Biology I - Nervous System - Structure of the Nervous System

Q: Damage to the spinal cord affects which division of the nervous system?

A: Central nervous system. brain and spinal cord together handle integration.

Q: A patient loses both sensation and motor control below a spinal injury. Which two neuron types are likely affected?

A: Afferent (sensory in) and efferent (motor out).

Q: Why would a brainstem lesion cause both impaired breathing and disrupted coordination?

A: It affects the medulla (vital signs) and cerebellum (coordination).

Q: In an embryo, a defect in the rhombencephalon will likely impact which adult brain functions?

A: Autonomic control (medulla), posture/balance (pons, cerebellum).

Q: If the midbrain is damaged but the forebrain is intact, what key function is most at risk?

A: Visual and auditory reflexes. midbrain integrates these responses.

Q: Which part of the brainstem acts as a relay between the cerebrum and cerebellum, and what is a clinical consequence of damage here?

A: Pons; damage impairs movement coordination and facial sensation/motor control, breathing, swallowing.

Q: A patient can still walk but can't maintain balance. Which structure is most likely impaired?

A: Cerebellum, which coordinates balance and movement fine-tuning.

Q: How do cranial and spinal nerves differ in function and origin?

A: Cranial handle head/neck from the brain; spinal serve body from spinal cord.

Q: Why are spinal nerves called “mixed nerves”?

A: They contain both sensory (afferent) and motor (efferent) fibers.

Q: Ganglia are affected in a viral infection causing pain and sensory loss. What does this imply about their function?

A: They house sensory neuron somas. damage impairs sensation.

Q: If spinal nerve roots are severed before merging, what happens to nerve function?

A: Sensory and motor functions are separately impaired, no “mixed” nerve.

Q: Why does nerve branching increase from proximal to distal in the body?

A: More precise targeting of peripheral tissues and organs