Allergic reactions to penicillins occur in 1 – 10% of exposed individuals; anaphylactic reactions occur in fewer than 0.05% of treated patients. Patients with a history of atopic allergy are at higher risk of anaphylactic reactions to penicillins. Patients with a history of anaphylaxis, urticaria, or rash immediately after penicillin use should not receive a penicillin or other beta-lactam antibiotics; about 0.5 – 6.5 % of penicillin-sensitive patients will also be allergic to the cephalosporins. Patients with a history of a more minor rash (i.e. non-confluent, non-pruritic rash restricted to a small area of the body) or delayed reaction (rash occurring more than 72 hours after penicillin administration), may not be truly allergic and may be considered for penicillin or beta-lactam treatment in severe infection (although possibility of allergy should be borne in mind). Other beta-lactam antibiotics (including cephalosporins) can be used in these patients.

Pericardiocentesis is a procedure done to remove fluid build-up in the sac around the heart known as the pericardium. The pericardium can be tapped from almost any reasonable location on the chest wall. However, for the usual blind pericardiocentesis, the subxiphoid approach is preferred. Ideally, 2-D echocardiography is used to guide needle insertion and the subsequent path of the needle/catheter.In the subxiphoid approach, the needle is inserted 1 cm inferior to the left xiphocostal angle with an angle of 30 degrees from the patient’s chest with a direction towards the left mid-clavicle. The fingers may sense a distinct give when the needle penetrates the parietal pericardium. Successful removal of fluid confirms the needle’s position.

The electron transfer system is responsible for most of the energy produced during respiration. The is a system of hydrogen carriers located in the inner mitochondrial membrane. Hydrogen is transferred to the electron transfer system via the NADH2molecules produced during glycolysis and the Krebs cycle. As a result, a H+ion gradient is generated across the inner membrane which drives ATP synthase. The final hydrogen acceptor is oxygen and the H+ions and O2 combine to form water.

Patients with sickle cell disease are prone to infection of the bone and bone marrow in areas of infarction and necrosis. Although Staphylococcus aureus is the most common cause of osteomyelitis in the general population, studies have shown that in patients with sickle cell disease, the relative incidence of Salmonella osteomyelitis is twice that of staphylococcal infection.

Flecainide inhibits the transmembrane influx of extracellular Na+ ions via fast channels on cardiac tissues resulting in a decrease in rate of depolarisation of the action potential, prolonging the PR and QRS intervals. At high concentrations, it exerts inhibitory effects on slow Ca2+ channels, accompanied by moderate negative inotropic effect.

Carpal tunnel syndrome (CTS) is an entrapment neuropathy caused by compression of the median nerve as it travels through the wrist’s carpal tunnel. It is the most common nerve entrapment neuropathy, accounting for 90% of all neuropathies. Early symptoms of carpal tunnel syndrome include pain, numbness, and paraesthesia’s. These symptoms typically present, with some variability, in the thumb, index finger, middle finger, and the radial half (thumb side) of the ring finger. Pain also can radiate up the affected arm. With further progression, hand weakness, decreased fine motor coordination, clumsiness, and thenar atrophy can occur.The muscles innervated by the median nerve can be remembered using the mnemonic ‘LOAF’:L– lateral two lumbricalsO– Opponens pollicisA– Abductor pollicisF– Flexor pollicis brevisIn the early presentation of the disease, symptoms most often present at night when lying down and are relieved during the day. With further progression of the disease, symptoms will also be present during the day, especially with certain repetitive activities, such as when drawing, typing, or playing video games. In more advanced disease, symptoms can be constant.Typical occupations of patients with carpal tunnel syndrome include those who use computers for extended periods of time, those who use equipment that has vibration such as construction workers, and any other occupation requiring frequent, repetitive movement.

