MEDICAL TERMS AND DEFINITIONS See Typhus . Cancer : A malignant and invasive growth or tumour (especially tissue that covers a surface or lines a cavity), tending to recur after excision and to spread to other sites. In the nineteenth century, physicians noted that cancerous tumours tended to ulcerate, grew constantly, and progressed to a fatal end and that there was scarcely a tissue they would not invade. Synonyms: malignant growth, carcinoma. Cancrum Oris : A severe, destructive, eroding ulcer of the cheek and lip, rapidly proceeding to sloughing. In the last century it was seen in delicate, ill-fed, ill-tended children between the ages of two and five. The disease was the result of poor hygiene acting upon a debilitated system. It commonly followed one of the eruptive fevers and was often fatal. The destructive disease could, in a few days, lead to gangrene of the lips, cheeks, tonsils, palate, tongue, and even half the face; teeth would fall from their sockets, and a horribly fetid saliva flowed from the parts. Synonyms: canker , water canker, noma, gangrenous stomatitis, gangrenous ulceration of the mouth.

Canine Madness: Rabies, hydrophobia (Fear of water). Canker : An ulcerous sore of the mouth and lips, not considered fatal today. Synonym: aphthous stomatitis. See Cancrum Oris . Carbuncle: Trance like state brought on by extreme fright (like a rabbit in car's headlights) Catarrh: Inflammation of a mucous membrane, especially of the air passages of the head and throat, with a free discharge. It is characterised by cough, thirst, lassitude, fever, watery eyes, and increased secretions of mucus from the air passages. Bronchial catarrh was bronchitis; suffocative catarrh was croup; urethral catarrh was gleet; vaginal catarrh was leukorrhea; epidemic catarrh was the same as influenza. Synonyms: cold, coryza. Cathartic: Laxative Caul: The membrane surrounding a baby before it is born. May not rupture at birth and cover the baby's head. (Supposed to have been lucky if child was born with it's caul intact.) Cellulitis: Inflammation of the cellular or connective tissue.

Cerebral: The brain. Pertaining to the cerebrum. Cerebritis: Inflammation of cerebrum or lead poisoning Cerebrospinal ï¿½ pertaining to the brain and spinal cord. Chagres fever Asphyxiating gas, largely carbon dioxide, accumulated in a mine, well, etc. Cholaemia: The presence of bile in the blood. Cholangitis: Inflammation of the bile duct. Cholecystitis: Inflammation of the gall bladder Cholelithiasis: Gall stones Cholera Infantum: A common, non-contagious diarrhoea of young children, occurring in summer or autumn. In the nineteenth century it was considered indigenous to the United States; was prevalent during the hot weather in most of the towns of the middle and southern states, as well as many western areas; and was characterised by gastric pain, vomiting, purgation, fever, and prostration. It was common among the poor and in hand-fed babies. Death frequently occurred in three to five days. Synonyms: summer complaint, weaning brash, water gripes, choleric fever of children, cholera morbus.

Cholera Morbus: Illness with vomiting, abdominal cramps and elevated temperature. Could be appendicitis Cholera: An acute, infectious disease, endemic in India and China and now occasionally epidemic elsewhereï¿½characterised by profuse diarrhoea, vomiting, and cramps. It is caused by a potent toxin discharged by the bacterium Vibrio cholerae, which acts on the small intestine to cause secretion of large amounts of fluid. The painless, watery diarrhoea and the passing of rice-water stool are characteristic. Great body-salt depletion occurs. Cholera is spread by faeces-contaminated water and food. Major epidemics struck the United States in the years 1832, 1849, and 1866. In the 1830s the causes were generally thought to be intemperance in the use of ardent spirits or drinking bad water; uncleanliness, poor living or crowded and ill-ventilated dwellings; and too much fatigue.

By 1850 cholera was thought to be caused by putrid animal poison and miasma or pestilential vapour rising from swamps and marshesï¿½or that it entered the body through the lungs or was transmitted through the medium of clothing. It was still believed that it attacked the poor, the dissolute, the diseased, and the fearfulï¿½while the healthy, well-clad, well-fed, and fearless man escaped the ravages of cholera. Choleric Fever Of Children: See Cholera Infantum Cholecystitus: Inflammation of the gall bladder. Cholelithiasis: Gall stones : Any of several diseases of the nervous system, characterised by jerky movements that appear to be well coordinated but are performed involuntarily, chiefly of the face and extremities. Synonym: Saint Vitusï¿½ dance. Chronic: Persisting over a long period of time as opposed to acute or sudden. This word was often the only one entered under "cause of death" in the mortality schedules. The actual disease meant by the term is open to speculation.

Cicatrized: Scarred Cirrhosis: A pathological change occurring in the tissue of certain organs, especially the lung and liver. The organ becomes contracted, granular and hard. A liver showing this appearance is often known as "hobnail" liver because of its knobbed surface. Climacteric: Pertaining to a critical period in human life. In females; the time after the menopause (the menopause is the first day of the last ever menstrual period). In males; the period when fertility and libido are in decline Clyster: Existing at the time of birth. Congestion : An excessive or abnormal accumulation of blood or other fluid in a body part or blood vessel. In congestive fever (see text), the internal organs become gorged with blood. Congestive Chills/Fever: Malaria Consumption: A wasting away of the body; formerly applied especially to pulmonary tuberculosis. The disorder is now known to be an infectious disease caused by the bacterial species Mycobacterium tuberculosis. Synonyms: marasmus (in the mid-nineteenth century), phthisis.

