Topic 1 - Lifestyle, Health & Risk Flashcards
definition of mass flow
A liquid medium and all the particles it contains is transported in one direction in the circulatory system
definition of adhesion
Water can stick to other things
definition of cohesion
water can stick to itself
definition of diffusion
The net movement of particles from an area of high concentration to an area of low concentration
explain how age can increase risk of cvd
- Elasticity and width of arteries decrease with age
- Increased risk of hypertension (high BP)-
explain how diet increases risk of cvd
- many correlations between dietary habits and levels of cvd. e.g. lipoprotein and salt levels; some might be causal, particularly for blood cholesterol levels
explain how genetics increase risk of cvd
inherit tendency to: high blood pressure; poor cholesterol metabolism; arteries that are more easily damaged; relative HDL:LDL levels in blood
explain how inactivity increases risk of cvd
- 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
explain why gender can increase risk of cvd
- Women have oestrogen
- Oestrogen reduces risk by downregulating inflammatory markers
- Less inflammatoin means, wider lumen and more blood flow
explain why smoking increases risk of cvd
- Chemicals in cigarettes damage artery linings
- Constricts the arteries by inflammation
- Reduces blood flow
function of valves
Prevents backflow of blood
how do freezing properties of water affect living organisms
- 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
how does high blood pressure increase risk of cvd
- 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
how is atherosclerosis an example of positive feedback
- 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)
how is water a solvent for ionic substances
- 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
how is water a solvent for polar substances (e.g. amino acids & glucose)
- Dissolve easily in water
- Their polar groups become surrounded by water and go into solution
how is water a thermal regulator
- 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
how is water a thermal regulator for living things
- 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
definition of positive feedback
When a change occurs that brings about more of that change to it
purpose of high elasticity of artery walls
Stretch and recoil, to maintain high blood pressure
purpose of lots of arterial muscle tissue
Contract and relax, to maintain high blood pressure
purpose of thick artery walls
To withstand high pressure
water as a solvent in living things (3 things)
- Transport medium (dissolving important substances)
- Medium for biochemical reactions (dissolving the substrates and products)
- Habitat, allowing aquatic organisms to exchange substances with their environment
what happens during atrial systole
- Atrium walls contracts
- Ventricle walls relax
- AV valves open
- Semi-lunar valves closed
