Transport in Humans Flashcards
features of unicellular organisms
-ToS through diffusion, osmosis and active transport
-Slow process
features of multicellular organisms
-ToS through transport systems
-xylem phloem
-blood and lymphatic system
-more efficient than diffusion to sustain life of organism
direction of blood
Heart Aorta/Arteries Arteriols CapillaryCells Venules Vein/Vena cava
function of heart
-muscular pump keeps blood circulating around body
-fills up with blood when relaxes
-squeeze out blood with great force when contracts
arteries
carry blood away from heart, aorta is largest leaving left side of heart
features of blood capillaries
-microscopic; found within cells; walls are made up of single layer of flattened epithelial that are partially permeable
-branch out to increase SA:V, for increase rate of EoS between blood and tissue cells
-total cross sectional area increase, lower blood pressure, slower blood flow, more time for EoS
blood capillaries unity
capillaries unit the form small veins called venules which join together to form bigger veins that carry blood to the heart
function of pulmonary circuit
transport deoxygenated blood from the heart to the lungs for gas exchange and transport the oxygenated blood back to the left side of the heart
function of systemic circuit
transport oxygenated blood from the heart to the rest of the body except and lungs and transport deoxygenated blood from the body back to the right side of the heart through the vena cava
advantages of double circulation
-blood enter the lungs at lower pressure due to thinner wall, blood flows through lungs slower, more time for oxygen to be absorbed into the blood before it returns to the heart
-LV pumps blood at a high pressure throughout the body so that oxygenated blood is sent to body tissues more quickly, maintain high metabolic rate in mammals
-oxy and deoxy blood don’t mix
function of pericardium
surrounds the heart and is made up of two layers of membrane, inner layer is in contact with the tissues making up the heart and fluid between membrane reduce friction when the heart beats
why do atria have thin muscular walls
they only force blood into the ventricles, does not require high blood pressure
why do ventricles have thick muscular walls
they pump blood away from the heart, requires high blood pressure
why does RV have thinner wall than LV
RV requires a lower blood pressure as it only pumps blood to the lungs which is close to the heart
function of median septum
muscular wall between right and left side of heart, prevent mixing of oxygen and deoxygenated blood
when do atrioventricular valves open and close
-pressure in atrium higher than pressure in ventricle
-vice versa, prevent back flow of blood into atria
points downwards to permit easy flow into ventricles
what are chordae teninae
attach ventricle flaps to ventricle walls
features of semilunar valves
-found in aorta and pulmonary artery
-ensures blood flows in correct direction instead of back to ventricles
features of coronary arteries
two small ones emerge in the aorta that provide the heart with nutrients and oxygen, vein remove CO2 and waste products, blood is returned to coronary sinus which in turns opens into the right atrium,