Flumazenil is a benzodiazepine antagonist that can be helpful in some overdose situations. It works quickly (in less than a minute), but the effects are fleeting, lasting less than an hour. The dose is 200 micrograms every 1-2 minutes with a maximum dose of 3 milligrams per hour.Flumazenil should be avoided by patients who are addicted to benzodiazepines or who take tricyclic antidepressants because it can cause withdrawal symptoms. It can cause seizures or cardiac arrest in these situations.

Causes of neutropaenia:Drug-induced (e.g. chemotherapy, chloramphenicol, co-trimoxazole, phenytoin, carbamazepine, carbimazole, furosemide, chloroquine, clozapine, some DMARDs)Benign (racial or familial)CyclicalImmune (e.g. SLE, Felty’s syndrome, hypersensitivity and anaphylaxis)LeukaemiaInfections (e.g. HIV, hepatitis, fulminant bacterial infection)General PancytopaeniaHypersplenism, aplastic anaemia, malignant infiltration of bone marrow, megaloblastic anaemia, chemotherapy, myelodysplasia

At three points along their course, the ureters are constricted denoting the most likely areas for renal calculi to lodge:the first point is at the ureteropelvic junction (where the renal pelvis becomes continuous with the ureter)the second point is where the ureter crosses the common iliac vessels at the pelvic brimthe third point is at the vesicoureteric junction (where the ureter enters the wall of the bladder)

Lymphatic drainage of the thyroid gland involves the lower deep cervical, prelaryngeal, pretracheal, and paratracheal nodes. The paratracheal and lower deep cervical nodes, specifically, receive lymphatic drainage from the isthmus and the inferior lateral lobes. The superior portions of the thyroid gland drain into the superior pretracheal and cervical nodes.

The pectoralis minor, in comparison to the pectoralis major, is much thinner and triangular in shape and resides below the major. It originates from the margins of the third to fifth ribs adjacent to the costochondral junction. The fibres consequently pass upward and laterally to insert into the medial border and superior surface of the coracoid process. It is crucial in the stabilization of the scapula by pulling it downward and anteriorly against the thoracic wall.Arterial supply to the pectoralis minor also derives from the pectoral branch of the thoracoacromial trunk. Nerve supply of the pectoralis minor is a function of the lateral pectoral nerve and the medial pectoral nerve.

The most potent diuretics are loop diuretics e.g. furosemide. They work by inhibiting the Na+/K+/2Cl-symporter in the thick ascending limb of the loop of Henle, which inhibits sodium, potassium, and chloride reabsorption. As a result, there is diuresis with loss of these electrolytes. There is a reduction in transcellular voltage difference, paracellular calcium and magnesium reabsorption.The medullary interstitium becomes more concentrated by salt reabsorption in the ascending limb. Loop diuretics block this process and reduce the ability of the kidney to concentrate urine. In the collecting duct, there is increased sodium delivery to the principal cells, which increases potassium secretion in return for sodium reabsorption.

Angiotensin-converting enzyme (ACE) inhibitors prevent angiotensin I from being converted to angiotensin II. Angiotensin II has a variety of effects:Sympathetic activity has increased.Vasoconstriction in the arteriesSecretion of VasopressinSecretion of aldosteroneThe increase in systemic blood pressure is caused by arteriolar vasoconstriction. Vasopressin stimulates water reabsorption in the kidneys as well as the thirst sensation. In the distal convoluted tubules and collecting ducts, aldosterone causes the reabsorption of sodium and water from the urine in exchange for potassium secretion. As a result, ACE inhibitors lower systemic blood pressure while also causing hyperkalaemia.Angiotensin-converting enzyme inhibitors (ACE inhibitors) are used in a variety of clinical settings, including heart failure. According to a meta-analysis, ACE inhibitors reduce death, MI, and overall admission in patients with heart failure by 28%.ACE inhibitors are also used in the following clinical settings:HypertensionChronic kidney diseaseDiabetic nephropathy Following a myocardial infarctionIn the presence of renal artery stenosis, ACE inhibitors are contraindicated because they can cause or exacerbate renal failure.The most common side effect of ACE inhibitors is a dry cough caused by increased bradykinin production. There is, however, no known link to fibrosis of the lungs.

