PHALANGES(TOE BONES)
Arches of the foot. The arrangement of bones in the foot,supported by associated ligaments and action of associated muscles,gives the sole of the foot and arched or curved shape. The…
DYSENTERY.
BACILLARY DYSENTERY. This infection of the large intestine is caused by bacteria of the shigella group. The severity of the condition depends on the organisms involved. It is usually a relatively mild…
TYPHOID FEVER.
This type of enteritis is caused by the bacterium salmonella typhi,ingested in contaminated food and water. As human are it's only host,it is acquired from an individual who is either suffering…
ÀPPENDICITIS.
The lumen of the appendix is very small and there is little room for swelling when it becomes inflamed. The initial cause of inflammation is not always clear. Microbial infection…
PEPTIC ULCERATION.
Ulceration involves the full thickness of the gastrointestinal mucosa. It is caused by disruption of the normal balance between the corrosive effect of gastric juice and the protective effect of…
ACUTE GASTRITIS
This is usually a response to irritant drugs or alcohol. The drugs most commonly implicated are non-steroidal anti-inflammatory drugs including aspirin,even at low doses,although many others may also be involved.…
What are carbohydrates?
Carbohydrates are mainly sugars and starches,which are found in a variety of foods,eg.sugar,jam,cereals,bread,biscuits, pasta,fruits and vegetables. They consist of carbon,hydrogen and oxygen,the hydrogen and oxygen being in the same proportion…
A BALANCED DIET.
A balanced diet contains all nutrients required for health in appropriate proportions,and is normally achieved by eating a variety of foods. This is because no single food contains the correct…
PROLAPSED INTERVERTEBRAL DISC.
This is the most common cause of compression of the spinal cord/or nerve roots. The vertebral bodies are separated by the intervertebral disc,each consisting of an outer rim of cartilage,the annulus…
THE CEREBELLUM.
The cerebellum is situated behind the pons and immediately below the posterior portion of the cerebrum occupying the posterior cranial fossa. It is ovaid in shape and has two hemispheres,separated…
THE SPINAL CORD.
The spinal cord is the elongated,almost cylindrical part of the central nervous system,which is suspended in the vertebral canal surrounded by the meninges and cerebrospinal fluid. The spinal cord is…
CEREBROSPINAL FLUID.
Cerebrospinal fluid is secreted into each ventricle of the brain by choroid plexuses. These are vascular area where there is a proliferation of blood vessels surrounded by ependymal cells in the lining…
THE MENINGES.
The brain and spinal cord are completely surrounded by three layers of tissue,the meninges,lying between the skull and the brain,and between the vertebral foramina and spinal cord. Named from outside inwards…
AXONS AND DENDRITES.
Axons and dendrites are extensions of cell bodies and form the white matter of the nervous system. Axons are found deep in the brain and in groups,called tracts,at the periphery of…
THE SPLEEN.
The spleen contains reticular and lymphatic tissue and is the largest lymph organ. The spleen lies in the left hypochondriac region of the abdominal cavity between the fundus of the…
THE THYMUS GLAND.
The thymus gland lies in the upper part of the mediastinum behind the sternum and extends upwards into the root of the neck. The thymus consists of two lobes joined…
LYMPH NODES.
Lymph nodes are oval or bean-shaped organs that lie,often in groups,along the length of lymph vessels. The lymph drains through a number of nodes,before returning to the venous circulation. These…
LYMPH VESSELS.
Lymph vessels are often found running alongside the arteries and veins serving the area. Their walls are about the same thickness as those of small veins and have the same…
INFECTIVE ENDOCARDITIS.
Pathogenic organisms(usually bacteria or fungi) in the blood may colonise any part of the endocardium,but the most common sites are on near the heart valves and round the margins of…
HEART(CARDIAC)FAILURE.
The heart is described as failing when the cardiac output is unable to maintain the circulation of sufficient blood to meet the needs of the body. In mild cases,cardiac output is adequate…
EDEMA/OEDEMA.
In oedema,excess tissue fluid accumulates,causing swelling. It may occur either in superficial tissues or deeper organs. SITES OF OEDEMA. When oedema is present in the superficial tissues,pitting of the surface may…
VÀRICOSE VEINS.
