1. Medical School Histology Basics Peripheral Nerve
VIBS 289 lab
Larry Johnson Texas A&M University

2. NERVOUS TISSUE FUNCTIONS: SPECIALIZED FOR THE TRANSMISSION, RECEPTION,
AND INTEGRATION OF
ELECTRICAL IMPULSES
DISTINGUISHING FEATURES:
NEURONS – VERY LARGE EXCITABLE CELLS WITH LONG PROCESSES CALLED AXONS AND DENDRITES. THE AXONS MAKE CONTACT WITH OTHER NEURONS OR MUSCLE CELLS AT A SPECIALIZATION CALLED A SYNAPSE WHERE THE IMPULSES ARE EITHER ELECTRICALLY OR CHEMICALLY TRANSMITTED TO OTHER NEURONS OR VARIOUS TARGET CELLS (e.g., MUSCLE). OTHERS SECRETE HORMONES.

3. NERVE IS LIKE EPITHELIUM ORIGIN OF NERVE IS ECTODERM LIKE EPIDERMIS (EPITHELIUM) OF SKIN

5. 492 Peripheral ganglion monkey
Myelinated axons

6. DEMO SLIDE BOX 76 . Ganglia, dog.
Nissl bodies =
cytoplasm for coarse
aggregates of basophilic substance =
Rough Endoplasmic
Reticulum and Polysomes
Nucleus contains a large, prominent nucleolus and an abundant amount of euchromatin
Satellite cells
Surrounding each cell body should be a variable number of nuclei of Satellite cells
= Neurons are metabolically active cells

7. 492
Peripheral ganglion
monkey
Nissl substance

8. 440
Ganglion cell bodies in pancreas

9. 29291
Bile ducts in monkey
Ganglion cell body in cystic bile duct
vein

10. DEMO SLIDE BOX 78. Dorsal root ganglion & nerve, cat
DEMO SLIDE BOX 78 . Dorsal root ganglion & nerve, cat. small ganglion and a cross-section of nerve

11. DEMO SLIDE BOX 78. Dorsal root ganglion & nerve, cat
DEMO SLIDE BOX 78. Dorsal root ganglion & nerve, cat. small ganglion and a cross-section of nerve
dark “dots” (these are the axons) surrounded by “white circles” (myelin sheath)

12. Remember Connective Tissue Layers of Skeletal Muscle
Epimysium, Perimysium, and Endomysium

13. Organization of Peripheral Nerves
Nerve fibers - axons invested by connective tissue
Epineurum - surrounding entire nerve
Perineurum - surrounding fascicles –
constitutes the PNS blood barrier via tight
junctions between fibroblasts
Endoneurum - between individual nerve axons

14. Organization of Peripheral Nerves

15. DEMO SLIDE BOX 78. Dorsal root ganglion & nerve, cat
DEMO SLIDE BOX 78 . Dorsal root ganglion & nerve, cat. small ganglion and a cross-section of nerve
Epineurum - surrounding entire nerve
Perineurum - surrounding fascicles –
Endoneurum - between individual nerve axons

16. Types of Nerves

17. bipolar neurons of the inner ear Slide HISTO0280 at the left hand side of the cochlea on the bottom circle
HISTO0280
Bipolar neurons

18. Duodenum (small intestine)
152
Nerve (Auerbach's plexus)
circular and longitudinal smooth muscle layers
Submucosal glands
mucosa
Gut lumen

19. Duodenum (small intestine)
152
Auerbach's plexus, which can be found in between the circular and longitudinal smooth muscle layers
Auerbach's plexus
Nerve cell bodies

20. 32409 Smooth muscle cells (Auerbach's plexus)Nerve cell bodies
epithelium
Smooth muscle
cells
Meissner’s plexus cell bodies
32409
(Auerbach's plexus)Nerve cell bodies

21. EM 10c: postganglionic neuronal cell body in an Auerbach’s plexus; 22,000x
Nissl substance
Neurosecretory vesicles

22. SCHWANN CELLS MYELIN

23. NODE OF RANVIER

24. DEMO SLIDE BOX 78. Dorsal root ganglion & nerve, cat
DEMO SLIDE BOX 78 . Dorsal root ganglion & nerve, cat. small ganglion and a cross-section of nerve
axons, myelin sheath, node of Ranvier
492
perineurium
Schwann
cell nucleus

25. Peripheral nerve, monkey nodes of Ranvier
193
Peripheral nerve, monkey nodes of Ranvier

26. 440
Nerve in connective tissue of a salivary gland
Perineurum

27. 492 Nerve
nodes of Ranvier

28. SCHWANN CELL STRUCTURE / FUNCTION

29. MYELINATION and SCHWANN CELLS

30. 109 Skin hand monkey nerve Fibroblasts nerve Endoneurum Perineurum

31. Nerves in tissues/organs
105
Nerves in tissues/organs
Nerves
109
105
Perineurum

32. 196
Human spermatic cord
with vessels and nerve

33. 196
spermatic cord UT 196
Nerve
Perineurum
Nerve

34. Perineurum EM 10d: Schwann cells and axons; 21,000x print Microtubule
Myelinated coat around a myelinated axon
Schwann cell cytoplasm around an unmyelinated axon
Vesicle in axoplasm
Nucleus of a Schwann cell