Contagious Pyrexia: Dysentery Convulsions: Severe contortion of the body caused by violent, involuntary muscular contractions of the extremities, trunk, and head. See epilepsy. Corruption: Mental retardation due to congenitally under-active thyroid Crop Sickness: Overextended stomach from over eating Croup: Any obstructive condition of the larynx (voice box) or trachea (windpipe), characterised by a hoarse, barking cough and difficult breathing occurring chiefly in infants and children. The obstruction could be caused by allergy, a foreign body, infection, or new growth (tumour). In the early-nineteenth century it was called cynanche trachealis. The crouping noise was similar to the sound emitted by a chicken affected with the pip, which in some parts of Scotland was called roup; hence, probably, the term croup. Synonyms: roup, hives, choak, stuffing, rising of the lights. Cyanosis: Dark skin colour from lack of oxygen in blood or poor circulation to the skin Cyesis: See Leishmaniasis Delirium Tremens : Hallucinations due to alcoholism.

Results from alcoholic intoxication and is represented by a picture of confusion, terror, restlessness and hallucinations. Commonly know as ï¿½the DTsï¿½ Dengue: Infectious fever endemic to East Africa Dentition: Cutting (eruption) of the teeth Deplumation: Disease or tumour of the eyelids which causes hair loss Diary Fever: A fever that lasts one day Diphtheria : An acute infectious disease caused by toxicogenic strains of the bacillus Corynebacterium diphtheriae, acquired by contact with an infected person or a carrier of the disease. It was usually confined to the upper respiratory tract (throat) and characterised by the formation of a tough membrane (false membrane) attached firmly to the underlying tissue that would bleed if forcibly removed. In the nineteenth century the disease was occasionally confused with scarlet fever and croup. Disseminated : Scattered. A disease characterised by the presence of inflammatory patches that later become sclerosed, scattered freely throughout the brain and spinal cord. Distemper: Disturbed condition of the body or mind; ill health, illness; a mental or physical disorder; a disease or ailment.

Usually animal disease with malaise and discharge from nose and throat. Dock Fever: Mental breakdown, depression (Post Natal Depression ?) Dropsy of the Brain: Encephalitis Dropsy : A contraction for Hydropsy. Oedema , the presence of abnormally large amounts of fluid in intercellular tissue spaces or body cavities. Abdominal dropsy is ascites; brain dropsy is hydrocephalus; and chest dropsy is hydrothorax. Cardiac dropsy is a symptom of disease of the heart and arises from obstruction to the current of blood through the heart, lungs, or liver. Anasarca is general fluid accumulation throughout the body. Dry Bellyache: Abdominal pain due to lead poisoning from lead containing medicines Dyscrasy: An abnormal body condition Dysentery: A term given to a number of disorders marked by inflammation of the intestines (especially of the colon) and attended by pain in the abdomen, by tenesmus (straining to defecate without the ability to do so), and by frequent stools containing blood and mucus. The causative agent may be chemical irritants, bacteria, protozoan, or parasitic worms.

There are two specific varieties: (1) amoebic dysentery caused by the protozoan Endamoeba Histolytica; (2) bacillary dysentery caused by bacteria of the genus Shigella. Dysentery was one of the most severe scourges of armies in the nineteenth century. The several forms of dysentery and diarrhoea accounted for more than one-fourth of all the cases of disease reported during the first two years of the Civil War. Synonyms: flux, bloody flux, contagious pyrexia (fever), frequent griping stools. Dysorexy: See Erysipelas Effluvia : Exhalations or emanations, applied especially to those of noxious character. In the mid-nineteenth century, they were called "vapours" and distinguished into the contagious effluvia, such as rubeolar (measles); marsh effluvia, such as miasmata; and those arising from animals or vegetables, such as odours. Elephantiasis Nostra: See elephantiasis Elephantiasis: Swelling of a limb caused by lymphatic obstruction.

Leads to thickening of the skin (pachyderma) often used as a synonym for filariasis but may result from syphilis or recurring streptococcal infection (elephantiasis nostra) Embolism : The presence in the blood-stream of a detached part of a thrombosis or the foreign body which travels with the stream until it reaches the vessel too small to allow it to pass, with the result that the circulation becomes obstructed. Emphysema : Pulmonary. A chronic, irreversible disease of the lungs, characterised by abnormal enlargement of air spaces in the lungs and accompanied by destruction of the tissue lining the walls of the air sacs. By 1900 the condition was recognised as a chronic disease of the lungs associated with marked dyspnoea (shortness of breath), hacking cough, defective aeration (oxygenation) of the blood, cyanosis (blue colour of facial skin), and a full and rounded or "barrel-shaped" chest. This disease is now most commonly associated with tobacco smoking.

Empiric: A person who practises medicine without scientific knowledge; a quack; a charlatan Empyema: A collection of pus, especially in the pleural cavity but may also occur in other closed body cavities. eg. Gall bladder. Encephalitis: Ertythaema Pernio: Chilblain Erysipelas : An acute, febrile, infectious disease, caused by a specific group 4 streptococcus bacterium and characterised by a diffusely spreading, deep-red inflammation of the skin or mucous membranes causing a rash with a well-defined margin. Synonyms: Rose, Saint Anthonyï¿½s Fire (from its burning heat or, perhaps, because Saint Anthony was supposed to cure it miraculously). Erysipeloid: Skin condition resembling Erysipelas occurring in butchers, fishmongers and cooks. Caused by the erysipelothrix of swine erysipelas Euphoria: Inappropriate happiness or laughing. Could be due to mania or in servicemen shell-shock, battle fatigue, post engagement stress syndrome. Exacerbation: Increased severity as of symptoms. Excision: Removal of a part by cutting away.

