MB ChB Year 1: Nutrition and Energy


It is desirable that students play an active part in the learning process, consulting text books, occasional review articles and the world wide web. It is not good teaching practice to provide all the information in a pre-digested form. Most of your lecture handouts are skeleton handouts, that are designed to be completed during and after each lecture. They provide a guide to the topics that you should know and understand, but they are not sufficient in themselves.

These web pages are intended to assist you in this process. Some contain more information than the lecture handouts, with additional hypertext links, coloured pictures, animated diagrams and self-test materials that can only be provided in the electronic version.

Lecture 1: Chewing, tasting and swallowing. (Dr Roberts) The anatomy of chewing, tasting and swallowing. This is an e-lecture, available via the VLE. You may view it at any time, but are advised to do so early in the course. You may experience difficulties in accessing this lecture from home or from a laptop if you do not have the appropriate software installed. If you do have problems, try accessing this material from one of the university computer clusters.

Lecture 2: Peritoneal reflections. (Dr McConnell) Arrangement of the gut tube and associated organs within the abdominal cavity. Disposition of the peritoneal membrance to form the mesenteries and omenta, the greater and lesser sacs and the supracolic and infracolic compartments. Clinical significance of this arrangement

Lecture 3: Motility. (Dr Hunter) The unitary nature of the smooth muscle of the GIT and the role of the nexi in the transmission of the electrical signal between cells; slow wave electrical activity, spike activity and contractile activity; receptive-relaxation; vago-vagal reflexes; enterogastric reflex and "enterogastrone"; peristalsis and segmentation; migrating motor complex; peristalsis, haustral shuffling and mass propulsive movements in the colon; the defaecation reflex, initiation, sampling and the control of external and internal sphincters

Lecture 4: Regulation. (Dr Hunter) Endocrine, paracrine and neurocrine secretion; criteria which should be met before a hormone can be assumed to be involved in regulation of the GIT in vivo; sites of synthesis and release of the major hormones gastrin, secretin, CCK-PZ GIP; the primary secretagogues of the major hormones and the actions of the hormones on the target tissues; the biochemical division of the hormones into the two families, gastrin-like and secretin-like hormones; the terminal amino acid sequence of gastrin and CCK-PZ which is responsible for the shared actions of these hormones; the distinction between the extrinsic and intrinsic nerve supplies to the GIT; the origins of the extrinsic nerves; the major effects of stimulation of the nerves on the GIT (e.g. motility, salivary, gastric and pancreatic secretions.

Clinical Session Overview of the GI tract and its diseases (Dr Donnellan)

Lecture 6 & 8: Immunology of the gut (2 lectures) (Dr Taylor-Robinson) An overview of the cellular organisation of the gut immune system, how it responds to antigen challenge, and the diseases that affect it.

Clinical Session: How patients are fed artificially (Dr Madhok) Routes, means, monitoring, risks and outcomes.

Lecture 5 & 7: Secretion (2 lectures) (Dr Hunter) Sympathetic or parasympathetic stimulation; composition and cellular origin of the various components; the two-stage hypothesis of salivary secretion; the cellular basis of acid secretion; active K+/H+-exchange; the protective bicarbonate/mucus barrier mechanism; induction and prevention of ulceration; control of gastric acid sectretion (cephalic, gastric and intestinal); components of pancreatic secretion (enzymes and electrolytes); reciprocal relationship between the concentration of bicarbonate and chloride in pancreatic juice and flow rate-dependence; cephalic, gastric and intestinal phases of control; the life-cycle of enterocytes; c-AMP and secretory diarrhoea of cholera

Clinical Session How patients are fed artificially (Dr Donnellan) Nutritional requirements and nutritional assessment. Artificial nutrition - reasons, routes, feed composition, monitoring, and complications.

Lectures 9 & 11: Digestion and absorption (2 lectures) (Dr Hunter) Elementary chemical structures of the main dietary foodstuffs (carbohydrates, fats and proteins) and their breakdown by digestive enzymes; sources of the digestive enzymes, secreted and brush border; mechanisms of absorption; coupled transport of monosaccharides and amino acids with sodium; facilitated diffusion of some monosaccharides; passive diffusion of monoglycerides, fatty acids and D-amino acids; emulsification and micelle formation in the duodenal lumen; unidirectional secretory and absorptive fluxes; calcium, iron and vitamin B12 handling; colon electrolyte handling and modulation by mineralocorticoids

Clinical Session: Nutrition in renal disease (Dr Wright)

Lecture 10: Development of the GI tract [1]. (Dr Nunn) Formation of the primitive gut tube. Formation of the vitelline duct. Blood supply to the gastrointestinal tract. Formation of the oesophagus and oesophageal abnormalities including Barrett's oesophagus and short oesophagus. Embryology of the stomach including its histogenesis and congenital pyloric stenosis. Modification of the primitive dorsal and ventral mesenteries.