Pericardiocentesis is a procedure done to remove fluid build-up in the sac around the heart known as the pericardium. The pericardium can be tapped from almost any reasonable location on the chest wall. However, for the usual blind pericardiocentesis, the subxiphoid approach is preferred. Ideally, 2-D echocardiography is used to guide needle insertion and the subsequent path of the needle/catheter.In the subxiphoid approach, the needle is inserted 1 cm inferior to the left xiphocostal angle with an angle of 30 degrees from the patient’s chest with a direction towards the left mid-clavicle. The fingers may sense a distinct give when the needle penetrates the parietal pericardium. Successful removal of fluid confirms the needle’s position.

One of the results of Klebsiella pneumoniae is pneumonia that is usually a very severe infection. It is characterised by thick, bloody sputum (red currant jelly sputum), and is associated with complications like lung abscess, cavitation, necrosis, empyema and pleural effusions.

At 3 months the following vaccines are given:Diphtheria, tetanus, pertussis, polio, Hib and hepatitis B (2nd dose)Pneumococcal (13 serotypes)Rotavirus (2nd dose)

The pain associated with external haemorrhoids is carried by a branch of the pudendal nerve, specifically the somatic fibres (S2-S4). It innervates the external anal sphincter and most of the skin over the perineum.

Negative feedback loops, also known as inhibitory loops, play a crucial role in controlling human health. It is a self-regulating mechanism of some sort. A negative feedback system is made up of three main components: a detector (often neural receptor cells) that measures the variable in question and provides input to the comparator; a comparator (usually a neural assembly in the central nervous system) that receives input from the detector, compares the variable to the variable set point, and determines whether or not a response is required. The comparator activates an effector (typically muscular or glandular tissue) to conduct the appropriate reaction to return the variable to its set point.

The current UK childhood immunisation schedule is as follows:8 weeks:DTaP/IPV(polio)/Hib/Hep B (diptheria, tetanus, pertussis, polio,Haemophilus influenzatype b and hepatitis B) – 6-in-one injection (Infranix hexa);plus:Rotavirus gastroenteritis (Rotarix) – oral route (drops)Meningitis B (Bexsero)12 weeks:DTaP/IPV(polio)/Hib/Hep B – 2nddose: 6-in-one injection, 2nddose (Infranix hexa);plus:PCV (pneumococcal conjugate vaccine) – in a separate injection (Prevenar 13)Rotavirus gastroenteritis 2nddose (Rotarix) – oral route (drops)16 weeks:DTaP/IPV(polio)/Hib/Hep B – 3rddose: 6-in-one injection, 3rddose (Infranix hexa);plus:Meningitis B 2nddose (Bexsero)Between 12 and 13 months:Hib/Men C (combined as one injection) – 4th dose of Hib and 1stdose of Meningitis C (Menitorix);plus:MMR (measles, mumps and rubella) – combined as one injection (Priorix or M-M-RVAXPRO);plus:PCV (pneumococcal conjugate vaccine) – 2nddose in a separate injection (Prevenar 13);plus:Meningitis B 3rddose (Bexsero)From 2 to end of primary school:Nasal flu spray (Fluenz Tetra). For children aged 2,3 and 4, this is usually given in the GP surgery. Children in school years 1,2 and 3 may have this at school.3 years and 4 months:Pre-school booster of DTaP/IPV (polio) – 4-in-one injection (Repevax or Infanrix-IPV);plus:MMR – 2nd dose (Priorix or M-M-RVAXPRO) – in a separate injectionBetween 12 and 13 years:HPV (human papilloma virus types 6,11, 16 and 18) –twoinjections of Gardasil given. The second injection is given 6-24 months after the first one.14 years:Td/IPV (polio) booster – 3-in-one injection (Revaxis)Men ACWY: combined protection against meningitis A, C, W and Y (Nimenrix or Menveo)The BCG vaccination against tuberculosis is only offered to neonates in high-risk areas or with high-risk backgrounds. When required it is usually given before leaving the hospital soon after birth.

