Human Health And Systems

Question 1

Ingestion/eating

Answer 1

Food is taken 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 unnecessary food

Question 6

Physical digestion

Answer 6

Mouth teeth stomach churning

Question 7

Chemical digestion

Answer 7

Uses enzymes. Enzymes are chemicals that speed up reactions

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 37°C
• 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

Arteries

Answer 12

• 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 13

Veins

Answer 13

• 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 14

Capillaries

Answer 14

• 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 15

The heart

Answer 15

• 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 16

Pulse rates

Answer 16

• 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 17

Two blood circuits

Answer 17

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 18

Structure of the heart

Answer 18

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 19

Left versus right

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

Blood vessels of the heart

Answer 20

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 21

System of tubes + pump

Answer 21

• 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 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

Answer 23

Respiration is the release of
energy from food.
• The equation for respiration in words is:
• Glucose + Oxygen Carbon dioxide + Water + Energ

Question 24

There are two types of
Respiration

Answer 24

• the first one is Aerobic Respiration needs oxygen to
release energy from food.

Question 25

The second type of respiration

Answer 25

• is 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 bo

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 Respira

Answer 28

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

Question 29

Remember

Answer 29

• Much less energy is released from food by
Anaerobic Respiration than by Aerobic
Respiration.

Question 30

Examples of anaerobic
respiration

Answer 30

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

Question 31

See for yourself

Answer 31

• Have you ever noticed what happens when
you breathe on glass??
• Yes as you can see from your experiment
water vapour forms on it!
• We can make sure this is water by using
cobalt chloride paper!

Question 32

Did you know

Answer 32

• When you get a cramp whilst exercising it is
caused by the acid that your cells produce when
they respire anaerobically (without oxygen).
• the only reason they do this is because your body
needs to produce so much energy while you
exercise that not enough oxygen reaches the cells
on time.
• To try to sort this out you start breathing fast and
get out of breath as your lungs are trying to take in
as much oxygen as possible!

Question 33

Nose and mouth

Answer 33

• These are the openings the air can enter
through!

Question 34

Pharynx

Answer 34

• This is the scientific name for your throat
area.

Question 35

Trachea

Answer 35

• This is the tube that leads into your lungs.
• It is very strong and is kept open by Rings
of Cartilage.
• If we didn’t have rings of cartilage what do
you think might happe

Question 36

Bronchus

Answer 36

• As we have two lungs our Trachea divides
to branch into each one.
• These two branches are called Bronchi.

Question 37

Bronchioles

Answer 37

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

Question 38

Alveoli

Answer 38

• 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.
• This is called Gas exchange. Why do you
think it is called this? • 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.
• This is called Gas exchange. Why do you
think it is called this?

Question 39

Alveolus

Answer 39

• In fact this is how they got the name
Alveolus from the Greek word meaning
“bunch of Grapes”!

Question 40

Capillaries

Answer 40

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

Question 41

Did you know

Answer 41

• If you joined all the capillaries in your lung
alone end to end they would travel up and
down Ireland a few times!!!

Question 42

Another amazing fact!

Answer 42

• If you took out you alveoli and cut them
open to spread out they would cover a
tennis court!!

Question 43

What is going on in the longs

Answer 43

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.