35. NEURONAL STRUCTURE / FUNCTION
Axonal transport
Anterograde - toward terminal - kinesin
Retrograde - toward cell body - dynein
Tetanus toxin
Neurotropic viruses (herpes and rabies) use path to get to cell body in CNS

36. Neuronal Structure / Function

37. Neuronal Structure/Function

38. : Skeletal muscle motor end plates Motor end plates in skeletal muscle
One nerve innervates several muscle cells
Slide HISTO007
Histo 07
Skeletal
muscle cells :
Skeletal muscle
motor end plates

39. Summary of the Physiological Events at the Synapse
Arrival of action potential
at axon terminal
Opening Ca++ channels
Influx of Ca++ into axon terminal
Exocytosis of neurotransmitter
Diffusion of neurotransmitter across synaptic cleft
Binding of neurotransmitter to receptors on target cell
Opening of Na+ channels causing depolarization of target cell
Removal of neurotransmitter

40. EM 10e: Nerve terminal on smooth muscle; 41,000x print
Synaptic cleft
Synaptic vesicles
Smooth muscle

41. 136 monkey tongue Skeletal muscle fibers (cells) Muscle spindles
Intrafusal muscle
fibers inside the capsule

42. Fingertip, monkey - sweat glands and ducts among Pacinian corpuscles
105
Fingertip, monkey - sweat glands and ducts among Pacinian corpuscles
Pacinian corpuscles

43. Skin hand monkey Hypodermis 109
url at
Adipocytes
Eccrine sweat glands
Hypodermis
Pacinian corpuscles
Dermal
papillae
Epidermal peg
Papillary layer

44. Slide HIST0 29: Thick Skin (ventral surface of finger)
Meissner’s corpuscles
in dermal papillae
Meissner’s corpuscle is a mechanoreceptor nerve ending for sensitivity to light touch; you would find more on your fingers because they are more sensitive to touch than your elbow.
Epidermis
Epidermis
Epidermal peg
Dermal papillae
Dermis

45. Histo 29
Meissner’s corpuscles
Slide HIST0 29

46. Slide 426: Renal artery and vein with nerves
Smooth muscle cells, peripheral nerve fibers and bundles of collagen fibers
Fibroblasts

47. 109 : Skin, hand, monkey Peripheral nerve fibers Fibroblasts
Smooth muscle cells
Bundles of collagen fibers
Fibroblast

48. Slide 196: Spermatic cord Peripheral nerve fibers Smooth muscle cells
Bundles of collagen fibers
White fat cells
Nerve
Smooth muscle cells

49. 34460 Human spermatic cord with nerve toluidine blue
Bundles of collagen fibers
Endothelium
Perineurum
Peripheral
nerve
fibers
Nerve
Smooth muscle
cells
Fibroblasts

50. Questions on nerves
Which is not a distinguishing feature of the nervous system
Comprise the central and peripheral nervous system.
Individual peripheral nerves are found in limited places in the body.
Individual neurons and clusters of neurons (called ganglia) are found in most organs
a and b
a, b, and c
Which embryonic origin – tissue type(s) match(s)?
Ectoderm – nerve
Endoderm – muscle
Mesoderm – nerve
a and b
a, b, and c

51. Many illustrations in these VIBS Histology YouTube videos were modified from the following books and sources: Many thanks to original sources!
Bruce Alberts, et al Molecular Biology of the Cell. Garland Publishing, Inc., New York, NY.
Bruce Alberts, et al Molecular Biology of the Cell. Garland Publishing, Inc., New York, NY.
William J. Banks, Applied Veterinary Histology. Williams and Wilkins, Los Angeles, CA.
Hans Elias, et al Histology and Human Microanatomy. John Wiley and Sons, New York, NY.
Don W. Fawcett Bloom and Fawcett. A textbook of histology. W. B. Saunders Company, Philadelphia, PA.
Don W. Fawcett Bloom and Fawcett. A textbook of histology. Chapman and Hall, New York, NY.
Arthur W. Ham and David H. Cormack Histology. J. S. Lippincott Company, Philadelphia, PA.
Luis C. Junqueira, et al Basic Histology. Lange Medical Publications, Los Altos, CA.
L. Carlos Junqueira, et al Basic Histology. Appleton and Lange, Norwalk, CT.
L.L. Langley, et al Dynamic Anatomy and Physiology. McGraw-Hill Book Company, New York, NY.
W.W. Tuttle and Byron A. Schottelius Textbook of Physiology. The C. V. Mosby Company, St. Louis, MO.
Leon Weiss Histology Cell and Tissue Biology. Elsevier Biomedical, New York, NY.
Leon Weiss and Roy O. Greep Histology. McGraw-Hill Book Company, New York, NY.
Nature ( Vol. 414:88,2001.
Arthur C. Guyton,1971.Textbook of Medical Physiology W.B. Saunders company, Philadelphia, PA
WW Tuttle and BA Schottelius Textbook of Physiology C.V. Mosby Co.
A.L. Mescher Junqueira’s Basis Histology text and atlas, 13th ed. McGraw

52. Big Bend National Park, TX

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