Clinical Conditions Flashcards
After a clavicular fracture which muscle pulls the medial 2/3 of the clavicle upwards?
Sternocleidomastoid
How can an elbow dislocation occur? What damage is usually caused?
A young child falling on a hand with the elbow flexed. The distal end of the humerus is driven through the weakest part of the joint capsule, which is the anterior side. The ulnar collateral ligament is usually torn and there can also be ulnar nerve involvement.
How are fractures of the scapula commonly caused?
Fractures of the scapula are relatively uncommon, and if they do occur, it is an indication of severe chest trauma. It is frequently seen in high speed road collisions, crushing injuries, or sports injuries
Describe simply the stages from inhalation of streptococcus pneumoniae type 3 to acute inflammation to resolution.
1) Congestion 2) Red hepatisation 3) Grey hepatisation 4) Resolution
How can a supraepicondylar fracture of the humerus occur?
A supraepicondylar fracture occurs by falling on a flexed elbow.
How can thrombocytopenia occur?
-Failure of platelet production -Increase in platelet destruction -Sequestering of platelets
How can nephrogenic diabetes Insipidus be caused?
Loss-of-function mutation to the V2 vasopressin receptor.
How can the long thoracic nerve be damaged?
-Trauma to the shoulder -Repetitive movements involving the shoulder -Structures becoming inflamed and pressing on the nerve.
How can disuse atrophy occur?
-Bed rest -Limb immobilisation -Sedentary behaviour
How do membrane enveloped viruses and toxins take advantage of receptor-mediated endocytosis to enter the cell?
-Exploit endocytic pathways to enter cells after adventitious binding to receptors -In the endosome the acidic pH allows the viral membrane and endosome membrane to fuse -Releases viral RNA into the cell where the host manufactures more of it
How can retinitis pigmentosa be caused?
Loss-of-function mutation to Rhodopsin
How can familial male precocious puberty be caused?
Gain-of-function mutation (Receptor active without ligand) to the luteinising hormone (LH) receptor
How do the symptoms of malignant hyperthermia occur?
-Exposure to the volatile anesthetic agents and the neuromuscular blocking agent, succinylcholine -Excessive calcium release -High amounts of ATP needed to put calcium back
How do you treat Kwashiorkor?
Make alterations to the diet to ensure correct amount of protein intake. However, be aware of refeeding syndrome!
How do you treat Marasmus?
Changes to the diet - avoid REFEEDING SYNDROME!
How does a nitrogen embolism occur?
Nitrogen bubbles formi in the blood with rapid decompression. (The Bends)
How does denervation atrophy occur?
The muscle no longer receives contractile signals that are required to maintain normal size and muscle fibres are replaced with fibrous and fatty tissue
How does muscular dystrophy occur?
Genetic faults cause the absence or reduced synthesis of specific proteins which anchor actin filaments to the sarcolemma (cell wall) to such a degree that muscle fibres may tear themselves apart during contraction
How does the cholera toxin interfere with the G protein cycle?
-Eliminates the GTPase activity of the alpha subunit of Gs -Gsα becomes irreversibly activated
How does the pertussus toxin interfere with the G protein cycle?
-Interferes with the GDP/GTP exchange on the alpha subunit of Gi. -This leads to the alpha subunit of Gi becoming irreversibly inactivated.
How is an anterior dislocation of the shoulder caused?
Trauma to a fully abducted arm, usually from a posterior direction.
How is I-cell disease caused?
Deficiency of the N-acetylglucosamine phosphotranferase enzyme which results in mannose-6-phosphate not being added to proteins so they can’t be targeted to lysosomes and end up in the blood/urine
How is myasthenia gravis caused?
It is caused by antibodies directed against NAchR’s, on the postsynaptic membrane of skeletal muscle. Endplate potentials are reduced in amplitude, leading to muscle weakness and fatigue.
How is neuromuscular transmission disrupted in Botulism?
Toxins block the release of acetylcholine
How is neuromuscular transmission disrupted in organophosphate poisoning? What is the main consequence?
Irreversibly inhibits the actions of acetylcholinesterase meaning the receptors are constantly activated - permanent muscle contraction
How is phenylketonuria treated?
