ABEM Anatomy & Neurophysiology Flashcards
6 cards from real ABEM practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 ABEM Anatomy & Neurophysiology flashcards as text
Which ion channel is primarily responsible for the upstroke of a nerve action potential?
Answer: Voltage-gated sodium channels
Voltage-gated sodium channels open rapidly in response to membrane depolarization, driving the fast upstroke of the action potential.
The anterior interosseous nerve is a branch of which major nerve?
Answer: Median nerve
The anterior interosseous nerve arises from the median nerve in the proximal forearm and supplies the deep flexor compartment.
What is the resting membrane potential of a typical mammalian motor neuron?
Answer: -70 mV
The resting membrane potential of most mammalian neurons is approximately -70 mV, maintained by the Na+/K+ ATPase pump.
Which structure forms the myelin sheath in the peripheral nervous system?
Answer: Schwann cells
Schwann cells wrap around peripheral nerve axons to form the myelin sheath, enabling saltatory conduction.
The dorsal interossei muscles of the hand are innervated by which nerve?
Answer: Ulnar nerve
The dorsal interossei are innervated by the deep branch of the ulnar nerve and function to abduct the fingers.
At a node of Ranvier, the action potential jumps from one node to the next in a process called:
Answer: Saltatory conduction
Saltatory conduction describes the jumping of the action potential between nodes of Ranvier, greatly increasing conduction velocity.