mikey neuro 1stshift practical

8/3/2019 Mikey Neuro 1stshift Practical

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L/S of nerve fascicle

Neurilemma(sheath of schwann

( with endonuerium?-pointer)

L/S of nerve fascicle

Perinerium w/vaso nervorum

(pointer)

x/s of myelinated nerve fibersvaso nervosum(pointer)

x/s of several nerve fascicles

epineurium(pointer)

Neural tube&

Notochord(pointer)

x/s of nerve fascicles

perineurium pointer

L/s of myelinated nerve fibers

Node of ranvier(pointer)

Neural tube and notochord(pointer)

Anterior neuropore pointer

L/s of nerve fascicle

Node of ranvier pointer


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L/s myelinated nerve fiber

Node of ranvier(pointer)

Neural tube

Prosencephalon(pointer)

HE stain muscle fibers-polygonal appearance

-subsarcolemmal nucleus

-pointer at endolysial blood

vessel

Neural tube pointer w/ notochord below

Neural tube notochord somites(pointer)

Telencephalic vesicle pointer

From prosencephalon

x/s myelinated fiber

axis cylinder pointer

x/s nerve fascicles perineurium

x/s sevrd nerve fascicles

epineurium(pointer)


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Medullated. Nerve trunk l.s

Paraxial Mesoderm

Muscle

Ls nerve fascicle

Node of ranvier

Muscle vasa nervorum at pointer

Neural cavity

Notochord(pointer) and neural tube

Perineurium

Neural tube


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Somite

Smooth muscle

Sacral

Cervical

Cervical spine

Sacral2

Sc thoracic

Sc cervical

Sc lumbar

Sc sacral


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Neuroanatomy Practical Notes: Shift 1

Spinal Cord-commences at the level of the foramen magnum-Foramen Magnum

- Opening at the base of the skull- Above=brain; below=cord- demarcates the junction of the brain and cord

-Spinal Cord- terminates at a conical expanded area Conus Medullaris- Lower border ends at the level of the adult 1st LV or in between L1-L2

*Lumbar Vertebra- has a hatchet (rectangular) shaped spine that points horizontally;kidney shaped body*Thoracic Vertebra- spine is thin, long and points downwards; heart shaped body

*Cervical Vertebra- bifid spines, presence of transverse foramens (vertebral artery)*Atlas- (C1) no spine and body; wide vertebral foramen*Axis (C2) has a very small body with a protrusion (Dens) which articulates with the

atlasParts of the Vertebra

1. Body2. Pedicel3. Transverse Process- in between pedicel and lamina4. Lamina5. Spine6. Intervertebral Disc- when one vertebra is placed one on top of the other, this is

the intervening structure that pushes the two together7. Supraspinous Ligament- joins spines together, they line the tip of the spine8. Interspinous Ligament- intervening ligament that joins the bodies of the vertebra

9. Ligamentun Flavum- breach the laminae of the vertebrae above and thevertebrae below

10. Intervertebral Foramen- opening formed when the individual vertebra are placedone on top of the other

a. Significance: exit of spinal nerves (not roots*)*from the spinal cord before the foramen, there are only roots; it is only after it goes outof the foramen that it becomes spinal nerves

11. Vertebral Foramen12. Vertebral Canal- formed by several vertebral foramina put one on top of the

other; spinal cord in located inside

*Cauda Equina- lower lumbar and sacral dorsal and ventral nerve roots that will have to

go to their corresponding intervertebral foramina below, for them to exit-spinal nerve roots because the have not yet exited the intervertebral foramina

Spinal Cord (cross section)

-outer is white matter; inner is gray matter (H-shaped)-In the slide, white matter is darkly colored and gray matter is lightly colored because ofthe stain used-Ependymal cells-line the central canal


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-identify1. Ventral Median Fissure2. Central Canal3. Dorsal Column4. Lateral Funiculus5. Ventral Funiculus