Diet low in phenylalanine.
How is sickle cell disease caused?
Autosomal recessive condition resulting in a mutation of A which turns to T resulting in a an amino acid change from glutamate to valine. This forms a sticky hydrophobic pocket, classic sickle shape and aggregation of these cells.
How is Volkmann’s ischaemic contracture caused?
Brachial artery damage leads to ischaemia/necrosis of the muscle fibres of the flexor group of muscles of the forearm, which becomes fibrotic and short.
How might the axillary nerve be damaged?
-Damage due to lesions/trauma in the quadrangular space -Anterior dislocation of the humerus at the glenohumeral joint -Surgical neck fracture of the humerus
How might the musculocutaneous nerve be damaged? What will this result in?
Stabbing in the axilla leading to weakened flexion at the shoulder and elbow, aswell as weakened supination.
How might the radial nerve be damaged?
-Dislocation/fracture of the proximal humerus (damage in the axilla) -Midshaft fracture (damage in the radial grove) -Posterior dislocation of radius at elbow
How would you treat myasthenia gravis?
Acetylcholine esterase inhibitors
If paracetamol overdose is not treated what will occur?
-Hepatocyte necrosis -Liver Failure -Death
If there is a defective CFTR protein what happens to the secretions of epithelial cells?
Becomes more viscous
In children what other condition is homocystinuria often misdiagnosed as?
Marfan’s syndrome
In cystic fibrosis which protein channel is affected? What does it transport?
Cystic fibrosis transmembrane conductance regulator (CFTR) channel transports chloride ions across epithelial membranes
List two problems, for molecules, of too much circulating glucose in persistent hyperglycaemia
-Aldose reductase converts glucose to sorbitol which depletes NADPH -Non-enzymatic glycosylation os plasma protein alters its structure and therefore function.
Name other things that can be causes of hyperthyroidism?
-Ectopic thyroid -Over secretion of TSH and T3/T4 by adenomas -Excessive therapy of hypothyroidism -Excessive treatment of other conditions with drugs - amiodarone
Suggest some of the possible causes of a deep vein thrombosis?
-Immobility/bed rest -Post-operative -Pregnancy and post-partum -Oral contraceptives -Severe burns -Cardiac failure -Disseminated cancer
Suggest some physiological and pathological causes of atrophy?
-Physiological - Ovarian atrophy in post menopausal women -Pathological - Muscle Atrophy (denervation) Cerebral atrophy (Alzheimer’s disease)
Suggest some things that ischaemic heart disease can result in
-Sudden Death -MI -Angina pectoris -Arrhythmias -Cardiac Failure
What are amyloidoses?
Incorrect folding of proteins which results in production of amyloid fibres infiltrating organs
What are the 5 main risk factors for osteoporosis?
-Age -Post-menopausal women (reduced oestrogen) -Smoking -Poor diet (not enough ions) -Exercise
What are skin blisters caused by?
-Heat -Sunlight -Chemicals
What are the 6 main features of diabetic ketoacidosis?
-Prostration -Nausea -Vomiting -Dehydration -Abdominal pain -Hyperventilation
What are the common signs/symptoms of a major pulmonary embolism?
-Shortness of breath -Cough -Blood stained sputum
What are the four main fractures of the humerus?
-Surgical neck fracture -Mid shaft fracture -Supraepicondylar fracture -Medial epicondyle frature
What are the long term complications of bacterial meningitis?
-Brain damage -Hearing loss -Learning disabilities
What are the macrovascular clinical complications of diabetes mellitus?
-Increased risk of MI -Increased risk of stroke -Poor peripheral circulation
What are the main management steps for multiple sclerosis?
-Steroids (treatment for relapses of MS symptoms) -Beta interferons to modify the disease course
What are the main presenting symptoms of myasthenia gravis?
-Ptosis (drooping eyelid) -Fatigue and sudden falling -Double vision
What are the main symptoms of achondroplasia?
-Short limbs -Increased spinal curvature
What are the main symptoms of Duchenne’s Muscular Dystrophy (DMD)?
-Gower’s sign (use of hands/knees for strength) -Contractures (shortened muscles, don’t stretch) -Pseudohypertrophy (enlarged calf/deltoid muscles before fat/CT show up) -Difficulty standing/weakness
What are the main symptoms of hyperammonaemia?
