Week 1 Neuroanatomy Lecture Notes

30 flashcards covering key concepts from Week 1 Neuroanatomy lecture notes including CNS/PNS, neurons, glial cells, autonomic/enteric systems, meninges, ventricles, CSF, and related structures.

What are the two main divisions in the anatomical classification of the nervous system?

Central nervous system (brain and spinal cord) and peripheral nervous system (everything else).

What is the primary function of the peripheral nervous system?

To link all parts of the body to the central nervous system.

What is the basic functional unit of the nervous system?

The neuron.

What are the two main parts of a neuron?

Nerve cell body and axon.

Where are motor neuron cell bodies located?

In the CNS (ventral horn of the spinal cord for spinal nerves; brainstem nuclei for cranial nerves).

What are fiber tracts and what do they form in the CNS?

Bundles of axons that form white matter.

What are nerve cell body bundles in the CNS called?

Nuclei (gray matter) when referring to aggregates of neuronal cell bodies.

What are the two major types of nerves in the peripheral nervous system?

Cranial nerves (12 pairs) and spinal nerves (31 pairs).

Where are the sensory neuron cell bodies for spinal nerves located?

In the dorsal root ganglia outside the spinal cord.

Where are the sensory neuron cell bodies for cranial nerves located?

In the sensory ganglia associated with the cranial nerves.

What are the general somatic sensory receptors and where are they found?

Located in skin, skeletal muscles, and joints; detect pain, temperature, tactile sense, proprioception, vibration, tickle, itch.

What are the somatic special sensory receptors?

Receptors for vision (retina), olfaction (nose), hearing and balance (inner ear).

Which special sense belongs to the autonomic system rather than the somatic system?

Taste.

What does afferent versus efferent mean in neural signaling?

Afferents carry information toward the CNS; efferents carry information away from the CNS.

What are the main functional subdivisions of the nervous system?

Somatic nervous system, autonomic nervous system, and enteric nervous system.

What is the enteric nervous system?

A subdivision of the autonomic nervous system; a 'gut brain' capable of substantial autonomous activity.

Name the two major enteric plexuses.

Submucosal (Meissner’s) plexus and myenteric (Auerbach’s) plexus.

How do autonomic sensory receptors differ from somatic receptors?

Autonomic receptors sense internal bodily states and are largely unconscious; visceral pain is an exception.

What are Schwann cells and what do they do?

Glial cells in the PNS that produce myelin around axons.

What are satellite cells?

Glial cells that cover sensory neuron cell bodies in ganglia; cushion and regulate diffusion.

Which glial cells produce myelin in the CNS?

Oligodendrocytes.

Which glial cells regulate the blood-brain barrier and synapses in the CNS?

Astrocytes.

What are microglia?

Immune cells of the CNS; phagocytose debris and present antigens.

What are ependymal cells?

Line the ventricles; contribute to the choroid plexus and CSF production.

What are the three meninges surrounding brain and spinal cord?

Dura mater, arachnoid mater, and pia mater.

What is the subarachnoid space?

Space between the arachnoid and pia maters through which CSF circulates.

What are dural venous sinuses?

Venous channels within the dura that carry venous blood and drain into the internal jugular veins (e.g., superior sagittal sinus).

Name the major meningeal folds.

Falx cerebri, tentorium cerebelli, and falx cerebelli.

Where is CSF produced and how does it circulate?

Produced by choroid plexus in the ventricles; flows through ventricles into the subarachnoid space around brain and spinal cord; reabsorbed via arachnoid villi into dural venous sinuses and drains to the internal jugular veins.

What is the approximate CSF volume and turnover in adults?

Approximately 140 mL; turnover about 3–4 times per day (roughly 0.5 L/day).

How does CSF differ from plasma in composition?

Similar in Na, Cl, pH, osmolarity, and oxygen; lower potassium; less protein; about half the glucose.