Passive diffusion is a process that describes the movement down a concentration gradient. This process accounts for movement across small distances like within the cytosol or across membranes. Factors that affect the diffusion of a substance across a membrane are the permeability (p) of the membrane, a difference in concentration across the membrane and the membrane area over which diffusion occurs. The membrane thickness and composition, and the diffusion coefficient of the substance also affects the permeability. Fick’s law describes the rate of diffusion of a substance within a solution, which can be modified to describe the rate of diffusion across a membrane.

Chickenpox (varicella zoster) is a highly contagious airborne disease and has an incubation period of between 7-21 days. It often has a prodromal phase when there is a fever, aches and headaches, dry cough, and sore throat before onset of rash.Some recognized complications of chickenpox are:OrchitisHepatitisPneumoniaEncephalitisInfected spotsOtitis mediaMyocarditisGlomerulonephritisAppendicitisPancreatitis

Primary hyperaldosteronism occurs when there are excessive levels of aldosterone independent of the renin-angiotensin axis. Secondary hyperaldosteronism occurs due to high renin levels.The causes of primary hyperaldosteronism include:Adrenal adenoma (Conn’s syndrome) – the most common cause of hyperaldosteronism (,80% of all cases). These are usually unilateral and solitary and are more common in women.Adrenal hyperplasia – this accounts for ,15% of all cases. Usually, bilateral adrenal hyperplasia (BAH) but can be unilateral rarely. More common in men than women.Adrenal cancer – a rare diagnosis but essential not to missFamilial aldosteronism – a rare group of inherited conditions affecting the adrenal glandsThe causes of secondary hyperaldosteronism include:Drugs – diureticsObstructive renal artery disease – renal artery stenosis and atheromaRenal vasoconstriction – occurs in accelerated hypertensionOedematous disorders – heart failure, cirrhosis and nephrotic syndromePatients are often asymptomatic. When clinical features are present, the classically described presentation of hyperaldosteronism is with:HypertensionHypokalaemiaMetabolic alkalosisSodium levels can be normal or slightly raisedOther, less common, clinical features include:LethargyHeadachesMuscle weakness (from persistent hypokalaemia)Polyuria and polydipsiaIntermittent paraesthesiaTetany and paralysis (rare)Often the earliest sign of hyperaldosteronism is from aberrant urea and electrolytes showing hypokalaemia and mild hypernatraemia. If the patient is taking diuretics, and the diagnosis is suspected, these should be repeated after the patient has taken off diuretics.If the diagnosis is suspected, plasma renin and aldosterone levels should be checked. Low renin and high aldosterone levels (with a raised aldosterone: renin ratio) is suggestive of primary aldosteronism.If the renin: aldosterone ratio is high, then the effect of posture on renin, aldosterone and cortisol can be investigated to provide further information about the underlying cause of primary hyperaldosteronism. Levels should be measured lying at 9 am and standing at noon:If aldosterone and cortisol levels fall on standing, this is suggestive of an ACTH dependent cause, e.g. adrenal adenoma (Conn’s syndrome)If aldosterone levels rise and cortisol levels fall on standing, this is suggestive of an angiotensin-II dependent cause, e.g. BAHOther investigations that can help to distinguish between an adrenal adenoma and adrenal hyperplasia include:CT scanMRI scanSelective adrenal venous sampling

Clostridium tetani (causing tetanus) produces the exotoxin tetanospasmin which causes its neurotoxic effects.