-Blurred vision -Tremors -Slurred speech -Coma
What are the main symptoms of hyperthyroidism disease?
-Exopthalmos -Osteoporosis (due to excessive bone turnover) -Weight Loss -Heat intolerance -Intestinal hypermotility
What are the main symptoms of hypothyroidism?
-Weight gain -Tiredness -Cold intolerance -Alopecia -Decreased BMR
What are the main symptoms of lactose intolerance?
-Flatulence -Diarrhoea -Nausea
What are the main symptoms of malignant hyperthermia?
- Uncontrolled increase in skeletal muscle oxidative metabolism -Sharp CO2 increase, O2 decrease -Circulatory collapse
What are the main symptoms of Marfan syndrome?
-Tall height + long arms and legs -Large elastic arteries (e.g. aorta) rupture high blood pressure due to size of wall -Streched lung tissue - pneumothorax
What are the main symptoms of multiple sclerosis?
-Numbness and tingling -Blurring of vision -Problems with mobility and balance -Muscle weakness and tightness
What are the main symptoms of osteogenesis imperfecta?
-Blue sclera -Fragility of bones (leads to fractures) -Hypermobility of joints -Hearing loss
What are the main symptoms of paracetamol overdose?
-Hepatic damage then necrosis -Liver damage -Kidney failure
What are the main symptoms of scurvy?
-.Periodontal ligament (high collagen turnover) is affected -Loss of teeth and bleeding gums
What are the main symptoms of type 1 diabetes mellitus?
-Polyuria -Polydipsia -Weight loss
What are the main symptoms of type 2 diabetes mellitus?
-Triad of symptoms -Lack of energy -Persistent infection -Visual problems
What are the main treatments for defects in the urea cycle?
Low protein diet and replacing the essential amino acids with keto acids that use up NH4+ when converted to amino acids, therefore lowering NH4+ concentration.
What are the management steps for sickle cell disease?
-Manage underlying symptoms -Prevent sickle cell crisis
What are the microvascular clinical complications of diabetes mellitus?
-Eye (glaucoma due to osmotic effects of glucose and blindness due to damaged blood vessels which is diabetic retinopathy) -Kidney (nephropathy poor blood supply and damaged glomeruli) -Neuropathy (damaged nerves leading to loss of sensation) -Feet (low peripheral blood vessels and nerves - might lose feet)
What are the signs and symptoms of glucose 6-phoshate dehydrogenase deficiency? How are they caused?
-Fatigue (heinz body formation) -Dark urine/Jaundice (bilirubin formation from haemolysis)
What are the symptoms of Galactosaemia?
-Cataracts -Glaucoma -Damage to the kidney, liver and brain possible by galactose-1-phosphate
What are the symptoms of Ethlers-Danlos disease?
-Unstable joints -Bruise easily -Flat feet
What are the symptoms of hypercalcaemia?
Stoans, moans and groans: -Kidney stones (renal calculi) -Depression and tiredness -Constipation and dehydration
What are the symptoms of hypercholesterolaemia (hyperlipoproteinaemias Type IIa)?
-Corneal Arcus -Tendonal Xanthoma (fatty deposits on tendons) -Xanthelasma - fatty deposits under skin (around eyes) -Absence or deficiency of LDL receptors
What are the symptoms of hypocalcaemia? How are they caused?
-Convulsions -Arrythmia -Tetany (involuntary muscle contraction) -Paraesthesia (tingling) Due to low calcium at neuromuscular junctions which leads to easier depolarisation
What are the symptoms of hypocalcaemia? How are they caused?
-Arrythmia -Tetany (involuntary muscle contraction) -Paraesthesia (tingling) Due to low calcium at neuromuscular junctions which leads to easier depolarisation
What are the symptoms of Kwashiorkor?
-Abdominal distension due to enlarged liver (hepatomegaly) and odema (ascites) -Anaemia (low serum albumin) -Lethargy/apathy
What are the symptoms of Marasmus?
-Muscle wasting -Loss of body mass -Thin and dry hair -No oedema -Diarrhoea
What are the symptoms of myasthenia gravis?
