Neuropath 1

components of PNS

-motor NS

-sensory NS

what part of the PNS are the efferent nn?

-motor nervous system

what part of the PNS are the afferent nn?

-sensory NS

organization of NS

CNS → motor NS → mm, organs, glands, sensory receptors → sensory NS → CNS

where are the association nn of brain and spinal cord?

-CNS

another name for CNS?

-integration center

what are the spinal regions?

-cervical nn

-thoracic nn

-lumbar nn

-sacral nn

recall:

areas of gray and white matter

-gray matter on inside

-white matter on outside

what are the (3) main nn in the hind legs?

-femoral nn

-scatic nn

-tibial nn

what surrounds the thalamus and hypothalamus?

-cerebrum

what is important to note about neuropath and other lesions?

-neurological signs can be secondary to primary lesions in other organs (not just CNS)

effects of ammonia accumulation (in brain and blood)

-acute brain edema

-intracranial hypertension

-profound confusion

-seizures

-coma

-potentially fatal

why is ammonia especially bad?

-can cross BBB

-disrupts E cycles

how much is brain mass?

2% of total body mass

how quickly can death occur when blood flow stops to neurons/brain?

6-10 minutes

generally, can neurons regenerate?

-no

-permanent cells so do not re-enter circulation

when is there no regeneration of fibers?

-when CNS is cut off by transection to the cord

what occurs when the spinal cord is cut?

-paralysis

-severe neuro deficit

what part of the NS may experience regeneration?

-PNS

recall:

fx - BBB

-selective regulation of CNS extracell compartment (aka no sudden biochem changes)

-control of drugs and antibiotics

-infection barrier

recall:

brain injury and size

-little area for it expand

-causes mechanical compression

steps to neuropath assessment

-neuro exam

-anatomic dx

-anatomic pathology

-damnitv category and differential dx

assessment:

neuro exam

-is the NS diseased?

assessment:

anatomic dx

-where is the problem?

assessment:

anatomic path

-are there any gross and/or histological lesions?

-what is the pattern?

what is part of the anatomic pathology assessment?

-gross lesion patterns

-histo lesion patterns

considerations:

gross lesion patterns

-deviation of normal anatomy?

-space occupying lesion?

-malacia/necrosis?

-pallor/softening of the white matter?

-hemmorhage?

considerations:

histo lesion patterns

-perivascular cuffing?

-spongy state?

-hypercellularity?

-accumulation of material in CNS cells?

-selective loss of neurons?

-selective loss of myelin/axons?

DAMNITV

-degenerative

-anamalous

-metabolic

-neoplastic

-infectious, inflammatory, idiopathic

-traumatic, toxic

-vascular

what is the highest percentage of type of neuro disease?

-degenerative (38%)

percentage of cases:

idiopathic

13%

percentage of cases:

neoplastic

9%

percentage of cases:

vascular

4%

percentage of cases:

inflammatory/infection

14%

percentage of cases:

traumatic

9%

percentage of cases:

anomalous

5%

percentage of cases:

metabolic/toxic

8%

what is the etiology of thrombotic meningoencephalatis?

-histophilus somni

what type of hemorrhages occurs from thrombotic meningoencephalitis?

-multifocal hemorrhages

definition:

perivascular cuffing

-accumulation of infla cells around the blood vessels

which (2) types of neurons are most resistant?

-astrocytes

-oligodendrocytes

why are neurons so sensitive to hypoxia?

-require a lot of O and E

why can’t the brain and spinal cord regenerate?

-no fibroblasts (collagen fibers)

• only found in arachnoid space outside of brain

which cell has minimal regeneration capability?

-astrocytes (long cytoplasmic processes that attach and form BBB)

what is the DAMNITV system?

-categorize gross and histo patterns into (7) possible causes

-used with hx and clinical signs (PE) to build differentials