Benzylpenicillin (although inactivated by bacterial beta-lactamases) is effective for many streptococcal (including pneumococcal), gonococcal, and meningococcal infections and also for anthrax, diphtheria, gas gangrene, leptospirosis, and treatment of Lyme disease. If meningococcal disease (meningitis with non-blanching rash or meningococcal septicaemia) is suspected, benzylpenicillin should be given before transfer to hospital, so long as this does not delay the transfer; benzylpenicillin is no longer the drug of first choice for pneumococcal meningitis. Although benzylpenicillin is effective in the treatment of tetanus, metronidazole is preferred. Benzylpenicillin is inactivated by gastric acid and absorption from the gastrointestinal tract is poor and therefore it must be given by injection.

Calcium-channel blockers, also known as calcium antagonists, stop calcium from entering cells through the L-type calcium channel. This causes vascular smooth muscle in vessel walls to relax, resulting in a decrease in peripheral vascular resistance. They can be used for a variety of things, including:HypertensionAnginaAtrial fibrillationMigraineCalcium-channel blockers can be divided into two categories: dihydropyridines and non-dihydropyridines. The basic chemical structure of these two classes differs, as does their relative selectivity for cardiac versus vascular L-type calcium channels.Dihydropyridines have a high vascular selectivity and lower systemic vascular resistance and blood pressure. As a result, they’re frequently used to treat hypertension. Modified release formulations are also used to treat angina, but their powerful systemic vasodilator and pressure-lowering effects can cause reflex cardiac stimulation, resulting in increased inotropy and tachycardia, which can counteract the beneficial effects of reduced afterload on myocardial oxygen demand.The suffix -dpine distinguishes dihydropyridines from other pyridines. Examples of dihydropyridines that are commonly prescribed include:AmlodipineFelodipineNifedipineNimodipineThe phenylalkylamine class and the benzothiazepine class are two subgroups of non-dihydropyridines.Phenylalkylamines are less effective as systemic vasodilators because they are relatively selective for the myocardium. This group of drugs lowers myocardial oxygen demand and reverses coronary vasospasm, making them useful in the treatment of angina. They are also occasionally used to treat arrhythmias. A phenylalkylamine calcium-channel blocker like verapamil is an example.In terms of selectivity for vascular calcium channels, benzothiazepines fall somewhere between dihydropyridines and phenylalkylamines. They can lower arterial pressure without producing the same level of reflex cardiac stimulation as dihydropyridines because they have both cardiac depressant and vasodilator effects. Diltiazem is the only benzothiazepine currently in clinical use.

Negative predictive value (NPV) is the proportion of individuals with a negative test result who do not have the disease.NPV = d/(c+d)

After the intial upstroke of the action potential, Na+channels and currents rapidly inactivate, but in cardiac myocytes, the initial depolarisation activates voltage-gated Ca2+channels (slow L-type channels, threshold approximately – 45 mV) through which Ca2+floods into the cell. The resulting influx of Ca2+prevents the cell from repolarising and causes a plateau phase, that is maintained for about 250 ms until the L-type channels inactivate. The cardiac AP is thus much longer than that in nerve or skeletal muscle.

Iliacus is innervated by the femoral nerve.

Lidocaine is a tertiary amine that is primarily used as a local anaesthetic but can also be used intravenously in the treatment of ventricular dysrhythmias.Lidocaine works as a local anaesthetic by diffusing in its uncharged base form through neural sheaths and the axonal membrane to the internal surface of the cell membrane sodium channels. Here it alters signal conduction by blocking the fast voltage-gated sodium channels. With sufficient blockage, the membrane of the postsynaptic neuron will not depolarise and will be unable to transmit an action potential, thereby preventing the transmission of pain signals.Each 1 ml of plain 1% lidocaine solution contains 10 mg of lidocaine hydrochloride. The maximum safe dose of plain lidocaine is 3 mg/kg. When administered with adrenaline 1:200,000, the maximum safe dose is 7 mg/kg. Because of the risk of vasoconstriction and tissue necrosis, lidocaine should not be used in combination with adrenaline in extremities such as fingers, toes, and the nose.The half-life of lidocaine is 1.5-2 hours. Its onset of action is rapid within a few minutes, and it has a duration of action of 30-60 minutes when used alone. Its duration of action is prolonged by co-administration with adrenaline (about 90 minutes).Lidocaine tends to cause vasodilatation when used locally. This is believed to be due mainly to the inhibition of action potentials via sodium channel blocking in vasoconstrictor sympathetic nerves.

