Hand Anatomy

A 29-year-old woman presents with difficulty performing fine motor tasks like buttoning her shirt and picking up small objects with her right hand. She reports that she can no longer "pinch" or "oppose" her thumb properly. On examination, there is noticeable wasting of the thenar eminence. Sensation over the lateral three and a half fingers is also reduced on the palmar side. There is no hypothenar muscle atrophy. Which of the following sets of muscles is most likely affected, and what is their nerve supply?

• Abductor pollicis brevis, Flexor pollicis brevis, Opponens pollicis — Supplied by Recurrent branch of median nerve

• Abductor pollicis brevis, Flexor pollicis brevis, Opponens pollicis — Supplied by anterior interosseus branch of median nerve

• Abductor pollicis brevis, Flexor pollicis brevis, Opponens digiti minimi — Supplied by deep branch of ulnar nerve

• Abductor digiti minimi, Flexor pollicis brevis, Opponens digiti minimi — Supplied by deep branch of ulnar nerve

A 22-year-old medical student is asked to abduct her fingers during a neuro exam. She is unable to abduct her middle finger in either direction. Which muscle group is likely affected?

• Thenar muscles

• Lumbricals

• Dorsal interossei

• Palmar interossei

A patient with a deep laceration to the palm is unable to adduct her 4th and 5th digits. Which intrinsic hand muscles are likely involved?

• Dorsal interossei

• Palmar interossei

• Thenar group

• Lumbricals 1 & 2

A 25-year-old woman falls on an outstretched hand and develops numbness in her lateral 3½ fingers. She can’t oppose her thumb. Which branch of the median nerve is affected?

• Palmar digital branch

• Recurrent motor branch

• Anterior interosseous nerve

• Dorsal cutaneous branch

A 60-year-old man presents with weakness in finger adduction and atrophy of the hypothenar muscles. Where is the likely site of ulnar nerve compression?

• Cubital tunnel

• Guyon’s canal

• Carpal tunnel

• Radial groove

A 38-year-old woman presents with pallor and coldness of the thumb following a traumatic wrist laceration. On examination, there is reduced capillary refill in the thumb, and Doppler ultrasound shows compromised blood flow from the radial artery. Which branch of the radial artery is primarily responsible for supplying the thumb, and is likely compromised in this patient?

• Common digital artery

• Deep palmar arch

• Princeps pollicis artery

• Palmar metacarpal artery

A 58-year-old man with chronic congestive heart failure presents with bilateral hand swelling and visible distention of superficial veins. Examination suggests impaired venous return from the upper limbs. Which superficial veins are primarily responsible for draining venous blood from the hand?

• Cephalic and basilic veins via the dorsal venous network

• Radial and ulnar veins

• Digital veins only

• Palmar venous plexus only

During carpal tunnel surgery, a surgeon accidentally injures the recurrent branch of the median nerve. Which of the following will the patient most likely experience?

• Loss of sensation over the palmar thumb

• Atrophy of the hypothenar muscles

• Inability to adduct the thumb

• Thenar muscle weakness and loss of thumb opposition

A young boy is brought to the clinic with difficulty flexing the tips of his fingers. On examination, he is unable to flex the distal interphalangeal (DIP) joints, but retains the ability to flex the proximal interphalangeal (PIP) joints.

• Flexor digitorum superficialis – Median nerve

• Flexor digitorum profundus – Median and ulnar nerves

• Lumbricals – Median nerve

• Interossei – Ulnar nerve

Following wrist trauma, a patient has poor capillary refill and absent radial pulse. Thumb and lateral index finger are pale and cool. Which arterial branches are compromised?

• Princeps pollicis and radialis indicis

• Common digital arteries

• Superficial palmar arch

• Palmar metacarpal arteries