Key Terminology & Definitions - Nervous System Flashcards
(112 cards)
1
Q
Metacestode
A
Cyst location in intermediate hose
2
Q
Gravid
A
Egg-containing
3
Q
Ovoviviparous
A
Animals born live
4
Q
Aberrant host
A
Accidental/dead-end host
5
Q
Glioma
A
Tumour in CNS
6
Q
Astrocytoma
A
Astrocyte cell tumour
7
Q
Oligodendroglioma
A
Oligodendrocyte cell tumour
8
Q
Hydrocephalus
A
Dilation of ventricles, probably congenital
9
Q
Leuko
A
White matter
10
Q
Malacia
A
Softening and necrosis of the nervous tissue - complete loss of architecture and cells
11
Q
Polio
A
Grey matter
12
Q
Encephalo
A
Brain
13
Q
Myelo
A
Spinal cord
14
Q
Leukoencephalomalacia
A
Affecting white matter of the brain
15
Q
Coup blunt force brain trauma
A
Lesions immediately below the site of the impact, more severe if the head is stationary but mobile at impact
16
Q
Contre- coup blunt force brain trauma
A
Brain moves within solid skull, lesions away from the site of impact , more severe if impact is with a stationary object
17
Q
Contusion
A
Bruising, ruptured capillaries, blunt force trauma, brain or SC collide with bone, damage to microvasculature (haemorrhage and oedema)
18
Q
Haematoma
A
Focal accumulation of blood
19
Q
Myelomalacia
A
Spinal cord necrosis/softening of spinal cord
20
Q
Vasogenic oedema in brain
A
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)
21
Q
Cytotoxic oedema
A
Intracellular = hydrotropic degeneration in other tissues, astrocytes, neurones, endothelial cells -> swelling of the cytoplasm +/- nucleus
22
Q
Hydrostatic (interstitial) oedema
A
Accumulation of fluid in interstitial space, commonly around ventricles with hydrocephalus - forces fluid out into surrounding tissues
23
Q
Hypo-osmotic oedema
A
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
24
Q
Hypoxia
A
Reduced O2 supply, cytotoxic oedema (cell swelling) -> necrosis
25
Anoxia
Complete lack of O2 supply
26
Vascular obstruction
Ischaemia e.g. thromboembolism -> infarction
27
Cessation of cerebral circulation
Hypoxia -> anoxia e.g. cardiac arrest
28
Sustained hypotension
Hypoxia e.g. shock
29
Hypoxaemia
Reduced arterial oxygenation e.g. sever pneumonia, severe anaemia, CO poisoning, asphyxiation
30
Impaired cell utilisation of O2
E.g. Cyanide poisoning, fluoroacetate (1080) poisoning
31
Dorsal nerves =
Sensory
32
Ventral nerves =
Motor
33
Encephalitis
Inflammation of the brain (doesn't always mean infectious agent)
34
Myelitis
Inflammation of SC
35
Encephalomyelitis
Inflammation of the brain and SC
36
Meningitis
Inflammation of the meninges
37
Leptominenigitis
Inflammation of the leptomeninges (arachnoid and pia mater) = thin meninges over the brain
38
Pachymeningitis
Inflammation of the pachymeninges (dura mater)
39
Prions
Proteinaceous and infectious particles, smaller than the smallest known virus, resistant to most disinfectants + treatments
40
Prion diseases
(Prionoses) chronic progressive fatal NS diseases characterised by spongiform encephalopathy
41
White matter
Myelin, inside in brain, outside SC
42
Grey matter
Outside in brain, inside SC
43
Frontal lobe
Prefrontal association area -coordinates information from other association areas, controls some behaviours
44
Primary motor cortex + motor association area (premotor cortex)
Skeletal muscle movement
45
Parietal lobe
Primary somatic sensory cortex, sensory association area - sensory info from skin, MSK, viscera and taste buds, proprioception, conscious perception of pain, touch and temp (body feelings)
46
Occipital lobe
Visual association area, visual cortex - Vision
47
Temporal lobe
Auditory function, behaviour and memory
48
Symmetrical lesion
Affecting whole organ = metabolic, endocrine, toxic
49
Focal lesion
Often infectious - bacterial, or abscess or tumour
50
Multifocal lesion
