Urinary System PDF

LECTURE 8 The Urinary System Functions Macro + Microscopic Anatomy Kidneys Bladder Functions of the Urinary System 1. Regulates plasma ion concentrations (Na+, K+, Cl-) 2. regulates blood volume and blood pressure 3. Helps to stabilize blood pH 4. Prevents the loss of...

LECTURE 8 The Urinary System Functions Macro + Microscopic Anatomy Kidneys Bladder Functions of the Urinary System 1. Regulates plasma ion concentrations (Na+, K+, Cl-) 2. regulates blood volume and blood pressure 3. Helps to stabilize blood pH 4. Prevents the loss of valuable nutrients 5. eliminates organic matter/waste ( urea) 6. Synthesizes calcitriol (active form of vitamin D) 7. Prevents dehydration 8. Aids the liver with some of its functions (detoxifying poisons) Components of the Urinary System Suprarenal gland Kidney Renal artery Produces urine and vein Ureter Transports urine toward Inferior the urinary bladder vena cava Urinary Bladder Aorta Temporarily stores urine prior to elimination Urethra Conducts urine to exterior; in males, transports semen Figure 26.1 as well  The Kidneys The Right Kidney = L.H.D sounds like a drug? – Covered by the liver, hepative flexure and the duodenum The Left Kidney = L for lifted – Covered by the spleen, stomach, pancreas = season shrimp please – positioned higher than the right kidney Both capped with the suprarenal glands positioned higher than the right kidney because of the liver the kidneys wear hats called adrenal  Diaphragm Left suprarenal gland Inferior vena cava Left kidney Right suprarenal Left renal artery gland Left renal vein Right kidney Hilum Left ureter Abdominal aorta Left common iliac artery Rectum (cut) Urinary bladder renal artery is on top of the renal vein a found in the lab Diagrammatic anterior view of the abdominopelvic cavity showing the kidneys, suprarenal glands, ureters, urinary bladder, and blood supply to the kidneys Figure 26.3a  Inferior Aorta vena cava Stomach Parietal peritoneum Renal artery Pancreas and vein Ureter Spleen Left kidney Vertebra Connective Tissue Layers Protecting the Kidneys fibrous capsule perirenal fat renal fascia paranenal fat this order is from Pararenal Adipose Spinal innermost to outermost fat tissue cord feathers peter really petah ?  The Kidney Sectional anatomy Blood supply Nephron……..functional unit of the kidney  plastic and human model to identify Sectional Anatomy of the Kidney Cortex Inner layer of Medulla fibrous capsule Renal pyramid Renal sinus Connection to minor calyx Renal pelvis Minor calyx Major calyx Hilum Renal lobe Renal papilia area around the pyramid the nipple Renal columns triangle is the renal pyramid lobes are the sections inbetween the renal pyramid Ureter Outer layer of point of the pyramid is called the fibrous capsule renal papilia minor calyx is the small opening Figure 26.4a  Sectional Anatomy of the Kidney Cortex Outer layer of fibrous capsule Medulla Renal pyramids Renal sinus Hilum Renal pelvis Ureter Major calyx Minor calyx Renal columns Renal papilla Renal lobe Outer layer of fibrous capsule Figure 26.4a  Structure of the Kidney collective cups Fig. 26-for 4 the kidney  Blood Supply to the Kidneys lab model 6. Cortical radiate veins 5. Cortical radiate arteries 3. Interlobar arteries 2. Segmental artery 1. Renal artery 9. Renal vein 7. Arcuate 8. Interlobar veins artery order veins really scary intelligent artist causes 4. Arcuate vein order arteries Fig. 26.5 causes actual injuries really  Circulation in the renal cortex Cortical radiate vein Glomerulus Afferent arterioles Cortical radiate artery Cortical Arcuate artery nephron Arcuate vein Renal Juxtamedullary pyramid nephron Interlobar vein Interlobar artery Fig. 26.5 Minor calyx  RENAL print BLOOD SUPPLY SUMMARY of and try to follow the pathway of blood Cortical radiate veins Fig. 26- 5 Fig. 26.5  The Nephron: Structure & Function tubular head Fig. 26.7  The Nephron glomerlum: intertwining capillaries Basic structural and functional unit of the kidney Renal tubule: long tubular passageway Main functions of the nephron: 1. reabsorbs useful organic materials from the filtrate Urine processing 2. Reabsorbs more than 80% of the water from the filtrate Prevents dehydration 3. secretes waste into the filtrate that was missed in an earlier process Urine processing mostly reabsorption and double checking for missed waste  The Nephron compare and contrast Two main types of nephrons 1. Cortical nephrons majority – 85% of the nephrons are cortical (located in the cortex) – have a relative short nephron loop 2. Juxtamedullary nephrons – 15% of the nephrons are juxtamedullary – capsule is located near the border of the cortex and the medullla – have a long nephron loop Named based on their location where they are found , cortical is a short word compared to