Key Terminology & Definitions - Nervous System Flashcards
Metacestode
Cyst location in intermediate hose
Gravid
Egg-containing
Ovoviviparous
Animals born live
Aberrant host
Accidental/dead-end host
Glioma
Tumour in CNS
Astrocytoma
Astrocyte cell tumour
Oligodendroglioma
Oligodendrocyte cell tumour
Hydrocephalus
Dilation of ventricles, probably congenital
Leuko
White matter
Malacia
Softening and necrosis of the nervous tissue - complete loss of architecture and cells
Polio
Grey matter
Encephalo
Brain
Myelo
Spinal cord
Leukoencephalomalacia
Affecting white matter of the brain
Coup blunt force brain trauma
Lesions immediately below the site of the impact, more severe if the head is stationary but mobile at impact
Contre- coup blunt force brain trauma
Brain moves within solid skull, lesions away from the site of impact , more severe if impact is with a stationary object
Contusion
Bruising, ruptured capillaries, blunt force trauma, brain or SC collide with bone, damage to microvasculature (haemorrhage and oedema)
Haematoma
Focal accumulation of blood
Myelomalacia
Spinal cord necrosis/softening of spinal cord
Vasogenic oedema in brain
Injury to vascular endothelium -> breakdown of BBB -> inc permeability + leakage /permeation of plasma, fluid spreads between cells (intersitium), white matter offers less resistance to passage of fluid in the interstitium -> oedema is more severe (grey matter has dense neuropil)
Cytotoxic oedema
Intracellular = hydrotropic degeneration in other tissues, astrocytes, neurones, endothelial cells -> swelling of the cytoplasm +/- nucleus
Hydrostatic (interstitial) oedema
Accumulation of fluid in interstitial space, commonly around ventricles with hydrocephalus - forces fluid out into surrounding tissues
Hypo-osmotic oedema
Over consumption of water leading to dilution of plasma - over hydration e.g. marathon runner, normal CNS and CSF is slightly higher osmolality than plasma, further reduction of plasma osmolality fluid to move into brain tissue, salt poisoning in pigs
Hypoxia
Reduced O2 supply, cytotoxic oedema (cell swelling) -> necrosis
Anoxia
Complete lack of O2 supply
Vascular obstruction
Ischaemia e.g. thromboembolism -> infarction
Cessation of cerebral circulation
Hypoxia -> anoxia e.g. cardiac arrest
Sustained hypotension
Hypoxia e.g. shock
Hypoxaemia
Reduced arterial oxygenation e.g. sever pneumonia, severe anaemia, CO poisoning, asphyxiation
Impaired cell utilisation of O2
E.g. Cyanide poisoning, fluoroacetate (1080) poisoning
Dorsal nerves =
Sensory
Ventral nerves =
Motor
Encephalitis
Inflammation of the brain (doesn’t always mean infectious agent)
Myelitis
Inflammation of SC
Encephalomyelitis
Inflammation of the brain and SC
Meningitis
Inflammation of the meninges
Leptominenigitis
Inflammation of the leptomeninges (arachnoid and pia mater) = thin meninges over the brain
Pachymeningitis
Inflammation of the pachymeninges (dura mater)
Prions
Proteinaceous and infectious particles, smaller than the smallest known virus, resistant to most disinfectants + treatments
Prion diseases
(Prionoses) chronic progressive fatal NS diseases characterised by spongiform encephalopathy
White matter
Myelin, inside in brain, outside SC
Grey matter
Outside in brain, inside SC
Frontal lobe
Prefrontal association area -coordinates information from other association areas, controls some behaviours
Primary motor cortex + motor association area (premotor cortex)
Skeletal muscle movement