Pathology of the Central Nervous System Flashcards
Nervous system is largely comprised of
Permanent cells (neurons) and stable cells (glia)
Do the CNS have an ability for. exansion
CNS exists within a physically unyielding and restrictive environment (the skull and spinal canal) with little ability for expansion
- Increased intracranial pressure is an event common to many pathological conditions
Human brain damage
Human brain exhibits remarkable regional specialization of function; clinical loss of function may result from damage to extremely small and specific regions
- Many diseases are the result of dysfunction at the level of receptors and transmitters, without apparent morphological changes
Blood-Brain-Barrier
Physico-chemical system regulating movement of nutrient and chemical into and out of the CNS
- BBB includes transporter that prevent surges of nutrients/AAs and neurotransmitter
- Primary BBB resides at the level endothelial cells, joined by tight junction to prevent promiscuous entry
- Astrocytes provide secondary BBB, fluid volume control
Where do BBB resides at?
The level of endothelial cells, joined
by tight junctions to prevent promiscuous entry
What provides secondary BBB
Astrocytes; fluid volume control
Cerebral Spinal Fluid
Transudate of blood formed by specialized cells (choroid plexus) within ventricles
- 600mL of CSF formed daily. 125-150mL in ventricles at any one time
- CSF replaced multiple times at each day
- CSF contains 0-6 WBCs/mL, 50-75mg/dL glucose (60% of serum glucose levels)
- CSF pressure is 80-180 mm water (5-14 mmHg) recumbent
CSF may be sampled
by Lumbar puncture
Where is transudate of blood formed
by specialized cells (choroid plexus) within ventricles
What do each part of the brain
Frontal Lobe
Parietal Lobe
Occipital Lobe
Temporal Lobe
Cerebellum
Brain Stem
Screen Shot
Frontal Lobe
- Problem solving
- Speaking
- Emotional traits
- Reasoning
- Voluntary motor activity
Brain Stem
- Breathing
- Temp
- Digestion
- Sleep/Alertness
- Swallowing
Cerebellum
- Balance
- Coordination and control of voluntary movement
- Fine muscle control
Temporal Lobe
- Understanding language
- Behavior
- Memory
- Hearing
Occipital Lobe
- Vision
- Color perception
Parietal Lobe
- Knowing right from left
- Sensation
- Reading
- Body orientation
Somatic Sensory Nuclei
Gets information by afferent sensory information
Somatic motor nuclei
Sends efferent signals to muscle and glands via the ventral root
Pattern of Pyramidal Motor Neuron Injury
- Upper motor neuron injury (‘brain injury’)
- Lower motor neuron injury (‘cord injury’)
Upper motor neuron injury (‘brain injury’)
- Primarily contralateral involvement
- Spastic paralysis, contractures
- Muscle is hypertonic
- Minimal atrophy
Lower motor neuron injury (‘cord injury’)
- Flaccid paralysis
- Prominent atrophy
- Contractures
Extrapyramidal Motor System
Function to fine tune and adjust action of the pyramidal system to enhance their precision and maintain muscle tone and posture
- Control automatic voluntary movements (eg. walking, riding a bicycle); inhibits involuntary movements
- Actions are involuntary and capable of great speed and precision
Input arises from deep brain nuclei, including the striate ganglia, substantia nigra, red nucleus
- Acts on ipsi and contralateral motor functions
- Damage causes increased muscle tone and rigidity or chorea (sudden involuntary movements)
Where do the extrapyramidal motor system input arises from?
Input arises from deep brain nuclei, including the striate ganglia, substantia nigra, red nucleus
What do Extrapyramidal Motor System do?
Functions to ‘fine-tune and adjust’ actions of the pyramidal system to enhance their precision, and maintains muscle tone and posture
- Controls automatic voluntary movements (eg. walking, riding a bicycle); inhibits involuntary movements