-Ptosis (drooping eyelid) -Profound weakness (increases with exercise) -
What are the symptoms of type I hyperlipoproteinaemias?
-Eruptive xanthomata -Abdominal colic
What are the three main causes of atrophy?
-Disuse -Age -Denervation
What are the two main autoimmune causes of Hashimoto’s disease (primary hypothyroidism)?
-Antibody blocks a TSH receptor -Destruction of follicles
What are the two main reasons for the creation of large amounts of ketone bodies in type 1 diabetes mellitus?
-High rate of Beta oxidation of fatty acids in liver -Low amount of insulin
What are the two main treatments for Duchenne’s Muscular Dystrophy (DMD)?
-Ataluren - makes dystrophin -Steroids - prednisolone
What are the two main types of osteoporosis and how are they caused?
Type 1 - Menopause Type 2 - Age
What are the two most common fractures of the wrist?
-Smith’s -Colles’
What are type I hyperlipoproteinaemias?
A defective lipoprotein lipase enzyme which means core TAGs cannot be removed from the chylomicrons - can’t break down fatty acids
What builds up when phenylalanine hydroxylase isn’t functioning correctly?
Phenylalanine accumulates in tissues and blood and is metabolised by other pathways to produce various products (phenylpyruvate) that are excreted in the urine.
What can be other causes of hypothyroidism?
-Adenoma preventing secretion of TSH -Iodine deficiency
What can cause hypotonia?
-Damage to cerebellum (lesions) -Cerebral/spinal shock -Breakdown of muscle tissue (myopathies) -Lesions of lower motor neurons
What can cause the hypocalcaemia in Osteomalacia?
Lack of Vitamin D as it helps the absorption of calcium in the small intestine
What can recurrent pulmonary embolisms lead to?
Pulmonary hypertension
What can reduced liver function can result in?
-Reduced uptake of conjugate bilirubin → Hyperbilirubinaemia → Jaundice - Decreased Urea production → Hyperammonaemia and increased Glutamine -Reduced Protein synthesis → reduced albumin, clotting factors and lipoproteins -Reduced Serum Albumin may produce oedema
What causes Galactosaemia?
The lack of the galactose kinase or galactose 1-phosphate uridyl transferase enzyme causes build up of galactose or galactose 1-phosphate and galactose respectively.
What causes Kwashiorkor?
A complete deficiency of protein, however, a small amount of carbohydrate remains in the diet
What causes Marasmus?
Marasmus is caused by a diet lacking in all types of food, it is not only a protein deficiency
What causes waiter’s tip?
Damage to the suprascapular and axillary nerves means the lateral rotators of the shoulder are no longer innervated. As the deltoid, infraspinatus and teres minor are no longer functioning there is unopposed medial rotation.
What clotting factor is deficient in haemophilia type A?
Factor VIII (8)
What clotting factor is deficient in haemophilia type B?
Factor IX (9)
What diagnostic tests should be performed when hepatitis is suspected?
-Bilirubin -Full bloot test (expect to see elevated white cell count) -Sonography (gall bladder wall thickening) -ASTs, ALTs (leaking out out of cells) -Prothrombin time (elevated as they can’t clot)
What does a derease in cortisol production result in?
-Muscle weakness -Hypotension -Hypoglycaemia
What does an increase in cortisol production result in?
-Increase in gluconeogenesis and glycogenolysis -Muscle proteolysis increases -Lipolysis increases (lipogenesis increases at very high levels) -Decreased immune system
What does elevated plasma levels of homocysteine cause?
Causes disorders of connective tissue, muscle, CNS and the cardiovascular system
What does the CBS normally convert homocysteine to? What is this further converted to?
Cystathionine further converted to cysteine
What effect does excessive alcohol consumption have on the body?
-Low NAD+ -High Acetyl CoA -Decrease in liver function (due to cell damage from toxic acetaldehyde) -Effect on GI tract (impaired absorption of vitamins and minerals)
What happens in a Colles’ fracture of the wrist?
A fracture of the distal radius in the forearm with dorsal (posterior) displacement of the wrist and hand.
What happens in a Galeazzi fracture?
Radial fracture with dislocation of the ulnar at distal radioulnar joint
What happens in a Monteggia fracture?
