Concise Flashcards Sem 1
List some major vital signs and indicate a normal range for each.
Vital Signs
- Heart rate – 60-100 bpm
- Respiratory rate – 12-20 breaths/minute
- Blood pressure – 90/60-140/90 mmHg
- Body temperature – 36.0-37.5°C
- Oxygen saturation – 95-100%
List four standard precautions.
Standard Precautions
- Handwashing – using correct technique
- Barriers to Infection – Gloves, gowns, masks, goggles etc.
- Appropriate Disposal of Sharps & Waste
- Aseptic Technique – to avoid wound contamination
Name the borders and contents of the femoral triangle.
Femoral Triangle.
- Floor: Psoas Major Muscle
- Lateral border: Sartorius Muscle
- Medial border: Adductor Longus Muscle
- Superior border (Base): Inguinal Ligament
- Contents (medial→lateral): Vein, Artery, Nerve (VAN out)
Name the two major forces governing movement of fluid in and out of capillaries.
- Hydrostatic Pressure – (Pc and Pif) – the force of water between the capillary and the interstitium (influenced by blood pressure)
- Oncotic Pressure (πp and πIF) – the concentration gradient between the capillary and the interstitium, exerted by proteins (influenced by plasma protein concentration)
List the rapid, intermediate and late responses to change in blood pressure.
Rapid/Immediate Response (seconds → minutes)
- Baroreceptors
- Chemoreceptors
- Central Ischaemic Response
- Intermediate Response (minutes → hours)
Volume Reflex (ANP)
- Stress Relexation
- Renin-Angiotensin System
- Capillary Fluid Shift
Long-Term Response (days → weeks)
- Renal Pressure Diuresis
- Erythropoesis
List the types of shock and summarise their pathogenesis.
List some physiological effects of alcohol.
(10)
- Slurred speech
- Motor incoordination
- Loss of balance
- Impaired judgement
- Memory loss
- Diuresis (inhibition of ADH)
- Cutaneous vasodilation
- Inhibition of platelet aggregation
- ↑ salivary and gastric secretions
- Tolerance & dependence
Outline a screening procedure for alcoholism.
CAGE during history taking to screen for alcoholism
- Cut Down - Have you ever felt you ought to cut down on your drinking?
- Annoyed - Have people annoyed you by criticising your drinking?
- Guilty - Have you ever felt bad or guilty about your drinking?
- Eye Opener - Have you ever had a drink first thing in the morning to steady your nerves?
List 6 ethical duties required of doctors.
Ethical duties required of doctors.
- Duty to diagnose and treat
- Duty to attend (e.g. make house calls)
- Duty to disclose – provide enough information for decision making
- Duty to follow-up
- Duty of confidentiality
- Duty to disclose errors
Is a doctor required to stop and help at a motor vehicle crash?
- No legal requirement to rescue in Australia (except NT) – exceptions e.g. doctor-patient relationship
- But doctors have a professional and ethical duty to provide aid in an emergency - failure to provide care may be regarded as unprofessional conduct
-
Good Samaritan Legislation – no liability to a health practitioner who provides aid in an emergency if:
- The negative action is done or omitted in good faith
- The act is done without gross negligence (doctors have higher standard of care than students/public)
- The act is performed without fee or expectation of fee
Differentiate between civil and criminal law.
Describe the general Evidence Based Medicine (EBM) process.
-
A specific question is asked regarding a patient’s problem
- P = Patient/Population/Proble
- I = Intervention/Indicator
- C = Comparison/Control
- O = Outcome
-
Literature is searched for articles related and relevant to the case
- Cochrane library - collection of evidence-based databases containing information related to specific interventions (systematic reviews and RCTs)
- Pubmed can be used to answer all types of clinical questions (clinical studies & systematic reviews)
- The evidence gathered from research is evaluated on an individual basis for its validity and usefulness for application to the case in question
- The findings, if useful, are applied to the case in question
Name four processes involved in Medical medical self-regulation.
- Education – MBBS → specialist training → CME
- AMC accreditation of medical schools
- Accreditation of general practice
- Professional Services Review Scheme
- Quality Assurance Committees
- Adverse Events research/ safety & quality systems
- Evidence-based medicine
- Legal standards of care
- Medical Boards
Name four functions of the Medical Board of Australia.
