Presentation on theme: "Sam and Arty. Approaching the End of Course Exams Gastroenteritis Gut Physiology Thyroid Physiology Depression Normal Development GIT Embryology Wrap-up."— Presentation transcript:
Sam and Arty
Approaching the End of Course Exams Gastroenteritis Gut Physiology Thyroid Physiology Depression Normal Development GIT Embryology Wrap-up and Questions Tonight…
Read the question Define key concepts Structure (Logical Flow) Tables & Diagrams Dot points Completely lost? Write what you know Approaching the End of Course Exam
Gastroenteritis A 5 yro child presents to the ED with symptoms of diarrhoea, vomiting and nausea. What is gastroenteritis? What are the common causative agents of gastroenteritis? How would you make a diagnosis? How would you manage this case?
Defining Gastroenteritis Inflammation of the GIT. Involving stomach/SI Diarrhoea, vomiting, malaise, nausea, abdominal discomfort.
Causative Agents-viral In Australia: viruses, bacteria, parasites Norovirus: most common in adults. Rotavirus: Second most common in children. Vaccine. Adenovirus: Most common in children Astrovirus, picornavirus, parvovirus, sapovirus
Causative Agents - bacterial Campylobacter jejuni: most common in Aust. Zoonotic potential. Salmonella non-typhoid: second most common. Food poisoning. Salmonella typhoid: s. Typhi, s. Paratyphi. Longer lasting, systemic Shigella: very low infectious dose. faecal/-oral, sexual Vibrio cholera: ‘rice water stools’
Sample Question Antony has just eaten a sugar-heavy meal. Describe the mechanism by which the sugars in the food are broken down and absorbed across the gastrointestinal lining.
What are the components of the process? Digestion Mouth (Salivary Amylase) Pancreas (Pancreatic Amylase) Small Intestine (Disaccharidases) Absorption (transport across the enterocyte into the bloodstream)
Digestion Salivary amylase breaks down complex sugars (eg. starch) into simple sugars Pancreatic amylase further breaks down complex sugars Disaccharidases break down disaccharides into monosaccharides Lactase (Lactose Glucose + Galactose) Maltase (Maltose 2 * Glucose) Sucrase (Sucrose Glucose + Fructose)
Absorption Across the enterocyte apical membrane Na+/Glucose Co-Transporter (SGLT1) for Glucose and Galactose GLUT5 for Fructose Across the enterocyte basal membrane GLUT2 Gradients maintained by the Na+/K+ ATPase
Effects of Thyroid Hormone Increase basal metabolic rate: glycogenolysis, gluconeogenesis, lipolysis, protein synthesis. Heat generation, increased energy usage, oxygen consumption. Growth effects: with GH Cardiac effects: increase contractility Developmental effects: neonatal CNS
Thyroid – clinical perspectives A 20yro patient presents with symptoms of fatigue, muscle weakness, cold intolerance, bradycardia, hypoglycaemia, constipation. Is this more likely to be hypothyroidism or hyperthyroidism? Why? Describe two causes of hypothyroidism How would you manage a patient with hyperthyroidism?
Causes of Hypothyroidism Definition –abnormally low level of TH 3-5% of the population. Women, age Hashimotos thyroiditis: inherited autoimmune Pituitary or hypothalamic disease Thyroid destruction Medications Severe iodine deficiency
Managing Hyperthyroidism Surgery Radioactive iodine Anti-thyroid drugs
Anti-Thyroid Drugs Carbimazole – inhibits thyroid peroxidase Propyl-Thiouracil (PTU) – inhibits thyroid peroxidase & blocks de-iodination of T4 to T3 More T4 produced. But T3 more potent at target
Example Mrs X is a 55-year-old South Sydney Rabbitohs supporter, who has come in complaining of a four- week history of tiredness and ‘just not feeling like doing anything’. You suspect she may be depressed. What questions could you ask Mrs X in order to help support a diagnosis of depression?
Answering the Example Question Work through ASADFACES! Establish Chronicity!! Discuss risk factors if relevant
Management Non-pharmacological methods! Pharmacological agents (name, class, mechanism of action, side effects) Electroconvulsive therapy
Pharmacological Management of Depression Selective Serotonin Reuptake Inhibitors (SSRIs) Monoamine Oxidase Inhibitors (MAOIs) Other (Venlafaxine, Buproprion)
Developmental Milestones A mother brings in her 2yro son, Michael, who has Down Syndrome. He said his first word last week, and although can crawl and cruise, has not yet started to walk. Is this normal? Why/why not? What is developmental delay? What could cause it? How would you assess this case?
Domains of Normal Development Gross Motor Fine Motor Cognitive (Piaget’s Theory) Personal/Social Speech/Language
Normal Developmental Milestones 6weeks: primitive reflexes 9months: sit alone, object permanence By 12months: pull to stand, precise pincer grip, first word By 2years: run, two words at two. 3years: tricycle, upstairs, mature pencil grip, use scissors, tower of 9 blocks, cooperative play, know gender, draw circle, understand 3keyword instructions 6years: skip, bounce and catch ball, write first name, know address.
Michael’s development Down syndrome – can delay development Michael’s case: reaching his milestones later Need to assess cases individually, and realise some range is normal
Developmental delay and its causes The failure to meet developmental milestones at expected periods. Global or Domain-Specific. Mental retardation, CNS problems (meningitis) In Utero: infection in womb, FAS, trauma Chronic infection: deafness/glue ear (gentamicin) Hormonal problems-eg. thyroid Genetic/Family history-eg. DS, Turner Idiopathic Nutritional problems
Assessing developmental delay observe child detailed history check milestones physical neurological exam developmental screening: eg. parents evaluation of developmental status (PEDS),
How to learn GIT Embryology By time points By organs Pay attention to abnormalities mentioned in the lecture!
GIT Embryology Time Points Week 3 – GASTRULATION (formation of the three germ cell layers) and FOLDING (around the notochord) Week 4 – Segmentation of Mesoderm (Paraxial, Intermediate, Lateral Plate – Splanchnic + Somatic), Formation of Foregut, Midgut and Hindgut Week 5 – 8 Recanalization. Weeks 8-10 Intestinal Rotation
GIT by Organ Liver Stomach (including rotation) Pancreas Spleen Learn about which germ cell layer, and key phrases (eg. Dorsal mesogastrium for spleen, septum transversum for liver)
GIT Abnormalities Oesophageal atresia (recanalization) Meckel’s diverticulum (improper closure of the vitelline duct)