Question

question 52 (0.5 points)
the thoracic duct is responsible for collecting lymph from which of the following regions, and where does it drain the lymph?

• the lower body, left upper limb, left thorax, left side of the head; drains into the junction of the left subclavian and left internal jugular veins.
• the left upper limb, left thorax, left side of the head; drains into the left brachiocephalic vein
• the entire body except for the right upper limb, right thorax, and right side of the head; drains into the superior vena cava.
• the right upper limb, right thorax, and right side of the head; drains into the right subclavian vein

Explanation:

To solve this, we recall the function of the thoracic duct: it collects lymph from the lower body, left upper limb, left thorax, and left side of the head, and drains into the junction of the left subclavian and left internal jugular veins. Let's analyze each option:

• Option 1: Matches the known function of the thoracic duct.
• Option 2: Incorrectly states the drainage site (should be the junction of left subclavian and left internal jugular, not left brachiocephalic vein) and misses the lower body.
• Option 3: Incorrect drainage site (superior vena cava is wrong; it drains into the junction of left subclavian and left internal jugular).
• Option 4: Describes the right lymphatic duct, not the thoracic duct.

Answer:

A. The lower body, left upper limb, left thorax, left side of the head; drains into the junction of the left subclavian and left internal jugular veins.