- To keep a register of medical practitioners
- To receive complaints re: practitioners and initiate proceedings
- To discipline practitioners, by imposing conditions on registration or bringing serious matters to the Health Practitioners tribunal
- To receive reports of impaired practitioners, provide monitoring and rehabilitation, and impose conditions on impaired practitioners
Name the layers of skin (in detail).
Layers of the Skin
-
Epidermis
- Stratum corneum
- Stratum lucidum (only thick skin)
- Stratum granulosum
- Stratum spinosum
- Stratum basale
-
Dermis
- Papillary dermis
- Reticular dermis
- Hypodermis
Summarise the nerve endings existing in the skin.
- Merkel Cells - Stratum Basale = sensory receptors for fine touch
- Free Nerve Endings – end in Stratum Granulosum
- Meissner’s Corpuscles – papillary dermis = fine touch/pressure, low-freq vibration
- Pacinian Corpuscles – reticular dermis/hypodermis = deep touch/pressure, vibration
- Krause’s End Bulbs – papillary dermis = like pacinian corpuscles
- Ruffini Endings – reticular dermis = mechanoreceptors
Name the functions of skin (7).
Functions of skin.
- Protection – mechanical, chemical, barrier
- Waterproofing – lipids
- Thermoregulation – vasodilation/constriction, sweating
- Metabolism – fat storage, Vitamin D activation
- Excretion – sebum, sweat, cerumin, milk
- Sensation – hairs, nerve endings
- Communication – colour, muscles, odour
Describe the four processes involved in the pathogenesis of acne.
Pathogenesis of Acne
- Poral Occlusion – from hyperkeratinisation, cosmetics, oils, tar, genetic factors
- Sebum Production – androgen-dependant (especially high in puberty)
- Bacterial Colonisation of Duct – by Propionibacterium acnes, feeding on sebum
- Dermal Inflammation – chemical mediators
Outline treatment options for acne.
Outline the mechanism of abcess formation.
Mechanism of abcess formation
- Presence of S. aureus
- Inflammation – necrosis, neutrophil immigration
- Pus –dead neutrophils, softened necrotic tissue
- Abcess Formation – membrane - fibrinous exudates
- Formation of Granulation Tissue (dense, fibrous)
Name 7 virulence factors of Staphylococcus Aureus.
Virulence Factors of Staphylococcus Aureus
- Lipase – degrades skin surface lipids
- Catalase – resists oxidative destruction
- Coagulase – catalyses fibrinogen → fibrin, forms layer of fibrin around abscess
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Endotoxins
- Leukocidin (kills WBC)
- Haemolysin (kills RBC)
- Enterotoxins
- Capsule – resists opsinisation/phagocytosis
- Protein A – binds Fc region of antibodies→ prevents clearance
- Adhesins – Elastin, Collagen-binding proteins
Outline the mechanisms of some major antibiotics.
Outline the three complement pathways.
Name the five signs of acute inflammation and outline their mechanisms.
Outline the process of lymphocyte production and maturation.
Outline the process of T lymphocyte-mediated killing.
Outline the process of B cell activation (6 steps).
B cell activation.