Lecture 12: Development of the GI tract [2]. (Dr Nunn) Development of the midgut. Fixation of the intestines. Histological development of the small intestine. Embryological abnormalities including omphalocoele, gastroschisis, congenital umbilical hernia, non-rotation of the midgut, midgut rotation and volvulus. Hindgut development.

Lecture 13: Development of the GI tract [3]. (Dr Nunn) Glands of the digestive tract. Formation of the liver and biliary apparatus. Dunctions of the developing liver. Biliary atresia and variations in the cystic artery. Formation of the pancreas at the gross and histological level. Ectopic and annular pancreas; formation and consequences.

Lecture 14: Introduction to metabolism (Dr Illingworth) the central importance of a stable blood glucose concentration despite unexpected 20-fold variations in supply and demand, sensory mechanisms, roles of the liver and perpheral tissues in defending blood glucose, overview of neural and hormonal signalling systems, sizes of human energy stores, time scale for responses, osmotic constraints, signals from the gut control food intake and downstream processing.

Lecture 15: Structure and functions of the liver. (Dr Whittle) The anatomical and cellular structure of the liver. An overview of liver function, and its role in bile formation, xenobiotic detoxification and haem breakdown.

Lecture 16: Post-absorption processing of carbohydrates. (Dr Whittle) The possible fates of carbohydrates after absorption. Glycolysis, glycogen synthesis and breakdown, fatty acid and triglyceride synthesis.

Lecture 17: Post-absorption processing of dietary lipids. (Dr Whittle) Transport of lipids, fate of lipids in peripheral tissue. Cholesterol and its role in atherosclerosis.

Clinical Session: Malabsorption (Dr Heatley) Main causes of malabsorption including coeliac disease, inflammatory bowel disease, pancreatic and liver disease. Main effects of malabsorption, e.g. anaemia, steatorrhoea, osteomalacia. Symptoms and signs of malabsorption, treatment.

Clinical Session: Obesity (Professor Hill, Dr Barth & Ms O'Kane) The recent increase in prevalence of obesity and reasons underlying this. The main approaches to obesity treatment. The dietetic approach to managing adult obesity.

Lecture 18: Post-absorption processing of dietary nitrogen. (Dr Whittle) Amino acid metabolism. Ureogenesis. Role of proteins in energy metabolism and as substrates for gluconeogenesis.

Clinical Session: Cystic fibrosis, a personal perspective (Lynsey Morton, Cystic Fibrosis Trust)

Clinical Session: Liver disease (Dr Aldersley) Normal structure and function of liver and biliary system. Principal pathological states, - acute inflammation (e.g. hepatitis), chronic disease (e.g. cirrhosis) and biliary obstruction - causes, signs and symptoms, and treatment options.

Lecture 19: Bioenergetics [1] - substrate oxidation. (Dr Illingworth) Sub-cellular compartments and the final common pathways for substrate oxidation via the citric acid cycle and the mitochondrial respiratory chain.

Lecture 20: Bioenergetics [2] - ATP synthesis. (Dr Illingworth) Proton gradients, oxidative phosphorylation, creatine phosphate and the subcellular transport of ATP.

Lecture 21: Pancreatic islets, release of insulin and its effects. (Dr Illingworth) Specialised metabolism in pancreatic b cells and the role of ATP in the regulation of insulin release. Oral hypoglycaemic agents. Insulin receptors. Immediate effects of insulin on glucose transport and enzyme activity, and its long-term effects on gene expression.

Lecture 22: Specialised metabolism of differentiated tissues. (Dr Illingworth) Metabolic differences between liver, muscle, adipose tissue and brain. Signalling and cooperation between tissues. Tissue differences in receptors and hormonal responses.

Lecture 23: Mobilisation of food reserves [1] - catecholamines & glucagon. (Dr Illingworth) Glycogen phosphorylase and mobilising lipase. Signal amplification by enzyme cascades. a and b-receptors, calcium movements, calmodulin, adenyl cyclase, protein kinases and cyclic AMP.

Clinical Session: Eating Disorders (Dr Hill) This will include a description of the main types of eating disorders, perspectives on their development, and an overview of their prevalence, characteristics and treatment. Details of resources for further information and assistance will also be provided.

Lecture 24: Mobilisation of food reserves [2] - ACTH & steroid hormones. (Dr Illingworth) Hypothalamic releasing factors, pituitary and adrenal cortex. Metabolic and physiological effects of corticosteroids and growth hormone on energy supply.

Lecture 25: Thyroid hormones, thermoregulation and basal metabolic rate. (Dr Illingworth) Roles of hypothalamus, pituitary and thyroid gland in regulating basal metabolic rate. Effects of thyroid hormones on gene expression and metabolism. Clinical and behavioural effects of abnormal thyroid function.

Lecture 26: Regulation of body weight. (Dr Illingworth) Feedback systems which normally coordinate food input with energy expenditure, and what happens when these go wrong.

Clinical Session: Diabetes (Dr Ajjan) The manifestations and recognition of diabetes - management and complications

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Study Guide
Work Sessions