A varicose vein is one that is so dilated that the valves do not close to prevent backward flow of blood. Such veins lose their elasticity,become elongated and tortuous,and fibrous…
GIGANTISM AND ACROMEGALY.
The most common cause is prolonged hypersecretion of growth hormone(GH),usually by a hormone-secreting pituitary tumour. The conditions are only occasionally due to excess growth hormone releasing hormone(GHRH) secreted by the…
CYSTITIS.
This is inflammation of the bladder and may be due to: Upward spread of microbes that are commensals of the bowel from the perineum via the urethra,especially in women. Trauma,with…
GLAUCOMA.
This is a group of conditions in which intraocular pressure rises due to impaired drainage of aqueous fluid through the scleral venous sinus(canal of Schlemm) in the angle between the…
MULTIPLE SCLEROSIS DISEASE.
In this disease there are areas of demyelinated white matter,called plaques,irregularly distributed throughout the brain and spinal cord. Grey matter in the brain and spinal cord may also be affected…
HYDROCEPHALUS.
In this condition the volume of cerebrospinal fluid(CSF) is abnormally high and is usually accompanied by increased intracranial pressure(ICP). An obstruction to CSF flow is the most common cause. It…
SPINA BIFIDA ABNORMALITY.
This is a congenital malformation of the embryonic neural tube and spinal cord. The vertebral(neural) arches are absent and the dura mater is abnormal,most commonly in the lumbosacral region. The…
PERIPHERAL NEUROPATY OF THE NERVES.
This is a group of diseases of peripheral nerves not associated with inflammation. They are classified as: Polyneuropathy: several nerves are affected. Mono neuropathy: a single nerve is usually affected.…
CEREBRAL HYPOXIA.
Hypoxia may be due to: Disturbances in the autoregulation of blood supply to the brain. Conditions affecting cerebral blood vessels. When the main blood pressure falls below about 60 mmHg,the…
INCREASED INTRACRANIAL PRESSURE.
This is a serious complication of many conditions that affect the brain. The cranial forms a rigid cavity enclosing; the brain,the cerebral blood vessels and cerebrospinal fluid(CSF). An increase in…
SPLENOMEGALY DISORDER.
This is enlargement of the spleen,and is usually secondary to other conditions,eg.infections,circulatory disorder,blood diseases,malignant neoplasms. INFECTIONS. The spleen may be infected by blood-borne microbes or by local spread of infections.…
ATRIAL SEPTAL DEFECT.
This is also known as 'hole in the heart'. Before birth,most oxygenated blood from the placenta enters the left atrium from the right atrium through the foramen ovale in the septum.…
CARDIAC ARRHYTHMIAS.
The heart rate is normally determined by intrinsic impulses generated in the SA node. The rhythm is determined by the route of impulse transmission through the conducting system. The heart…
LYMPHOMAS.
These are malignant tumours of lymphoid tissue and are classified as either Hodgkin's or non-Hodgkin's lymphomas. HODGKIN'S DISEASE. In this disease there is progressive,painless enlargement of lymph nodes throughout the…
LYMPHADENITIS.
Acute lymphadenitis(acute infection of lymph nodes)is usually caused by microbes transported in lymph from other areas of infection. The nodes become inflamed,enlarged and congested with blood,and chemotaxis attracts large numbers…
HEART BLOCK.
Heart block occurs when normal impulse transmission is blocked or impaired. A common form involves obstruction of impulse transmission through the AV node, but conducting tissue in the atrial or…
What is rheumatic heart disease.
Rhematic fever is an inflammatory illness that sometimes follows streptococcal throat infections,most commonly in children and young adults. It is an autoimmune disorder; the antibodies produced to combat the original…
Myocardial infarction.
The myocardium may infart when a branch of a coronary artery is blocked. The commonest cause is an atheromatous plague complicated by thrombosis. The extent of myocardial damage depends on…
ANGIOMAS IN BLOOD AND LYMPH VESSELS.
