life style health and risk (Topic 1, 1.1-1.11) Flashcards
(26 cards)
what is Ficks law
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
describe the cardiac cycle in mammalians?
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.
what is the meaning of systole and diastole ?
Systole means contractions
Diastole means relaxation.
where is the superior and inferior vena cava?
semi lunar valves?
and atrioventricular valves?
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.
state process of singular circulatory system in fish
- Deoxygenated blood is pumped by the heart through the blood vessels to the gills
- in the gills blood passes through the capillaries and o2 diffuses from the water into the blood
- 02 blood travels from gills to body tissue through vessels
- oxygenated blood passes through capillaries in body tissue and o2 diffuses from blood into body tissue.
why do mammals have a circulatory system ?
To overcome the limitations of simple diffusion
how to calculate heart rate?
record how the time one cycle takes. divide that time by 60 to calculate heart rate
what is the definition of mass transport
the flow of fluids in one direction due to pressure changes usually by vessels or tubes
what is the meaning of surface are to volume ratio.
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.
in microscopic organisms they can exchange all needed substances via diffusion directly through cell membrane.
to calculate surface area to volume ratio divide surface area by volume
describe the process of coronary circulation?
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.
describe the structure and function of aorta
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
what is coronary circulation ?
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.
describe the structure and function of an artery ?
- The outside layer is made of connective tissue which has strength due to collagen within it.
most arteries don’t have valves
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.
Describe the structure and function of capillaries.
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
Describe the structure and function of a vein ?
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 because dont reqire much strength.
Valves to prevent back flow of blood as blood flows at lower pressure.
what are the benefits of using daphnia to record the effect caffeine has on the heart rate ?
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
what is the specific word for caffeine ?
It is a stimulant there for it increases activity of brain , nervous system and heart rate.
what factors can cause high blood pressure
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 Hdl colestorol ratio. more ldl cholestrol in body.
stress - cortisol causes smooth muscle to contract
describe the process of atherosclerosis?
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 wbc 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 blood pressure.
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.
what is the importance of platelets in blood, what are they
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
order of blood vessels
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.
Indepth clarification, explanation
Say deoxygenated blood was in heart and coming our of pulminary artery. that pulminar artery would carry the deoxygenated blood out of the heart to the arteriols wich conne t to caillaries which are site of gas exchange bc one cell thick etc. once it reaches capillaries o2 form aveoli will diffuse into blood and co2 out of blood bc of concentartion gardients ( onec blood is deoxygenated it has higher co2 concentartion than o2 concentartion) once blood gets its o2 at capillaries it will travel though venuoles which are attached to pulmnary vein. 02 blood will enter heart through pulmenar vein and go our of the aorta. when it reaches body tisue it connects to venules which connect to capillaries and o2 in blood is delivered to the body tissue. de 02 blood still in capillaries traven to venuoles which attach to veins fo blood to be carreus back to heart and entre vina cava.
process of blood clotting ?
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 ctylises fibrinogen in the blood to form fibrin. mesh like protein structure which binds to platelets and traps cells, and platelets floating blood causing a blood clot.
Are thromboplastins, prothrombin, thrombin, fribrinogen and fibrin soluble or insoluble enzymes or substances
Draw and describe the cardiac cycle graph ?
the cardiac cycle begins with the ventricles finning up with blood
