General Flashcards
What is necrosis? Give 4 types and descriptions
Dead tissue Gangrene (discoloured) Coagulative (discoloured) Liquifactive (turns into mush) Caseous (granulomas are amorphous)
What stain is needed to see mycobacterium?
Ziehl-Nielsen stain
Stains mycobacterium red
What is oncosis?
Cell death associated with rupture of cell membranes
Always pathological, inflam occurs
What is apoptosis?
Programmed cell death (requires ATP) cell breaks down into smaller apoptotic bodies
What is apoptosis initiated by?
Caspases
Give 6 causes of cell injury
Lack of O2 (hypoxia) Trauma Drugs Microorganisms Radiation Toxins
What is the commonest cause of hypoxia?
Ischaemia (when only one artery supplies an organ and it becomes blocked)
Necrosis due to ischaemia is
An infarction
Give 3 situations where apoptosis is normal
Menstrual cycle, fetal development, lymphocytes that recognise self as foreign
What is autolysis?
Death of a cell either after death of the organism or removal from the organism
What is a granuloma?
A mass of epithelioid macrophages and lymphocytes aggregated together
Occurs when cause of inflammation is hard to digest (mycobacterium, parasites etc)
What is a giant cell?
When macrophages fuse together when trying to ingest the same thing
What is it called when a giant cell has a wreath of nuclei around the periphery
Langhans giant cell
What are cytokines?
Inflammatory mediators produced at site of inflammation when needed
Which main cytokines stimulate fibroblasts, increase coagulation and act as endothelial adhesion molecules?
TNF-a and IL-1
Which cytokine just gives systemic effects?
IL-6
What does Il-10 do?
Inhibits cytokine secretion, reduces antigen presentation
Which inflam cells look pink, purple and blue?
Eosinophils- pink
Neutrophils- purple
Basophils-blue
What is a scar?
Dense fibrous tissue (fibrosis)
What can fibrosis lead to?
Stricture (abnormal narrowing of duct/passage
What process does dead tissue turn into granulation tissue?
Organisation
Why does granulation tissue involve?
Red granular surface
Inflam cells, fibroblasts and myofibriblasts and epithelial cells
How does granulation tissue turn into a scar?
Maturation
Where does liquefactive necrosis occur?
In CNS
5 symptoms of prostate hyperplasia
Poor stream Hesitancy of flow Dribble Decreased bladder emptying Increased freq (esp at night)
What is hypertrophy?
Tissue enlargement as a response to increased work (enlargement of size of cells)
What is hyperplasia?
Enlargement of a tissue due to an increased number of cells
Atrophy is
The reduction in mass of a tissue due to reduction in cell size or cell number or both. from normal to below normal size
Hypoplasia
Failure to develop to normal size
Define metaplasia
Change of one mature adult tissue type into another (always pathological)
Adaption to environment
5 causes of atrophy
Loss of endocrine stimulation Disuse Diminished blood supply Loss of nerve supply Pressure
Define ectopia
Presence of a differentiated tissue in an abnormal location as a result f a defect in embryogenesis
Fever is -
Thermoregulation disrupted by cytokines, hypothalamus set point is increased
What proportion of people in UK have one copy of the mutated gene for cystic fibrosis?
1/22
Define neoplasm
Mass of abnormal tissue
Growth exceeds and is uncoordinated with that of normal tissue
Malignant means
A mass that invades adjacent tissues and can make new, separate tumours (cancer)
What is a metastasis?
A separate lesion from the tumour (a secondary neoplasm)
Define benign neoplasm
Unable to spread to adjacent tissues, confined to organ of origin, can still cause disease through
- abnormal secretion of hormones
- atrophy of adjacent tissues
- compression of adjacent structures
What is cachexia?
Extreme wasting of muscles and far due to cancer
Aetiology is
The underlying cause of disease (eg tobacco smoke with lung cancer)
Pathogenesis is-
The mechanism by which the aetiology interacts with the cells and organs of the body to produce disease
Define idiopathic
Unknown cause
Congenital means
You are born with the disease (inherited or due to environmental factors before birth)
May manifest itself later in life but still congenital
What are the three suffixes used to name tumours
OMA- benign tumour
CARCINOMA- malignant epithelial cancer
SARCOMA- malignant non-epithelial tumour (CT&bone)
Define inflammation
The coordinated response by vascularised tissue to injury or the presence of micro-organisms
What is exudation?
Blood plasma passing out of blood stream in the extra vascular space through gaps between endothelial cells
Occurs in inflammation
Give an example of an adhesion molecule
Selectin
What substances have a chemoattractive effect on wbcs?
Cytokines and complements
What are the first cells to enter tissues during inflammation?
Neutrophils
What defines acute inflammation?
Time frame of a week or less
Presence of neutrophils but not other inflam cells in tissue
Where to white blood cells adhere to?
Venular endothelium
Name 2 opsonins
C-reactive protein
C3b complement
What increases vascular permeability?
Histamine and prostaglandins
What are acute phase proteins and where are they produced?
Proteins that are helpful in defence
Produced by the liver
Name 4 types of acute phase proteins
Complements, coagulation proteins, C-reactive protein, protease inhibitors
What is caseous necrosis characteristic of?
Mycobacterium infection
Why is gangrene dangerous?
It can spread and makes tissues very weak (can rupture)
How do cells die via oncosis?
Rupture of lysosomes membranes which hydrolyse cell components
Why do oncotic cells expand?
Lots of smaller pieces in cell increases oncotic pressure
How are apoptotic bodies broken down?
They have phosphatidylserine on their membranes so many cells can phagocytose and digest them
By is apoptosis advantageous over oncosis?
No inflammatory response so no tissue damage
Cell parts are rapidly recycled
What do nacroophages do that neutrophils don’t?
Digest dead tissue and foreign matter
What is diapedesis?
Passive escape of red blood cells through damaged endothelium