Angiomas are benign tumours of either blood vessels(haemangiomas) or lymph vessels(lymphangiomas). The latter rarely occur, so angioma is usually taken to mean haemangioma. Haemangiomas. These are not true tumours,but are sufficiently…
Aneurysms in arteries.
Aneurysms are abnormal local dilations of arteries,which vary considerably in size. Predisposing factors include atheroma,hypertension and defective formation of collagen in the arterial wall. COMPLICATIONS OF ANEURYSM. If an aneurysm…
ARTERIOSSCLEROSIS.
This is a progressive degeneration of arterial walls,associated with ageing and accompanied by hypertension. In large and medium-sized arteries,the tunica media is infiltrated with fibrous tissue and calcium. This causes…
ATHEROMA IN BLOOD VESSEL PATHOLOGY.
ATHEROMA. Pathological changes. Atheromatous plagues are patchy changes that develop in the tunica intima of large and medium-sized arteries. Initial changes show a fatty streak in the artery wall. Mature…
Thrombus formation
The risk of a thrombus developing within a blood vessel is increased by any condition that slows blood flow,damages the smooth intimal lining of blood vessels or increases blood coagulability.…
Pulmonary circulation
This is the circulation of blood from the right ventricle of the heart to the lungs and back to the left atrium. In the lungs,carbon dioxide is excreted and oxygen…
PULSE.
The pulse is a wave of distension and elongation felt in an artery each time the left ventricle ejects blood into the system. Each contraction of the left ventricle forces…
Understanding blood pressure.
Blood pressure is the force or pressure that the blood exerts on the walls of the blood vessels. Systemic arterial blood pressure maintains the essential flow of blood into and…
The nervous system as an internal communicator.
The nervous system is a rapid communication system. The central nervous system consists of: The brain,situated inside the skull. The spinal cord,which extends from the base of the skull to…
CIRCULATORY SYSTEM.
This consists of a network of blood vessels and the heart blood vessels. There are three types: Arteries- which carry blood away from the heart. Veins- which return blood to…
HOMEOSTASIS
The composition of the internal environment is tightly controlled,and this fairly constant state is called homeostasis. Literally,this term means 'unchanging' but in practice it describes a dynamic,ever-changing situation kept within…
CERVICAL CARCINOMA.
Dysplastic changes,referred to as cervical intraepithelial neoplasia(CIN) begin in the deepest layer of the cervical epithelium,usually at the junction of the stratified squamous epithelium of the lower third of the…
GOUT
This condition is more prevalent in males than females and there is a familial tendency. It is caused by the deposition of sodium urate crystals in joints and tendons,provoking an…
OSTEOARTHRITIS.
This is a degenerative non-inflammatory disease that results in pain and restricted movement of affected joints. OSTEOARTHRITIS is the more appropriate name but less commonly used. In it's early stages,it's…
POLYARTHRITIS.
Polyartritis means inflammation of more than one joint. This group of autoimmune inflammatory arthritic diseases has many characteristics similar to rheumatoid arthritis but the rheumatoid factor is absent. The changes…
RHEUMATOID ARTHRITIS.
This is a chronic progressive inflammatory autoimmune disease mainly affecting peripheral synovial joints. It is a systematic disorder in which inflammatory changes affect not only joints but also many other…
OSTEOPOROSIS.
In this condition,bone density( the amount of bone tissue) is reduced because it's deposition does not keep pace with resorption. Although the bone is adequately mineralised,it is fragile and microscopically…
HYPERSENSITIVITY(ALLERY)
Allergy is powerful immune response to an antigen (allergen). The allergen itself is usually harmless (eg. house dust,animal dander,grass pollen). It is therefore usually the immune response that causes damage…
BURNS
These may be caused by many types of trauma including : heat,cold,electricity,ionising radiation and corrosive chemicals,including strong acids or alkaline. Local damage occurs disrupting the structure and functions of the…
CYSTITIS.
This is inflammation of the bladder and may be due to: Upward spread of microbes that are commensals of the bowel from the perineum via the urethra,especially in women. Trauma,with…
ACUTE TUBULAR NECROSIS.
This is the most common cause of acute renal failure. There is severe damage to the tubular epithelial cells caused by ischaemia or,less often,by nephrotoxic substances. There is reduced glomerular…
RENAL CALCULI.
