BIOLOGY Topic 1 Revision

What is Mass Flow?
When substances move in one direction at the same speed due to different pressures
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What does Frick's Law state?
Rate of diffusion is greatest when: concentration gradient is steep, short diffusion distance, large SA:Volume
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What is the equation for rate of diffusion?
Rate of diffusion ∝SA ╳ difference in concentrations/ thickness of surface
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What type of organisms have open circulatory systems?
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Talk about a closed circulatory system?
Blood is enclosed in blood vessels which generated a higher BP. This allows blood to move faster, making this system more efficient
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Give an example of an organism which had a single circulatory system
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Why do mammals and birds need a double circulatory system?
They require more oxygen and energy due to them expending more energy from not being supported by water and having to maintain a constant body temperature even when surroundings are warmer
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The hydrogen bonds present between water molecules give what properties to water?
cohesion, high surface tension, high boiling temperature, good solvent for ionic/polar molecules
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What are the 6 functions of water?
lubricates joints, salvia, shock absorber, keep muscle membrane moist, regulated body temperature, digestion
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What is the function of valves? Describe there structure
Valves prevent back flow of the blood. Valves are made from tendons to in order to stop the valve from inverting when blood pressure rises
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What is the function of the connective tissue and collagen fibres in blood vessels?
Strengthen blood vessels. In arteries the connective tissue & collagen fibres also help to withstand the high BP
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What size is the lumen in an artery? Why?
Small - maintain BP and maintain speed of blood flow
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Vasodilation and vasoconstriction is the function of what structure in the blood vessels?
Smooth muscle
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What do the elastic fibres do in the middle layer?
Stretch and recoil which smooth BP
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Endothelium cells?
Reduce friction
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Why is the lumen large in veins?
Less restriction on the blood flow therefore, the blood can be transported back to the heart quicker
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How is blood assisted back to the heart?
Muscular contraction and low pressure in thorax when breathing
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Describe capillaries...
Endothelium is only one cell thick so that there is a short short diffusion distance. Lumen is one RBC wide, slows flow of blood so that there is time for gas exchange
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Cardiac Diastole...
Heart relaxes. Higher pressure in the aorta / pulmonary trunk therefore the semilunar valve closes "dub". AV valves open and blood is passively flowing into atria then ventricles.
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Atrial Systole
Atria contract (higher pressure in atria) blood is ejected into ventricles
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Ventricular Systole
AV valves close "lub" (higher pressure in ventricles). Ventricles contract therefore semilunar valves are forced open and blood is ejected into the aorta / pulmonary artery
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What is atherosclerosis ?
Disease process which leads to CV diseases
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Describe the process of atherosclerosis...
Artery wall damaged > Inflammatory response (WBC go to damage site) > Cholesterol accumulates > ATHEROMA > Calcium salt and fibres build up > Hard plaques forms which narrows artery > Increase in BP
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Describe the process of blood clotting...
Damage to artery wall > Platelets become sticky and form a plug > Thromboplastin is released + calcium ions + vitamin K > Prothrombin > Thrombin > Fibrinogen > Fibrin > Blood clot
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What are causes of hypertension?
stress, adrenaline, loss of blood artery elasticity, atheromas
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Formation of tissue fluid?
At the arterial end of the capillary (higher pressure) > forces water and other nutrients out > cells absorb this matter and release CO2 > a venule end of capillary the tissue fluid will move back into the blood by osmosis.
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Formation of oedemas?
BP is very high. Therefore more fluid id forced out the capillary and this fluid will acculamate
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Definition of risk?
The likelihood of an unwanted event happening
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Definition of probability?
A numerical value for the size of the risk
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What is epidemiology?
Study of disease
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Explain a cohort study?
A group of people are selected > over a period of time they are monitored to see wether they develop a certain condition > subjects are interviewed to assess risk factors
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What is a case control study?
Two groups of people are selected - one group with the condition being studies and one without > their past medical histories are reviewed to assess risk factors
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Evaluation of a cohort study?
PROS = professionals are used therefore more reliable. Moreover, the study doesn't rely on memory. CONS = expensive and takes a long period of time
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Evaluation of a case control study?
PROS = cheaper and takes less time. CONS = data relies on memory therefore less accurate. Moreover, subjects could have incomplete medical records etc
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What are the key elements of a good study?
Large sample size, clear aim, controlling variables, valid and reproducible results, representative sample
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Risk factors of CV disease?
stress, smoking, diet high in fatty and salty foods, inactivity, genetics, high BP, age, gender
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Definition of blood pressure...
A measure of the hydrostatic forces of the blood against the walls of the blood vessel.
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What unit is blood pressure measured in?
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What range should systolic pressure be?
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What range should diastolic pressure be?
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How do you take blood pressure?
Wrap cuff around arm and inflate until you can't hear blood through stethoscope > deflate cuff > once hear blood flow through brachial artery = systolic > when no sound = diastolic
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What is the general formula for carbohydrates?
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Describe a glucose molecule...
small, soluble in water, rapid source of energy, doesn't need to be broken down before it is used in respiration
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What bonds are present in disaccharide?
1,4 glycosidic
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What monosaccharides is maltose made from?
glucose and glucose
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What monosaccharides is sucrose made from?
glucose and fructose
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What monosaccharides is lactose made from?
glucose and galactose
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Other cards in this set

Card 2


What does Frick's Law state?


Rate of diffusion is greatest when: concentration gradient is steep, short diffusion distance, large SA:Volume

Card 3


What is the equation for rate of diffusion?


Preview of the front of card 3

Card 4


What type of organisms have open circulatory systems?


Preview of the front of card 4

Card 5


Talk about a closed circulatory system?


Preview of the front of card 5
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