In: Biology
Which statement about mammalian blood flow is NOT true?
Select one:
a. The pulmonary veins carry oxygen rich blood from the lungs into left atrium.
b. The right atrium receives oxygen poor blood from veins and contracts, forcing blood into the right ventricle.
c. The left ventricle contracts and sends oxygenated blood into the aorta, which sends it to body tissues.
d. The systemic circuit carries blood between heart and lungs; CO2 diffuses into blood from lungs and O2 diffuses into lungs from blood, which then returns to the heart.
Blood flow in human :-
• Human utilise double circulation system of blood.
• There are two loops of blood circulation in our body.
• Blood passes twice through heart in one circulation.
Pulmonary circuit / loop :-
• Right atrium receive oxygen poor blood from vena cava and pumps
it to right ventricle.
• Right ventricle pumps oxygen poor blood to lungs through
pulmonary artery where CO2 diffuse into lungs from blood and O2
diffuse into blood from lungs.
• In lungs blood become oxygen rich.
• This oxygen rich blood reaches left atrium through pulmonary
vein.
Systemic circuit/ loop :-
• Left atrium pumps oxygenated blood into left ventricle.
• Left ventricle pumps blood to systemic circulation.
• In systemic circulation, O2 diffuse out from blood to body organs
and CO2 diffuse from body organs to blood.
• Here, blood becomes deoxygenated or oxygen poor.
• This oxygen poor blood reaches right atrium and this cycle starts
again.
Now in question,
Option (d) is false statement.
• This statement is suitable for pulmonary circuit not for systemic
circuit.
Other statements are correct.
(*Explained above).