Medical Pathophysiology

Interruption of blood supply in brain, leading to necrosis of brain tissue. Can be ischemic (blockage from a thrombus or embolism) or haemorrhagic (blood), for 24 hours. A TIA has same signs and symptoms, but lasts for less than 24 hours. Causes – hypertension, smoking, AF, diabetes, alcohol, obesity.

An abnormal depolarisation of neurones, normally less than 5 mins. Can be generalised or partial. Can present as “absences” or “tonic clonic”, followed by a “Post ictal” phase of recovery (exhaustion). Status Epilepticus is a continuous state of convulsions without recovery.

Bacteria infect the meninges, causing inflammation. These bacteria multiply in the CSF and release toxins. Inflammation causes increased pressure resulting in a stiff neck, headaches, photophobia, fever, rash, high resp rates and decreased LOC.

Bacteria invade the bloodstream, releasing toxins. Leads to signs o shock quickly. Related to meningitis. These bacteria live in the nasopharynx, and are only a problem when they cross into the bloodstream.

Anaphylaxis is a severe allergic reaction affecting the entire body. An antigen creates an antibody reaction in Mast Cells, which release Histamine (vasodilation and bronchoconstictor), Heparin (anticoagulant), and Cytokenes (bring more WBCs to the site). Under normal circustances this allergic reaction fights antigens, but in anaphylaxis this causes a extreme reaction. This can leade to anaphylactic shock - an example of distributive shock (dilation of peripheral vascular system, and a lack of vascular tone, creating “leaky vessels”).

Infection invades the body, and enters the blood. WBCs are called to the blood, but cannot enter circulatory system. Vasdilation occurs, making walls more permeable; fluid leaks out causing dehydration and oedema. The holes in the vessel can lead to septic shock (distributive shock), and potentially hypovolaemic shock (lack of volume).

Exposure to a substance via inoculation, ingestion, inhalation or absorption. Check Toxbase for more info. Consider vital signs for more clues, can be varied depending on the poison or intoxicating substance. Often causes lowered LOC and respiratoruy depression, vomiting, nausea.

Cholesterol lodges between the tunica intima and the tunica media in the artery. Monocytes engulf the cholesterol forming a plaque – this is an ATHEROMA.

Where a atheroma narrows and blocks an artery, reducing blood flow leading to ischemia or infarction in the heart, brain or kidneys or lung.

a thrombus can travel, becoming an embolism. Can be any mass in the blood. Can arise from a DVT, where a clot travels up the fermoral vein to the vena cava, then to the heart and then the pulmonary artery. This is a PE.

ANEURYSM – an abnormal dilation of the arteries, creating holes in the artery wall, and blood goes between the layers (tunica intima, media and adventitia). Can be saccular (one sided), fusiform (two sides), or dissecting (burst). Common in the brain. If an aneurysm ruptures it disrupt blood supply (particularly in the brain), causing ischemia.

When coronary arteries become narrowed by atheroma, leading to atherosclerosis (a thickening of arteries, meaning a lack of elasticity, reducing rhe ability of arteries to dilate/constrict).

Reduction of blood supply to the myocardium, caused by a narrowing of arteries due to CHD. Stable angina is when the pain subsides at rest. Unstable angina is when there is pain at rest.

When the heart is unable to pump adequately. Can be either LVF or RVF, or both. Organs are not able to receive enough oxygenated blood. Can be the resuklt of MI, hypertension, and also from alcohol and drugs. Diseased arteries are inelastic causing a rise in mean arterial pressure.   LVF is a failure to pump out to the body, resulting in a pooling of blood in the lungs, characterised by pulmonary oedemas. RVF created peripheral oedemas, as the blood pools in the body.

An abrupt reduction in blood supply to the heart muscle, leading to myocardial ischaemia. Caused by an atheroma of the coronary artery, leading to atherosclerosis. Unstable angina, NSTEMI and STEMI are signs of ACS. A sudden reduction of blood supply to the heart is time critical and cn cause death of the heart tissue, leading to a lack of oxygenated blood going to the organs.

The appendix becomes blocked with faecal matter and bacteria cause the appendix to become inflamed, swollen and filled with pus, can lead to rupturing. Pain starts around belly/umbilical area, and the RIGHT LOWER abdo. If ruptured it will hit the diaphragm, which irritates the phrenic nerve, causing referred pain in the shoulder

Acute inflammation of gall bladder, due to the obsruction of the cyctic duct by gall stones. Sharp UPPER RIGHT abdo pain.

Can be upper or lower. Upper from small intestine, stomach, oesophagus (dark blood). Lower from large intestine, colon, rectum (red blood). Can lead to hypovolaemic shock. Altered bowel habit are key signs.

Impared perfusion of the alveoli, from an airway obstruction, leading to hypoxia. Pulmonary tissue causes airway obstruction inside the lungs. Can be the result of bronchitis (acute or chronic), an inflammatory infection and increase in mucus (“blue bloaters”). Or emphysema, (“Pink Puffers”) which is a distension ad destruction of the alveoli, creating a reduced surface area within the alveoli and an impared gas exchange, and a lack of elasticity in lung tissue. Often caused by smoking.

Can be extrinsic or intrinsic. Different triggers, such as exercise, cold weather, allergies, perfume. It is a chronic inflammation of the bronchi, which makes them always sensitive and inflamed, making bronchi smaller and leads to excess production of mucus, creating a wheeze and DIB, bronchospams and bronchoconstriction. This decreases the tidal volume. During an attack air is trapped withi the lungs, causing hyperinflation.

Inhaled bacterial air or viral infection. If the body’s defences cannot cope, a build up of fluid (mucus, blood cells) occur. This causes a consolidation of the lungs.

a thrombus can travel, becoming an embolism. Can be any mass in the blood. Can arise from a DVT, where a clot travels up the fermoral vein to the vena cava, then to the heart and then the pulmonary artery. This is a PE.

2 types of diabetes. Type I – the pancreas doesn’t produce insulin; Type II – the pancreas does produce insulin, but receptor sites for insulin are mutated or blocked so insulin is unable to enter cells. There is then an excess of sugar around the bidy, and the body relies on other sources for energy. In a hyperglycaemic attack the patient may have an infection or not be compliant with meds, or may be having an MI. In a hypoglycaemic attack the patient may have an insulin overdose an infection, may be alcoholic, or may not have eaten. A hypo can present as a stroke.