BIO 151 1st Edition Lecture 38 Outline of Last Lecture 1. Clonal selection2. 2 lines of cells3. Lymphatic system4. IG domain proteins5. Cellular mechanism of immune response6. 2 big issues about immune system makes antibodies7. T cell receptor8. B cells9. MHCII10. Kidney 11. Cytotoxic T cellsOutline of Current Lecture 1. Kidney2. Filtration3. Osmolarity of extracellular fluidCurrent Lecture - 4/24/15Kidney:- physical filter- retains protein- retrieve water, salt, nutrients- let go of some water, nitrogenous waste, waste products- 3 steps-filtration-reabsorption-secretion- 1 million nephrons per kidney- urine collected in ureter- nephron - tissue, consists of fiber- simple cuboidal epithelia- tubular - crossing duct collects filtrate, receives output from several nephrons- glomerulus - filter, consists of capillary bed, surrounds upper part of nephron, folded over surface of capillaries- Bohman's capsule - kidney's tubule- less than 7000 Da molecular range goes through glomerulus - podocytes - extensions, interweaved, not closed (have space between them)- filtration slits - spaces between fingers = filter - proteins less than 7000 retained- smaller ones will get through if you add more proteinsThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.- proteins much smaller than filtration slits, need special meshwork of nephron to act as filterFiltration:- fluid and small molecules pushed through pores into Bohman's capsule- large molecules retained in bloodstream- nephron forms barrier (mesh)- filtration slits wrap around vessel- pores in blood vessel- filtrate processed by rest of kidney tubules- regulate what we excrete- secrete concentrated or dilute urine- proximal tubule - filtrate in cortex, most nutrients absorbed here- distal tubule - also in cortex- osmotic strength determines water flow- loop of henle - in outer medulla- collecting duct - in inner medulla- descending limb very permeable to water- osmolarity increases as you go down- osmolarity - what happens to concentration of water when you add a solute to it- need water, change properties of collectivityOsmolarity of extracellular fluid:- rare quality of kidney- active transport of urea - activates
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