Transport in Animals - The Heart Flashcards
what is the function of the right side of the heart
pumps deoxygenated blood the the lungs
what is the function of the left side of the heart
pumps oxygenated blood around the rest of the body
describe the heart
lies slightly towards the left of the chest cavity. It consists mainly of firm, dark red cardiac muscle
what is the function of coronary arteries
supply the heart muscle cells with oxygen and glucose for aerobic respiration
what is the function of cardiac veins
remove waste CO2
what is the effect of restricted flow in these vessels
- can cause angina
- a blockage of these arteries leads to myocardial infarction (heart attack) because the heart muscle is deprived of oxygen and so dies
what is the function of the septum
separates the two sides of the heart preventing oxygenated and deoxygenated blood mixing
why do the atria have thin muscular walls
they do not need to create much pressure but receive blood and push it to the ventricles
why are the walls of the left ventricle thicker
they need to create a higher pressure, to pump blood further/overcome the resistance of the systemic circulation
high pressure in the lungs could damage the alveoli
how are the atria and ventricles separated
atrioventricular valves (tricuspid on right, bicuspid on left)
what is the function of valves
prevent backflow of blood
how are the atrioventricular valves attached to the ventricular wall
by string-like tendinous cords which prevent the valves turning inside out
what are the two major arteries leaving the heart
- aorta
- pulmonary artery
describe the flow of blood in the aorta
from left ventricle to the head and body
describe the flow of blood in the pulmonary artery
from right ventricle to the lungs
what are the two major veins returning blood to the heart
- vena cava
- pulmonary vein
describe the flow of blood in the vena cava
from body and head into right atrium
describe the flow of blood in the pulmonary vein
from lungs into the left atrium
describe cardiac muscle
myogenic (can generate its own excitory impulse)
what are the adaptations of cardiac muscle
- intercalated discs
- uninucleate and contractile units
- branched
- many mitochondria
what is the function of intercalated discs
help ensure synchronised contraction
describe the cells in cardiac muscle
each cell has one nucleus and is divided into contractile units called sacromeres
what is the function of branched muscle fibre
cross bridges help spread the contraction to produce a “squeezing” action
why do cardiac cells have many mitochondria
many mitochondria between the muscle fibrils to supply energy for contraction in aerobic respiration
how many layers is the wall of the heart divided into
3 - middle layer is myocardium
