Urinary System Review Questions:

Transcription

1 Urinary System Review Questions: 1. This system would be lined with what type of membrane? 2. What type of epithelial tissue would line the opening of the urethra (the exit of the tract)? 3. What type of epithelial tissue would line the majority of the tract? 4. What type of muscle would line the walls of this tract? 5. What parasympathetic nerve would supply the urinary system? Hint: We re below the hips!

2 Functions Influences blood pressure (Renin) Controls ph Removes excesses Activates Vitamin D

3 Peritoneum Renal vein Renal artery Body of vertebra L 2 Body wall (a) Anterior Peritoneal cavity (organs removed) Posterior Inferior vena cava Aorta Supportive tissue layers Renal fascia anterior posterior Perirenal fat capsule Fibrous (True) capsule T12 L3 Adrenal gland Hilum 12th rib (b) 962

4 filtering Renal cortex Salt, collecting ducts Renal medulla Major calyx Renal hilum Papilla of pyramid Renal pelvis Minor calyx Ureter Renal pyramid in renal medulla Renal column Fibrous capsule (b) Diagrammatic view 963

5 Cortical radiate vein (Interlobular) Cortical radiate artery(interlobular) Arcuate vein Arcuate artery Interlobar vein Interlobar artery Segmental arteries Renal vein Renal artery Renal pelvis Ureter Renal medulla Renal cortex (a) Frontal section illustrating major blood vessels 964

6 Aorta Renal artery Segmental artery Inferior vena cava Renal vein Interlobar vein Interlobar artery Arcuate artery Cortical radiate artery Interlobular Afferent arteriole Arcuate vein Cortical radiate vein Peritubular capillaries and vasa recta Efferent arteriole Interlobular Glomerulus (capillaries) Nephron associated blood vessels (see Figure 25.7) (b) Path of blood flow through renal blood vessels 964

7 Cortical nephron Juxtamedullary nephron Renal corpuscle Kidney Glomerular capillaries (glomerulus) Glomerular (Bowman s) capsule Proximal convoluted tubule Peritubular capillaries Ascending or thick limb of the loop of Henle Cortex Medulla Renal pelvis Ureter Efferent arteriole Arcuate vein Arcuate artery Loop of Henle Descending or thin limb of loop of Henle Cortical radiate vein Cortical radiate artery Afferent arteriole Collecting duct Distal convoluted tubule Afferent arteriole Efferent arteriole Corticomedullary junction Vasa recta (a) 967

8 The Nephron Glomerular capsule: parietal layer Renal cortex Renal medulla Renal pelvis Kidney Renal corpuscle Glomerular capsule Glomerulus Ureter Distal convoluted tubule Basement membrane Fenestrated endothelium of the glomerulus Glomerular capsule: visceral layer Microvilli Podocyte Mitochondria Proximal convoluted tubule Cortex Highly infolded plasma membrane Proximal convoluted tubule cells absorption Medulla Thick segment Thin segment Loop of Henle Descending limb Ascending limb Collecting duct Distal convoluted tubule cells Loop of Henle (thin-segment) cells Principal cell Intercalated cell Collecting duct cells 965

9 Renal corpuscle Efferent arteriole Glomerular capsular space Afferent arteriole Glomerular capillary covered by podocytecontaining visceral layer of glomerular (Bowman s) capsule filtrate Parietal layer of glomerular Capsule (Bowman s) Proximal convoluted tubule Podocyte cell body Cytoplasmic extensions of podocytes Filtration slits (a) Glomerular capillaries and the visceral layer of the glomerular capsule Fenestrations (pores) Glomerular capillary endothelium (podocyte covering and basement membrane removed) Foot processes of podocyte 970

10 DCT Efferent arteriole Afferent arteriole Glomerular capsule Glomerulus Efferent arteriole Parietal layer of glomerular capsule Capsular space Foot processes of podocytes Podocyte cell body (visceral layer) Red blood cell Proximal tubule cell Juxtaglomerular apparatus Macula densa cells of the ascending limb of loop of Henle Extraglomerular mesangial cells Granular cells Afferent arteriole Juxtaglomerular apparatus Renal corpuscle Lumens of glomerular capillaries Endothelial cell of glomerular capillary Mesangial cells between capillaries 968