Calculi(stones) form in the kidneys and bladder when urinary constituents normally in solution are precipitated. The solutes involved are usually oxalates and phosphates. Most originated in the collecting tubules or…
CHRONIC RENAL FAILURE.
This occurs when the renal reserve is lost and there is irreversible damage of nephrons. Onset is usually slow and asymptomatic,progressing over several years. The main causes are diabetes mellitus,glomerulonephritis …
NEPHROTIC SYNDROME.
This is not a disease in itself but is an important feature of several kidney diseases. The main characteristics are: Marked proteinuria. Hypoalbuminemia. Generalised oedema. Hyperlipidemia. When glomeruli are damaged,the…
GLOMERULONEPHRITES(GN)
This term suggests inflammatory conditions of the glomerulus, but there are several types of GN and inflammatory changes are not always present. In many cases immune complexes damage the glomeruli.…
LIVER FAILURE.
This occurs when liver function is markedly impaired. It can be acute or chronic and may be the outcome of a wide variety of disorders,eg, Acute viral hepatitis. Extensive necrosis…
HERNIAS
A hernia is a protrusion of an organ or part of an organ through a weak point or aperture in the surrounding structures. In those affecting the digestive system, a…
COLORECTAL CANCER
This is the most common malignancy of the alimentary tract and as a cause of cancer related death is second only to lung cancer. The tumours are adenocarcinomas with about…
LUNG COLLAPSE
The clinical effects of collapse of all part of a lung depend on how much of the lung is affected. Fairly large sections of a single lung can be out…
ADDISON’S DISEASE.
This is due to hyposecretion of glucocorticoid and mineralocorticoid hormones. The most common causes are development of autoantibodies to cortical cells,metastatic tumours and infections. Autoimmune disease of some other glands…
PNEUMONIA
Pneumonia means infection of the alveoli. This occurs when protective processes fail to prevent inhaled or blood- borne microbes reaching and colonising the lungs. PREDISPOSING FACTORS. IMPAIRED COUGHING: Coughing is…
Emphysema
PULMONARY EMPHYSEMA. This usually develops as a result of long- term inflammatory conditions of irritation of the airways, eg in smokers or coal miners. Occasionally,it may be due to a…
THE PHARYNX
The pharynx is a tube 12 to 14 cm long that extends from the base of the skull to the level of the 6th cervical vertebra. It lies behind the…
THE TONGUE
The tongue is a voluntary muscular structure that occupies the floor of the mouth. It is attached by its base to the hyoid bone and by a fold of its…
TUBERCULOSIS
This infection is caused by one of two similar forms of mycobacteria,the main one being mycobacterium tuberculosis. Humans are the main host. The microbes cause pulmonary tuberculosis and are spread…
ASTHMA
Asthma is a common inflammatory disease of the airways associated with episodes of reversible over-reactivity of the airway smooth muscle. The mucous membranes and muscle layers of the bronchi become…
DIABETES MELLITUS
This is the most common endocrine disorder and usually occurs when there is deficiency or absence of insulin or rarely impairment of insulin activity. Varying degrees of disruption of carbohydrate…
BRONCHIAL CARCINOMA
Primary bronchial carcinoma is a very common malignancy. The vast majority of cases in smokers and or those who inhale other people's smoke( passive smokers). Other risk factors include exposure…
CYSTIC FIBROSIS.
This is one of the most common genetic diseases. Almost 5% of people carry the abnormal recessive gene which must be present in both parents to cause the disease. The…
CHRONIC BRONCHITIS LUNG DIORGER
Chronic bronchitis is a common disorder that becomes increasingly debilitating as it progresses. It is defined when an individual has had a cough with sputum for 3 months in 2…
JAUDICE AND ITS TYPES
Jaudice is not a disease in itself,but yellowing of the skin and mucous membranes is a sign of abnormal bilirubin metabolism and excretion. Bilirubin is produced from the breakdown of…
SHOCK
This occurs when the metabolic needs of cells are not being met because of inadequate blood flow. In effect,there is a reduction in circulatory blood volume in blood pressure and…