Gentamicin, an aminoglycoside antibiotic, acts by binding to the 30S subunit of the bacterial ribosome inhibiting the binding of aminoacyl-tRNA and thus preventing initiation of protein synthesis.Vancomycin inhibits cell wall peptidoglycan formation by binding the D-Ala-D-Ala portion of cell wall precursors. Penicillins and cephalosporins are the major antibiotics that inhibit bacterial cell wall synthesis. They inactivate transpeptidases that help cross-link peptidoglycans in cell walls. Metronidazole and the other 5-nitroimidazole agents inhibit nucleic acid synthesis by forming toxic free radical metabolites in the bacterial cell that damage DNA. Ciprofloxacin inhibits prokaryotic enzymes topoisomerase II (DNA gyrase) and topoisomerase IV.

Hypocalcaemia occurs when there is abnormally low level of serum calcium ( >2.2 mmol/l) after correction for the serum albumin concentration.Rhabdomyolysis causes hyperphosphatemia, and this leads to a reduction in ionised calcium levels.Patients with rhabdomyolysis are commonly cared for in a high dependency care setting. Addison’s disease, hyperthyroidism, thiazide diuretics and lithium all cause hypercalcaemia.

As part of the investigation of hyponatraemia, serum osmolality is commonly requested in combination with urine osmolality to aid diagnosis.When: Serum osmolality is decreased and urine osmolality is decreased with no intake of fluid, the causes areHyponatraemiaOverhydrationAdrenocortical insufficiencySodium loss (diuretic or a low-salt diet)Serum osmolality is normal or increased and urine osmolality is increased the causes include:DehydrationHyperkalaemiaHyperglycaemiaHyponatremiaMannitol therapyDiabetes mellitusAlcohol ingestionCongestive heart failureRenal disease and uraemiaSerum osmolality is normal or increased and urine osmolality is decreased the usual cause is diabetes insipidusSerum osmolality is decreased and urine osmolality is increased the usual cause is syndrome of inappropriate antidiuresis (SIAD)

Passive inspiration is produced by contraction of the diaphragm (depressing the diaphragm) and the external intercostal muscles (elevating the ribs). In inspiration, elevation of the sternal ends of the ribs (‘pump handle’ movement), elevation of the lateral shafts of the ribs (‘bucket handle’ movement) and depression of the diaphragm result in expansion of the thorax in an anteroposterior, transverse and vertical direction respectively. This results in an increased intrathoracic volume and decreased intrathoracic pressure and thus air is drawn into the lungs.

Dorsiflexion and eversion of the foot are innervated by the deep fibular nerve and the superficial fibular nerve, respectively. The common fibular nerve runs obliquely downward along the lateral border of the popliteal fossa (medial to the biceps femoris) before branching at the neck of the fibula. Thus, it is prone to being affected during an impact injury or fracture to the bone or leg. Casts that are placed too high can also compress the fibular nerve.

