Causes of disease Flashcards
What is etiology?
Cause of disease
What are conditions with no known cause called?
Idiopathic
What are causes of disease usually categorised as?
- Intrinsic- from within
- Extrinsic- from outside
What are intrinsic causes?
Changes in an individuals genome
- Can be nuclear or mitochondrial
- Inherited mutations and other genetic variations
- de novo mutations
- Epigenetic modifications
Typically, any of these genetic changes will impact on the function of a gene (or group of genes)
- E.g. more/less protein or same amount but more/less activity
What does cell autonomously mean?
Cell X no longer expresses structural protein Y, so cell X is the wrong shape
What does non cell autonomously mean?
Cell X no longer secretes protein hormone Y, so cell Z no longer functions
What are extrinsic causes?
- Injury
- Infection
- Nutrition/diet
- Lifestyle, e.g. smoking, exposure to workplace toxins
- Chemical poisoning (acute and chronic)
- Exposure to radiation
Why are the terms intrinsic and extrinsic ambiguous? Why can some causes of disease be thought of as grey areas?
Causes of disease are often a chain of events
- Are allergies caused by a sensitive immune system (intrinsic) or the preceding allergen (extrinsic)?
Intrinsic or extrinsic depends on viewpoint, i.e. extrinsic to what: cell, tissue, organ, body?
What can be a more accurate term than cause?
Risk factor
How is age a cause?
Age often just means ‘time’, in the context of causes that accumulate
When can age be an intrinsic cause?
When it describes the biological process
e.g. Risk of osteoporosis- decreased oestrogen- menopause- ageing
What other terms can causes be termed as
Genetic and environmental
Give intrinsic causes of disease relevant to module
- Cancer
- (Inc. Leukaemia, Lymphoma, Myeloma, Breast, Prostate)
- Developmental diseases
- (e.g. Neural tube defects)
- Inherited anaemia
- (e.g. Sickle cell disease, B- thalassaemia)
- Inherited metabolic diseases
- (e.g. phenylketonuria)
Give extrinsic causes of disease relevant to module
- Nutrition and diet
- (e.g. Nutritional anaemias- Developmental disorders, e.g. lack of dietary folate and neural tube closure)
- Lifestyle, e.g. smoking, exposure to workplace toxins
- Chemical poisoning (acute and chronic)
- Exposure to radiation
What are the phases of the cell cycle?
Mitosis
- PMAT
Interphase
- G1 (cell growth)
- S (DNA replication)
- G2 (preparation for Mitosis)
What are mitogens?
A mitogen is a small bioactive protein or peptide that induces a cell to begin cell division, or enhances the rate of division (mitosis). Mitogenesis is the induction (triggering) of mitosis, typically via a mitogen