Vascular, embolic (showering of thrombi/septic emboli from other parts of body e.g. heart valve
51
CNS fibrosis
Fibrogenic cells restricted to meninges and vascular
52
Derivation of normal anatomy
Malformations
53
Space-occupying mass
Tumour, abscess, granuloma, cyst
54
Malacia
With inflammation (abscesses), degeneration and tumours
55
White matter pallors/softening
Myelin
56
Haemorrhage
Trauma, vascular lesion, tumour, inflammation
57
Primary traumatic lesion injury
Mechanical disruption of tissue - penetrating wounds (compressed fracture of skull), haemorrhage and oedema (vasogenic) - brain swelling, confined -> knock-on effects in tissues
58
Secondary traumatic lesion injury
Occurs within hours to days after injury, cascade of changes, frequently fatal, haemorrhage and oedema (cytotoxic)
59
Haemorrhage
Space-occupying lesion in CNS - contusion and haematoma, goes out into epidural, subdural, subarachnoid and intracerebral space, eventually stopped by pressure of the calvarium (skull portion including braincase)
60
Oedema
Causes compression of the CNS within the bony vault of the skull or vertebrae due to 1^y or 2^y injury, can occur as part of congenital disease e.g. hydrocephalus, cytotoxic/vasogenic/hydrostatic/hypo-osmotic (may get combination), localised = less clinical effect
61
Cervical stenotic myelopathy
"Wobbler syndrome" - large breed horses, dogs, young, rapid growing, static or dynamic types, lead to cord depression (similar to disc herniation), axonal swelling followed by necrosis
62
Gyri
Folds or bumps in the brain
63
Sulci
Indentations or grooves of brain
64
Foramen magnum
Hole in the base of the skull through which the spinal cord passes (site of herniation)
65
Falx cerebri
Strong crescent-shaped sheet that represents an invagination of the meningeal layer of the dura mater into the longitudinal fissure, found between the medial surfaces of the cerebral hemispheres (site of herniation)
66
Falx cerebelli
Small sickle-shaped fold of dura mater projecting forwards into the posterior cerebellar notch as well as projecting into the vallecula of the cerebellum between the two cerebellar hemispheres.
67
Tentorium cerebelli
Second largest dural fold after the falx cerebri, lies in the axial plane attached perpendicularly to the falx cerebri and divides the cranial cavity into supratentorial and infratentorial compartments (site of herniation)
68
Vermis
Midline of cerebellum
69
Internal carotid and vertebral arteries
O2 supply to brain, anastomose ventral to the brainstem and at the circle of WIllies, major cerebral arterial vessels have extensive anastomoses in leptomeninges
70
Leptomeninges
Pia mater and arachnoid (inner meninges)
71
Infarction
Obstruction of blood supply, because of abundance of lipids (v. soft) and enzymes and relative lack of firbous connective tissue in CNS, infacts undergo liquefactive necrosis and soften (malacia) and swell
72
Arterial infarcts of grey matter
Red (haemorrhagic) in acute phases
73
Arterial infarcts of white matter
Pale - grey matter has a denser capillary network than WM
74
Venous infarcts
In GM + WM appear haemorrhagic (rarer)
75
Nystagmus
Involuntary movements of the eye
76
Opisthotonus
Strange 'star gazing' posture
77
Polioencephalomalacia
Thiamine deficiency
78
Equine leukoencephalomalacia
Fungal toxin - fumonisin B, eating mouldy feed
79
Focal symmetric encephalomalacia (FSE)
Clostridial toxin
80
Oedema disease in pigs
E. coli toxin, enterotoxaemic colibacillosis
81
Enzootic ataxia
Copper deficiency - neurodegenerative disorder in sheep and goats; 'Swayback'
82
Nissl bodies
Granules in the cytoplasm of nerve cell bodies that are strongly stained by basic dyes and appear as basophilic clumps on light microscopy. They consist of aggregates of free polyribosomes and rough endoplasmic reticulum.