6. Dorsal Gray Horn7. Ventral Gray Horn8. Intermediate Zone

Gray Matter-contains nerve cell bodies (nuclei)-divided into 3 parts

-Dorsal Horn-Somatosensory-Rexed Lamina 1-6 and Dorsal Nucleus of Clark (which actually

belongs to Lamina 7, and conveys UNCONSCIOUS propioception thru the DorsalSpinocerebellar Tract)

-Intermediate Zone

-Autonomic; T1-L2; Sympathetic Preganglionic Efferents-B fibers

-short conduction velocity; thinnest myelin sheath; motorfunction

-IMM; IML; Sacral Autonomic Nuclei-Rexed Lamina 7, 10 (surrounds the central canal)

-Ventral Horn-Somatomotor-Rexed Lamina 8,9-Motor Neurons A (alpha/gamma); primarily located in lamina 9

-Medial Motor Neuron Group*-Lateral Motor Neuron Group*

*Proximal-Distal Rule1. Medial Motor Neurons- will supply the medially proximally located muscles of

the body which will be the neck, trunk, and girdle muscles (shoulder, pelvic)2. Lateral Motor Neurons- will supply muscles that are laterally distally located,

both upper and lower extremities (hands, feet)

White Matter- contains the numerous fiber tracts-can be divided into 3 groups

1. Ventral Funiculus- b/w ventral median fissure and ventrolateral sulci2. Dorsal Column- b/w dorsal median sulcus and dorsolateral sulci3. Lateral Funiculus- b/w dorsolateral and ventrolateral sulci

-Fiber tracts- ascend and descendAscending-usually sensory*Descending-usually motor8*

*not always

Dorsal Column-purely ascending fiber tracts (sensory)-associated with CONSCIOUS propiopception, fine touch, & vibration sense


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-A-alpha fibers-division of Dorsal Column

1. Fasciculus Gracilis*-medially located- Conscious propioception from lower trunk and extremities

2. Fasciculus Cuneatus*- laterally located- Conscious propioception from upper trunk and extremities

* The dorsal intermediate sulcusis found between the fasciculus gracilis and cuneatusonly at the cervical and mid-thoracic level. At the lumbar level, there are no fibers fromthe upper trunk/extremitiesonly fibers from the lower extremities

Ventral and Lateral Funiculi- Ventral Funiculus-look for ventral median fissure- Lateral Funiculus-can be seen without looking under a microscope- Both ascending and descending tracts- Ascending

-spinal cord to the thalamus to the cortex

1. Lateral Spinothalamic Tract- fibers for pain and temperature

a. Receptor- Free Nerve Endingsi. Nociceptors/ Thermoreceptors

1. peripheral nerve fibers A-delta & C enter the spinalcord as the dorsal root, which will then synapse at thesensory nucleus in the dorsal horn that will ascend asthe lateral spinothalamic tract in the lateral funiculus forpain and temperature sensation

2. Ventral Spinothalamic Tract- fibers for crude toucha. Receptor- Mechanoreceptors

i. Peripheral nerve fibers A-beta will synapse at the sensory

nucleus, will ascend as the ventral spinothalamic tract in theventral funiculus.

-Descending-Corticospinal Tract- for movement; from the cortex down to the cord

1. Ventral Corticospinal Tracta. Ventral Funiculusb. Trunk muscles

2. Lateral Corticospinal Tracta. Lateral Funiculusb. Lower and upper extremities

Spinal Cord Slides

1. Cervicala. Relatively small dorsal and ventral hornb. Thick dorsal, lateral, and ventral funiculusc. White matter is thicker compared to the grayd. No lateral horn

2. Thoracic


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a. Intermediolateral Cell Column is found here T1-L2b. Sympathetic Preganglionic Efferentsc. Will appear as the LATERAL HORN(only found in thoracic)d. Ventral Horn and Dorsal Horn are thine. White Matter is Thick

3. Lumbara. Thicker gray, Thinner white matterb. Thin ventral funiculus & Thin lateral funiculusc. Wide Ventral Horn; Thin Dorsal Horn

mikey neuro 1stshift practical

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