Definitions Flashcards
Disseminated Intravascular Coagulopathy (DIC)
- syndrome characterised by the systemic activation of blood coagulation, generating intravascular fibrin, leading to thrombosis of small- and medium‐sized vessels, and eventually organ dysfunction
- eventually many clotting factors are used up – therefore patients begin to bleed
Activated partial thromboplastin time (aPTT or PTT)
a measure of the functionality of the intrinsic and common pathways of the coagulation cascade
Prothrombin time (PT)
a measure of the functionality of the extrinsic and common pathways of the coagulation cascade
Acute Respiratory Distress Syndrome (ARDS)
- syndrome of respiratory failure with the formation of non-cardiogenic oedema leading to reduced lung compliance and hypoxemia which is refractory to oxygen therapy
- There are bilateral diffuse pulmonary infiltrates on CXR or CT, a pulmonary wedge pressure of <18 mmHg and PaO2:FiO2 ration <200 mmHg
Monroe-Kellie Doctrine
- Cranial vault is a fixed space consisting of 3 components: blood (10%), CSF (10%), and brain parenchyma (80%).
- Expansion of one of these components leads to a compensatory decrease in another in order to maintain ICP.
- When this compensatory mechanism can no longer can compensate – a small increase in volume in volume leads to exponential rise in ICP.
Aneurysm
An abnormal, permanent, localised dilatation of a vessel wall to >1.5x its normal diameter
Sepsis
- a systemic inflammatory response syndrome in the presence of confirmed or suspected infection
Severe Sepsis
- sepsis with evidence of end-organ dysfunction e.g. raised lactate, oliguria, altered mental state
Septic Shock
- severe sepsis with hypotension unresponsive to fluid resuscitation
Multi-Organ Dysfunction Syndrome (MODS)
- clinical syndrome characterised by the development of progressive and potentially reversible physiological dysfunction in 2 or more organs or organ systems induced by a variety of acute insults including sepsis
Refeeding Syndrome
- metabolic disturbances that occur as a result of shifts in fluid and electrolytes that may occur when nutrition is re-instated in the malnourished patient
Cushing reflex
- a mixed vagal and sympathetic stimulation occurring in response to elevated intracranial pressure – leading to hypertension and bradycardia
TURP Syndrome
- rare but potentially fatal conition condition that occurs post-TURP procedure as a result of absorption of fluids into the prostatic venous sinuses
Compartment Syndrome
- an increase in interstitial fluid pressure within an osseo-facial compartment with sufficient magnitude to cause compromise of the microcirculation leading to myoneural necrosis
Melanoma
- Malignant neoplasm of melanocytes
Basal Call Carcinoma
- Locally invasive epidermal skin tumour (rarely metastases and thought to arise from hair follicles)
Squamous Cell Carcinoma
- Malignant neoplasm arsing from the keratinocytes of the epidermis
Breslow Thickness
- Tumour invasion depth from top of granular layer of the epidermis (stratum granolosum) to the deepest point of the tumour
Thrombosis
- The process of formation of a solid mass in living circulation from flowing blood constituents
Clot
- Solidification of blood when it is static
Embolism
- An abnormal mass of undissolved material that is carried in the bloodstream from one place to another
Rheumatic heart disease
- Complication of rheumatic fever in which the heart valves are damaged
Giant Cell Arteritis
- a systemic immune-mediated vasculitis affecting medium-sized and large-sized arteries, particularly the carotid artery and its extracranial branches
Endometriosis
- Chronic oestrogen-dependent condition characterised by the growth of endometrial tissue in sites other than the uterine cavity
- most commonly the pelvic cavity (including the ovaries), the uterosacral ligaments, the pouch of Douglas, the rectosigmoid colon, and the bladder and distal ureter.
