Basic Neuroanatomy 2 Flashcards
What is the difference between white matter and grey matter in the spinal cord?
White Matter: Contains axons (nerve fibers).
Grey Matter: Contains neuronal cell bodies.
Name the functional regions of the spinal cord grey matter.
Dorsal (posterior) horn: Sensory processing.
Intermediolateral horn: Sympathetic preganglionic neurons.
Ventral (anterior) horn: Motor output.
What are Rexed’s Laminae, and what are their roles?
Lamina I–VI: Sensory processing.
Lamina VII: Autonomic functions (preganglionic sympathetic neurons).
Lamina VIII & IX: Somatic motor output.
Lamina X: Surrounds the central canal.
How do somatomotor pathways function?
Afferent fibers: Sensory input from skin/muscle → Dorsal root → Dorsal horn.
Efferent fibers: Motor output → Ventral horn → Ventral root → Skeletal muscle.
How do visceromotor pathways function?
Afferent fibers: Sensory input from organs → Dorsal root ganglia → Deeper in dorsal horn.
Efferent fibers: Preganglionic neurons → Ventral root → Autonomic ganglion → Target organs.
What are the layers of connective tissue around peripheral nerves?
Endoneurium: Surrounds individual axons.
Perineurium: Encases bundles of axons.
Epineurium: Dense outer layer enclosing bundles and blood vessels.
What are the three meninges covering the CNS?
Dura Mater: Tough, protective outer layer.
Arachnoid Mater: Web-like, supports CNS, contains CSF in subarachnoid space.
Pia Mater: Thin, vascularized layer that clings tightly to CNS.
What are the main functions of cerebrospinal fluid (CSF)?
Cushions the CNS.
Provides buoyancy to the brain.
Nourishes and removes waste from CNS.
Where is cerebrospinal fluid (CSF) produced?
Produced by choroid plexuses in the walls and roofs of the brain ventricles.
How is CSF circulated?
Ventricles → Subarachnoid space.
Flows through arachnoid villi into venous sinuses.
What are the ventricles of the brain, and how are they connected?
Lateral ventricles → Third ventricle (via Foramina of Monro).
Third ventricle → Fourth ventricle (via Cerebral Aqueduct).
What is the cauda equina?
A collection of nerve roots extending from the lower end of the spinal cord (below L1/L2).
What is hydrocephalus, and how is it treated?
Excess CSF due to overproduction, flow blockage, or drainage obstruction.
Treated with a shunt to drain fluid, e.g., into the peritoneal cavity.
What is meningitis?
Inflammation of the meninges due to bacterial or viral infection.
How many pairs of spinal nerves are there?
31 pairs:
Cervical (8), Thoracic (12), Lumbar (5), Sacral (5), Coccygeal (1).