Ulnar fracture with dislocation of the radius at the proximal radioulnar joint
What happens in a Smith’s fracture of the wrist?
A fracture of the distal radius in the forearm where the distal fracture fragment is displaced anteriorly (ventrally)
What intervention is usually given for placenta praevia?
Caesarian section
What is a common cause of osteomalacia/rickets? Why?
Vitamin D defiency as involved in the absorption of calcium and phosphate by the small intestine
What is a glycogen storage disease?
An abnormality in one or many of the enzymes of glycogen metabolism.
What is a transient ischaemic cerebral attack?
Infarction of part of the brain causing symptoms (FAST) for 24 hours
What is Achondroplasia?
Autosomal dominant condition resulting in decreased endochondral ossification and decreased cartilage matrix formation - common cause of dwarfism
What is acromegaly?
Excessive growth hormone release leads to an increase in bone width by periosteal growth - no lengthening occurs
What is an ectopic pregnancy?
Where there is implantation anywhere other than the uterus (possibly in the fallopian tube)
What is an iatrogenic embolism?
Embolism due to medical intervention i.e. air bubble in an IV
What is Bennet’s fracture? How is it caused?
Hyperabduction of the thumb causes fracture of the first metacarpal bone (bone of the thumb closest to carpal bones). Common in bike injuries.
What is Boxer’s fracture? How is it caused?
A clenched fist hitting a hard object can cause the fracture of the 5th metacarpal (little finger) and possibly the 4th aswell.
What is clostridium tetnai? What is its significance in humans?
Bacterium that causes tetanus producing a complete contraction of muscle (tetany)
What is compartment syndrome?
Blood leaking into a compartment of the body
What is cretinism?
A deficiency of thyroid hormones leading to mental and physical retardation
What is Crohn’s disease characterised by?
Transmural inflammation with granulomas, this leads to thickened and fissured bowel. This then leads to intestinal obstruction and fistulation.
What is disseminated intravascular coagulation (DIC)?
Activation of coagulation mechanisms around the body forming small clots to form throughout the body. This disrupts normal coagulation as they use up all the clotting factors.
What is Erb’s palsy? (aka Erb–Duchenne palsy) How is it most commonly caused?
Damage to the upper parts of the brachial plexus (C5-C6) which commonly results in damage to the musculocutaneous, axillary and suprascapular nerves. Basically you’ve fucked your arm, but, your forearm is doing well so you get a waiter’s tip. Commonly occurs when babies are born head first and their heads are pulled away from one of the shoulders (shoulder dystocia)
What is Ethlers-Danlos disease caused by?
A deficiency in reticular fibres (type III collagen fibres) causing ruptures in tissues with high amounts of these fibres - high elasticity
What is homocystine?
The oxidised form of homocysteine
What is homocystinuria?
A rare inherited autosomal recessive defect in methionine metabolism, caused by a deficiency in the cystathionine β-synthase (CBS) enzyme
What is hypotonia?
Lack of muscle tone.
What is intermittent claudication?
Muscle pain commonly in the calf muscle, which occurs during exercise, such as walking, and is relieved by a short period of rest.
What is ischaemic colitis?
Inflammation and injury of the large intestine result from inadequate blood supply
What is Klumpke paralysis? How is it commonly caused?
Damage to the lower parts of the brachial plexus (C8-T1) which commonly results in a claw hand due to damage mostly to the ulnar nerve i.e.interossei, thenar, hypothenar muscles, flexor carpi ulnaris and ulnar half of the flexor digitorum profundus. Commonly caused by catching a tree branch when falling. Klumpke the monkey hung from a tree.
What is lactose intolerance caused by?
Low activity of lactase enzyme results in lactose build up - has to be broken down by bacteria in the gut
What is lateral epicondylitis commonly known as?
Tennis elbow - tennis players experience pain in the lateral epicondyle from the common extensor origin
What is Leriche syndrome?
Atherosclerotic occlusive disease involving the abdominal aorta and/or both of the iliac arteries. Presenting with gluteal pain and absent/decreased femoral pulses.
What is malignant hyperthermia?