83
Chromatolysis
Reactive change that occurs in the cell body of damaged neurones, involving the dispersal and redistribution of Nissl substance (rough endoplasmic reticulum and polyribosomes) in order to meet an increased demand for protein synthesis such as is required to regenerate axons.
84
Hypomyelinogenesis
Absence or reduction of myelination, congenital, toxic or viral, often associated with tremor in young animals
85
Leukodystrophy/myelinolytic disease
Loss of myelin that had initially been formed, mainly genetic basis
86
Spongy myelinopathies
Vacuolation of myelin sheath (no loss of myelin, it is retained), idiopathic/genetic, hepatic and renal encephalopathy more common
87
Blood-brain-barrier
Capillary level - endothelial cells, pericytes and astrocytic foot processes, endothelial cells - adherent junctions, tight junctions, transport systems that reduce paracellular flux, tighter barrier around endothelium
88
Microglia
Resident phagocytes of brain, similar to macrophages involved in neuronphagia = removal of individual neurones (viral infections)/neuropil
89
Astrocytes
React non specifically to many stimuli, fill in tissue spaces (bit like fibroblasts)
90
Bacterial lesion
Suppurative, fibrinous, fibrinopurulent inflammation
91
Viral lesion
Lymphoplasmacytic inflammation
92
Fungal/viral/mycobacteria lesion
Granulomatous and pyogranulomatous inflammation
93
Parasitic lesion
Eosinophilic inflammation
94
Gitter
Microglia that phagocytose cellular debris in the brain
95
Thrombotic meningoencephalitis (TME)
Feedlot cattle, caused by Histophilus somni, acute vasculitis, haemorrhages and thrombosis
96
Histophilus somni
Gram -ive coccobacillus, normal inhabitant of respiratory flora
97
Rarefaction
Less dense on histo = spongiosis
98
Listeriosis
Meningoencephalitis, brain stem (pons, medulla, cerebellum, thalamus), route of infection - Listeria monocytogenes - penetrates damaged oral mucosa, ascends axons of trigeminal nerve into medulla oblongata -> inflammation of leptomeninges +/- extension
99
Gliosis
Proliferation of larger glial cells (cells that support nerve cells = astrocytes, microglia + oligodendrocytes). These new glial cells can cause scars in your brain (due to viral infection)
100
Perivascular cuffs
Lymphocytes and plasma cells around blood vessels (inflammation)
101
Distemper virus
Targets WM
102
EHV-1 in horses
Tropism for endothelial cells -> vascular lesions
103
Demyelination histo
Rarefaction (spongiosis - vacuolation) in WM
104
Protozoan infection
Tachyzoites -> necrosis (+/- inflammation), cysts (containing bradyzoites) -> little host reaction
105
Coenurosis (Gid)
Taenia multiceps metacestode name (cyst matures into this larval stage)
106
Granulomatous menigoencephalomyelitis (GME)
Non-infectious encephalitides (auto-immune disease), probably T-cell-mediated delayed-tye hypersensitivity reaction, white matter and leptomeninges, granulomatous inflammation and perivascular cuffs, toy breeds (poodles, terriers)
107
Necrotising meningoencephalitis (NME)
Non-infectious encephalitides (auto-immune disease) - type unknown, GM of cerebral cortex, necrosis, inflammation and gliosis (pugs, Maltese + chihuahua)
108
CWD
Chronic masting disease (cervidae = deer) (prion disease/transmissible spongiform encephalopathy)
109
TME
Transmissible mink encephalopathy (prion disease/transmissible spongiform encephalopathy)
110
FSE
Feline spongiform encephalopathy (prion disease/transmissible spongiform encephalopathy)
111
ARR
High resistance (never absolute), scrapies (sheep)
112
VRQ
High susceptibility to scrapie
