Blood from the face and scalp is drained by the:
A.
Superior vena cava.
B.
Subclavian vein.
C.
External jugular vein.
D.
Cephalic vein.
The Correct answer and Explanation is:
The correct answer is:
C. External jugular vein.
Explanation:
The external jugular vein is primarily responsible for draining blood from the face and scalp. It is one of the key veins in the venous drainage system of the head and neck. The external jugular vein begins near the angle of the mandible (jaw) and runs down the side of the neck, just beneath the skin. It is formed by the union of the posterior division of the retromandibular vein and the posterior auricular vein. As it descends, it crosses the sternocleidomastoid muscle and eventually drains into the subclavian vein.
Anatomy and Function:
- Face and Scalp Drainage: The external jugular vein receives blood from the superficial parts of the face, scalp, and some areas of the neck. Smaller veins from the scalp and face, such as the occipital vein, superficial temporal vein, and maxillary vein, contribute to the external jugular vein.
- Clinical Relevance: The external jugular vein is often visible on the surface of the neck and can be used for medical procedures like central venous access in emergencies. It is also an important indicator of venous pressure; distension of the external jugular vein may indicate conditions like congestive heart failure.
The other options are incorrect as they do not directly drain blood from the face and scalp:
- A. Superior vena cava: Drains blood from the upper body, including the head and neck, but it does not directly receive blood from the face and scalp. Instead, it receives blood from the subclavian and internal jugular veins.
- B. Subclavian vein: Collects blood from the arm, shoulder, and the external jugular vein, but is not directly involved in draining the face and scalp.
- D. Cephalic vein: A superficial vein of the upper limb, primarily draining the arm, and has no role in draining the face or scalp.
In summary, the external jugular vein is the primary vessel responsible for draining blood from the face and scalp, making it the correct choice in this context.