Key Terminology & Definitions - Pathology Flashcards
Acanthosis
Increased thickness of stratum spinosum; epidermal hyperplasia
Lichenification
Extreme epidermal hyperplasia
Callus
Thickened, often pigmented + hyperkeratotic plaque (focal epidermal hyperplasia)
Vesicle / bulla
Fluid-filled cavities within of beneath the epidermis (blister), vesicle = < 1 cm in diameter; bulla = > 1 cm in diameter
Between epithelium and lamina propria of mucosa
Pustule
Vesicle contained pus (= degenerate neutrophils, inflammatory cells), it will become a crust (scab)
Scale
Hyperkeratosis (dandruff)
Erosion
Partial-thickness loss of epidermis resulting in shallow, moist, glistening depression, still have basement mem with no bleeding
Ulcer
Full-thickness loss of epithelium and basement membrane, bleeding, granulation tissue forming, exposing lamina propria
Scar
Granulation tissue and fibrosis - repair injured tissues (scarring)
Crust
Dried exudate or secretion with/without epithelial or bacterial debris
Atrophy
Decrease in the mass of a tissue due to decreased size + no. cells (after it has reached its normal size)
Wheal
Sharply circumscribed skin elevation of oedema of the superficial dermis, often erythematous
Neoplasm
An abnormal mass of tissue, the growth of which exceeds and is uncoordinated with that of normal tissue and persists in the same excessive manner after cessation of the stimuli, which evoked the change.
Dermatitis
Inflammation of dermis
Vasculitis
Inflammation targeting the walls of venules or arterioles
Alopecia
When inflammation affects the hair follicles
Papilloma
Benign epithelial tumour growing exophytically (outwardly projecting)
Sarcoid
Papilloma-induced lesion in the horse and cat
Folliculitis
Inflammation of hair follicle
Furunculosis
Inflammation of the hair follicle but then it ruptures, almost always infections e.g. staphylococcus, Demodex + dermatophytes (fungi).
Spindle (mesenchymal) cell tumour
Ends in sarcoma if malignant
Epithelial tumour
Ends in carcinoma if malignant; if benign = adenoma, adeno means glandular tissue
Round cell tumour
Depends on type of cell: macrophages = histiocytoma; lymphocytes = lymphoma; plasma cells = plasmacytoma, mast cells = mastocytoma
Hyperaemia
Excess of blood in vessels
Epidermal hyperplasia
More keratinocytes = more layers
Hyperkeratosis
Increased thickness of stratum corneum only
Granulomatous inflammation
Usually due to infectious agents e.g. mycobacterium and Leishmania, made up of macrophages
Haemangioma
Benign neoplasia of endothelial cells
Fibroma
Benign neoplasia of fibroblasts
Macrophage precursor
Monocyte
Erythema
Increased blood supply to an area and vasodilation - in the skin only. Hyperaemia elsewhere
Wooden tongue
Caused by Actinobacillus lignieresii gram-negative bacteria
Thrush
Caused by Candida albicans opportunistic pathogenic yeast (fungus)
Schisis
Clefts
Cheilo
Lips
Pro
Long
Brachy
Short
A-
Absent
Gnatia superior
Maxilla
Gnatia inferior
Mandible
Cheiloschisis
(Hare lip) Failure of fusion of the upper lip along the midline of philtrum
Palatoschisis
Failure of fusion of the lateral palatine processes
Stomatitis
Inflammation of oral cavity
Cheilitis
Inflammation of lips
Pharyngitis
Inflammation of pharynx
Glossitis
Inflammation of tongue
Tonsillitis
Inflammation of tonsils
Gingivitis
Inflammation of gingiva (gum)
Choke
Oesophageal obstruction subsequent to stenoses (abnormal narrowing) or blockage
Megaoesophagus
Dilation of the oesophagus because of insufficient, absent or uncoordinated peristalsis in the mid and cervical oesophagus
Can be caused by persistence of fourth right aortic arch
Volvulus
When a loop of intestine twists around itself and the mesentery that supplies it
Haematemesis
Blood in vomit
Melena
Blood digested in stomach, passes through intestine, leads to black faeces
Gastritis
Inflammation of stomach
Stenosis
Narrowing of the intestinal lumen
Atresia
Occlusion of the intestinal lumen as the result of anomalous development of the intestinal wall
Atresia coli
Colon occluded
Atresia ani
Anus occluded
Segmental atresia
If a segment of the bowel is either entirely missing or completely occluded because of a lack of epithelial development and confluence between two contiguous portions.
Megacolon
Large, usually faecal-filled colon
Aganglionosis (colon)
Absence of ganglion cells
Enterolith
Struvite = magnesium ammonium phosphate (stones)
Stricture
Abnormal narrowing
Eventration
Hernia
Strangulation
Compression of blood or air-filled structures which impedes circulation or function.