Excrescence: An unnatural or disfiguring outgrowth of the skin or any unnecessary physical development. Extravasted blood: Rupture of a blood vessel See catarrh. Glomerulonephritis: Glomerulus. A coil of minute arterial capillaries of the capsule at the commencement of the uriniferous tubules of the kidney: Glossal Pharyngolaryngeal Paralysis: Tongue, pharynx (back cavity of mouth) paralysis of the muscles of both. Glycoasuria: The presence of sugar in the urine. Goitre Endocarditis: Inflammation of the endocardium and valves. The most common causes are rheumatic and septicaemia. Gout: Any inflammation due to the formation of crystals of sodium bi-urate caused by a build up of urate or uric acid in the blood. It most often occurs in joints where circulation is poor, and can even cause gallstones or kidney stones Gravel: A disease characterised by multiple small calculi (stones or concretions of mineral salts) which are formed in the kidneys, passed along the ureters to the bladder, and expelled with the urine. Synonym: kidney stone.

Great Pox: Body temperature elevates because of surrounding environment temperature and body does not perspire to reduce temperature Hectic(al) fever: A daily recurring fever with profound sweating, chills, and flushed appearanceï¿½often associated with pulmonary tuberculosis or septic poisoning. Hemiplegy, Hemiplegia: Paralysis of one side of body Hip gout: Osteomylitis Hives: A skin eruption of wheals (smooth, slightly elevated areas on the skin) which is redder or paler than the surrounding skin. Often attended by severe itching, it usually changes its size or shape or disappears within a few hours. It is the dermal evidence of allergy. See the discussion under croup; also called cynanche trachealis. In the mid-nineteenth century, hives was a commonly given cause of death of children three years and under. Because true hives does not kill, croup was probably the actual cause of death in those children. Horrors: Fit (convulsion); sudden pulsation or stroke Impetigo : Contagious skin disease usually of the face characterised by pustules and crusts Inanition: Exhaustion from lack of nourishment; starvation.

A condition characterised by marked weakness, extreme weight loss, and a decrease in metabolism resulting from severe and prolonged (usually weeks to months) insufficiency of food. Incubus: Nightmare; demon taking on male form to have sexual intercourse with a woman in her sleep Infantile Paralysis: Poliomyelitis (polio) Infarct: A wedge shaped area of dead tissue, which is deprived of blood by the sudden blockage of a terminal or end artery. Infection: The affection or contamination of a person, organ, or wound with invading, multiplying, disease-producing germsï¿½such as bacteria, rickettsiae, viruses, moulds, yeasts, and protozoa. In the early part of the last century, infections were thought to be the propagation of disease by effluvia (see above) from patients crowded together. "Miasma" were believed to be substances which could not be seen in any formï¿½emanations not apparent to the senses. Such miasmas were understood to act by infection. Inflammation: Redness, swelling, pain, tenderness, heat, and disturbed function of an area of the body, especially as a reaction of tissue to injurious agents.

This mechanism serves as a localised and protective response to injury. The word ending -itis denotes inflammation on the part indicated by the word stem to which it is attachedï¿½that is, appendicitis, pleuritis, etc. Microscopically, it involves a complex series of events, including enlargement of the sizes of blood vessels; discharge of fluids, including plasma proteins; and migration of leukocytes (white blood cells) into the inflammatory focus. In the last century, cause of death often was listed as inflammation of a body organï¿½such as, brain or lungï¿½but this was purely a descriptive term and is not helpful in identifying the actual underlying disease. Intermittent Fever: Illness marked by episodes of fever with return to completely normal temperature; usually malaria. Interstitial: Situated between. Distributed through the connective structure. Intussusception : The slipping of one part within another, as the prolapse of one part of the intestine into the lumen of an immediately adjoining part. This leads to obstruction and often must be relieved by surgery. Synonym: intussusception. Ischaemia: Local anaemia due to defective blood supply to the part.

Ischaemic Heart Disease: Form of insanity characterised by inappropriate happiness, mental and physical restlessness and grandiose delusions Marasmus: Malnutrition occurring in infants and young children, caused by an insufficient intake of calories or protein and characterised by thinness, dry skin, poor muscle development, and irritability. In the mid-nineteenth century, specific causes were associated with specific ages: In infants under twelve months old, the causes were believed to be unsuitable food, chronic vomiting, chronic diarrhoea, and inherited syphilis. Between one and three years, marasmus was associated with rickets or cancer. After the age of three years, caseous (cheese like) enlargement of the mesenteric glands (located in the peritoneal fold attaching the small intestine to the body wall) became a given cause of wasting. After the sixth year, chronic pulmonary tuberculosis appeared to be the major cause. Marasmus is now considered to be related to kwashiorkor, a severe protein deficiency.

Mayer: Diphtheria Meningitis : Inflammation of the meninges (the three membranes covering the brain and spinal cord), especially of the pia mater and arachnoidï¿½caused by a bacterial or viral infection and characterised high fever, severe headache, and stiff neck or back muscles: Synonym: brain fever. Mesentery: A large fold of peritoneum, passing between a portion of intestine and the posterior abdominal wall. Meteorism: Flatulent distension of the abdomen with gas in the gut Metritis: Inflammation of uterus or purulent vaginal discharge Miasma: Poisonous vapours thought to infect the air and cause disease Milk Fever: Short lived fever which sometimes accompanies lactation Milk Leg: Thrombosis of veins in the thigh usually seen after childbirth (at one time thought to be due to excess milk being directed to the leg) Milk Sick(ness) : Poisoning resulting from the drinking of milk produced by a cow who had eaten a plant known as white snake root. Mitral Regurgitation: Defect in the closure of the valve whereby blood tends to flow backward into the auricle from ventricle.