- Sensitised B cells migrate to lymphoid tissue through high endothelial venules
- Antigen-presenting B cells (MHCII) are captured in the T cell zones (paracortex) of lymph nodes
- Activated TH2 cells bind to the antigen presented by the naive B cells
- IL-4 released by the T cell and CD40L on the T cell surface stimulate clonal expansion of B cells
- Some B cells differentiate to plasma cells - IgM-secreting, immediate
- Most B cells (and their corresponding T cells) migrate to the primary lymphoid follicles
- In the primary follicles, B cells (now known as centroblasts) form a germinal centre where they undergo affinity maturation – involves:
- Mature B cells differentiate into plasma cells and memory B cells
- Plasma cells secrete antibodies (IgM, primary response
- Memory B cells remain in circulation ready for a secondary response
Name 6 functions of antibodies
Functions of Antibodies
- Neutralisation – prevent activity of toxins, entry of microbes into cells
- Opsonisation - phagocytosis (phagocytes express Fc receptors)
- Antibody-dependant cell-mediated cytotoxicity (activate NK cells to undergo cytotoxic killing)
- Complement Activation – classical complement pathway = opsonisation, recruitment, direct killing
- Triggering of mast cells, basophils, activated eosinophils
- Recognition of antigens by B cells (BCR)
Identify specific characteristics of the different classes of antibody (GAMED)
IgG - Most common antibody
- Involved in secondary immune response - complement activation
- Crosses placental barrier – passive immunity from mother to child
IgA - Neutralisation
- Can form a dimer (with J chain)
- Found in secretions – saliva, sweat, tears, breast milk (passive immunity from mother to child)
IgM - Mostly in primary immune response – complement activation
- Monomeric form on B cells, but pentameric form in circulation (+ J chain)
IgE - Involved in allergic response- stimulates histamine release by mast cells and basophils
IgD - B cell receptor (BCR)
Describe four ways that antibodies develop diversity.
- Chain Diversity – Different combinations of heavy and light chains
- Somatic Recombination – Genetic switching of variability, domain and junction regions
- Junctional Diversity – Alteration at the site of cleavage in the joining region
- Somatic Hypermutation – Mutations in antibody genes which alter antibody structure
Outline the pathogenesis of fever.
Outline the process of determining an APGAR score.
Name the ligaments that attach to the liver and where they connect to (6).
- Coronary ligament - connects the liver to the diaphragm above
- Triangular ligaments (left & right) – where the anterior and posterior coronary ligaments come together
- Falciform ligament - connects liver to anterior body wall
- Round ligament (ligamentum teres) - remnant of fetal umbilical vein
- Lesser ommentum - connects the liver to the stomach, and contains the ligamentum venosum, a remnant of the fetal ductus venosus
- Porta hepatis (transverse fissure) - transmits the portal vein, the hepatic artery proper, the common hepatic duct, nerves and lymphatics
What valve controls the cystic duct?
Spiral valve/ valve of Hesler
Explain the concept of zones within a liver acinus.
- Zone I: closest to periportal axis; well perfused with O2, nutrients & toxins – resists hypoxic damage but susceptible to drugs/toxins
- Zone II – transitional zone; between I and III
- Zone III – near central vein; blood is deoxygenated, low in nutrients and high in drug metabolising enzymes – susceptible to hypoxic damage and drugs (paracetamol)
Name the seven Baltimore groups of viruses and give an example of each.
Outline the stages of viral infection (7).
Stages of Viral Infection
- Attachment – viral protein contacts cell receptor
- Penetration – fusion of viral coat with cell membrane
- Uncoating - release of viral genome
-
Transcription and/or Translation
- DNA viruses – transcription/replication occurs in the nucleus & proteins translated in the cytoplasm
- RNA viruses – transcription/translation/ replication all occur in the cytoplasm
- Genome Replication
- Assembly – formation of viral particles from proteins
- Release - lysis of cell or budding
Outline the mechanisms of action of acyclovir, interferon-α and AZT.
- Acyclovir – inhibits DNA polymerase
- AZT – inhibits reverse transcriptase
- Interferon-α – stimulates cells to inhibit viral translation
Describe some defining features of Hepatitis A, B, C and D.
Describe some liver function tests and what abnormal levels indicate.
Outline the process of heme catabolism.
Outline the causes of jaundice.
Causes of Jaundice
-
Pre-Hepatic Jaundice: excessive bilirubin production from Haemolysis, glomerular nephritis
- ↑ unconjugated bilirubin in blood, ↑ urobilinogen in urine & stools, normal urine and stool colour
-
Hepatic Jaundice: impaired liver function or hepatocellular damage from hepatitis, toxins, cirrhosis
- ↓Uptake → ↑unconjugated plasma bilirubin, normal urine, pale stools
- ↓Conjugation → ↑unconjugated plasma bilirubin, normal urine, pale stools
- ↓Excretion (hepatic cholestasis) → ↑conjugated plasma bilirubin, dark urine & pale stools
-
Post-Hepatic Jaundice: blockage of outflow from liver from gallstones, head of pancreas cancer
- ↑ unconjugated bilirubin in blood, dark urine & pale stools
Outline some of the clinical features of Down Syndrome.