Intussusception
When one segment of intestine become telescoped into the immediately distal segment of intestine
Herniations
Displacements of intestine; the intestine is not in the right place where it should physiologically normally be (external and internal)
Torsion/volvulus
Rotation (twisting) of the intestine on its long axis
Peduncle
Stalklike part by which an organ is attached to an animal’s body
Internal herniations
Herniations formed through a normal or pathological foramen in the abdominal cavity
External herniations
Herniations formed when a hernial sac, formed by a pouch f parietal peritoneum, penetrates outside the abdominal cavity
Enteritis
Inflammation of small intestine
Duodenitis
Inflammation of duodenum
Jejunitis
Inflammation of jejunum
Ileitis
Inflammation of ileum
Colitis
Inflammation of colon
Proctitis
Inflammation of rectum
Diarrhoea
Increase in stool mass, stool frequency, and/or stool fluidity
Dysentery
Painful, bloody diarrhoea
Petechiae
Microscopic haemorrhage
Hypertrophy
Inc size of cells
Hyperplasia
Inc no. cells
Metaplasia
Replacement of a cell type by another of the same germline e.g. healing after mastitis, low columnar —> squamous
Dysplasia
Abnormal pattern of tissue growth, disorderly arrangement of cells within epithelium
Atrophy
Dec size of cells
Exostosis
Extra growth of bone that extends outward from existing bone (bone changes = permanent)
Laminitis
Loss of integrity of the basement membrane and cellular attachments to basal epidermal cells
Dysbiosis
Disturbed or altered gut flora, inadequate mucous layer, lowered levels of protective antibodies
Evisceration
Taking intestines out
Space of Disse
Between hepatocytes and sinusoids
Kupffer cells
Attached to sinusoids, liver macrophages, remove bacteria from portal blood, phagocytosis without inflammation
Stellate (lto) cells
In space of Disse - store retinoids e.g. vitamin A, important in fibrosis
Sunusoids
Lined by fenestrated endothelium, no BM, drain into central vein
Liver zone 1
Peripheral - most prone to direct toxic injury - where blood is arriving
Liver zone 2
Midzonal / intermediate
Liver zone 3
Periacinar / centrilobular - most active in detoxification of metabolites, lowest O2, most prone to injury and hypoxic injury
Liver limiting plate
Single layer of hepatocytes separating portal region from lobule
Portal tract
Portal vein, bile duct, one or more arteriole, connective tissue
Enterotoxins
Toxins produced in or affect the intestines
Braxy
Acute disease of sheep caused by C. septicum and characterised by inflammation of the abomasal wall (a lot of haemorrhage and blood-stained tissues)
Acinus/lobule
Functional unit of liver
Hepatocellular atrophy
Reduced demand (illness, starvation)
Hepatic atrophy
Due to impaired hepatocyte replication (not cytoplasm loss), not enough cells
Hepatocellular hypertrophy
Increased cytoplasmic volume
Glycogenosis
Build-up of glycogen-filled vacuoles but function remains normal in liver (should be storing glycogen anyway)
Steatosis/lipidosis
Round, well circumscribed cytoplasmic fat globules - microvesicular (multiple, don’t displace nucleus) and macrovascular (displaces nucleus, one per cell)
Tension lipidosis
Mostly in cattle, focal hypoxia due to pull of fibrous attachments
Necrosis
Stimulates inflammation
Massive necrosis of liver
Death of entire lobule (not whole liver)
Piecemeal necrosis
Necrosis and inflammation at the limiting plate/periportal - between the portal tracts and rest of liver
Biliary epithelium
Ductular cells of liver
Cirrhosis
Nodular regeneration, bridging fibrosis, vascular disruption of liver
Lipofuscin
Golden cytoplasmic granules due to membrane lipid breakdown
Bile plugs
When bile canaliculi distended (between cytoplasm)
Haematin
Artefact of formic acid reacting with haemoglobin (darker than haemosiderin and usually extracellular)
Iron porphyrin
Black - associated with fluke migration tracts
Acute liver failure
Uncommon, due to severe and rapid injury - usually toxins, sometimes hyperthermia/acute ischaemia
End-stage liver
Chronic liver failure due to progressive fibrosis and loss of functional mass
Acute-on chronic liver
Chronic liver failure - a compensated failing liver suddenly flips into acute failure
Cholestasis
Impaired bile secretion and/or flow
Jaundice
Yellow pigmentation of tissues due to excess plasma bile pigments
Photosensitisation
Inflammation of skin (usually unpigmented) due to action of UV light on photodynamic compounds bound to dermal cells
Ascites
Oedema in abdomen, low protein fluid commonly seen with venous congestion/hypoproteinaemia
Congenital portosystemic shunt (PSS)
Abnormal connection between portal vein and vena cava (portocaval) or azygous vein (portozygous)
Extrahepatic/intrahepatic
Hepatitis
Characterised by presence of inflammatory cells and/or infectious agents in the parenchyma, focal or diffuse
Cholangitis
Inflammation of the biliary tree
Cholecystitis
Inflammation of the gallbladder
Cholangiohepatitis
Inflammation centred on the biliary tract and extending into the parenchyma (more common than cholangitis)
Acute hepatitis
Mix of inflammation, apoptosis/necrosis, regeneration, lymphocytes in portal region, neutrophils among hepatocytes, +/- pathogens and Kupffer cells enlarge and accumulate vacuoles and debris
Chronic hepatitis
Fibrosis = consistent feature
Cholelithiasis
Stones anywhere in biliary tree - usually form in gallbladder, mix of cholesterol, bile pigment and salt
Xenobiotics
Ingested foreign chemicals
Cytotoxic injury (hepatobiliary toxic diseases)
Hepatocyte degeneration, zonal necrosis, apoptosis, lipidosis
Cholestatic injury (hepatobiliary toxic diseases)
Failure of bile excretion, leading to obstructive jaundice
Mixed injury (hepatobiliary toxic diseases)
Combination of cytotoxic and cholestatic injury
Leiomyoma
Benign smooth muscle tumour
Mylolipoma
BM fatty tumour
Hemangiosarcoma
Tumour of blood vv.
