Health And Risk Flashcards
(30 cards)
Why is water a good solvent?
- it’s polar, ions can easily dissolve in it.
- most biological reactions take place in solution
What is cohesion?
Attraction between two molecules of the same type
What is adhesion?
Attraction between two molecules of different types.
What is a mass transport system used for?
Used to carry raw materials from specialised exchange organs to body cells, and remove metabolic waste.
Why do multicellular organisms need a mass transport system?
Diffusion across the outer membrane doesn’t yield a fast enough rate of diffusion to meet the metabolic demands of the organism.
Which side of the heart pumps deoxygenated blood?
The right side pumps deoxygenated blood to the lungs.
Why is the left ventricle thicker than the right?
It needs to produce enough pressure on contraction to pump blood all around the body.
What do the atrioventricular and semilunar valves do?
Atrioventricular valves link the atria to ventricles and prevent back flow.
Semilunar valves link ventricles to the pulmonary artery and aorta and present backflow.
What is the difference between veins, arteries and capillaries?
- arteries are thick, muscular and have the most elastic tissue. They have an endothelial lining to smooth blood flow.
- veins are wider, blood flows under low pressure. They have valves to prevent back flow.
- capillaries are the site of metabolic exchange. They are only one cell thick
what happens during atrial systole?
- ventricles relaxed, atria contract, AV valves open
- pressure in atria increases, pushing blood into ventricles
what happens in ventricular systole?
- atria relax, ventricles contract
- pressure in ventricles increases, causes pressure to become higher in the ventricles, AV valves shut.
- pressure in ventricles higher than aorta and PAs, SL valves open
what happens during cardiac diastole?
- ventricles and atria relax
- higher pressure in aorta causes SL valves to close
- blood flows back to heart under low pressure
what are the ethical issues surrounding the use of invertebrates in experiments on HR?
- cant give consent
- daphnia have a less developed nervous system than vertebrates
- causes distress/suffering to a living organism
how does an atheroma form?
- damage to endothelium = inflammatory response
- white blood cells, connective tissue + lipids accumulate
- fibrous plaque builds up, smaller lumen, higher pressure.
what are the series of reactions leading to formation of a thrombus?
- thromboplastin (TP) released
- TP + Ca ions = triggering of conv. prothrombin -> thrombin
- thrombin catalyses fibrinogen -> fibrin
- fibrin mesh traps platelets.
how does atheroma lead to the formation of a heart attack?
- atheroma damages endothelium causing a rough surface to form
- causes a blood clot to form at the site
- blood clot can obstruct coronary artery
how does smoking increase the risk of developing CVD?
- CO binds to haemoglobin, inhibits it
- nicotine makes platelets sticky
- smoking causes decrease in antioxidants
how do antioxidants help reduce the risk of CVD?
they protect the cells from damage, preventing cell damage helps prevent atheroma from forming
why might people overestimate a risk?
if they are constantly exposed to information about the risk of developing the disease
name 3 different types of antihypertensives
- beta blockers
- vasodilators
- diuretics
what are the risks and benefits of antihypertensives?
- helps reduce risk of CVD
- palpitations, abnormal HR, fainting, headaches and drowsiness.
what does energy budget refer to?
the amount of energy taken in by an organism and the amount of energy used up
what is lactose?
beta glucose and galactose with a 1,4-glycosidic bond
what is sucrose?
alpha glucose and fructose with a 1,2-glycosidic bond