Name some categories of notifiable diseases (8).
- Gastroenteric pathogens (some transmitted by food or water) - e.g. salmonella • Sexually transmissible infections - e.g. HIV, gonorrhoea
- Vaccine preventable diseases - e.g. Measles, pertussis, rubella
- Blood-borne viruses - e.g. Hepatitis c
- Vector-borne infections - e.g. Dengue fever
- Zoonotic infections - e.g. Brucellosis, q-fever
- Invasive bacterial diseases - e.g. Invasive meningococcal disease, invasive pneumococcal disease
- Potential bioterrorism agents - e.g. Smallpox
- New and emerging infections - e.g. Severe Acute Respiratory Syndrome (SARS)
Name some retroperitoneal organs.
SAD PUCKER (retroperitoneal organs)
- Suprarenals
- Aorta & inferior vena cava
- Duodenum (descending & horisontal)
- Pancreas (except tail)
- Ureters
- Colon (ascending & descending)
- Kidneys
- (O)Esophagus
- Rectum (middle 1/3)
dentify structures, blood supply and innervation of the foregut, midgut and hindgut.
Identify anterior and posterior relations of the stomach.
Posterior Relations
- Omental bursa
- Left kidney
- Diaphragm, spleen,
- left adrenal
- Pancreas
- Transverse mesocolon
Anterior Relations
- Diaphragm (fundus)
- Left lobe of liver
- Anterior abdominal wall
Identify distinguishing features of the ileum and jejunum.
What parts of the colon are mobile and what parts are fixed?
- Ascending colon - fixed
- Transverse colon - mobile
- Descending colon – fixed
- Sigmoid colon - mobile
Identify the two plexuses of the enteric nervous system.
-
Myenteric (Auerbach’s) Plexus
- Outer plexus between the longitudinal and circular muscle layers
- Controls movements throughout the length of the GIT
-
Submucosal (Meissner’s) Plexus
- Inner plexus within the submucosa
- Controls GIT secretion and blood flow – more localised
List types of diarrhoea and give a mechanism and example for each.
DOMES
- Deranged Motility
- Osmotic
- Malabsorptive
- Exudative
- Secretory
Name some common gastrointestinal pathogens, their incubation period and duration of illness.
Outline the pathogenesis of infection with Entero- haemorrhagic E. Coli.
Pathogenesis of E. Coli
- EHEC ingested
- Eating undercooked, contaminated ground beef
- Drinking raw milk or contaminated water
- 2-4 day latency period
- Abdominal cramps, non-bloody diarrhoea (1-2 days)
- Bloody diarrhoea (5-7 days)
- Resolution or → haemolytic uraemic syndrome
- 5% chronic renal failure
- 30% proteinuria
- 3-5% death
- 6% resolution
dentify four types of protozoa, describe them and give an example.
- Flagellates –with whip-like flagella (e.g. Giardia lamblia)
- Amoebae – temporary pseudopodia (e.g. Entamoeba histolytica)
- Sporozoa – non-motile ‘spores’ (e.g. Cryptosporidium parvum)
- Ciliates – hair-like cilia (e.g. Balantidium coli)
Name the major causes of anaemia (9).
- Acute blood loss (haemorrhage)
- Chronic blood loss (e.g. lesion in GIT)
- Extravascular haemolysis – reduced RBC deformability means they can’t fit through sinusoids and are sequestered in the spleen –> phagocytosis (sickle cell, hypersplenism)
-
Intravascular haemolysis
- Mechanical Trauma, RBC infections (malaria), autoimmune/drug-induced haemolysis, toxins (lead poisoning, snake venom), membrane lipid abnormalities
- Genetic disorders - fanconi anaemia
-
Malnutrition
- B12 (pernicious anaemia), folate, iron deficiency anaemia
- Aplastic anaemia - hematopoietic failure
- Pure red cell aplasia - suppression of erythrocyte progenitors
- Iron sequestration (inflammation)