Mitral Stenosis: Narrowing of, usually due to recurrent attacks of rheumatism. Mitral: Pertaining to the valve dividing the left auricle and ventricle of the heart. Mollities Ossium: Red line on the forehead seen in tuberculous meningitis Teething: The entire process which results in the eruption of the teeth. Nineteenth-century medical reports stated that infants were more prone to disease at the time of teething. Symptoms were restlessness, fretfulness, convulsions, diarrhoea, and painful and swollen gums. The latter could be relieved by lancing over the protruding tooth. Often teething was reported as a cause of death in infants. Perhaps they became susceptible to infections, especially if lancing was performed without antisepsis. Another explanation of teething as a cause of death is that infants were often weaned at the time of teething; perhaps they then died from drinking contaminated milk, leading to an infection, or from malnutrition if watered-down milk was given. Testaceous Powders: Medicinal powders prepared from the shells of animals.

Tetanus Neonatorum: Tetanus in the new born due to infection of the umbilical cord stump following birth in unhygienic conditions Tetanus : An infectious, often-fatal disease caused by a specific bacterium, Clostridium tetani, that enters the body through wounds; characterised by respiratory paralysis and tonic spasms and rigidity of the voluntary muscles, especially those of the neck and lower jaw. Synonyms: trismus, lockjaw. Thorax: Thrombosis: Blood clot inside blood vessel Thrush : A disease characterised by whitish spots and ulcers on the membranes of the mouth, tongue, and fauces caused by a parasitic fungus, Candida albicans. Thrush usually affects sick, weak infants and elderly individuals in poor health. Now it is a common complication from excessive use of broad-spectrum antibiotics or cortisone treatment. Synonyms: aphthae, sore mouth, aphthous stomatitis. Thyrotoxicosis: Module 5 Nervous system Muscle Physiology Flashcards - Cram.com Spinothalamic tracts - lateral and anterior Which of the following is incorrect regarding the CNS? 1. There are 100 billion neurons 2.

Microglia as the scavenger cells - i.e. macrophages 3. Macroglia include oligodendrocytes, schwann cells and astrocytes 4. Astrocytes form the BBB and support neurons 5. Myelin is produced by oligodendrocytes solely 5. Myelin is produced by oligodendrocytes solely - Incorrect Also produced by schwann cells in the Peripheral NS Name the parts of a neuron What are the different types of neurons? Unipolar (invertebrate neuron) Pseudo unipolar (Ganglion of dorsal root) Multipolar (motor neuron, parking of cerebellum) What happens to a neuron if it is cut? Wallerian degeneration Orthograde vs retrograde transport in an axon? Orthograde - down the axon away from the cell body via kinesin Retrograde - away from the cell body - via dynein - i.e. Nerve growth factor and some viruses (VZV, HSV) Regarding neurons which of the following is incorrect: 1. Action potential propagation is a passive process 2. The 3Na/2K ATPase pump maintains the resting membrane potential 3.

Resting membrane potential is -70mV 4. The membrane is more permeable to K than Na 5. Decreasing the ECF Na concentration reduces the size of the AP but has little effect on resting membrane potential 1. Action potential propagation is a passive process - INCORRECT - Active, self-propagating process, poor conductance What is required for a potential difference to exist? 1. Unequal distribution of ions of one or more species across a membrane 2. The membrane must be permeable to one of more ions - via channels or pores @ Equilibrium the concentration forces = electrical force Describe the events in the development of an Action potential. 1. Stimulus 2. Some voltage gated Na channels open --> membrane potential becomes less negative --> THRESHOLD POTENTIAL ~-55mV 3. VGNa Channels open rapidly --> massive influx of Na+ 4. Depolarisation of the cell in positive feedback fashion until membrane potential ~+30mV 5. NA influx slows as electrical forces change direction and K channels open 6. VGNa channels enter inactivated state 7. K efflux repolarises the cell in a slower manner 8.

K channels slow to close --> hyper polarisation True / False? Hyperkalemia (ECF) moves the resting potential closer to the threshold for eliciting an AP and thus the neutron becomes more excitable Hypokalemia moves the resting potential closer to the threshold for eliciting an AP and thus the neutron becomes more excitable TRUE for HYPERKALAEMIA - hyper excitable Hypokaelaemia - the membrane potential is reduced and the neuron is hyper polarised i.e. when the K+ level is greater outside the cell the concentration gradient for K to move out is less pushing the resting membrane potential less negative What is the relative refractory period/absolute refractory period? Absolute - No AP possible - No VGNa channels in resting state Relative - Some channels still in inactivated state and are unable to be opened --> requires supernormal stimulus for AP What is the effect of Ca2+ levels on membranes and APs Hypercalcaemia --> increases membrane stability Which of the following are correct/incorrect regarding nerves? 1. APs occur in an all-or-none fashion 2. Threshold potential is -55mV 3. The fastest nerve fibres are the C type fibres 4.

Saltatory conduction involves the jumping of depolarisation from one node of Ranvier to the next 5. The smallest nerves are the C type fibres The fastest nerve fibres are the C type fibres - Incorrect A - alpha fiber > A-beta > other A > B > C What are the different types of A fibre nerves? Alpha - proprioception, somatic MOTOR Gamma - Motor to muscle spindles Delta - pain/temp What are the different types of nerve fiber? A, B, C Order the nerve fibre types by thickness. Thickest ----> Thinest alpha > beta > gamma > delta > B > C Same order for speed fast --> slow Which fibres are most sensitive to: hypoxia Hypoxia B > A > C --> Autonomic Pressure A > B > C --> Motor / sensory LA C > B > A --> Autonomic / Pain Which of the following statements about glia is true? 1. Microglia arise from macrophages outside of the nervoussystem and are physiologically and embryologically similarto other neural cell types. 2. Glia do not undergo proliferation. 3.

