biology: topic 1

atrial systole: blood flow

into right atrium from body, into left atrium from pulmonary vein

atrial systole: pressure

moderately increases in the atria

atrial systole: blood direction

blood fills relaxed ventricles

ventricular systole: blood direction

forced up and out through aorta/pulmonary artert

ventricular systole: valves

av valves shut due to pressure, semilunars open

ventricular systole: pressure

increases rapidly in ventricles

diastole: pressure

high in aorta and p. artery

diastole: chambers

relaxed

diastole: blood flow

into atria and ventricles through p. vein and vena cava

atherosclerosis

condition in which fatty deposits build up on the inner walls of the arteries

atheroma

a deposit of plaque on or within the arterial wall

hypertension

abnormally high blood pressure

process of atherosclerosis

1. endothelial injury due to high blood pressure
2. inflammatory response (white blood cells)
3. cholesterol accumulates, atheroma forms
4. calcium salts, tissue accumulates, forms plaque
5. wall elasticity reduced

clotting cascade

1. injury to endothelium
2. exposed collagen
3. platelets rush to form temporary plug
4. thromboplastin
5. prothrombin - thrombin
6. fibrinogen - fibrin
7. mesh, blood cells trapped, clot formed

factors affecting the risk of cvd

age, sex, genetics, diet, blood pressure, stress, smoking, exercise

adaptations of an artery

elastic fibres for elastic recoil, muscle, folded endothelium, smooth endothelium, narrow lumen

adaptations of a capillary

3 monosaccharides

glucose, fructose, galactose

maltose

glucose + glucose

sucrose

glucose + fructose

lactose

glucose + galactose

amylose

unbranched, only formed of 1,4 glycosidic bonds, not a straight chain but is a spiral so can REALLY pack together to store lots of energy

amylopectin

branched polysaccharide, 1,4 and 1,6 glycosidic bonds. means it can rapidly release glucose, is compact

why is glycogen branched

rapid release of glucose to liver and muscles

starch

- made of amylose and amylopectin
- insoluble in water so is a good storage compound
- alpha glucose

glycogen

- alpha glucose
- shorter branches to it is more compact
- faster hydrolysis of starch in animals as it's more necessary

cellulose

- beta glucose
- unbranched glucose linked with hydrogen bonds
- this prevents water entering so it is an excellent structural protector of cells

why is water a good solvent for transport?

- high surface tension
- capillary action due to adhesion
- forces of attraction between water molecules (cohesion) enables mass flow
- high specific heat capacity
- universal solvent/ionic compounds dissolve easily

polarity of water

- it has opposite charges on opposite ends
- hydrogen bonds form causing water to stick together

why do animals need a circulatory system?

- sa:v increases
- diffusion distance decreases
- metabolic rate increases
therefore diffusion becomes insufficient so a system allows exchange of substances to take place

BMI

weight (kg) / height (m^2)

unhealthy waist:hip ratio

above 1

saturated lipids

found in animal fats, don't contain C=C bonds

unsaturated lipids

found in plants, contain C=C bonds and melt at lower temperatures

intermolecular forces and lipids

weaker in unsaturated fats, the C=C bonds reduce strength of forces by creating a 'kink'

properties of lipids

- waterproof
- compact
- non-polar and insoluble
- thermal insulators

triglycerides

1 glycerol, 3 fatty acids joined by ester bonds formed in a condensation reaction

triglycerides and phospholipids

one fatty acid is substituted for a phosphate containing group

HDL (high density lipoprotein)

"good" cholesterol - unsaturated fats, (more) protein and cholesterol
- transports cholesterol from tissues to the liver to reduce cholesterol levels

LDL (low density lipoprotein)

"bad" cholesterol - saturated fats, protein and cholesterol
- transports cholesterol from the liver to the blood, increasing cholesterol levels

correlation between saturated fats and high cholesterol

this is because saturated fats are in LDLs
is casual as cholesterol is involved in plaque formation

anticoagulants

CVD treatment
reduce the risk of clot formation
- may lead to uncontrolled bleeding

statins

CVD treatment
reduce blood cholesterol by blocking producing enzyme
should be with a healthy diet and causes nausea/inflammation

platelet inhibitors

CVD treatment
make platelets less sticky, reduce the risk of atheroma formation
can cause stomach bleeding

beta blockers

antihypertensive to reduce heart contraction frequency and power by blocking response to hormones
-may increase risk of diabetes

diuretics

antihypertensive to increase volume of urine to lower blood volume and pressure
side effect: dizziness, nausea

ACE inhibitors

antihypertensive to block the conversion of enzymes that cause constricted arteries
side effects: arrhythmia, dizziness

why does cvd damage heart muscle

narrow lumens or coronary arteries

reducing blood flow to muscles

reducing aerobic respiration