juxtamedullary , this relates to the length of the nephron. Cortical is at the top to indicate that it is the majority  Cortical nephron Juxtamedullary nephron Proximal convoluted tubule Renal corpuscle Distal convoluted tubule Cortex Connecting tubules in the cortex you have the tubule Thin descending limb Nephron loop Thick ascending Medulla limb in the medulla you have ducts Collecting duct Papillary duct Renal papilla Minor calyx Figure 26.8a  The Nephron: Structure & Function Fig. 26.7  The Renal Corpuscle ~200um in diameter, Produces a protein free-solution: glomerular filtrate 1. Glomerular capsule Parietal layer: epithelial cells that are continuous with the lining of the proximal convoluted tubule, folds back to form the visceral layer Visceral layer: makes up the epithelial lining of the capillaries and podocytes cells that wrap around the capillaries of the glomerulus 2. Glomerular Capillaries (glomerulus) made out of capillaries  The Renal Corpuscle Vascular pole Glomerular Glomerulus Capsule Parietal epithelium Efferent arteriole Capsular space (empty) Visceral epithelium Juxtaglomerular (podocytes) Complex Macula densa Proximal convoluted Extraglomerular tubule mesangial cells Juxtaglomerular cells Tubular pole Glomerular capillary Distal convoluted Afferent arteriole tubule Fig 26.9  The Renal Corpuscle - Filtrations Filtration occurs as blood pressure forces fluid and dissolved solutes out of the glomerulus and into the capsular space. Filtration within the renal corpuscle involves three layers: 1. Capillary endothelium 2. Basal lamina 3. Glomerular epithelium  Filtrations in the Renal Corpuscle 1. Capillary endothelium the glomerular capillaries are fenestrated Too small for blood cells to pass through 2. Basal lamina surronds the capillary endothelium restricts the passage of large proteins but permits smaller proteins permits the passage of ions and nutrients  Filtration in the renal corpuscle 3. Glomerular epithelium consists of special cells called podyctes Podocytes have long cellular extensions, wrap around the basal lamina these extenxisons have gaps called filteration slits Filtrate passing through consists of water / ions / small organic molecules (glucose / fatty acids / amino acids / vitamins), very few plasma proteins any potential useful productes are reabsored THE FILTRATION STRUCTURES Basal Lamina  Filtration Apparatus Nucleus of podocyte Podocyte Pores Mesangial cell Capillary endothelial cell Filtration Membrane Capillary endothelium (blocks passage of blood cells) RBC Basal lamina (blocks passage of large plasma proteins) Secondary Filtration silts between secondary processes processes of podocytes (blocks Capsular space containing passage of almost all plasma proteins) glomerular filtrate (yellow) Parietal epithelium Figure 26.9  The Renal Corpuscle Efferent arteriole Vascular pole Glomerulus Juxtaglomerular Glomerular Capsule Parietal epithelium Complex Capsular space (empty) Visceral epithelium (podocytes) Macula densa production of Na and Cl Proximal convoluted tubule Extraglomerular Tubular pole mesangial cells provides structure for the area Glomerular capillary Juxtaglomerular cells secretion of hormones Distal Afferent convoluted arteriole tubule Fig 26.9  The Juxtaglomerular Complex 1. Macula densa cells: monitor electrolyte concentration (Na & Cl) 2. Juxtaglomerular cells: secretes hormones 3. Mesangial cells: provides physical support for the arteries Produces two hormones produced by the juxtaglomerular cells 1. Renin: involved in regulating blood pressure 2. Erythropoietin: involved in erythrocyte production - Erythropoietin (EPO) is a hormone made by the kidneys in response to low oxygen levels in the blood - r for regulating  Macula Densa & Juxtaglomerula If Low blood pressure/flow, or oxygen or [Na+ / Cl-] Secrete RENIN (angiotensin system)  increase BP (contract smooth muscle)/ (aldosterone secretion) Secretion of erythropoeitin  stimulates increased hemoglobin levels (oxygen)  The Nephron: Structure & Function Renal tubule Efferent arteriole Afferent arteriole Descending Ascending limb of limb of loop begins loop ends Ascending limb Descending limb Capillaries of glomerulus Fig. 26.7  The Proximal Convoluted Tubule Reabsorbs: All of the organic nutrients Plasma proteins 60% of the sodium and chloride ions and water Calcium / Potassium / Magnesium / Bicarbonate / Phosphate / Sulfate ions i guess a trick is that the proximal has an “o” to indicate the organic nutrients present, has microvilli indicates that is has absorption  microvilli increases the surface area for reabsorption proximal vs distal tubule difference is the reaborption of organic maters vs the rabsorption of ions Fig. 26- 7  The Nephron Loop Descending portion Water leaves this portion and enters the bloodstream (preventing dehydration) capillaries surrounding the nephron loop are called vasa recta Ascending portion Pumps ions (sodium ions and chloride ions) out of the thick ascending loop preventing the loss of these ions Thin ascending not permeable to water - d for dehydration - ascending pumps ion its like the distal that reabsorption of ions  The Distal Convoluted Tubule active secretion of ions and acids Selective reabsorption of sodium and calcium ions reabsorption of water lacks microvilli smaller compared to the proximal *Juxtaglomerular Complex  The Collecting System The filtrate that enters the DCT of various nephrons empties into a common tube called the collecting duct collecting duct passes through the renal pyramids Filtrate then enters the: Papillary duct / Minor calyx / Major calyx Filtrate leaves the kidneys: Ureter / Urinary bladder / Urethra then excretion  NEPHRON COLLECTING SYSTEM DISTAL CONVOLUTED TUBULE PROXIMAL CONVOLUTED TUBULE Secretion of ions, acids, drugs, toxins Microvilli Connecting tubules Renal tubule Collecting duct Efferent arteriole CONNECTING TUBULES AND COLLECTING DUCT Afferent arteriole RENAL CORPUSCLE Descending Ascending limb of limb of loop begins loop ends Ascending Descending limb limb PAPILLARY DUCT NEPHRON LOOP Delivery of urine to Thin Minor minor calyx descending calyx limb Thick ascending limb Fig 26.7 The Collecting System Connecting tubules Collecting duct CONNECTING TUBULES AND COLLECTING DUCT Consists of: Connecting tubules transportation Collecting ducts Papillary ducts PAPILLARY DUCT Delivery of highlight and identify them urine to Minor calyx minor calyx dcts of several nephrons drain into collecting ducts - final adjustments to the concentration of the urine that is about to exit the kidneys Fig 26.7 NEPHRON VASCULARIZATION capillaries that wrap aroun proximal convoluted Fig. 26- 8  Structures for Urine Transport, Storage, & Elimination muslcar layer- longitudinal and circular layer of smooth muscle -every 30 sec peristallic contracctions milk urine throigh ureters  Structures for Urine Transport, Storage, & Elimination The Ureters exist the kidney at the hilum Extend to the urinary bladder Enter the urinary bladder on the posterior/inferior side the ureteral opening enter the urinary bladder in the trigone area, spilts helps to prevent backflow  Median umbilical 3 muscular layers ligament (urachus) Ureter Lateral umbilical ligament Detrusor muscle Rugae Trigone this is the slipt Ureteral Center of openings trigone Neck of Internal urethral urinary sphincter bladder Prostate Prostatic gland urethra External urethral Membranous sphincter (in urogenital urethra diaphragm) Fig 26.11  Structures for Urine Transport, Storage, and Elimination The Urinary Bladder – Males the base of the urinary bladder is between the rectum and the symphysis pubis – Females the base of the urinary bladder is inferior to the uterus and anterier to the vagina  Left Peritoneum ureter Rectum Urinary bladder Pubic symphysis Prostate gland External urethral sphincter Spongy urethra External urethral orifice Urethra Urogenital [see part c] diaphragm Fig 26. 11  Rectum Right ureter Uterus Peritoneum Urinary bladder Internal urethral sphincter Pubic symphysis Urethra External urethral sphincter (in urogenital diaphragm) Vagina Vestibule Fig 26. 11  Structures for Urine Transport, Storage, and Elimination The Urethra – Female 3 to 5 cm in length The external urethral orifice is near the anterior wall of the vagina  Structures for Urine Transport, Storage, and Elimination The Urethra – Male 18 to 20 cm in length Subdivided to form the prostatic urethra, membranous urethra, and spongy urethra Prostatic urethra – passes through the prostate gland Membranous urethra – short segments that goes throgh the irogenital diagraphm Spongy urethra (penile urethra) – extends throgh the penis to the external urethral orifice  Structures for Urine Transport, Storage, and Elimination The Urethra – As the urethra passes through the urogenital diaphragm there is a skeletal muscle that makes up the external urethral sphincter This is under voluntary control – this is the sphincter we learned to control as an infant We lose control as we age We lose control due to some spinal cord injuries  Median umbilical ligament (urachus) Ureter Lateral umbilical ligament Detrusor muscle Rugae Trigone Ureteral Center of openings trigone Neck of Internal urethral urinary sphincter bladder Prostate Prostatic gland urethra External urethral Membranous sphincter (in urogenital urethra diaphragm) Fig 26.11  struture difference in male and female Rectum Right ureter Uterus Peritoneum Urinary bladder Internal urethral sphincter Pubic symphysis Urethra External urethral sphincter (in urogenital diaphragm) Vagina Vestibule Fig 26. 11 Questions?