Dysplasia
abnormal cellular growth and differentiation that is confined to the basement membrane of the epithelium
Metaplasia
- a change in epithelium from one type to another
Anaplasia
- lack of differentiation
Adenoma
- benign neoplasm derived from glandular cells
Polyp
- mass projecting from an epithelial (mucosal) surface
Carcinoma
- malignant neoplasm derived from epithelial cells
Sarcoma
- malignant neoplasm derived from mesenchymal cells e.g. fat, muscle
Lymphoma
- malignant neoplasm derived from lymphocytes
Germ Cell Tumour
- malignant neoplasm derived from germ cells
Hamartoma
- a tumour-like malformation composed of a haphazard arrangement of the different amounts of tissue normally found at that site
Necrosis
- Abnormal, irreversible, uncontrolled cell death due to cellular injury (hypoxia, ischaemia, physical/chemical agents, trauma, infectious agents, toxins, radiation etc)
Coagulative Necrosis
- type of necrosis in which protein denaturation is more prominent than enzymatic breakdowns
- microscopic: increased eosinophila of cytoplasm and decreased basophilia of the nucleus – preservation of general cellular architecture
Liquefactive Necrosis
- occurs in situations where enzymatic breakdown is more prominent than protein denaturation or in organ that lack a substantial protein-rich matrix e.g. lipid rich organs such as the brain
- loss of organ cellular architecture e.g. in brain – sheets of lipid laden macrophages replace dead tissue
Fat Necrosis
- change in adipose tissue due to trauma or release of enzymes from adjacent organs e.g. pancreas. This causes breakdown of lipid and release of fatty acids which combine to form chalky deposits
Caseous Necrosis
- ‘cheesy-looking’ necrosis with associated granulomatous diseases processes e.g. TB
Ulcerative Colitis
- idiopathic chronic inflammatory disease of the colon, predominantly affecting the mucosa
Ulcer
- break/dissolution of the epithelial layer
- pathological definition: loss of the mucosa and deeper layers. NB: If only mucosa lost then correct term is erosion
Tumour suppressor genes
- genes that function to help control cell growth
- their loss results in uncontrolled cell growth through loss of regulated division
Proto-oncogenes
- genes used in normal growth and development; without control they have potential to produce neoplasms through their uncontrolled expression
- Oncogenes – genes that have made the transition and now capable of producing neoplasms via unregulated cell growth
Granuloma
- a focus of chronic inflammation consisting of a microscopic aggregation of macrophages surrounded by a collar of lymphocytes and plasma cells
Frozen Section
- Rapid pathological procedure that performs microscopic analysis of a specimen using a cryotome
Immunohistochemical Staining
- Process of immunostaining to identify antigens of cells of tissue section by using antibodies to bind specifically to the antigens of the biological tissue
Pathological fracture
- is a bone fracture caused by disease that led to weakness of the bone structure
Gangrene
- tissue death occurring due to ischaemia with or without infection
Dry Gangrene
- tissue death occurring due to ischaemia that is characterised by coagulative necrosis e.g. limbs with arteriosclerosis
Wet Gangrene
tissue death occurring due to ischemia and superimposed bacterial infection that is characterised by liquefactive necrosis e.g. bowel ischaemia
Diverticulum
- an abnormal outpouching of a hollow viscus into surrounding tissue
Abscess
- a localised collection of pus surrounded by granulation/fibrous tissue
Pus
- a collection of neutrophils together with dead/dying microorganism
Sinus
- a blind ending track lined by granulation tissue (normally connects an abscess to skin)
Fistula
- an abnormal epithelial communication between two surfaces
Stoma
- a surgical opening into a hollow viscus
Acute inflammation
- a stereotypical response to tissue injury characterised by heat, pain, redness and swelling
Pseudoaneurysm
- Defect in arterial wall which allows communication of arterial blood with adjacent extra luminal space enclosed by fibrous tissue
Necrotising fasciitis (NF)
a severe and rapidly progressive soft tissue infection that causes necrosis of the subcutaneous tissues and fascia
Cyst
Abnormal membranous sac containing gaseous, liquid or semisolid substance
Pseudocyst
Differs from cyst in that it lacks epithelial / endothelial cellls
Hypersensitivity Reaction
- An exaggerated response of the hosts immune system to a particular stimulus
Tumour Marker
- Substance which can be found in the circulation of a patient with neoplasia
Neoplasm
An abnormal growth of tissue which displays:
- Uncoordinated growth,
- Growth which exceeds that of normal tissue
- Growth which continues despite removal of the original stimulus
hyperproliferation
Hyperplasia
An increase in the size of an organ or tissue due to an increase in the NUMBER of cells
hypergrowthy / muscle hypertrophy
Hypertrophy
- An increase in the size of an organ or tissue due to an increase in the SIZE of cells
