Peripheral nerves and Dermatomes + Cubital Fossa and Elbow Region

What is the difference between a sensory and motor nerve root?

Sensory root is dorsal; motor root is ventral

How is a mixed nerve formed in the peripheral nervous system?

By the joining of the dorsal (sensory) and ventral (motor) roots

Which statement best describes the difference between the anterior (ventral) ramus and posterior (dorsal) ramus?

The anterior ramus forms mixed nerves to limbs and anterior body; the posterior ramus mainly supplies deep back muscles

Which of the following nerves primarily supplies the anterior surface of the arm?

Musculocutaneous nerve

The radial nerve primarily innervates which area?

Posterior arm and forearm muscles and skin

The supraclavicular nerve, which supplies the upper chest wall and part of the shoulder, arises from which spinal nerves?

C3 and C4

The palmar branch of the median nerve provides sensation to which area?

The thumb and lateral two and a half fingers

Which nerve supplies the medial side of the hand including the little finger?

Ulnar nerve

Which of the following best defines a dermatome?

An area of skin supplied by a single spinal nerve

Which dermatome corresponds to the lateral (thumb) side of the hand?

C6

Dermatomes T1 and T2 mainly supply which region of the upper limb?

Medial arm

Dermatomes often overlap. Which pair below represents a common overlap?

C3 and C4

Herpes zoster (shingles) arises due to reactivation of which virus in which anatomical location?

Varicella-zoster virus in the dorsal root ganglia

What clinical feature helps differentiate herpes zoster rash from other skin rashes?

Rash strictly confined to a dermatome with sharp borders

Which spinal nerve dermatomes are most commonly involved in herpes zoster affecting the upper limb and shoulder?

C3 to T2

Which of the following nerves is NOT considered one of the five major mixed nerves of the upper limb?

Sciatic nerve

The motor supply to the muscles controlling thumb movements is primarily from which nerve?

Median nerve

The olecranon of the ulna fits into which structure of the humerus?

Olecranon fossa

Why can ossification centers at the elbow be confused with fractures in children’s X-rays?

They appear as separate bone ossification centers resembling fracture lines

The cubital fossa is located at which anatomical site?

Anterior hollow of the elbow joint

Which vein commonly crosses the cubital fossa and is often used for venepuncture?

Median cubital vein

Golfer’s elbow is inflammation of which structure?

Medial epicondyle and flexor muscles

Tennis elbow involves inflammation of which region?

Lateral epicondyle and extensors

What is "student's elbow" primarily caused by?

Bursitis over the olecranon due to prolonged pressure

Bursae are best described as:

Fluid-filled sacs that reduce friction around joints