Cell Injury And Consequences Flashcards
What does etiology mean?
Causes of disease
What does pathogenesis mean?
Mechanisms of disease
What are examples of abnormalities in cells and tissues?
(3)
Molecular
Functional
Morphologic
What do clinical manifestations mean?
Signs and symptoms of disease
What does homeostasis mean?
Maintenance of internal conditions within the body
What is the basis of all diseases?
Cell injury
What is the cellular response for homeostasis?
(6)
Healthy cell
Injuries stimulus
Reversible injury
Severe, progressive
Irreversible injury
Cell death- either necrosis or apoptosis
What are the causes of cell injury?
(8)
Hypoxia (oxygen deficiency) and ischemia (reduced blood supply)
Toxins (insecticides, carbon monoxide, asbestos, cigarette smoke, etc)
Infectious agents (virus, bacteria, fungi, etc)
Immunological reactions (autoimmune diseases)
Genetic abnormalities (chromosomal abnormalities or mutations)
Nutritional imbalances
Physical agents
What is necrosis?
When there’s a sever injury, which leads to cell death
What happens in necrosis?
(4)
Cell membranes fall apart
Cell enzymes leak out and digest the cell
The cell increases in size, due to an inflammatory reaction (caused y substances being released from death cells)
The inflammation helps to eliminate the debris and start the repair process
What is necrosis always an indicator of?
A pathological process
What is apopotosis?
Regulated cell death, where the body restores homeostatic conditions
Which organ does apoptosis the most?
The liver
What happens in apoptosis?
(5)
It serves to eliminate cells with abnormalities
It mostly occurs in healthy tissues
Reduced cell size
Fragments break off
No inflammatory response
What are the cellular adaptations to stress?
(4)
Hypertrophy
Hyperplasia
Atrophy
Metaplasia
What is hypertrophy?
The enlargement of cells- increase in the size of the organ
What is hyperplasia?
The increase in the number of cells in an organ
What is atrophy?
The reduced size in an organ due to a reduction in the size and number of cells
What is metaplasia?
When an adult cell type is replaced by another adult cell type
Why does inflammation occur?
As a response of vascularized tissues to infections and tissue damage
What does inflammation do?
(3)
It brings cells and molecules of host defense from the circulation to the sites they’re needed, to eliminate the offending agents
It’s a protective response that’s essential for survival
Leukocytes and proteins start the process of elimination
What are the 2 types of inflammation?
Acute inflammation
Chronic inflammation
How does inflammation work?
(6)
Recognition of the offending agents
Recruitment of blood cells and proteins to the tissue site
Removal of the offending agent
Regulation of the reaction
Repair of injured tissue
Homeostatic conditions return
What are examples of external manifestations of inflammation?
(4)
Heat
Redness
Swelling
Pain
What are causes of inflammation?
(3)
Tissue necrosis
Foreign bodies
Immune reactions
What are the 2 ways for tissue repair/healing to occur?
Regeneration
Scar formation
What is regeneration?
The proliferation (increase in the number) of cells that survive the injury
What is scar formation?
The repair occurs by the lawing down of fibrous tissue
When does regeneration occur?
When there’s a mild, superficial injury
When does scar formation occur?
When there’s a severe injury
What is neoplasia?
A cancer (genetic disorder) caused by DNA mutations
What 2 things can tumours be?
Malignant
Or
Benign
What are genetic alterations in cancer cells?
(H)
Heritable
What are examples of haemodynamic disorders?
(4)
Hyperaemia
Congestion
Oedema
Lymphatic obstruction
What is an example of oedema?
Ascites
What is hyperaemia?
An increase of blood volume
What is congestion?
An impaired outflow of venous blood (blood in the vein)
What is oedema?
The accumulation (build up) of interstitial fluid within tissues
What id lymphatic obstruction?
When there’s something that compromises the reabsorption of fluid from interstitial spaces
What’s an example of a haemodynamic disorder?
Haemorrhage
What happens in a haemorrhage?
(3)
Extravasation of blood from vessels (blood flows out of the vessel into the surrounding area)
The blood accumulates within a tissue (haematoma)
Large bleeds into body cavities are described according to their location- e.g. haemothrax
What is a haemotoma?
When blood accumulates within a tissue
What is haemotosis?
The mechanism that leads to the cessation (stopping) of bleeding from a blood vessel
What does haemostasis include?
(2)
Platelets
Coagulation factors
What does haemostasis lead to?
The formation of a blood clot
What are the 3 stages of haemostasis?
Vasoconstriction
Formation of a platelet plug
Deposition of fibrin and clot stabilisation
What are the stages of thrombosis?
(6)
Endothelium is a thin membrane that lines the inside of the blood vessels
Endothlial injury
Platelet activation
Thrombus formation
Abnormal blood flow, causing endothelial injury or dysfunction
Hypercoagulability
What is an embolism?
A detached intervascular solid, liquid or gaseous mass that is carried by the blood from its point of origin to a distant site, where it often causes tissue dysfunction or infarction
What is infarction?
An area of ischemic necrosis (decreased blood flow) occurs and is caused by the occlusion (blocking) of the vascular supply of the affected tissue
What is infarction a type of?
Stroke
What is shock?
When there’s inadaquate tissue perfusion (passage of blood), resulting in cellular and organ dysfunction
What does shock cause?
(3)
Diminished cardiac output
Reduced effective circulating blood volume
Leads to cellular hypoxia (lack of oxygen)
What is hypoxia?
A lack of oxygen
Is shock usually reversible o irreversible?
Reverible
What are the types of shock?
(3)
Cardiogenic
Hypovolemic
Septic
What is cardiogenic shock?
A failure in heart pumping, due to arrhythmia, pulmonary embolism
What is hypovolemic shock?
Inadequate blood or plasma volume due to haemorrhage, vomiting, diarrhoea
What is septic shock?
Peripheral vasodilation (widening of blood vessels in extremities) and pooling of blood, causing endothelial activation/injury. This leads to leukocyte- induced damage due to infections
