Transcript Fig 17.2
Chapter 17 Physiology of the Kidneys A. Kidney Function Regulates Volume of _______________, which contributes to BP plasma & ________________ by formation of urine Waste products in blood Concentration of ___________________ Including Na+, K+, HC03-, & others Plasma ____ B. Kidney Structure Fig 17.1 kidneys located on either side of vertebral column below __________ About size of ____ Urine flows from kidneys into ________which empty into________ ______ contains many capillaries & outer parts of ________ _____ consists of _________ separated by _____________ Pyramid contains ___________ which unite to form a _______________ ___________ Fig 17.2 join to form ________ which collects urine C. Micturition Reflex (Urination) Actions of _______ & __________________ are regulated by reflex center located in sacral part of cord Bladder fills __________________ activated Contraction of _____________ relaxes internal urethral _____________ voluntary control over external _________________ D. Nephron functional unit of kidney responsible for forming __________ >1 million ___________/kidney Is a long tube & has associated _______ ______ Fig 17.2 E. Renal Blood Vessels Blood enters kidney through ____________ Which divides into ___________, then __________ then ______________, then ______________ which supply _____________ Fig 17.4 F. Nephron Tubules Tubular part of nephron begins with _______________ which transitions into _________________ (PCT), then to ______________ & ___________________________ (LH), & _____________________ (DCT) Tubule ends where it empties into _________________ (CD) Fig 17.2 G. Glomerular (Bowman's) Capsule Surrounds glomerulus Together they form PCT ______________ Glomerular Is where glomerular capsule filtration occurs Filtrate passes into ______ Fig 17.6 H. Glomerular Filtration Glomerular capillaries & ________________ form a filter for blood Glomerular Caps are ____________--have large pores between its endothelial cells 100-400 times more permeable than other Caps Small enough to keep RBCs, platelets, & WBCs from passing H. Glomerular Filtration continued To enter tubule filtrate must pass through narrow ______________ Fig 17.8 Glomerular Filtration Rate (GFR) volume of filtrate produced by both kidneys/min Averages ________ in women; 125 ml/min in men Totals about 180L/day (____________) So most filtered water must be reabsorbed or death would ensue from water lost through urination controlled by extrinsic & intrinsic _______________) mechanisms Vasoconstriction or dilation of afferent arterioles affects rate of blood flow to glomeruli & thus ________ I. Sympathetic Effects Sympathetic activity constricts ____________ Helps maintain BP & shunts blood to ______ _____________ Fig 17.11 J. ______________ of Salt & H20 by Glomerular Capsule About 180 L/day of ultrafiltrate produced; only 1–2 L of urine excreted/24 hours Minimum of 400 ml/day urine necessary to excrete metabolic wastes (________________ _________________) •Return of filtered molecules is called _______________ K. Loop of _________ 1. ______________ 2. ______________ permeable Impermeable to H20; permeable to ___ to ___, salt Fig 17.17 L. Collecting Duct (CD) Plays important role in _____ ________________ Is impermeable to salt in medulla Permeability to H20 depends on levels of _____ __________ Post pituitary ___________ ___________ Water drawn out of ___________ M. Renal Clearance Refers to ability of kidney to remove substances from _______ & excrete them in ________ Occurs by filtration & by ___________ Many drugs, toxins, & metabolites are secreted by organic anion transporters of the PCT Thus 40-60% of filtered urea is always ___________ Fig 17.22 Only ______ of blood is filtered N. Glucose & Amino Acid Reabsorption glucose & amino acids are _____________________ Occurs in ____ ______________- presence of glucose in urine Occurs in ______________when exceed renal plasma threshold (> 180-200mg/100ml plasma) _________________ occurs when hyperglycemia results in _________________ O. Hormonal Effects 1. ________________ • 90% filtered Na+ & K+ reabsorbed ______________ • 80% of remaining Na+ is reabsorbed in DCT & cortical CD controls K+ secretion & ___ ____________ only way K+ ends up in urine •Control of plasma Na+ is important in regulation of _________________________ •Control of plasma of K+ important in proper function of cardiac & skeletal muscles ____________________________ (JGA) – Activates alderosterone secretion Located near Glomerulus • Senses ___________________ Fig 17.26 _______________________________ System Regulates _____ in blood Fig 17.27 O. Hormonal Effects (cont.) 2. ____________________________ (ANP) Is produced by atria due to stretching of walls Acts opposite to ____________________ Stimulates salt & H20 excretion Acts as an endogenous _________________ P. Na+, K+, & H+ Relationship Na+ reabsorption creates electrical gradient for _____________ secretion High extracellular H+ = H+ moves into cells causing K+ to diffuse out & vice versa ______________ can cause acidosis In severe acidosis, H+ is secreted at _________________ Insert fig. 17.27 Fig 17.28 Q. Renal Acid-Base Regulation help regulate blood pH by excreting H+ &/or reabsorbing HC03 Normal urine is _______________ (pH = 5-7) because kidneys reabsorb almost all HC03- & excrete H+ Kidneys R. Urinary Buffers Nephron cannot produce urine with pH < 4.5 Excretes more H+ by buffering H+s with HPO4-2 or NH3 before excretion Buffering reactions HPO4-2 + H+ H2PO4 NH3 + H+ NH4+ (ammonium ion) S. Clinical Aspects ____________ used to _________ blood volume due to ___________, congestive heart failure, or edema Increase volume of ________ by increasing proportion of glomerular filtrate that is excreted _______________ ____ ________ prevent H20 reabsorption in PCT when HC0s- is reabsorbed _____________ inhibit NaCl reabsorption in 1st part of DCT ____________ are most powerful; inhibit AT salt in thick ascending limb of LH ____________ increase osmotic pressure of filtrate Fig 17.30 T. Kidney Diseases 1. _____________________- kidneys fail to excrete wastes & regulate blood volume, pH blood creatinine rises Can result from atherosclerosis, inflammation of tubules, kidney ischemia, or overuse of NSAIDs 2. _________________________ - inflammation of glomeruli •Autoimmune attack glomerular capillary basement membranes •Causes leakage of protein into urine resulting 3. _________________________- nephrons have been destroyed as a result of a ____________ Observe salt & H20 retention & ___________ high plasma H+ & K+ can cause uremic coma Treatment includes ______________ Patient's blood is passed through a dialysis machine which separates molecules on basis of ability to diffuse through _______________ _______________________ Urea & other wastes are removed