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

Digestion 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)
Stomach (churning)

Question 7

Chemical digestion

Answer 7

Enzymes to break down food

Question 8

Enzymes are

Answer 8

Chemicals that speed up reactions without being used up in the reaction

Question 9

Enzymes act on substrate

Answer 9

And break it down into a product ex. Substrate = starch , enzymes =amylase (saliva)=product =maltose (sugar)

Question 10

Most chemical digestion happens

Answer 10

In the small intestine

Question 11

Amylase

Answer 11

In the mouth

Question 12

Enzymes

Answer 12

In the stomach

Question 13

Plasma

Answer 13

Liquid part of the blood
Pale yellow
Mostly water
Functions:to transport chemicals and heat
Chemicals (useful) food hormones
Chemicals(waste) Co2, salts, urea
Neat:generated from chemical reactions, transported around to maintain 37degrees Celsius
Also carries the red blood cells white blood cells and platelets

Question 14

Red Blood Cells

Answer 14

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 15

White Blood Cells

Answer 15

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 16

Platelets

Answer 16

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 17

System of Tubes + Pump

Answer 17

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 18

Arteries

Answer 18

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 19

Veins

Answer 19

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 20

Capillaries

Answer 20

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 21

The heart

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

Pulse rates

Answer 22

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:
– Atthewrist
– Innerarmnearelbowjoint – Atthesidesoftheneck
• 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 23

Two blood circuits

Answer 23

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
– Bloodleavestheheart
– goestothelungstobecomeoxygenated – returnstotheheart
• 2: Systemic Circulation
– Bloodleavestheheart
– travelstootherpartsofthebody – returnstotheheart

Question 24

Structure of the Heart

Answer 24

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 25

Left versus Right

Answer 25

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 26

Blood Vessels of The Heart

Answer 26

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 27

Ingredients for energy

Answer 27

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 28

• The equation for respiration in words is:

Answer 28

Glucose + Oxygen -> Carbon dioxide + Water + Energy

Question 29

2 types of respiration

Answer 29

Aerobic Respiration needs oxygen to release energy from food.

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

Question 30

How does Oxygen get to our Cells??

Answer 30

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

Question 31

Aerobic Respiration

Answer 31

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

Question 32

Anaerobic Respiration

Answer 32

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

Question 33

Much less energy is released from food by

Answer 33

Anaerobic Respiration than by Aerobic Respiration.

Question 34

Examples of anaerobic respiration

Answer 34

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

Question 35

Breathing

Answer 35

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 36

Nose and mouth

Answer 36

These are the openings the air can enter through!

Question 37

Pharynx

Answer 37

This is the scientific name for your throat area.

Question 38

Trachea

Answer 38

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

Question 39

Bronchus

Answer 39

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

Question 40

Bronchioles

Answer 40

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

Question 41

Alveoli

Answer 41

The final place the air we breathe in goes to in our lung is the ALVEOLI.

Question 42

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.

Answer 42

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

Question 43

What are capillaries

Answer 43

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

Question 44

So what’s going on??

Answer 44

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

Question 45

?

Answer 45

This is able to happen because the INTERCOSTAL MUSCLES contract between the lungs and the DIAPHRAGM pushes up and down.