Topic 1 - Lifestyle, Health & Risk

Question 1

definition of mass flow

Answer 1

A liquid medium and all the particles it contains is transported in one direction in the circulatory system

Question 2

definition of adhesion

Answer 2

Water can stick to other things

Question 3

definition of cohesion

Answer 3

water can stick to itself

Question 4

definition of diffusion

Answer 4

The net movement of particles from an area of high concentration to an area of low concentration

Question 5

explain how age can increase risk of cvd

Answer 5

• Elasticity and width of arteries decrease with age
• Increased risk of hypertension (high BP)-

Question 6

explain how diet increases risk of cvd

Answer 6

• many correlations between dietary habits and levels of cvd. e.g. lipoprotein and salt levels; some might be causal, particularly for blood cholesterol levels

Question 7

explain how genetics increase risk of cvd

Answer 7

inherit tendency to: high blood pressure; poor cholesterol metabolism; arteries that are more easily damaged; relative HDL:LDL levels in blood

Question 8

explain how inactivity increases risk of cvd

Answer 8

• Fatty material can deposit in arteries (atheroma)
• If arteries become clogged and damaged, it can lead to a heart attack
• Exercise makes the heart stronger, so it can pump more blood with less effort - reduced force on arteries

Question 9

explain why gender can increase risk of cvd

Answer 9

• Women have oestrogen
• Oestrogen reduces risk by downregulating inflammatory markers
• Less inflammatoin means, wider lumen and more blood flow

Question 10

explain why smoking increases risk of cvd

Answer 10

• Chemicals in cigarettes damage artery linings
• Constricts the arteries by inflammation
• Reduces blood flow

Question 11

function of valves

Answer 11

Prevents backflow of blood

Question 12

how do freezing properties of water affect living organisms

Answer 12

• bodies of ice reflect light energy
• acts as thermal insulating layers
• allows water to remain liquid
• allows water to be a habitat for aquatic organsisms
• very cold regions can still have an ecosystem

Question 13

how does high blood pressure increase risk of cvd

Answer 13

• High BP causes damage to the endothelium lining of arteries
• Inflammatory response leads to the formation of an atheroma (fatty deposits)
• Plaque develops and narrows the lumen of the artery

Question 14

how is atherosclerosis an example of positive feedback

Answer 14

• Atherosclerosis results in a smaller lumen and reduced blood flow, which leads to increased blood pressure
• Also the hardened plaque makes the walls less elastic
• These effects further increase the likelihood of more damage and thus more athersclerosis (self-perpetuating)

Question 15

how is water a solvent for ionic substances

Answer 15

• Dipole nature means it can interact with both positive and negative ions
• When ionic substances dissolve, it’s not hydrogen or ionic bonding between water and solute that allows it to dissolve
• Negative ions are attracted to the positive ends of the water molecule and positive ions are attracted to the negative ends. They become surrounded by water molecules so become hydrated in aqueos solution

Question 16

how is water a solvent for polar substances (e.g. amino acids & glucose)

Answer 16

• Dissolve easily in water
• Their polar groups become surrounded by water and go into solution

Question 17

how is water a thermal regulator

Answer 17

• Temp of a substance increases when particles move faster
• Due to the H2 bonds (preventing KE of the molecules increasing) the temp of the water remains stable despiting external temp changes
• Water has a very high SHC

Question 18

how is water a thermal regulator for living things

Answer 18

• Water’s high specific heat capacity allows it to:​
• Have a stabilising effect on the body temperatures of all organisms​
• Have a stabilising effect on the temperature of large bodies of water, so they are suitable habitats for aquatic organisms

Question 19

definition of positive feedback

Answer 19

When a change occurs that brings about more of that change to it

Question 20

purpose of high elasticity of artery walls

Answer 20

Stretch and recoil, to maintain high blood pressure

Question 21

purpose of lots of arterial muscle tissue

Answer 21

Contract and relax, to maintain high blood pressure

Question 22

purpose of thick artery walls

Answer 22

To withstand high pressure

Question 23

water as a solvent in living things (3 things)

Answer 23

1. Transport medium (dissolving important substances)
2. Medium for biochemical reactions (dissolving the substrates and products)
3. Habitat, allowing aquatic organisms to exchange substances with their environment

Question 24

what happens during atrial systole

Answer 24

• Atrium walls contracts
• Ventricle walls relax
• AV valves open
• Semi-lunar valves closed

Question 25

what happens during ventricular systole

Answer 25

• Ventricle walls contract
• Atrium walls relax
• AV valves closed
• Semi-lunar valves open

Question 26

what happens during diastole

Answer 26

• Relaxed atria
• Relaxed ventricles
• AV valves open
• Semi-lunar valves closed
• Blood moves atria -> ventricles (passive)

Question 27

what is peripheral resistance

Answer 27

Contact between blood and the walls of blood vessels cause friction, this impedes blood flow

Question 28

what is the process of blood clotting

Answer 28

1. When the endothelium of blood vessels are damaged, platelets rupture and release thromboplastin
2. Thromboplastin catalyses the reaction of prothrombin to thrombin, in the presence of calcium ions and vitamin K
3. Thrombin then catalyses the reaction of fibrinogen to Fibrin
4. The fibrin mesh together to gorm a net to trap the blood cells

Question 29

what makes glucose a good main respiratory substrate

Answer 29

• Polar: can be dissolved, transported/used in chemical reactions
• Can be dissolved in plasma for transport
• Dissolves in cytoplasm for chem reactions
• Stores chemical potential energy