Malignant hyperthermia is a rare, autosomal dominant disorder that causes a life threatening reaction to certain drugs used for general anaesthesia due to a faulty protein channel for calcium
What is malignant melanoma?
Malignant growth of melanocytes
What is medial epicondylitis commonly known as?
Golfer’s elbow - golfers experience pain in the medial epicondyle from the common flexor origin.
What is mesenteric ischaemia?
Inflammation and injury of the small intestine result from inadequate blood supply.
What is Myasthenia gravis?
-An autoimmune destruction of the end plate Ach receptors -Widening of the synaptic cleft -Loss of junctional folds at the end plate
What is organ and tissue atrophy typically caused by?
A combination of atrophy and apoptosis
What is Osteogenesis Imperfecta?
Rare heritable (Autosomal dominant) disorder which results in the inability/decreased ability of osteoblasts and fibroblasts to produce correct fibres (normally type I collagen) and therefore connective tissue
What is osteoporosis?
Reduced bone density due to a high rate of bone turnover (osteoclasts more than osteoblasts)
What is Paget’s disease?
Chronic disorder that can result in enlarged and misshapen bones (usually localised to a few bones)
What is pericarditis?
Inflammation of the serous cavity of the pericardium
What is phenylketonuria?
Inherited disorder in which the urine contains large amounts of phenylketones produced from phenylalanine (can’t break down phenylalanine)
What is placenta praevia?
Implantation in the lower uterine segment which leads to the placenta growing and blocking the cervix.
What is the autoimmune cause of Grave disease and therefore main cause of hyperthyroidism?
Formation of an antibody that stimulates TSH receptors on the thyroid producing excess T3/T4
What is the cause of multiple sclerosis?
An autoimmune condition where the myelin sheath around axons is destructively removed, in a patchy fashion, then replaced with scar tissue. The conduction velocity slows down, as salutatory propagation is impaired.
What is the cause of rickets and osteomalacia?
Calcium deficiency where bone matrix (osteoid) does not calcify normally and the epiphyseal plate becomes distorted by strains of body weight and muscle activity. (bends)
What is the cause of scurvy?
Vitamin C deficiency results in defective tropocollagen synthesis leading to degeneration of connective tissue as Vit C and Fe2+ needed for prolyl hydroxylase activity.
What is the consequence of muscle fibre being replaced by fibrous tissue?
It can lead to contractures and as the muscle shortens it may lead to debilitating and disfiguring contractures
What is the crisis point of Myasthenia Gravis?
When it affects respiratory muscles
What is the difference between Becker’s and Duchenne’s muscular dystrophy?
Duchenne’s is the complete inability to produce dystophin whereas Becker’s is just an insufficient dystrophin production
What is the difference between Cushings syndrome and disease?
Cushings syndrome relates to an elevated level of cortisol detected whereas Cushings disease relates to a tumour in the pituitary resulting in the elevated cortisol
What is the difference between rickets and osteomalacia?
-Rickets occurs in children -Growing bones in rickets (opposed to remodelling in osteomalacia)
What is the karyotype for Klinefelters syndrome? What symptoms usually present?
47, XXY symptoms include infertility, male and tits
What is the karyotype for Triple X syndrome? What symptoms usually present?
47, XXX which results in a small head and tall stature
What is the main cause of Marfan syndrome?
Genetic defect in chromosomes that code for fibrillin which is a component of elastic fibres - easier to rupture
What is the main cause of Psoriasis?
Extreme proliferation of the epidermal basal layer - gross thickening of prickle cell layer + excessive stratum corneum production
What is the main drug treatment for Myasthenia Gravis?
Acetylcholinesterase inhibitors
What is the main problem cystic fibrosis causes for the lungs?
Thick and viscous mucous leads to recurrent infection
What is the main problem cystic fibrosis causes for the pancreas?
The mucous blocks the pancreatic ducts reducing the production of insulin and preventing digestive enzymes from reaching the intestines to aid digestion
What is the main reason high levels of ammonia can be so damaging to the body?
Ammonia may react with αlpha ketoglutarate to form glutamate in mitochondria via glutamate dehydrogenase removing α¬-ketoglutarate from the TCA cycle
What is the main symptom of Psoriasis?
