Taste, Swallow, and Speak!
This cranial nerve carries taste sensation from the posterior one-third of the tongue.
Glossopharyngeal nerve (CN IX)
These specialized vascular structures in the brain ventricles produce most cerebrospinal fluid.
Choroid plexuses
The spinal cord has 31 pairs of spinal nerves. Divide them into all five regional groups and provide the number of pairs in each.
8 cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal
A microscope reveals dark-staining patches of rough endoplasmic reticulum in a neuronal soma. Identify these structures and explain their general role.
Nissl bodies (Nissl substance) — protein synthesis
This major brain structure lies posterior to the pons and medulla and contains two hemispheres joined by a vermis.
Cerebellum
This mixed cranial nerve supplies important motor functions for swallowing and phonation through muscles of the pharynx and larynx.
Vagus nerve (CN X)
Cerebrospinal fluid passes from each lateral ventricle into the third ventricle through these openings.
Interventricular foramina (of Monro)
A spinal sensory neuron has its cell body in one structure, while its axon enters the spinal cord through another. Name both.
Posterior root ganglion (DRG) — cell body; posterior root — sensory axon
A sensory neuron has a single process that splits into peripheral and central branches. Identify its structural classification and a common location for its soma.
Pseudounipolar neuron — posterior root ganglion
This prominent groove separates the frontal lobe from the parietal lobe of the cerebrum.
Central sulcus
Damage to one nerve eliminates taste from the anterior two-thirds of the tongue while posterior taste remains intact. Which cranial nerve is primarily affected?
Facial nerve (CN VII)
CSF travels from the third ventricle to the fourth ventricle through this narrow passage located within the midbrain.
Cerebral aqueduct
A selective injury damages the anterior spinal nerve root without damaging the posterior root. Predict the principal type of neurological deficit and explain why.
Motor weakness or paralysis because the anterior root contains efferent motor axons; sensory fibers enter through the posterior root
One CNS glial cell can myelinate portions of several axons, whereas the corresponding PNS glial cell myelinates one axonal segment. Name both.
Oligodendrocyte (CNS) and Schwann cell (PNS)
This large bundle of commissural white matter connects the right and left cerebral hemispheres.
Corpus callosum
This mixed cranial nerve provides major parasympathetic innervation to thoracic and abdominal organs and also supplies muscles of the larynx.
Vagus nerve (CN X)
CSF leaves the fourth ventricle through these two types of apertures to enter the subarachnoid space around the brain and spinal cord.
Median aperture and lateral apertures
The anterior and posterior rami are both mixed, yet they supply different regions. Identify the general distribution of each.
Posterior rami supply deep back muscles and overlying skin; anterior rami supply the anterolateral trunk and limbs
Name the three CNS glial cell types that correspond to these functions: lining ventricles, supporting the blood-brain barrier, and phagocytosing cellular debris.
Ependymal cells, astrocytes, and microglia, respectively
Identify the three major regions of the brainstem, starting superiorly and moving inferiorly toward the spinal cord.
Midbrain → Pons → Medulla oblongata
Patient A loses taste from the posterior third of the tongue. Patient B develops hoarseness and difficulty swallowing following an injury involving laryngeal and pharyngeal motor pathways. Identify the most relevant cranial nerve for each patient.
Patient A: CN IX (Glossopharyngeal). Patient B: CN X (Vagus)
During embryonic brain development, identify the secondary brain vesicles produced by the prosencephalon and rhombencephalon. Then identify the primary vesicle that retains its name as a secondary vesicle.
Prosencephalon → telencephalon + diencephalon; rhombencephalon → metencephalon + myelencephalon; mesencephalon remains mesencephalon
A patient experiences reduced sensation over a region that follows one spinal nerve level, although some sensation remains because neighboring levels overlap. What anatomical map describes the region, and why does complete sensory loss not necessarily occur?
Dermatome map — neighboring sensory root territories overlap, providing some shared cutaneous innervation
Three tissue samples are examined. Sample A contains myelinated axons in CNS white matter. Sample B contains myelinated axons in a peripheral nerve. Sample C contains sensory neuron somas surrounded by supporting cells in a spinal ganglion. Name the characteristic glial cell for each sample.
A: Oligodendrocytes. B: Schwann cells. C: Satellite cells.
In a midsagittal view, the fourth ventricle is located between two major anatomical structures. Identify its anterior relationship and the structure posterior to it.
Pons and upper medulla anteriorly; cerebellum posteriorly