Protoplasmic astrocytes produce substances that are tropic to neurons to help maintain the appropriate concentrationof ions and neurotransmitters by taking up K+ and theneurotransmitters glutamate and GABA. 4. Oligodendrocytes and Schwann cells are involved in myelinformation around axons in the peripheral and centralnervous systems, respectively. 5. Macroglia are scavenger cells that resemble tissuemacrophages and remove debris resulting from injury,infection, and disease. Protoplasmic astrocytes produce substances that are tropic to neurons to help maintain the appropriate concentration of ions and neurotransmitters by taking up K+ and the neurotransmitters glutamate and GABA. A 13-year-old girl was being seen by her physician becauseof experiencing frequent episodes of red, painful, warmextremities. She was diagnosed with primary erythromelalgia,which may be due to a peripheral nerve sodium channelopathy.Which part of a neuron has the highest concentration of Na+channels per square micrometer of cell membrane? 1. dendrites 2. cell body near dendrites 3. initial segment 4. axonal membrane under myelin 5.

node of Ranvier Which one of the following nerves hasthe slowest conduction velocity? A. Aα fibers Which of the following is not correctly paired? A. Synaptic transmission: Antidromic conduction B. Molecular motors: Dynein and kinesin C. Fast axonal transport: ~400 mm/day D. Slow axonal transport: 0.5–10 mm/day E. Nerve growth factor: Retrograde transport A. Synaptic transmission: Antidromic conduction Which of the following ionicchanges is correctly matched with a component of the actionpotential? 1. Opening of voltage-gated K+ channels: After-hyperpolarization 2. A decrease in extracellular Ca2+:Repolarization 3. Opening of voltage-gated Na+ channels: Depolarization 4. Rapid closure of voltage-gated Na+ channels: Resting membrane potential 5. Rapid closure of voltage-gated K+ channels: Relative refractory period 3. Opening of voltage-gated Na+ channels: Depolarization Which of the following is incorrect (multiple) regarding muscle: 1. Striated muscle include skeletal and cardiac 2.

Cardiac muscle acts as a functional syncytial unit 3. Skeletal mm has pacemaker capabilities 4. Smooth muscle has 2 types - unitary or multiunit 5. The type of SM found in hollow viscera acts like a multi unit with pacemakers that discharge regularly 6. Multiunit SM is found in the eye and has no pacemaker function 3. Skeletal mm has pacemaker capabilities - incorrect - it is the only type that DOES NOT have this function 5. The type of SM found in hollow viscera acts like a multi unit with pacemakers that discharge regularly - Incorrect - Hollow viscera is unitary with pacemakers that discharge irregularly Which of the following is incorrect (multiple) regarding SKELETAL muscle: 1. Sarcolemma is the cell membrane of a muscle cell 2. On microscopy the region between two Z lines is a sarcomere 3. Thick filaments are made up of actin, tropomycin, troponin and thin filaments of myosin 4. Muscle end in tendons 3.

Thick filaments are made up of actin, tropomycin, troponin and thin filaments of myosin Other way around --> THIN filaments are made up of actin, tropomycin, troponin and THICK filaments of myosin What are the main contractile elements of Skeletal muscle? Myosin II Length of AP in Skeletal muscle? Compared to cardiac? 2-4ms - but very short contraction period vs cardiac Cardiac - 2ms but PROLONGED plateau and depolarisation 200ms Which of the following is Incorrect regarding SKELETAL Muscle? 1. Fast muscle fibres are involved in strong gross sustained movements and have a twitch duration of 7.5ms 2. Slow muscle fibres are concerned with strong gross sustained movements and have a twitch duration of 100 ms 3. There is a 2ms delay from AP to contraction Fast muscle fibres are involved in strong gross sustained movements and have a twitch duration of 7.5ms - incorrect FAST fibers --> fine, rapid precise movements What happens on a molecular level during muscle contraction?

AP via T system --> Ca2+ influx from SR Ca binding to Troponin C --> weakening the interaction of Troponin I with the actin binding site Binding of myosin (one) head to actin Release of ADP from myosin head on binding and movement at the junction of the head/neck - POWERSTROKE (due to stored energy in head cocked position from ATP hydrolysis) Head remains attached whilst the other head now attaches and has the power stroke - once attached the first head releases ATP binds and is hydrolysed and the head cocked ready for the next beat (repeats as long as Ca2+ present) Function of the dihydropyridine receptor? Ryanodine receptor? in skeletal and cardiac muscle dihydropyridine receptor - voltage gated Ca2+ channels - AP activates this channel allowing Ca efflux from the SR in SKELETAL muscle via a physical interaction with the ryanodine receptor on the SR In cardiac muscle the dihydropyridine receptor causes Ca influx from the ECF which then activates the ryanodine receptor Which of the following are incorrect/correct? 1. Isometric contractions involve a length decrease 2.

Isotonic contraction is against a constant load 3. Contraction and relaxation are both energy dependent events 4. SERCA is a ATP dependent Ca pump on the SR to remove Ca2+ from the cytosol 1. Isometric contractions involve a length decrease - incorrect - no length change in ISOMETRIC (SAME LENGTH) 2. Isotonic contraction is against a constant load - true - Same tension but decrease in length 3. Contraction and relaxation are both energy dependent events (SERCA on relaxation) 4. SERCA is a ATP dependent Ca pump on the SR to remove Ca2+ from the cytosol What is Summation of Contractions? What is the result of this? Multiple APs arrive prior to relaxation (contractile units do NOT have a refractory period) This results in tetanic contraction Frequency of the AP required depends on the twitch duration Mutation in the Ryanodine receptor can result in what condition? Malignant hyperthemia with certain anaesthetics or in rare cases exposure to high environmental heat or strenuous exercise At what muscle length can the maximal tension develop and the maximal velocity of contraction occur?

