Chapter 2 - Organisation

Question 1

Organ systems?
Circulatory?
Respiratory?
Digestive?

Answer 1

• Digestive - mouth, oesophagus, stomach, small intestine, large intestine, rectum.
• Respiratory - nose, mouth, trachea, bronchi, diaphragm, intercostal muscles, ribs, lungs, bronchiole, alveoli.
• Circulatory( components of blood) - plasma 55% , red blood cells 45%, white blood cells and platelets.

Question 2

Mouth?

Answer 2

• Begins with mechanical digestion. Food is broken up into smaller pieces and mixed with saliva.
• Salvia contains enzymes and helps lubricate food so it can be swallowed.

Question 3

Oesophagus?

Answer 3

• When you swallow foods, the walls of oesophagus squeeze together (contract). This moves the food down the oesophagus to the stomach.
• This is call PERISTALSIS.

Question 4

Stomach?

Answer 4

Begins the digestion’s of protein; small molecules such as alcohol absorbed. HCL creates the correct ph for enzymes to kill any microbes we might have consumed.

Question 5

Small intestine?

Answer 5

Continues digestion of carbohydrates and protein. The walls of the small intestine are highly folded into villi.
This gives a large surface area

Question 6

Large intestine?

Answer 6

Where water is absorbed.

Question 7

Rectum?

Answer 7

Stores faeces.

Question 8

Enzymes?

Answer 8

Are biological catalysts - they speed up chemical reactions but do not get used up. They are made of protein.

Question 9

Bile and its functions?

Answer 9

Bile is a greenish-yellow liquid that is produced in the liver and stored in the gall bladder. It then travels via the bile duct into the small intestine.
Functions:
•It is an alkali so it neutralises the food coming from the stomach.
•It emulsifies fats-breaks then into smaller droplets so there is a larger surface area for lipase to work on.

Question 10

Lipase?

Answer 10

Lipases catalyse the breakdown of fats and oils into fatty acids and glycerol in the small intestine. Produced in pancreas.

Question 11

Protease?

Answer 11

Proteases catalyse the breakdown of proteins into amino acids in the stomach and small intestine. Produced in stomach, pancreas.

Question 12

Amylase?

Answer 12

Amylase catalyses the breakdown of starch into maltose in the mouth and small intestine. Produced by pancreas and salivary glands.

Question 13

Maltase?

Answer 13

Maltase catalyses the breakdown of maltose into glucose in the small intestine. Produced in small intestine.

Question 14

Villi?

Answer 14

The villi (one is called a villus) are tiny, finger-shaped structures that increase the surface area. They have several important features:
-wall just one cell thick - ensures that there is only a short distance for absorption to happen by diffusion and active transport
(They help to absorb digested food)

Question 15

How to test for starch?

Answer 15

Use Iodine solution
No heat needed
Result - blue/black colour

Question 16

How to test for simple sugars?

Answer 16

Use Benedict’s solution
Heat required
Result - orange/red

Question 17

How to test for protein?

Answer 17

Use Biuret solution
No heat needed
Result - pale lilac (pink/purple)

Question 18

How to test for fat?

Answer 18

Use ethanol
No heat needed
Result - Oil drops form at surface (a white (milk-like) colour)

Question 19

Digestion?

Answer 19

Is the breakdown of large insoluble molecules into small soluble ones.

Question 20

Order of structures?

Answer 20

Cells => tissues => organs=> => organ systems

Question 21

How blood travels through the heart?

Answer 21

Deoxygenated Blood from two vena cavae enters the right atrium. Blood from the pulmonary veins enters the left atrium.The blood then goes into the ventricles. Blood is prevented from flowing back into the atria by heart valves.

Blood leaves the heart in the body’s main artery - the aorta (oxygenated blood) - from the left side, and the pulmonary artery (deoxygenated blood), from the right.

Question 22

What does an artificial pacemaker do?

Answer 22

Sometimes, the rhythm of the heart’s natural pacemaker process becomes disrupted - a person’s heart beats abnormally. It can be abnormally slow or fast, or irregular.

An artificial pacemaker is a small, battery-operated electronic device implanted in a person’s chest that sends out regular, adjustable electrical impulses to produce normal contractions of the heart.

Question 23

Arteries?

Answer 23

Always carry blood away from the heart
Carry oxygenated blood, except for the pulmonary artery
Carry blood under high pressure
Have thick muscular and elastic walls to pump and accommodate blood
A type of supporting tissue called connective tissue provides strength
The channel in the blood vessel that carries blood - the lumen - is narrow

Question 24

Veins?

Answer 24

Always carry blood to the heart
Always carry deoxygenated blood, except for the pulmonary vein
Carry blood under low or negative pressure
Have thin walls - have less muscular tissue than arteries
Have less connective tissue than arteries
Have a wide lumen

Question 25

Capillaries?

Answer 25

The walls of capillaries are just one cell thick. Capillaries therefore allow the exchange of molecules between the blood and the body’s cells - molecules can diffuse across their walls. This exchange of molecules is not possible across the walls of other types of blood vessel.

Question 26

Statins?

Answer 26

Statins are drugs that help to lower cholesterol in the blood. They do this by lowering its production in the liver.

Statins are prescribed for people with heart disease or who have a high risk of developing it. They need to be taken long-term. Cholesterol levels will rise again if a person stops taking them.

Question 27

Stents?

Answer 27

Coronary arteries that are blocked or have become narrow can be stretched open and a stent inserted to restore and maintain blood flow.

Question 28

Vena Cava?

Answer 28

It carries deoxygenated blood from the lower half of the body to the right atrium of the heart.

Question 29

Aorta?

Answer 29

The aorta begins at the top of the left ventricle, the heart’s muscular pumping chamber. The heart pumps blood from the left ventricle into the aorta through the aortic valve.

Question 30

What happens in the respiratory system?

Answer 30

The trachea, or windpipe, branches into two bronchi – one bronchus to each lung. Rings of cartilage in the walls of the trachea help to keep it open as air is drawn in.

The bronchi split into smaller branches and then into smaller tubes called bronchioles. Each bronchiole ends in a cluster of microscopic air sacs called alveoli.

Question 31

The human lungs provide an exchange surface adapted for:

Answer 31

• absorbing oxygen – needed for respiration – into the blood from the air
• transferring carbon dioxide – produced by respiration – from the blood into the lungs then the air

Question 32

Ventilation?

Answer 32

Air is moved into and out of the lungs, as it is carried to and from the exchange surfaces of the alveoli.

The diaphragm and rib cage move to create a lower air pressure in the lungs than that of the air outside the body. Air then rushes into the lungs.

The most important muscle when we inhale normally is the diaphragm. The external intercostal muscles are the second most important muscles. Breathing is a passive process resulting from pressure changes in the lungs.