Cell injury, apoptosis and death Flashcards
Steps taken to diagnose a patient
Observe medical history. Examine signs and symptoms. Obtain clinical tests and investigations including scans
Quantitative diagnostic measurement
Measure a sample from the patient to see whether or not it is within the normal range of values e.g. ELISA
Subjective for diagnostic assessment
Based on the assessment of a pathologist to see whether something is pathological or not e.g. microscopy
Epidemiological diagnostic approach
Recording and analysing data of a specific disease in groups of people rather than an individual to give indication as to how the disease spreads in order to prepare introduce public health prevention measures
Aims of epidemiological studies
To provide aetiological clues (risk factors rather than actual cause), planned preventative measures, provide adequate medical facilities and population screening for early diagnosis
Basic approaches to conduct epidemiological studies
Prospective studies, retrospective studies and cross-sectional studies
Prospective studies
Subjects are followed longitudinally, risk factors monitored and a relative risk is determined. Measures the incidence of death and those exposed as well as those on exposed to the risk factor
Quantitative system that determines indicates risk factor
No risk = 1
More likely to cause risk = <1
Less likely to cause risk = >1
Retrospective studies
Looks at past exposures disrespected aetiological factors. Odds ratio is determined
Cross-sectional studies
Prevalence between different populations at a particular time. Mainly used for public health planning
Purpose of medicolegal autopsies
To determine the cause of death, collect evidence for forensic investigations. To be performed by state forensic pathologist
Purpose of clinical autopsies
To gather useful information but the cause of death particularly if the diagnosis was unclear. For example Kennedy samples
Cell injury
A change or loss of function or morphology
Necrosis
Caused by cell injury in particular as it disrupts cellular function
Apoptosis
Programmed cell death that is more controlled by Intrinsic as well as extrinsic pathways
When does a cell injury become irreversible?
When the injury persists always frequently re-occurring.
The lysosome breaks open meaning enzymes leak out and act on other organelles
Changes that occur within the cell during injury
Karyolysis – the nucleus shrinks and eventually dissolutes.
Chromatin clumps caused by the degradation of DNA and nuclear condensation.
The ER and mitochondria swell.
Irreversible if:
The lysosomal breaks down causing enzymes to leak into the cell and agreed other organelles including ribosomes.
Causes of cell injury
Oxygen deprivation, physical agents, chemical agents, infectious agents, immune responses, nutritional imbalances and genetic to arrangements
Examples of oxygen deprivation
Hypoxia (lack of oxygen) and ischaemia (lack of blood flow)
Examples of Physical agents
Mechanical trauma, extreme temperature such as burning or frostbite
Examples of Chemical agents
Cyanide which blocks electron transport of cytochromes to cause respiratory failure, alcohol, carbon monoxide, acid burns
Examples of Infectious agents
Viruses and bacteria
Examples of Immune responses
Anaphylactic reaction to a protein, severe in for now response to Covid in the lungs
Examples of Nutritional imbalances
Deficiencies of specific vitamins, malnutrition or obesity