Resting length Shorter muscle - less distance to move Longer - less overlap between actin and myosin What are the 3 types of muscle fibres? Characteristics? Fast IIA - Oxidative - Glycolytic - Red Fast IIB - Glycolytic - WHITE - Fatiguable Besides ATP what is another energy source for contraction? Phosphorylcreatine During light exercise what is the main macro source of energy? This changes to what during increasing intensity exercise? Lipids - free fatty acids Carbohydrates for more intense exercise - glucose / glycogen How much anaerobic energy production is required for : 100m sprint What is a motor unit? The motor neuron and all the muscle fibres it innervates. All muscle fibres must be of the SAME type Recruitment occurs in an ordered fashion - S (slow) fibres then FR (fast red) then FF (fast) - recruitment is asynchronous Describe the features of cardiac muscle that are different from skeletal muscle? Function syncytia Intercalated discs at Z lines Each myofibril - enclosed by membrane Gap junctions for AP propagation Describe the Action potential in a cardiac muscle cell.

Phase 0 - Voltage gated Na channels open - rapid depolarisation + Overshoot Phase 1 - Initial rapid repolarisation - due to closure of Na channels and opening of K channels Phase 2 - Prolonged plateau opening Ca2+ voltage gated channels (L type) - INFLUX Phase 3 - Final/ late rapid depolarisation of the membrane due to closure of Ca channels and a delayed increase in K efflux Phase 4 - Resting membrane potential Tetany can occur in cardiac cells. T/F? False due to the prolonged absolute refractory period and relatively long AP Long QT syndrome is most commonly due to? Mutations in the voltage gated K channel 90% MOA of catecholamines on the heart? increase in cAMP which activated protein kinase A Which phosphorylates voltage gated Ca channels causing them to stay open longer In smooth muscle what does activation of calmodulin dependent myosin light chain kinase do? phosphorylation of myosin which allows for increased myosin ATPase activity and binding of myosin to actin ACh vs adrenalin effect on SM ?

ACH - contraction via phospholipase C --> IP3 --> Ca influx Adrenalin - relaxation The contractile response in skeletal muscle: A. starts after the action potential is over. B. does not last as long as the action potential. C. produces more tension when the muscle contracts isometrically than when the muscle contracts isotonically. D. produces more work when the muscle contracts isometrically than when the muscle contracts isotonically. E. decreases in magnitude with repeated stimulation. C. produces more tension when the muscle contracts isometrically than when the muscle contracts isotonically. D - No work done if no change in length What are the 3 types of synaptic vesicles? There are three kinds of synaptic vesicles:small, clear synaptic vesicles that contain acetylcholine, gly-cine, GABA, or glutamate; small vesicles with a dense corethat contain catecholamines; and large vesicles with a densecore that contain neuropeptides. Which proteins are involved in the fusion-exocytosis complex?

Vesicle - V-snare - synaptobrevin interaction inhibited by toxins from clostridium tetani and clostridium botulinum Baclofen MOA? Presynaptic inhibition via g protein coupled reaction resulting in increased K conductance used for spasticity Function of GABA a receptor? Increases Cl- conductance What is a Renshall cell? Inhibitory interneuron affecting spinal motor neurons Glycine is the Neurotransmitter Describe the events at the NMJ T/F - Acetylcholinesterase is presentin high concentration at the neuromuscular junction TRUE Name the different types of nociceptors. Mechanical nociceptors respond to strong pressure (eg, froma sharp object). Thermal nociceptors are activated by skintemperatures above 42°C or by severe cold. Chemically sensitive nociceptors respond to various chemicals like bradykinin,histamine, high acidity, and environmental irritants. Polymodal nociceptors respond to combinations of these stimuli. Types of Pain fibres?

Thinly myelinated A delta (fast) - glutamate Unmyelinated C (slow) - glutamate + substance P - dull intense pain allodynia? is a sensation of pain in response to a normallyinnocuous stimulus Substances that can activate or sensitise nociceptors? Histamine, bradykinin, serotonin, prostaglandin, K+ Afferent fibers from visceral structures reach the CNS via? sympathetic and parasympathetic nerves including CNs Name the tracts in the spinal cord that carry: Pain/temp Describe the monosynaptic stretch reflex Ie muscle spindle receptor or golgi tendon organ Rapid reflex Describe the single twitch, tetanus and the Treppe effect Single twitch - Single AP i.e. at 1hz Tetanus - high frequency AP resulting in no relaxation period, maintaining maximal voluntary contraction (MVC) Treppe - means the increase in peak force as twitches are repeated at a high frequency (i.e.

not enough time for all the Ca to be removed thus increased force) Describe muscle Fatigue REDUCED FORCE or SHORTEN velocity with repeat near maximal contractions at short intervals Fatigue is present in fast muscle but absent or small in slow muscleand cardiac muscle. The latter have high oxidative capacity capable of producingthe ATP needed for each contraction. In fast muscle phosphocreatine (PCr) is broken down and glycolysis acceleratedso that phosphate and creatine and lactate and protons (lactic acid) accumulate. Accumulation of phosphate appears to be one important cause of fatigue. Lactic acid accumulation appears to be unimportant• Fatigue is also associated with reduced Ca release How can the cortex increase force produced by skeletal muscle?

