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PATH 693 - CNS (Reference Wheater's) 00:00:00 Anterior Pituitary (pg 330) - PITUITARY is NOT part of CNS, but it's included

because NEUROSURGEONS are responsible for taking it out!

arranged in nests! Multiple cell types

! basophilic (darker cells)! eosinophilic (lighter cells)

! Most common lesion = Pituitary ADENOMA (will look different and be allone cell type)

!

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!

Posterior Pituitary (pg 332)! Makes OXYTOCIN and VASSOPRESSIN (ADH)! Herring bodies = round inclusions containing the hormone secretions

!

Distended terminations of the axons where neurosecretory granulescontact capillaries ! Cystic structures = remnants of embryologic medial pituitary lobe

! Can enlarge and become a cyst (which can be clinicallysymptomatic)

Spinal cord! CLEFT = ANTERIOR = motor nerve bers (posterior = sensory)! Large ANTERIOR spinal artery - main blood supply! *Don't get confused with rami when it comes out b/c those are mixed

nerves Medulla! lining by 4th ventricle = ependymal cell lining

! Ependymal cells are epithelial cells! Useful landmarks:

! Inferior Olive /Inferior Olivary (squiggle) - made up of neurons! Take sections for autopsy

! Pyramids = main motor descending ber tract (white matter tracts)! Neurons (Gray Matter) = light pink (i.e., Cortex)!

White matter tracts = dark pink! Dorsal nucleus of the Vagus = pigmented nuclei

Pons! can see the 4th ventricle! Locus ceruleus = pigmented nuclei (take sections for autopsy)

Midbrain! Substantia nigra = pigmented nuclei ! cerebral aqueduct (lined by ependymal cells)! Cerebral peduncles = main descending white matter tract

Cerebellum! vermis (midline)! cause vermal atrophy*

! Alcohol ! Dylantin or Phenytoin (anti-epileptic drug) ! Heavy metal poisoning (mercury) ! Spinocerebellar ataxias

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! Cortex (3 Layers)! Molecular layer - pink layer ! Purkinje cells - big (neuron) cells, fairly easy to recognize ! Granular la yer - on the inside (are also neurons, but they don't have

big nucleoli like the ??paraminal? ?pyramidal?? neurons do) ! Bergmann Glia (astrocytes that proliferate when u have loss of

purkinje cells)! Deep nuclei (Fat Girls Eat Donuts)

! Dentate (most lateral)! Fastigial! Globus! Emboliform

! Lipofuscin - golden yellow pigment in neurons as they age (non-specic

aging change, common in dentate, NOT PATHOLOGIC )! Hippocampus

! temporal horn of 4th ventricle - choroid plexus has brovascularcores makes them papillary --> can proliferate into a choroid plexuspapilloma (looks almost like normal choroid plexus)

! Dentate fascia! CA 1-4

! CA1 = most impt for pathology out of the 4 ! susceptible to hypoxia/ischemia also includes purkinje

cells and layers 3 & 5 of the cerebral cortex! E nterorrhinal cortex - where the PLAQUES and TANGLES start in

ALZHEIMER'S disease; look for early change in Alzheimer's! Inferior temporal gyrus

! WHAT AREAS OF THE BRAIN ARE THE MOST SUSCEPTIBLE TOHYPOXIC INJURY?

! CA1 of Hippocampus! Purkinje cells of ...! Layers 3 & 5 of the cort ex

!

Parkinsons Disease: neurodegenerative disease that cause neuronal lossin the pigmented nuclear groups (to nd the pathology, you need to beable to nd the normal structure rst)

! What is a dead neuron? ! Red nucleus (think RED = DEAD) - NOT PIGMENTED (TRICK

QUESTION)! ! Microscopic calcications in the brain:

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! Corpora amylacia (aka Brain Sand) ! Microglia - see w/ damage to purkinje cells

! Be able to recognize the tissue type and structures !

Low power ! Med power ! High power

PITUITARY :

PIGMENTED NUCLEI OF THE BRAINSTEM:Midbrain Substantia nigraPons Locus ceruleusMedulla oblongata Dorsal nucleus of the Vagus

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HIPPOCAMPUS :

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SPINAL CORD:

MAKE-UP LECTURE 01:40:47 BASAL GANGLIA :

! ventricular lining - single layer of ependymal cells (epithelial cells; next to

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caudate nucleus! Internal capsu le - main descending white mater tract! Putamen - looks histologically identical to caudate! Globus pallidus = darker part!

Anterior commissure - landmark for nucleus basalis of Meynert( important in Alzheimer's disease --> degenerates) - main cholinargicoutput nucleus of the brain (therapy = cholinesterase inhibitors)

! Blood vess el - post-mortem bacterial overgrowth - bacteria can be gas-forming and make create holes/cavities (post-mortem artifact that lookslike swiss cheese --> gets mistaken for lacunar infarcts and smellshorrible)

Thalamus :! looks histologically identical to the globus pallidus, but it's not symmetrical

(so you can tell them apart)! ependymal lining ! lipofuscin - pigment in larger neurons

CORTEX :! Leptomeninges = aracnoid + pia (contain blood vessels)! 6 layers

White mater = darker pink! ogliodendrocytes - make myelin

! Injury results in myelin loss !

astrocytes are hard to see in normal white matter (inconspicuous)! Pathology makes them larger and reactive

! Sections from:! Frontal Lobe! Parietal Lobes! Occipital Lobe

! Hard to tell difference b/t FRONTAL and PARIETAL lobes! Thicker in older people due to brosis (common)

! OCCIPITAL LOBE :!

stria of genarie - easier to see on gross brains! If someone asks you where in the cortex a section is from, the

answer is usually the occipital lobe b/c of stria of genarie

PATHOLOGIC SECTIONS: (01:50:43) Squash prep - good for cytologic detail & its a fast process

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! whorls - characteristic of menigioma (a more common type of braintumor)

! pseudo-inclusions in nuclei - invaginations of cytoplasm inside the nucleus! Disadvantage = lose architecture and the relationship of lesion

Do FS on all the neuro specimens Muscle Bx : never put a muscle Bx in formalin ! Holes = freeze artifact! muscle cells (myobrils) are round to polygonal

! Extend from origin to insertion of muscle! nuclei (multi-nucleated) on the periphery of muscle ber = normal muscle

! Pathologic processes = nuclei tend to move towards the center ofthe myobril

! Myopathy - primary pathologic process of muscle!

Muscles are innervated by peripheral nerves! Neuropathy (secondary pathologic process) causes atrophy of

muscle ber s! Atrophic muscle bers = angulated in shape when denervated

! Case = neurogenic atrophy of skeletal muscle! Groups of atrophic bers = peripheral nerve disease ! Nuclei cluster together (don't mistake for inammatory cells) =

pyknotic nuclear clumps or nuclear bags ! Common reason for muscle Bx = inammatory myopathies

THINGS WE NEED TO KNOW :! Do NOT FIX the muscle (keep it fresh) ! Squash preps and FS on neural tissues (save some tissue for permanent

sections - xed)! Pigmented Nuclei! Areas susceptible to Hypoxic injury:

! Purkinje cells (cerebellum) - * BE ABLE TO RECOGNIZE *! Areas 3 & 5 of pyramidal layers of the cortex! CA1 region of Hippocampus

!

Lipofuscin

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