11 Hepatic veins (cut) Esophagus (cut) Inferior vena cava Adrenal gland Aorta Iliac crest Fibrous CT Smooth muscle circular longitudinal Transitional Ep. Renal artery Renal hilum Renal vein Kidney Ureter Retroperitoneal Rectum (cut) Uterus (part of female reproductive system) Urinary bladder Urethra 961

12 Below Peritoneum (Holding Chamber) Peritoneum Ureter Rugae Transitional Ep. Detrusor muscle 3 layers Adventitia Ureteric orifices Trigone of bladder Bladder neck Internal urethral sphincter Prostate Prostatic urethra Urogenital diaphragm External urethral sphincter Membranous urethra Micturation Reflex (para.) Mucous membrane & Submucosa Spongy urethra Erectile tissue of penis External urethral orifice (a) Male. The long male urethra has three regions: prostatic, membranous and spongy. 987

13 Peritoneum Ureter Rugae Detrusor muscle Ureteric orifices Bladder neck Internal urethral sphincter External urethral sphincter Urogenital diaphragm (b) Female. Cystitis Trigone Urethra layers mucosa spongy sm. muscle External urethral orifice

14 Afferent arteriole Glomerular capillaries Cortical radiate artery Efferent arteriole Glomerular capsule Rest of renal tubule containing filtrate Three major renal processes: Glomerular filtration Tubular reabsorption Tubular secretion Urine Peritubular capillary To cortical radiate vein 971

15 Sympathetic stim. Glomerular capsule Afferent arteriole Myogenic Autoregulation -increased stretch causes constriction -decreased stretch causes dilation Net Filtration Pressure NFP= (BHP-CHP)-BOP Glomerular filtration rate 10 mm Hg Net filtration pressure Glomerular (blood) hydrostatic pressure (HP g = 55 mm Hg) out Blood colloid osmotic pressure (Op g = 30 mm Hg) in Capsular hydrostatic pressure (HP c = 15 mm Hg) in 971

16 Efferent arteriole Glomerular capsule Glomerulus Afferent arteriole Efferent arteriole Parietal layer of glomerular capsule Capsular space Foot processes of podocytes Podocyte cell body (visceral layer) Red blood cell Proximal tubule cell Monitors NaCl in filtrate at DCT Juxtaglomerular apparatus Macula densa cells of the ascending limb of loop of Henle (DCT) Extraglomerular mesangial cells Granular cells (JG cells) High filtrate production= more NaCl Low filtrate production= less NaCl Afferent arteriole Juxtaglomerular apparatus Renal corpuscle Lumens of glomerular capillaries Endothelial cell of glomerular capillary Mesangial cells between capillaries 968

17 Macula Densa High Flow (high NaCl) Low Flow (low NaCl) JG (granular) cells vasoconstrictor to afferent arteriole Decreases BHP at glom. and filtrate production JG (granular) cells vasodilator to afferent arteriole Renin Increases BHP at glom. and increases filtrate production

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19 80% of reabsorption in PCT Filtrate in tubule lumen Na + Glucose Amino acids Some ions Vitamins H 2 O Lipid-soluble substances Cl, Ca 2+, K + and other ions, urea Primary active transport Secondary active transport Passive transport (diffusion) Nucleus obligatory Tubule cell Tight junction 3Na + 2K + 1 Interstitial fluid K + Cl Paracellular route Transport protein Ion channel or aquaporin 3Na + 2K + Renal Plasma Threshold Peritubular capillary 1 At the basolateral membrane, Na + is pumped into the interstitial space by the Na + -K + ATPase. Active Na + transport creates concentration gradients that drive: 2 Downhill Na + entry at the luminal membrane. 3 Reabsorption of organic nutrients and certain ions by cotransport at the luminal membrane. 4 Reabsorption of water by osmosis. Water reabsorption increases the concentration of the solutes that are left behind. These solutes can then be reabsorbed as they move down their concentration gradients: 5 Lipid-soluble substances diffuse by the transcellular route. 6 Cl (and other anions), K +, and urea diffuse by the paracellular route. 976