Scaling of the skin
What is the main treatment for Grave’s disease and how does it work?
-Carbimazole which works by preventing the iodination of thyroglobulin. -Thyroid removal
What is the main treatment for hypothyroidism?
Oral thyroxine
What is the main treatment for malignant hyperthermia?
-Treat hyperthermia + complications -Discontinuation of triggering agent -Dantrolene which works by preventing calcium release
What is the treatment for alcoholism and how does it work?
Disulfiram blocks the 2nd enzyme of alcohol metabolism (acetaldehyde dehydrogenase) which causes a build up of acetaldehyde which causes serious “hangover” systems
What is thrombocytopenia?
The platelet count is reduced below the reference range
What is ulcerative colitis characterised by?
Ulcers that are irregular and start running together to form a mass which often haemorrhage
What is used to manage type 1 diabetes mellitus?
Insulin injection
What is used to manage type 2 diabetes mellitus?
-Sulphonylureas (increase insulin release from beta cells) -Metformin (reduces gluconeogenesis) -Diet and exercise management -Insulin injection
What is Volkmann’s ischaemic contracture?
permanent flexion contracture of the hand at the wrist, resulting in a claw-like deformity of the hand and fingers.
What metabolic changes often occur during hypertrophy?
-Increased glycolysis enzyme activity -Increased mitochondria -Increased muscle glycogen stores -Increased blood flow
What might a scaphoid fracture result in?
-Pain in the anatomical triangle -Avascular necrosis
What motor defects will be present if there is damage to the axillary nerve?
There will be no abduction of the arm until 90 degrees as the supraspinatus and deltoid are not innervated. Beyond that the trapezius and serratus anterior kick in as they are innervated by the accessory nerve and long thoracic nerve respectively. Long term damage can lead to deltoid muscle atrophy.
What occurs in kelloid?
Connective tissue disease where an abnormal amount of collagen forms scars of the skin
What occurs in systemic sclerosis (SSc)?
-Connective tissue disease where all organs have excessive accumulation of collagen (fibrosis) -Skin, digestive tract, muscles and kidneys hardening leads to functional impairment.
What occurs to muscle fibres if they aren’t exposed against resistance frequently?
They shrink and weaken (smaller diameter due to loss of protein)…they don’t die
What organism may cause bacterial meningitis in adults/older age groups?
Streptococcus pneumoniae type 3
What organism may cause bacterial meningitis in young adults?
Neisseria meningitidis type b
What organisms may cause bacterial meningitis in neonates?
-E. Coli -Streptococcus agalactiae (GBS) -Listeria monocytogenes
What possible treatments and management steps are available for cystic fibrosis?
-Physiotherapy -Antibiotics -Infection management -Gene replacement
What problems are caused in sickle cell disease?
-Blockage of blood vessels due to aggregations - starvation of oxygen -Taken to spleen early producing excess bilirubin - Jaundice -Sickle cell shape - tears capillaries -Sickle cell anaemia - destroyed red blood cells results in not enough haem
What problems can the accumulation of phenylpyruvate cause?
Competitive inhibition of pyruvate uptake by the brain: -Brain development inhibition -Seizures -Albinisim
What problems does a low NAD+ in excessive alcohol consumption cause?
-Build up of lactate as NAD+ used for conversion from pyruvate -Reduces kidneys ability to get rid of uric acid - you get urate crystal and gout -Gluconeogenesis can’t be activated
What structure could be damaged in a medial epicondyle fracture of the humerus?
Ulnar nerve
What structure is most commonly damaged by a clavicular fracture? What would this result in?
Suprascapular nerve damage causes paralysis of the lateral rotators of the upper limb at the shoulder and therefore a waiter’s tip
What structures can be damaged in an anterior dislocation of the shoulder?
-Axillary nerve (paralysis of the deltoid and loss of sensation over the regimental badge) -Rotator cuff muscles -Radial nerve (in the radial groove)
What structures could be damaged in a mid-shaft fracture of the humerus?
-Radial nerve (as it runs through the radial groove) -Profunda brachii artery
What structures could be damaged in a supraepicondylar fracture of the humerus?
-Median, ulnar or radial nerve as they all pass above the two epicondyles -Brachial artery
What structures could be damaged in a surgical neck fracture of the humerus?
