Q 01/05

Blood travels around the human body in which two major circuits?

A) Arterial and venous

B) Pulmonary and systemic

C) Cardiac and lymphatic

D) Coronary and cerebral

Answer · why

B) Pulmonary and systemic

Pulmonary and systemic loops are joined end to end, so every full lap takes blood through the heart twice, once bound for the lungs and once for the r...

Q 02/05

What is the largest artery in the human body?

A) The carotid

B) The aorta

C) The femoral

D) The coronary

Answer · why

B) The aorta

The aorta has a stretchy wall that swells with each surge from the heart and then springs back, which keeps blood moving between beats and smooths the...

Q 03/05

Which two large veins return deoxygenated blood from the body to the right atrium?

A) The jugular and femoral veins

B) The superior and inferior vena cava

C) The subclavian and iliac veins

D) The hepatic and renal veins

Answer · why

B) The superior and inferior vena cava

The superior and inferior vena cava are named for position, not rank: 'inferior' only means lower, and the inferior vena cava, which drains the legs a...

Q 04/05

Blood on its way out from the heart reaches the capillaries through which small vessels?

A) Venules

B) Arterioles

C) Sinusoids

D) Lymphatics

Answer · why

B) Arterioles

Arterioles have muscular walls that tighten or relax to control how much blood reaches each capillary bed, and that squeeze makes them the main place ...

Q 05/05

Most capillaries are so narrow that red blood cells can only pass through them how?

A) In single file

B) Two abreast

C) In short stacks

D) As broken fragments

Answer · why

A) In single file

In single file is the only way through a vessel barely wider than one red cell, and the narrowest are tighter still, so the flexible cells have to ben...