Increase frequency of firing Increase the number and size of motor units recruited Describe the structure of SM Long, thin, spindle, fusiform cells Connected by gap junctions Actin + myosin but not organised (no striations) - allowing for greater fractional shortening --> they attach to the membrane by dense bodies Define Latch State and its functional role in SM Latch State --> Specialised function of SM that allows contraction to be maintained for long periods with minimal energy consumption - Ca and energy consumption decline but force is preserved - Remain in attached/latched state (Do not cycle) - (in isometric Skeletal muscle contraction cross bridge cycles and ATP is consumed) Describe the innervation and excitation of SM Supply: SNS (NA) or PSNS (ACh) mainly but some voluntary and enteric NT: many ; released from axon varicosities - no specific synaptic region Receptors - usually G protein coupled --> depolarisation --> opening of voltage gated Ca channels --> Ca influx --> contraction Indicate the intracellular pathway by which contraction is activated in SM Ca influx --> binds to Calmodulin which activates (dephosphorylation) myosin light chain kinase MLCK phosphorylates MLC to it's phosphorylated/active form --> Myosin

 and actin for XBs Slow excitation-contraction coupling due to slow diffusion of Ca and enzymatic processes are slow.

Relaxation is partly dependent on endogenous phosphatases How does NO/cGMP/phosphodiesterase inhibitors affect contraction in SM? Nitrates/NO activate Guanylate cyclase --> Increases cGMP --> activates Protein Kinase A --> Inactivates MLCK and prevents activation of MLC --> hence relaxation Phosphodiesterase inhibitors block the breakdown of cGMP Describe the characteristics of the BBB Capillary - Not leaky like elsewhere (tight junction) - anatomical block Exchange is through the cell only - physiological restriction Lipid soluble molecules easily pass through Surrounded by astrocytes Barrier between the blood and CNS Identify sources of energy utilised in the brain.

GLUCOSE (90%) - via GLUT 1 tranport (not insulin dependent) Describe the effect of hypoxia, hypoglycaemia and temperature on the brain Hypoglycaemia --> Mood change, trembling, sweating, blurred vision, headaches, dizziness, hungry, tiredness --> 2 minutes to unconsciousness Hypoxia --> 10 sec to unconsciousness, cortex most sensitive Temperature --> Hypothermia - reduces cerebral 02 consumption --> EEG isoelectric @ 20C Hyperthermia - Increased o2 consumption - over 42C enzymatic function disrupted Function of astrocytes? 1. Induce endothelium to have tight junctions 2. Produce substances which affect which carrier proteins are present in the endothelium 3. Participate in the cross cellular transport i.e. K+ Function of BBB? Provide constant environment for the CNS - i.e. electrolytes Protect brain from endogenous and exogenous toxins in the blood Prevention of the escape of NTs into the general circulation What happens to the BBB near infection or tumours? Other things that affect it?

Infection - Breakdown Tumours - rapid angioneogenesis without surround astrocytes Hypertonic fluid, +++ HTN, newborns (immature BBB) What are the circumventricular organs? Function? Median eminence of the hypothalamus Area postrema (Vomiting) Organum vasculosum of the lamina terminalis - OVLT (osmolarity - Vasopressin) Subfornical organ - SFO Here the capillaries have fenestrations with increased permeability Function as chemoreceptor zones Which of the following are incorrect/correct regarding the CNS: 1.The main source of energy for the brain is FFA 2. The brain uses 20% of the the body's 02 as rest 3. The cortex is the most sensitive part of the brain to hypoxia 4. Cerebral glucose utilisation is insulin dependent 5. Cerebral 02 consumption is 49ml/min 1.The main source of energy for the brain is FFA - incorrect (Glucose) 4. Cerebral glucose utilisation is insulin dependent - Incorrect (insulin independent How does the brain remove ammonia?

Glutamate + Ammonia --> Glutamine --> removal from CNS Describe the physiology of sleep Sleep is an essential, readily reversible physiologicalstate characterised by unconsciousness, reduced muscletone, analgesia, amnesia, respiratory and autonomicdisturbances and dreaming 2 types REM (eye movements) + NREM (slow wave - deep) Describe the primary rhythms of the EEG EEG - Recording of spontaneous electrical activity of the brain Alpha - 7.5-13Hz - normal relaxed state, occipital Beta - >14 Hz - fast, symmetrically, frontal, alert, anxious, eyes open Theta - 3.5-7.5 - normal in children and sleep, not in adults Delta - <3 Hz, highest amplitude, normal in infants and sleep, NOT adults Describe EMG. Electromyography (EMG) is an electro-diagnostic technique used for evaluating andrecording the electrical activity produced byskeletal muscles. Electrodes measure electricity over a muscle Describe the characteristics of NREM sleep. 4 stages 1. low voltage, mixed frequency pattern on EEG 2. Appearance of sleep spindles + K complexes 3. High amplitude delta rhythm 4.

Slow wave sleep, synchronisation may be MSK movement but no eye movement Normal level of REM sleep in adult? 25% › Has value in localizing pathologic processes withinthe brain › Detecting seizure activity, monitoring seizureactivity. › Used in anesthesia to assess levels of sedation - entropy › Diagnosis of generalized encephalopathies of metabolic or infective origin › To prognosticate at times in coma Describe the factors that control ICP BRAIN TISSUE, CSF, CEREBRAL BLOOD 1. Increased volume of any of the components = increased pressure 2. CSF translocation or increased absorption (linear 10-30mmH2O - or drainage via EVD 3. Decrease interstitial H2O 4. Blood flow - affected by MAP, CO2, temp, O2, metabolic rate (all increase except O2) 5. Sedation 6. Coughing, straining - intermittent spikes in ICP 7. Intra-abodminal and intrathoracic pressure Define the monroe - kelpie doctrine The CNS and its accompanying fluidsare enclosed in a rigidcontainer whose total volumetends to remain constant.

