11 topics with brief reviews: definitions, key facts, and class questions.
In this section, we examine the microscopic structure of the peripheral nervous system and the spinal cord. You will learn how the somatic and autonomic nervous systems are structurally organized, and trace the pathway of an impulse through sympathetic, parasympathetic, and metasympathetic reflex arcs in detail.
We will systematically study the tissue composition of the peripheral nerve and learn to distinguish spinal and sympathetic ganglia under a microscope. A separate module is dedicated to the spinal cord, covering everything from its embryonic development and meninges to the topography of grey and white matter. You will analyze the neuronal composition of the nuclei, with a special emphasis on motor neurons of the ventral horns.
Instructor's tip: in practical classes and exams, you will most frequently be asked to differentiate between a spinal ganglion and an autonomic ganglion on histological specimens, as well as to flawlessly draw diagrams of reflex arcs, linking them to specific horns and funiculi of the spinal cord. Pay utmost attention to these topics.
What is the difference between white matter and gray matter?
Gray matter consists of clusters of neuron cell bodies in the central nervous system (nuclei and cortex). White matter consists of nerve fibers (processes) that form conduction tracts.
Where are the cell bodies of ANS effector neurons located?
Their cell bodies are always located outside the central nervous system — in specialized autonomic ganglia.
Where are the cell bodies of central sympathetic neurons located?
In the lateral horns of the spinal cord at the level of all thoracic and the upper three lumbar segments ($T_1$–$L_{III}$).
Can Dogiel cells be distinguished from each other under a microscope during class?
No, on standard slides (hematoxylin-eosin staining) it is impossible to distinguish sensory, association, and effector neurons. Special impregnation methods are required for this.
Why does the myelin sheath look empty and pale in a histological slide (hematoxylin-eosin)?
Alcohols are used during the histological preparation processing. They completely dissolve lipids, which comprise myelin, leaving a light uncolored space in place of the sheath under the microscope.
Where are the neuronal cell bodies localized within the spinal ganglion?
The neuronal cell bodies lie in groups predominantly at the periphery of the ganglion, directly beneath the connective tissue capsule.
Master the entire topic in the "Histology" course
This is a summary. The course covers everything tested in classes and exams.
3,485 pages of study guides for all topics
Assignments and quizzes after every topic — just like in a colloquium