Renal System

Front 1

Major Urinary System Functions

Back 1

Water + ion balance*, excretion of metabolic wastes + foreign substances, hormone production, ECF volume, osmolarity, acid-base balance

Front 2

Urinary System Components

Back 2

Kidneys, ureters, bladder, urethra

Front 3

Retroperitoneal Cavity

Back 3

Between abdominal peritoneum and back bones + muscles

Front 4

Kidney Layers

Back 4

Outer cortex, inner medula, renal pelvis (upper end of ureter)

Front 5

Nephron Portal System

Back 5

Blood from renal arteries flows into afferent arterioles + enters glomerular capps. Leaves out efferent arterioles into peritubular capps in juxtamedullary nephrons + exits thru renal vein.

Front 6

Nephron Anatomy

Back 6

Renal corpuscle (glomerulus + Bowman's capsule), proximal tubule, loop of Henle, distal tubule + collecting duct.

Front 7

Kidney Functions

Back 7

Filtration, reabsorption, secretion.

Front 8

Filtration driven by...

Back 8

Hydrostatic pressure, colloid osmotic pressure, and fluid pressure.

Front 9

Filtration Fraction

Back 9

% total plasma volume that filters into tubule

Front 10

Renal Corpuscle Filtration Barriers

Back 10

Capillary endothelium (fenestrated capillaries), basal lamina (course sieve), Bowman's capsule epithelium (filtrations slits)

Front 11

Glomerular Filtration Rate

Back 11

Volume that filters into Bowman's capsule per unit time

Front 12

GFR Regulation

Back 12

Net filtration pressure, filtration coefficient, total SA available

Front 13

GFR Influences

Back 13

Hydrostatic pressure (pos.); colloid osmotic pressure (neg.) and fluid pressure created in Bowman's (neg.)

Front 14

GFR Arteriole Resistance

Back 14

Afferent resistance (site of most reg.) dec. hydrostatic pressure + GFR; efferent resistance inc. glomerular pressure + GFR

Front 15

Autoregulation

Back 15

Maintains constant GFR thru myogenic response, tubuloglomerular feedback, and hormones

Front 16

Myogenic Response

Back 16

Inc. blood pressure stretches artery smooth muscle to vasoconstrict. Dec. blood pressure results in maximal vasodilation

Front 17

Tubuloglomerular Feedback

Back 17

Paracrine signaling mechanisms thru which loop of Henle influences GFR: macula densa senses [Na+] while granular cells secrete renin

Front 18

Hormone Autoregulation

Back 18

Sympathetic neurons innervate alpha-receptors to induce vasoconstriction; angiotensin II vasoconstricts; prostaglandins vasodilate

Front 19

Reabsorption Routes

Back 19

Transepithelial transport, paracellular pathway, urea (passive), or plasma proteins (via transcytosis)

Front 20

Reabsorption of Solutes + Water

Back 20

Na+ transport creates electrochemical gradient, drives anion reabsorption, water osmotically follows solutes, dilutes lumen, solutes diffuse into ECF

Front 21

Na+-linked Glucose Reabsorption

Back 21

Apical Na+-glucose cotransporter (SGLT, active), basolateral glucose transporter (GLUT)

Front 22

Saturation

Back 22

Max. rate of transport occurs when all available carriers occupied by substrate

Front 23

Filtration, Reabsorption, Excretion Relationship

Back 23

When no secretion occurs, amt. excreted = amt. filtered - amt. reabsorbed; normal conditions, filtration=reabsorption; renal threshold, filtration > reabsorption & excretion begins

Front 24

Secretion

Back 24

Active transport of molecules from ECF into neph. lumen. Enhances neph. excretion. Competitive process (ex. penicillin + probenicid)

Front 25

Excretion

Back 25

Filtration - reabsorption + secretion

Front 26

Clearance

Back 26

Rate @ which solute leaves the body, by excretion or metabolism

Front 27

Inulin

Back 27

Admin. by continuous IV infusion, 100% excreted, so clearance = GFR

Front 28

Creatinine

Back 28

Endogenous, in muscles via PCr breakdown, 99% excreted, but need not be admin.