Week 2 - E. Coli, Kidneys, Fluids Flashcards
Outline daily fluid losses and fluid requirements in health What are the types and approximate values of fluid loss
Requirement / loss both about 2.5L Sensible - can sense and measure - urine, faeces, blood, sweating Insensible - can NOT sense / measure - breathing, evaporation from skin Sweating - 100ml Faeces - 100ml Urine - 1500ml Insensible (skins, lungs - not involving solutes) - 700ml Approximately 2.5L (2,500mL) a day Exercise, environmental factors increase output Normal water intake - 2-2.5 l per day TOTAL
Describe the main body fluid compartments, the major differences in their composition, the factors affecting water and solute transport between them
Intracellular - in cells about 2/3 Extracellular (Interstitial, plasma, transcellular) - about 1/3 Interstitial between cells Plasma in blood Transcellular is everything else (joints, CSF, etc) Solutes / fluid move between them through both active and passive transport (fluid can move due to osmotic pressure)
Hyper, hypo, isotonic
If ICF is more solute concentrated than ECF, conditions are hypotonic and fluid will try to move INTO the cell to balance which can result in lysis If ICF is less solute concentrated than ECP, conditions are hypertonic and fluid will try to move OUT of the cell which can result in shrivelling of the cell If equal, they are at equilibrium
Describe how and why the ECF and ICF alters in a) salt and water depletion b) net water depletion and c) net salt depletion
HYPOtonic dehyradtion - solute loss is greater than water loss - water will rush into cells to try to maintain ICF water content HYPERtonic - water loss is greater than solute loss - water will rush out of cells to try to maintain ECF water content ISOtonic - loss of both - water and solutes may move out of ICF into ECF
Describe the factors that influence membrane permeability to small and non-polar molecules (4 gradients, 1 other factor)
Concentration gradient, electrochemical gradient, pressure gradient, osmotic pressure gradient Properties of the membrane Membrane thickness/composition Aqueous pores in the membrane Transport mechanisms - Carrier-mediated transport Semi-permeable – allow H2O through
Outline what prevents transmembrane movement of polar molecules. Examples of can and can’t
Due to hydrophobic nature of tails inside membrane, uncharged, non-polar small molecules most easily through the membrane CAN: O2, CO2, H2O (smaller polar molecules CAN, larger CAN’T) CAN’T: Glucose, Ions (regardless of size)
Outline the types of passive transport (4)
Diffusion - Movement of solutes from high to low concentration, down concentration gradient, no energy required Osmosis - Movement of water from low to high solute concentration, down concentration gradient, no energy required Ion channels / Facilitated diffusion - does not require energy, through carrier protein, for ions /glucose etc. to move down concentration gradient - uniport
Outline the types of active transport (2 with examples)
Primary - directly uses ATP - PUMPs - Sodium / potassium pump Secondary - Uses existing favourable gradient symport, antiport, sodium glucose linked transporters, sodium calcium exchanger
Describe the rationale for oral rehydration therapy based on understanding of sodium, glucose and water transport mechanisms in the intestine
Isomotic dehydration means patient is losing both electrolytes and water Rehydration requires both of these to prevent differences between ICF / ECF Glucose required to maintain sodium/potassium pump so electrolytes and water continue start moving into cells equally
Describe gross structure of kidney - location, structure, blood supply
At the posterior alongside spinal column, renal artery/vein, surrounded by capsule, containing medulla and cortex regions, all filters into renal pelvis, which moves into ureter
Describe a nephron - structure, function
Afferent/efferent arteriole, Glomulerus, Bowman’s capsule, Proximal, convoluted tubule, loop of Henle, distal convoluted tubule, collecting duct
What is the kidney’s role in fluid balance? (4)
Filtration, reabsorption (out of nephron into blood), secretion (into nephron), excretion
Define what a drug is.
Drug - chemical that produces biological effects
Compare and contrast the anatomy and chemical transmission of the sympathetic and parasympathetic nervous systems.
Sympathetic - excite Thoracic / lumbar region Parasympathetic - calm Cervical / sacral region
Appreciate the different approaches to learning anatomy (5); understand ‘the anatomical position; appreciate the necessity to use correct anatomical terminology
Approaches: embryological, regional, cross sectional, systems, surface
Identify the embryonic origin in terms of endoderm, mesoderm and ectoderm of different body layers and the major viscera of the thoracic, abdominal and pelvic cavities
Endoderm - lining of gastro-intestinal system, respiratory and urogenital tract Mesoderm - Heart, blood vessels, muscle, kidneys, urogenital, connective tissue, skeleton Ectoderm - skin, brain, CNS, snesory organs, tooth enamel, hair, nails
Use appropriate anatomical terminology to describe the relationships between the major viscera and parts of the body
Discuss elements
Understand the principles of a systematic approach to clinical examination
Introduction and preparation - intro, consent, handwashing IPPA - including bedside observation Closure
Demonstrate awareness of the non-clinical determinants of health, including social, political, economic, environmental and gender disparities
Discuss elements
