THE URINARY SYSTEM kidneys and nephron structure and

THE URINARY SYSTEM kidneys and nephron- structure and fx Pages 511 -516

THE URINARY SYSTEM URINE for a great time today!!!

© 2015 Pearson Education, Inc. FUNCTIONS OF THE URINARY SYSTEM Elimination include: of waste products which Nitrogenous wastes Toxins Drugs Regulation as: Water, of homeostatic factors such acid/base, electrolyte balance BP RBC mfr Vitamin D activation

© 2015 Pearson Education, Inc. ORGANS OF THE URINARY SYSTEM Kidneys (contain the nephron) Ureters Urinary Urethra bladder

FIGURE 15. 1 A ORGANS OF THE URINARY SYSTEM. Hepatic veins (cut) Inferior vena cava Adrenal gland Aorta Iliac crest Renal artery Renal hilum Renal vein Kidney Ureter Rectum (cut) Uterus (part of female reproductive system) (a) Urinary bladder Urethra

© 2015 Pearson Education, Inc. KIDNEYS Location and structure against the dorsal body wall at the level of the T 12 to L 3 vertebrae right kidney is slightly lower than the left It is crowded by the liver renal hilum medial indentation where structures enter or exit the kidney (ureters, renal blood vessels, and nerves) An adrenal gland sits atop each kidney

FIGURE 15. 1 B ORGANS OF THE URINARY SYSTEM. 12 th rib (b)

© 2015 Pearson Education, Inc. KIDNEYS Protective tissue structures: (from deep to superficial) Enclosed by a fibrous connective tissue capsule Lies directly on the kidney Protects from infection Perirenal fat capsule surrounds the kidney and cushions against blows Renal fascia is the outermost capsule anchors the kidney and adrenal gland to surroundings Pararenal fat capsule surrounds renal fascia

© 2015 Pearson Education, Inc. KIDNEYS Three kidney regions 1. 2. Renal cortex—outer region Renal medulla—deeper region Renal (medullary) pyramids—triangular regions of tissue Renal columns—extensions of cortex-like material 3. Renal pelvis—medial region; flat, funnel-shaped tube Calyces—extensions of the renal pelvis separate the pyramids enclose the renal pyramids collect urine and send it to the renal pelvis>ureter>urinary bladder Nephrons comprise the bulk of cortex and medulla and are made of specialized endothelial and/or epithelial tissues

FIGURE 15. 2 A INTERNAL ANATOMY OF THE KIDNEY. Longitudinal section of the right kidney Renal cortex Renal column Major calyx Minor calyx Renal pyramid (a)

FIGURE 15. 2 B INTERNAL ANATOMY OF THE KIDNEY. Renal cortex Cortical radiate vein Cortical radiate artery Arcuate vein Arcuate artery Renal column Interlobar vein Interlobar artery Segmental arteries Minor calyx Renal pyramid Fibrous capsule (b) Renal vein Renal artery Renal pelvis Major calyx Ureter

© 2015 Pearson Education, Inc. BLOOD SUPPLY One-quarter of the total blood supply of the body passes through the kidneys each minute The abdominal aorta supplies the renal artery Renal artery provides each kidney with arterial blood supply Renal artery divides into smaller vessels Renal vein Smaller vessels get bigger to supply renal vein Renal vein returns blood to the inferior vena cava

FIGURE 15. 2 B INTERNAL ANATOMY OF THE KIDNEY. Renal cortex Cortical radiate vein Cortical radiate artery Arcuate vein Arcuate artery Renal column Interlobar vein Interlobar artery Segmental arteries Minor calyx Renal pyramid Fibrous capsule (b) Renal vein Renal artery Renal pelvis Major calyx Ureter

© 2015 Pearson Education, Inc. NEPHRONS – structural & functional unit of the kidney Responsible Two 1. main structures of a nephron: Renal corpuscle – includes: 1. 2. forming urine glomerulus, Bowman’s capsule, podocytes Renal tubule – includes: 1. 2. 3. proximal convoluted tubule Loop of Henle distal convoluted tubule

FIGURE 15. 3 A STRUCTURE OF THE NEPHRON. Cortical nephron Collecting duct Renal cortex Renal medulla Renal pelvis Fibrous capsule Proximal convoluted tubule Glomerulus Renal cortex Distal convoluted tubule Ureter Nephron loop Renal medulla (a) Juxtamedullary nephron

© 2015 Pearson Education, Inc. NEPHRONS 2 locations for nephrons: Cortical nephrons Located entirely in the cortex Include most nephrons Juxtamedullary Found nephrons at the boundary of the cortex and medulla Nephron loop dips deep into the medulla

FIGURE 15. 3 A STRUCTURE OF THE NEPHRON. Cortical nephron Collecting duct Renal cortex Renal medulla Renal pelvis Fibrous capsule Proximal convoluted tubule Glomerulus Renal cortex Distal convoluted tubule Ureter Nephron loop Renal medulla (a) Juxtamedullary nephron

© 2015 Pearson Education, Inc. NEPHRONS Each 1. Glomerulus 1. 2. nephron has two capillary beds: fed and drained by the afferent/efferent arterioles High pressure - for filtration Peritubular capillaries 1. 2. Drains the glomerulus Low pressure and porous - for absorption

FIGURE 15. 3 C STRUCTURE OF THE NEPHRON. PCT Glomerular capsular space Glomerular capillary covered by podocytes Efferent arteriole Afferent arteriole (c)

FIGURE 15. 3 D STRUCTURE OF THE NEPHRON. Filtration slits Podocyte cell body Foot processes (d)

FIGURE 15. 3 B STRUCTURE OF THE NEPHRON. Peritubular capillaries Proximal convoluted tubule (PCT) Glomerular capillaries Distal convoluted tubule (DCT) Glomerular (Bowman’s) capsule Efferent arteriole Afferent arteriole Cells of the juxtaglomerular apparatus Cortical radiate artery Arcuate Cortical radiate vein Collecting duct (b) Nephron loop