Fundamental of pathophysiology Flashcards
What is pathophysiology?
The study of how disease affects the functioning of the body
Ashelford et. al (2019)
What is Integration?
It is crucial that the cells can communicate with each other effectively
This communication and the subsequent co-ordination of activity around the body to keep us disease free
What is the order of body systems Small-Large?
Give an example.
Specialised cell. Tissue. Organ. System. Organism
Muscle cell. Muscle tissue. Heart. Circulatory system. The circulatory system makes up part of the human body
How do cells communicate?
‘Signalling Cell’ is the cell that wants to send a message to another cell to make something happen
‘Ligands’ are the ‘messages’ which are being sent to another cell – these come in different forms as discussed later
Cells have ‘receptors’ on the cell membrane which are the ‘letterbox’ of the cell – it will only let certain messages (ligands) in
The ‘Receptor Cell’ is the cell that receives the ‘message’ and acts upon it.
Explain the key points in nerve cell signalling with an example disease
- Used exclusively by neurones
- Uses neurotransmitters to send chemicals through a gap- ‘synapse’ - to another neurone or to a receptor cell e.g.: muscles
- Fast, long-distance action
- Specific routes of movement
- Example: Parkinson’s Disease
Explain the key points in Endocrine signalling with an example disease
Endocrine cells send chemicals called hormones into the blood stream and are received by a receptor cell to stimulate an action
Slow-acting and diffuse around the entire body as it is within the circulation
Example: Diabetes
Explain Local signalling with an example
Features heavily in pathophysiology
Occurs between cells which are close together stimulating a local affect or action
Cells for example, will often signal damage to other cells as part of the body response to damage -inflammatory mediators
Example: Sprained ankle
Cells can adapt as a response to stimuli or changes in the body environment; which broadly fit into two categories:
Physiological
Pathological
What’s the difference?
Physiological – where changes occur in normal tissues/organs
Pathological – occurring due to disease
What is cell atrophy?
Atrophy is a decrease in cell size
Organ size changes if sufficient cell changes occur – shrinks.
Examples:
Skeletal muscle atrophy in the elderly
What is cell Hyperplasia
Hyperplasia is an increase in the number of cells.
Occurs due to increase cell mitosis either for a compensatory reason for tissue or organ generation; or hormonal stimulation.
Abnormal hyperplasia (pathologic) is an abnormal increase e.g.: Endometriosis (observed on a Pap smear)
Example:
Benign prostatic hyperplasia
Congenital adrenal hyperplasia
What is cell Metaplasia?
A cell of a specific type is replaced with another type of cell normally less specific than the first.
Seen in smoking; where mucous producing cells with cilia (columnar epithelial) are replaced with cells with no mucous production and cillia (squamous epithelium) thus affecting the respiratory system.
If continued; can turn into dysplasia which can eventually turn to carcinoma
Example:
Barrett’s oesophagus
Intestinal metaplasia
What is cell Dyplasia?
Abnormal changes and variations in the shape, size and organisation of cells.
Can potentially later turn into carcinoma.
Example:
Cervical dysplasia
Developmental dysplasia of the hip
Explain about cellular death
Cellular death is an important process in disease as death of cells normally results in a cascade of other processes; often stimulating the immune or inflammatory responses. There are two types of cellular death:
APOPTOSIS
Known as ‘programmed cell death’ – planned!
NECROSIS
Unplanned/Accidental cell death due to injury or damage to the cell
What is cell Necrosis how does it occur?
Not to be confused with skin necrosis in wound care – this necrosis isn’t black – but the same process will have happened in the cells.
Necrosis occurs due to injury – toxins, infection, trauma.
May initially be reversible as part of the inflammatory response but if injury is extensive or prolonged necrosis will occur.
Cell contents start to swell and the cell membrane becomes deformed; eventually the cell membrane ruptures and the contents/organelles leak out.
This leakage of content may stimulate the inflammatory and immune responses as these are picked up by cells to be digested and/or removed.
What is cell Apoptosis and how does it occur?
Often referred to a ‘programmed cell death’ – the cell dies at the end of it’s life; controlling the population of cells.
The cell does not become damaged; the membrane does not rupture but the cell membrane forms ‘blebs’ which contain cell contents and organelles.
These are again removed by inflammatory cells such as macrophages
Although apoptosis is a natural process; the cell can be coerced into it’s own ‘suicide’ by the immune system if it starts to replicate abnormally or is infected (e.g.: by a virus)
