transport in animals (topic 9) Flashcards
what does the circulatory system consist of?
a pump (the heart) to keep the blood moving
blood vessels to carry blood
valves to make sure that the blood flows in one direction only.
Describe the single circulation of a fish
deoxygenated blood flows from heart to gills for oxygenation and then to the rest of the body as oxygenated blood and then back to the heart
Describe the double circulation of a mammal
heart → lungs → heart → rest of the body → heart
In the first (shorter) circuit, the blood flows from the heart to the lungs for oxygenation and then back to the heart.
In the second (longer) circuit, the blood flows from the heart to the other parts of the body and then back to the heart.
what are the advantages of double circulation
higher pressurized blood
greater flow of blood
further blood can travel in body
Oxygen and glucose for respiration are supplied rapidly to the cells in the body, and waste carbon dioxide and water are removed quickly from them.
Blood can be supplied to distant parts of large animals.
what are the structures of the heart, describe
septum divides left of ehart to right, thus separating deoxygenated blood to oxygenated blood
muscular wall of the left side is thicker to pump blood at higher pressure
heart has 4 chambers, left and right atriums (upper chamber) and right and left ventricles (lower chamber)
one way valves where blood leaves atrium and enters ventricle and also a valve where blood leaves a ventricle
arteries carries blood away from the heart and veins into the heart
what are the two valves present
A semilunar or pocket valve is found at an exit of the heart.
An atrioventricular valve is found between an atrium and a ventricle,
describe thickness of walls in different chambers and why
walls of ventricles are thicker than atrium, and walls of left ventricles are thicker than right, this is due to amount of pressure the blood needs to travel a certain distance
eg. atria only pumps blood into the ventricle, ventricle pumps blood to lung or rest of body (further away)
right ventricle only pumps blood to the lungs, left ventricle pumps blood to all other body organs
what are the 4 entries and leavings of the heart
vena cava- blood from rest of body to heart (vein) deoxygenated blood
pulmonary artery- carries blood away from the heart towards lung (artery) deoxygenated blood
pulmonary vein- carries blood into heart from lung, oxygenated blood (vein)
aorta- carries blood from heart to rest of body, oxygenated blood (artery)
importance of septum
separates deoxygenated to oxygenated blood, if there is a whole in the septum where these bloods are mixed, causes symptoms such as tiredness, especially during physical activity, shortness of breath
how can the acitivty of the heart be monitored
electrocardiogram (ECG)
listening to the sounds of valves closing
determining the pulse rate.
arteries vs veins
arteries carries oxygenated blood away from heart, accept pulmonary artery
veins carries deoxygenated blood into heart accept pulmonary vein
stages in a heartbeat
1.Blood flows from veins into the atria.
2.The atria contract, pushing blood into the ventricles. The fall in pressure in the atria causes the atrioventricular valves to close.
3.The ventricles contract, pushing blood into arteries. The fall in pressure in the ventricles causes the semilunar valves to close.
what happens to your heart rate when excersing
heart rate increases because your muscle cells need more energy, energy comes from aerobic respiration
More glucose and oxygen must be supplied by the blood to the respiring muscle cells. Your heart beats faster in response, increasing the blood flow to these cells, and increasing the rate at which waste products of respiration (carbon dioxide and water) are removed
what to coronary arteries do
supply blood to heart itself supply with nutrients and oxygen
what is coronary heart disease
disease that happens when coronary arteries are blocked, thus unable to supply oxygen rich blood to the heart, as a result heart muscle may be damaged and die
what are risk factors for CHD
age
diet
genetic predisposition (whether or not there is a family history of CHD)
gender
smoking
stress.
how can diet and exercise affect CHD
consuming variety of foods, containing oils from plants and fish and reducing amount of animal fat
keeping body weight at a suitable level with regular excercise, decreases blood pressure and suitable weight obtained, also reduces stress
structure of artery and reasoning
carry blood away from heart
-thick outer wall
-thick muscle wall
-smooth linning
-small lumen
to carry blood in high pressure, structure withstands this pressure, to far away organs
structure of veins and reasoning
pressure much lower
thin outer layer
thin muscle layer
smooth lining
large lumen
have valves to ensure one way flow of blood
structure of capillaries and reasoning
one cell thick
very small lumen
allow exchange of nutrients
function of cappilaries
Capillaries are tiny blood vessels which allow the exchange of materials between the blood and body cells.
main blood vessels of heart
vena cava
aorta
pulmonary vein
pulmonary artery
main blood vessels of lungs
pulmonary vein
pulmonary artery
main blood vessels of kidney
renal vein- away from kidney
renal artery- towards kidney