-Anterior and posterior circumflex humeral arteries (anterior is too small to be an issue) -Axillary nerve
What tests are used to diagnose diabetes mellitus?
-Random venous plasma glucose of or above 11.1mmol per litre -Fasting plasma glucose of or above 7mmol per litre -Oral glucose tolerance test of or above 11.1mmol per litre two hours after eating glucose
What treatments are available for treating hyperlipoproteinaemias?
-Lifestyle -Diet -Statins (block the HMG CoA reductase enzyme) -Bile sequestrants (prevent reabsorption of bile into gut)
What treatments can be given for a deep vein thrombosis? How do they help?
-IV heparin (anticoagulant and co-factor for anti-thrombin III) -Oral warfarin (interferes with synthesis of vitamin K dependent clotting factors)
What triosomy is Downs Syndrome?
21
What triosomy is Edwards Syndrome?
18
What triosomy is Patau Syndrome?
13
What two conditions make up chronic (idiopathic) inflammatory bowel disease?
-Crohn’s disease -Ulcerative colitis
What type of mutations can affect the LDL-receptor in hypercholesterolaemia?
-Non-functioning receptor -Receptor spread around the entire cell surface -Receptor deficiency
What type of thalassaemias result in not enough alpha chains in the protein?
Alpha thalassaemias
When is malignant melanoma considered to have a poor prognosis?
Penetration through epidermal basement membrane
Where could you test for axillary nerve damage?
Over the regimental badge area as the axillary nerve is this areas sensory nerve.
Where is a clavicular fracture most likely to occur? Why?
The junction of the medial 2/3 and lateral 1/3 as this is the weakest point due to the direction of bone fibres
Which clinical condition can be identified by a decreased level of cortisol due to adrenal adenoma?
Addisons disease
Which clinical condition can be identified by a increased level of cortisol and ACTH caused by pituitary adenoma?
Cushings disease
Which enzyme is normally defective in phenylketonuria?
Phenylalanine hydroxylase
Which is more common anterior or posterior dislocation of the shoulder joint?
Anterior dislocation, posterior is very rare and it is vital to see what caused it and check for other damage.
Which skin condition results in patches of depigmentation? How is it caused?
Vitiligo - autoimmune destruction of melanocytes
Which skin condition results in patchy hair loss? How is it caused?
Alopecia areata caused by the autoimmune destruction of hair follicles
Why are abscesses usually painful?
Due to the high pressure from liquefactive necrosis
Why does a fracture to the clavicle commonly occur?
-A fall onto the shoulder -A fall onto an outstretched hand
Why does winging of the scapula occur when there is damage to the long thoracic nerve?
Serratus anterior is paralysed so instead of what it usually does (attaches the costal face of the scapula, pulling it against the ribcage) it becomes winged
Why is it that ectopic pregnancy can quickly become a life-threatening emergency?
It can cause damage to the site it is growing in.
Why is paracetamol overdose an issue?
Saturation of the normal Phase II pathway and movement to Phase I pathway which produces toxic product NAPQI
Why is the diagnosis of osteogenesis imperfecta of significant legal importance?
Symptoms and signs can often be confused with abuse
Why is the exudate that comes from skin blisters relatively clear?
Contains only a small amount of inflammatory cells
Why is there no wrist drop when there is a posterior dislocation of radius at elbow causing radial nerve damage?
The ECRL originates more proximally, from supracondylar ridge (so comes off before the fracture), as it is a strong extensor there is no wrist drop .
Why is there weakened flexion at the elbow in musculocutaneous nerve damage?
Flexion at the elbow is affected due to brachialis and biceps brachii being non functional. But, flexion can still be performed because of the brachioradialis muscle.
Why is there weakened flexion at the shoulder in musculocutaneous nerve damage?
Eventhough biceps brachii, brachialis and coracobrachialis are not innervated, pectoralis major still is so you get some shoulder flexion.
Why is there weakened supination at the forearm in musculocutaneous nerve damage?
Supination is greatly weakened as the Biceps Brachii isn’t working, but is still produced by the supinator muscle.
Why is vitiligo considered psychologically less serious in caucasians?
Less noticeable in white people