Majority of carbohydrates are broken down into monosaccharides (glucose, fructose galactose) and are absorbed by the small intestine. Enzymes released from the brush border break down carbohydrate. Some carbohydrates, such as cellulose, are not digested at all, despite being made of multiple glucose units. This is because the cellulose is made out of beta-glucose that makes the inter-monosaccharide bindings different from the ones present in starch, which consists of alpha-glucose. Humans lack the enzyme for splitting the beta-glucose-bond.The principal brush border enzymes are dextranase and glucoamylase. Other brush border enzymes are maltase, sucrase, and lactase.Pancreatic amylase breaks down some carbohydrates (notably starch) into oligosaccharides. Dextranase and glucoamylase, then further break down oligosaccharides.Trypsin aids in digestion of protein.Chymotrypsin is a proteolytic enzyme that digests proteinCarboxypeptidase hydrolyses the first peptide or amide bond at the carboxyl or C-terminal end of proteins and peptides

A phaeochromocytoma is a rare functional tumour that develops in the adrenal medulla from chromaffin cells. Extra-adrenal paragangliomas (extra-adrenal pheochromocytomas) are tumours that arise in the sympathetic nervous system’s ganglia and are closely connected to extra-adrenal paragangliomas (extra-adrenal pheochromocytomas). Catecholamines are secreted by these tumours, which generate a variety of symptoms and indications associated with sympathetic nervous system hyperactivity.Hypertension is the most prevalent presenting symptom, which can be continuous or intermittent.Symptoms are usually intermittent, occurring anywhere from many times a day to occasionally. The symptoms of the condition tend to grow more severe and frequent as the disease progresses.The ultimate therapy of choice is surgical resection, and if full resection is done without metastases, hypertension is typically cured.Preoperative medical treatment is critical because it lowers the risk of hypertensive crises during surgery. This is commonly accomplished by combining non-competitive alpha-blockers (such as phenoxybenzamine) with beta-blockers. To allow for blood volume expansion, alpha-blockade should be started at least 7-10 days before surgery. Beta-blockade, which helps to regulate tachycardia and some arrhythmias, can be started after this is accomplished. Hypertensive crises can be triggered if beta-blockade is started too soon.There should also be genetic counselling, as well as a search for and management of any linked illnesses.

In patients with exertional stable angina, nitrates improve exercise tolerance, time to onset of angina, and ST-segment depression during exercise testing. In combination with beta-blockers or calcium channel blockers, nitrates produce greater anti-anginal and anti-ischemic effects.While they act as vasodilators, coronary vasodilators, and modest arteriolar dilators, the primary anti ischemic effect of nitrates is to decrease myocardial oxygen demand by producing systemic vasodilation more than coronary vasodilation. This systemic vasodilation reduces left ventricular systolic wall stress.

Pronator quadratus is a deep-seated, short, flat, and quadrilateral muscle with fibres running in a parallel direction. It arises from the oblique ridge on the anterior surface of the distal fourth of the Ulna. It is inserted in lateral border and anterior surface of the distal fourth of the radius. It is innervated by the anterior interosseous nerve, a branch of the median nerve (C8-T1). It is vascularized by the anterior interosseous artery.The action of the pronator quadratus muscle along with the pronator teres result in the pronation of the radioulnar joint. Contraction of this muscle pulls the distal end of the radius over the ulna, resulting in the pronation of the radioulnar joint

Concomitant treatment with NSAIDs increases the risk of renal damage, and with potassium-sparing diuretics (or potassium-containing salt substitutes) increases the risk of hyperkalaemia. Hyperkalaemia and other side effects of ACE inhibitors are more common in the elderly and in those with impaired renal function and the dose may need to be reduced.

Mitochondrial diseases are a group of disorders caused by dysfunctional mitochondria. Most cases are maternally inherited, as we inherit our mitochondrial DNA from our mothers only, although mutations in nuclear DNA cause some cases.Examples of Mitochondrial Diseases include:1. Mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS)2. Mitochondrial epilepsy with ragged red fibres (MERRF)3. Leber’s hereditary optic neuropathy (LHON)4. Diabetes mellitus and deafness (DAD)5. Neuropathy, ataxia, retinitis pigmentosa, and ptosis (NARP)6. Leigh syndrome (subacute sclerosing encephalopathy). Red-green colour blindness and G6PD deficiency have an X-linked recessive pattern of inheritance. Tay-Sachs Disease and spinal muscular atrophy have an autosomal recessive pattern of inheritance.