Neuroanatomy, Cells & Development
This type of nervous system tissue contains mostly neuron cell bodies, dendrites, and synapses, while the other type contains mostly myelinated axons.
What is gray matter?
This division of the nervous system automatically regulates functions such as heart rate, blood pressure, sweating, digestion, pupil size, body temperature, and reproductive functions.
What is the autonomic nervous system?
A patient closes their eyes and can identify whether their wrist is flexed or extended without looking.
What is proprioception?
These neurons are the final common pathway from the nervous system to skeletal muscle.
What are lower motor neurons?
This structure helps make movement smooth, accurate, coordinated, and well timed, but does not directly activate muscles.
What is the cerebellum?
A patient has damage near the boundary between the frontal and parietal lobes. This sulcus would be the key landmark separating those two lobes.
What is the central sulcus?
A clinician explains that autonomic regulation generally follows a reflex-like sequence beginning with detection and ending with an organ-level response. Name the four major steps in order.
What are receptor detection, afferent pathway, CNS processing, and efferent pathway to effector tissue?
A patient can feel that something touched the hand, but cannot identify whether one or two nearby points touched the skin.
What is impaired two-point discrimination?
An alpha motor neuron innervates this type of muscle fiber, while a gamma motor neuron innervates this type.
What are extrafusal fibers and intrafusal fibers?
This cerebellar movement region is linked with the vestibular system and is especially important for equilibrium and balance.
What is the vestibulocerebellum?
A weak depolarizing input occurs repeatedly at the same synapse in a short time window until the neuron reaches threshold.
What is temporal summation?
A patient has referred pain during appendicitis because internal sensory signals interact with this type of pathway after entering the CNS.
What are somatosensory neurons or somatosensory pathways?
A patient has sensory loss that follows a spinal root pattern rather than the distribution of a named peripheral nerve.
What is dermatomal sensory loss?
During elbow flexion, the biceps contracts while the triceps is inhibited. This spinal mechanism allows smooth agonist-antagonist coordination.
What is reciprocal inhibition?
This cerebellar region is associated with the dentate nucleus and is especially important for motor planning and fine distal voluntary movement.
What is the cerebrocerebellum?
During development, this embryonic structure becomes the central nervous system, while a nearby migratory population contributes heavily to peripheral nervous system structures.
What is the neural tube?
A patient’s carotid body detects low blood oxygen and sends information through cranial nerve IX to the solitary nucleus. This is an example of this type of incoming autonomic information.
What is visceral afferent information?
A patient loses pain and temperature sensation from one side of the body after a spinal cord lesion. This pathway is most likely affected.
What is the anterolateral column pathway?
A tendon tap quickly stretches a muscle, activating muscle spindle afferents and causing contraction of the same muscle through alpha motor neurons.
What is the phasic stretch reflex?
This basal ganglia pathway allows the selected movement to occur, while another pathway suppresses competing unwanted movements.
What is the Go pathway/direct pathway?
A developmental error affects the mesoderm-derived structure that contributes to vertebrae, skeletal muscle, and dermis. Name the structure and its three subdivisions.
What is the somite: sclerotome, myotome, and dermatome?
A neurologic lesion affects parasympathetic output from the brainstem and sacral spinal cord. Give the anatomical name for this outflow and identify the major cranial nerves involved.
What is craniosacral outflow: cranial nerves III, VII, IX, and X, plus S2–S4?
A patient has impaired vibration sense, conscious proprioception, and difficulty identifying an object in the hand without vision. Name the pathway and where its second-order neurons cross.
What is the dorsal column/medial lemniscus pathway, and it decussates in the medulla?
A patient has impaired isolated wrist extension, toe extension, ankle dorsiflexion, and intrinsic hand control. This specific descending tract is most likely affected.
What is the lateral corticospinal tract?
A patient has difficulty selecting the appropriate action while suppressing competing actions. Their problem is less about movement accuracy and more about action selection, initiation, and inhibition.
What is basal ganglia dysfunction?