Which chamber of the heart has the thickest muscle wall?
A left atrium
B left ventricle
C right atrium
D ight ventricle
The diagram shows the human heart and some of the blood vessels connected to it. Before blood in W reaches Z it must:
A gain glucose.
B give up heat to the skin.
C pass through capillaries.
D travel to the head.
Which blood vessel has a high carbon dioxide concentration, a low oxygen concentration and a high blood pressure?
A aorta
B pulmonary artery
C pulmonary vein
D vena cava
The diagram shows a section through the heart. Which part pumps blood to the aorta?
A
B
C
D
The diagram shows a section through a blood vessel in the leg. Which type of blood vessel is shown, and in which direction does the blood flow?
artery; blood flow is P to Q.
vein; blood flow is P to Q.
artery; blood flow is Q to P.
vein; blood flow is Q to P.
Which statement is correct for most veins in the human body?
A They carry blood at high pressure.
B They have a pulse.
C They have valves.
D They take blood away from the heart.
The diagrams show some components of the blood of a mammal. Which component causes the blood to start clotting?
Why is the circulatory system of mammals described as a double circulation?
A Blood flows firstly through arteries and then through veins.
B Blood flows through the heart twice on one complete circuit of the body.
C In the heart, blood flows firstly through atria and then through ventricles.
D The atria and the ventricles contract alternately.
In which list do all three blood vessels carry oxygenated blood?
A aorta, pulmonary artery, renal artery
B aorta, pulmonary vein, renal artery
C vena cava, pulmonary artery, renal vein
D vena cava, pulmonary vein, renal vein
The diagram shows a double circulatory system. Which vessels carry oxygenated blood?
A 1 and 2
B 1 and 4
C 2 and 3
D 2 and 4
Which route is taken by air passing from the lungs of a human to the atmosphere?
A alveolus → bronchus → trachea
B alveolus → trachea → bronchus
C bronchus → alveolus → trachea
D trachea → alveolus → bronchus