Anincrease in volume of onecomponent (e.g., brain, blood,or cerebrospinal fluid) willelevate pressure anddecrease the volume of one ofthe other elements Identify factors that affect cerebral perfusion MAP Cerebral flood flow - blood viscosity, medications (anaesthetics) Define auto regulation of CPP Auto regulation --> Ability of the cerebralcirculation to maintain cerebral blood flow (CBF) at arelatively constant level despite changes in cerebralperfusion pressure(CPP), by altering cerebrovascularresistance (CVR) Which of the following is incorrect/correct 1. A 100ml volume change in the skull always produces a equal predictable change in pressure 2. CCP = MAP - ICP 3. Cerebral blood flow ~ 54ml/100g/min 4. Brain wt 1400 grams 5. Normal ICP 5-15mmHg 1.

A 100ml volume change in the skull always produces a equal predictable change in pressure The volume change will cause different pressure changes depending on where the current ICP is on the P/V curve (high pressure - a small volume will cause a +++ increase in pressure) Result of raised ICP? Cushing Effect - ↑MAP with ↓HR & ↑RR Unconciousness ⟹ ↓CMRO2 (cerebral metabolic rateof O2) ↳ exhaustion of these ⟹ death via herniation Which of the following is correct/incorrect? 1. Autoregulation of CBF is limited to MAP between 50-150 2. Autoregulation is dependent on metabolic, myogenic (Stretch) and neurogenic (autonomic) mechanisms 3. Regarding cerebral blood flow - SNS causes vasoconstriction and PSNS cause vasodilation 4. ICP changes with coughing and straining are unimportant as the are non sustained 5. Temperature reduction causes a reduction in metabolic rate and reduces blood flow 4.

ICP changes with coughing and straining are unimportant as the are non sustained incorrect Buoyancy and cushioning for neural tissue Metabolic sink lateral ventricles - basal cisterns - over convex surface of the brain etc Removal of CSF? Arachnoid granulations projecting into venous sinuses- Active excretion process Across cribriform plate into cervical lymphatics Absorption is effectively zero for CSF pressure < 7 cm H20 and increases linearly with CSF pressure. Absorption and production balanced for CSF pressure11 cm H20 Describe the blood supply to the spinal cord. Paired Dorsal (Posterior) Spinal Arteries - Dorsal columns Single Ventral (Anterior) spinal artery Collaterals - Many for the dorsal. Limited to the Ventral. Ventral --> In the thoracolumbar area - limited collateral flow --> Artery of Adamkiewicz/great vertebral radicular artery (at risk for vascular insufficiency) Describe the regulation of spinal cord blood flow.

Same as for CPP Spinal PP = MAP - Intraspinal pressure Intraspinal pressure is determined by CSF or venous pressure Autoregulation occurs at MAP 60-150 Affected by CO2 (20-80), Hypoxia (<60) Which of the following is correct/incorrect regarding the anatomy relevant to accessing the spinal neuraxis: 1. Conus Medullaris @ L 2-3 level 2. Local anaesthetics block nerve conduction at the level of the spinal roots 3. The contents of the epidural space includes fat and vertebral venous plexus, spinal nerve roots pass through it 4. Skin --> Sub cut tissue --> supra spinal ligament --> Interspinous ligament --> Ligamentum Flavum --> Epidural space --> dura --> subarachnoid space 5. Blockage of finer order = Autonomic > C and A delta > A alpha > A beta 6. Autonomic > Pain and temp > Touch > Motor 1. Conus Medullaris @ L 2-3 level - incorrect (L1-2 ) 5.

Blockage of finer order = Autonomic > C and A delta > A alpha > A beta - incorrect ( A beta > A alpha - last) Describe the physiological effects of neuraxial blockade. LA blockade at the level of the SPINAL ROOTS Blockade order - Autonomic > Pain and temp - C/A delta > Touch - A beta > Motor - A alpha Vasodilation below the level, decrease SVR/VR/CO Above T5 - (block SNS outflow to the heart) - bradycardia GIT peristalsis unopposed No direct effect on the lungs - except muscle weakness Apnoea, nausea, vomiting - due to poor cerebral flow + hypotension Urinary retention Describe the features of spinal shock. Acute SCI (e.g. transection) Loss of descending activation in the vestibulospinal and reticulospinal tracts Immediate loss of sympathetic outflow and reflexes - Bradycardia Loss of bladder and colon reflexes Gradual recovery of segmental reflexes - Abnormal flexion response - babinski Describe the key features of somatosensory receptors and pathways.

Tactile - Dorsal columns - discrimination, joint position, vibratory detection Describe processes of nociception All nociceptors are free nerve endings Aδ fibers (high threshold mechanoreceptors) - Fast, small, myelinated, secrete L-glutamate - Mechanical or thermal stimuli - Slow, small, unmyelinated , secrete L-glutamate andsubstance P, calcitonin gene-related peptide (CGRP) - Chemical, persisting mechanical and thermal stimuli Neurogenic Flare Response? Antidromic propagation: release of neurotransmittersfrom the nerve ending at the site of injury - Bradykinin, substance P and other neuropeptides - Local vasodilatation, increased vascular permeability andinflammatory response Duration of a nerve action potential? 30 milliseconds IPSP are caused by influx of what ion? Cl- Biosynthesis of Glutamate ? Glutamate is synthesized in the Krebs cycle bythe conversion of α-ketoglutarate to the amino acid via the enzyme GABA-T or in nerve terminals by the hydrolysis of glutamine by the enzyme glutaminase 2 methods.

Question: Which infective disease caused by toxins is characterised by the violent and prolonged contraction of skeletal muscle fibres?
Answer: Tetanus