioxide + Water + Energy

Question 24

Aerobic respiration

Answer 24

• Aerobic Respiration needs oxygen to
release energy from food.

Question 25

Anaerobic respiration

Answer 25

• Anaerobic Respiration does not use
oxygen to release energy from food.

Question 26

How does Oxygen get to our
Cells??

Answer 26

• Oxygen is carried by the haemoglobin in
red blood cells to all other cells of the body.

Question 27

Aerobic Respiration

Answer 27

• Takes place in ALL the living cells in the
body as well as in most animal and plant
cells.

Question 28

Anaerobic Respiration

Answer 28

• Some living things can get energy from
food without using oxygen.

Question 29

Examples of anaerobic
respiration

Answer 29

• Yeast converts sugars to alcohol in
“Fermentation” – this produces alcohol for
drinks such as beers and wine!

Question 30

Breathing

Answer 30

• As you can see from the Equation Oxygen
and food are the two important things our
cells need to give us energy.
• We’ve learned how the food gets to our
cells by digestion.
• The oxygen gets to our cells by breathing!

Question 31

Nose and mouth

Answer 31

• These are the openings the air can enter
through!

Question 32

Pharynx

Answer 32

• This is the scientific name for your throat
area.

Question 33

Trachea

Answer 33

• This is the tube that leads into your lungs.
• It is very strong and is kept open by Rings
of Cartilage.

Question 34

Bronchus

Answer 34

• As we have two lungs our Trachea divides
to branch into each one.

Question 35

Bronchioles

Answer 35

• To spread out through all our lungs the
bronchi break up to even smaller little
branches called BRONCHIOLES.

Question 36

Alveoli

Answer 36

• The final place the air we breathe in goes to
in our lung is the ALVEOLI. • It is in the Alveoli that Carbon Dioxide is
brought into the lungs to be exhaled and
oxygen is brought into the body for
respiration.

Question 37

Capillary

Answer 37

• Tiny, tiny blood vessels known as
capillaries carry blood to and from the
alveoli and allow the gases to pass in and
out.

Question 38

Rib cage

Answer 38

• Our rib cage is around our lungs to protect
them.
• When we take in air the rib cage seems to
lift up to give more room for all the air. • This is able to happen because the
INTERCOSTAL MUSCLES contract
between the lungs and the DIAPHRAGM
pushes up and down.