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21 Osmolality of interstitial fluid (mosm) Active transport Passive transport Water impermeable Filtrate entering the loop of Henle is isosmotic to both blood plasma and cortical interstitial fluid. H 2 O H 2 O H 2 O NaCI NaCI NaCI Cortex Obligatory reabsorption into vasa recta (peritubular capillaries) The descending limb: Permeable to H 2 O Impermeable to NaCl As filtrate flows, it becomes increasingly concentrated as H 2 O leaves the tubule by osmosis. The filtrate osmolality increases from 300 to 1200 mosm. H 2 O H 2 O H 2 O H 2 O Loop of Henle NaCI NaCI Outer medulla Inner medulla (a) Countercurrent multiplier. The long loops of Henle of the juxtamedullary nephrons create the medullary osmotic gradient. The ascending limb: Impermeable to H 2 O Permeable to NaCl Filtrate becomes increasingly dilute as NaCl leaves, eventually becoming hypo-osmotic to blood at 100 mosm in the cortex. NaCl leaving the ascending limb increases the osmolality of the medullary interstitial fluid. 980

22 Active transport Passive transport Descending limb of loop of Henle Cortex Collecting duct DCT H 2 O H 2 O Water channels inserted in collecting duct (facultative reabsorption) NaCI H 2 O H 2 O H 2 O Outer medulla H 2 O NaCI NaCI H 2 O Urea H 2 O Urea Caffeine & Alcohol Inner medulla H 2 O (b) Maximal ADH Small volume of concentrated urine 982

23 Tubular Secretion Na + (65%) Glucose Amino acids H 2 O (65%) and many ions (e.g. Cl and K + ) Milliosmols Cortex (a) (d) 300 (e) Outer medulla (b) (c) Some drugs Penicillin Histamine H +, NH 4 + HCO 3 Blood ph regulation 600 Inner medulla 1200 (a) Proximal convoluted tubule: 65% of filtrate volume reabsorbed Na +, glucose, amino acids, and other nutrients actively transported; H 2 O and many ions follow passively H + and NH 4+ secretion and HCO 3 reabsorption to maintain blood ph (see Chapter 26) Some drugs are secreted Active transport (primary or secondary) Passive transport 983

24 H 2 O regulated by ADH Milliosmols Cortex (a) (d) Regulated by aldosterone: Na + Blood ph regulation K + Urea; increased by ADH Outer medulla (b) (c) (e) H + HCO 3 Inner medulla NH (e) Collecting duct H 2 O reabsorption through aquaporins regulated by ADH Na + reabsorption and K + secretion regulated by aldosterone H + and HCO 3 reabsorption or secretion to maintain blood ph (see Chapter 26) Urea reabsorption increased by ADH Active transport (primary or secondary) Passive transport 983

25 ADH (Vasopressin) Osmolality Na + concentration in plasma Stimulates Plasma volume BP (10 15%) Osmoreceptors in hypothalamus Negative feedback inhibits Stimulates Baroreceptors in atrium and large vessels Inhibits Stimulates Posterior pituitary Releases ADH Diabetes Insipidus -Low ADH Antidiuretic hormone (ADH) Collecting ducts of kidneys Osmolality Plasma volume Targets Effects Water reabsorption Results in Scant urine Vasoconstriction Water channels 1000

26 Aldosterone K + (or Na + ) concentration in blood plasma* Renin-angiotensin mechanism Adrenal cortex Stimulates Negative feedback inhibits Aldosterone Releases Targets Kidney tubules Effects DCT and collecting ducts Na + reabsorption K + secretion Addison s Disease (low) Aldosteronism (High) Restores Homeostatic plasma levels of Na + and K

27 Hypocalcemia (low blood Ca 2+ ) stimulates parathyroid glands to release PTH. Rising Ca 2+ in blood inhibits PTH release. Bone 1 PTH activates osteoclasts: Ca 2+ and PO 4 3S released into blood. 2 PTH increases Kidney Ca 2+ reabsorption in kidney tubules. 3 PTH promotes kidney s activation of vitamin D, which increases Ca 2+ absorption from food. Intestine Ca 2+ ions PTH Molecules Bloodstream 614

28 proteins Fatty acids WBC s -bilirubin -hepatitis or cirrhosis

29 CSF Humors

30 variable Metabolism 10% Foods 30% 250 ml 750 ml 2500 ml 100 ml 200 ml 700 ml Feces 4% Sweat 8% Insensible losses via skin and lungs 28% Beverages 60% 1500 ml 1500 ml Urine 60% controlled Average intake Average output per day per day 2500 ml ml. 999

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