life style health and risk

Question 1

what is Ficks law

Answer 1

rate of diffusions is proportional to the difference in concentration

rate of diffusion is proportional to surface area

rate of diffusion is inversely proportional to thickness of surface area

rate of diffusions is proportional to diffusion constant

Question 2

describe the cardiac cycle in mammalians?

Answer 2

While heart is in diastole blood enters through vena cava and pulmonary vein.

The pressure in atria rises causes the atrioventricular valves to open and blood flows into ventricles. atrial systole then takes place forcing rest of blood into ventricles.

as the pressure in the ventricles is now greater than in the atria the av valves close.

A few moments later ventricular systole takes place causing the blood to be forces into pulmonary artery and aorta. as the pressure in aorta and pulmonary artery becomes greater then ventricles the semilunar valves close and blood is pumped out of the heart.

Question 3

what is the meaning of systole and diastole ?

Answer 3

Systole means contractions

Diastole means relaxation.

Question 4

where is the superior and inferior vena cava?

semi lunar valves?

and atrioventricular valves?

Answer 4

superior vena cava is at top inferior at bottom

semilunar valves are valves in pulmonary artery and aorta

atrioventricular (av) valves are connected to atrium and ventricles.

Question 5

state process of singular circulatory system in fish

Answer 5

1. Deoxygenated blood is pumped by the heart through the blood vessels to the gills
2. in the gills blood passes through the capillaries and o2 diffuses from the water into the blood
3. 02 blood travels from gills to body tissue through vessels
4. oxygenated blood passes through capillaries in body tissue and o2 diffuses from blood into body tissue.

Question 6

why do mammals have a circulatory system ?

Answer 6

To overcome the limitations of simple diffusion

Question 7

how to calculate heart rate?

Answer 7

record how the time one cycle takes. divide that time by 60 to calculate heart rate

Question 8

what is the definition of mass transport

Answer 8

the flow of fluids in one direction due to pressure changes usually by tussles or tubes

Question 9

what is the meaning of surface are to volume ratio.

Answer 9

higher surface are to volume ratio. objects has larger surface area than the size of it itself. simple diffusion is enough

humans are examples of lower surface area to volume ratio so simple diffusions is not enough

Question 10

describe the process of coronary circulation?

Answer 10

oxygenated blood is supplied to the heart through the pulmonary vein. It then goes into aorta which have coronary arteries attached. o2 diffuses from the blood to heart and the heart also receives glucose. this oxygen and glucose is then used in aerobic respiration.

Question 11

describe the structure and function of aorta

Answer 11

outer layer of aorta is called connective tissue which has the protein collagen to strengthen it.

smooth muscles with elastuc fibres to reduce frinction and allow aorta to strech and recoil.

smaller lumen to maintain high blodd preassure

aorta has to transport blood all around teh body

Question 12

what is coronary circulation ?

Answer 12

blood which contains 02 and glucose travels via aorta into culinary arteries. o2 diffuses form blood to hear muscle.
heart muscle provided with energy due to aerobic respiration.

Question 13

describe the structure and function of an artery ?

Answer 13

• The outside layer is made of connective tissue which has strength due to collagen within it.

The second layer in the artery is smooth thick muscle with elastic fibres in it, which allows for the artery to stretch and recoil and withstand the higher pressure of blood and maintain its high pressure.

The muscle is smooth to reduce friction between the blood and itself which may occur due to bloods high pressure. reducing risk of damage to the endothelium.

The lining of the lumen is called the endothelium which is thin and delicate. it has folds so that the artery Ann easy stretch and recoil.

Artery has a smaller lumen to maintain high blood pressure.

Question 14

Describe the structure and function of capillaries.

Answer 14

Site of gas exchange

walls are one cell thick to allow or a shorter diffusion distance.

it has a thin delicate basement membrane that lines the outside of capillaries.

the lumen of capillary is similar size to that of a red blood cell so that only on can flow through at a time for efficient diffusion/ gas exchange.

Spaces/ gaps between the capillary cells are called pores. these allow for white blood cells enter blood

Question 15

Describe the structure and function of a vein ?

Answer 15

Vein has a large lumen to reduce resistance to blood flow because blood flows at a low pressure to the heart.

endothelium is smooth so less friction
thin connective tissue.

Valves to prevent back flow of blood as blood flows at lower pressure.

Question 16

what are the benefits of using daphnia to record the effect caffeine has on the heart rate ?

Answer 16

because they are transparent so it allows for their internal functions to be studies more easily

Ethical considerations mat be needed for daphnia survival such as not exposing them to the chemical that is being tested for an extended period of time

Question 17

what is the specific word for caffeine ?

Answer 17

It is a stimulant there for it increases activity of brain , nervous system and heart rate.

Question 18

what factors can cause high blood pressure

Answer 18

smoking - damages endothelium

salt - water is pulled into blood stream, more water in blood stream higher blood pressure gets.

saturated fats - causes a higher ldl to cdl ration. more ldls in body.

stress - cortisol causes smooth muscle to contract

Question 19

describe the process of atherosclerosis?

Answer 19

high/ increased blood pressure due to multi factors (salt, stress, saturated fat, smoking)

this hypertension damages the endothelium due to extreme friction between blood and endothelium.

as a result many LDLs begin to accumulate at the damaged region of endothelium.

an inflammatory response is then triggered and abc engulf LDLs

the accumulation of LDLs an WBCs causes a soft atheroma to from.

this atheroma is then impregnated by calcium salts and forms a hard plaque. This can narrow the arteries even more increasing blouse pressure.

the build up of fatty deposits in gases are actually called atheroma.

other explanation - damaged endothelium
inflammatory response where wbc uniter damaged endothelium. they then absorb/ engulf LDLS in blood causing soft atheroma. impregnated by calcium salts. hard plaque. the atheroma can rupture exposing collagen and that is when blood clots can form.

Question 20

what is the importance of platelets in blood, what are they

Answer 20

they cause coagulation of blood which is blood clotting. They are fragments of red blood cells. clotting prevents us form bleeding to death and protects us form pathogens entering body

Question 21

order of blood vessels

Answer 21

arteries transport blood away from the heart. the arteries are attached to ateriols which are smaller arteries and they branch of and connect to capillaries where gas exchange takes place. the capillaries are then connected to venuoles which connect to veins and transport blood back to heart.

Answer 22

collagen is exposed when atheroma raptures or cut/ scrape. platelets are activates/ react with collagen and become filaments and sticky. platelets stick together at exposed collagen and release thromboplastin which reacts with Prothrombin and calcium ions in the blood to form thrombin. This is a soluble enzyme that ctalyses fibrinogen in the blood to form fibrin. mesh like protein structure which binds to platelets and traps cells causing a blood clot.

Question 24

Draw and describe the cardiac cycle graph ?

Answer 24

the cardiac cycle begins with the ventricles finning up with blood