Ch. 23 Urinary System

Front 1

Urinary System :

Back 1

1. Kidney Anatomy
-external layers, internal layers, blood flow, individual units=nephrons

2. Urine formation
A.Filtration
-squeeze blood into nephrons (squeezing something through coffee filter)
-bloodnephronfiltrate
-regulate flow +systemic BP
B. Reabsorption
-filtrateback into blood
-NOT in urine
-reabsorb water and electrolytes
-Secretion
-actively secrete from blood filtrate in urine
-nitrogenous wastes
-drugs, toxins
D. Water conservation
-can make a large volume of low concentration
-can make a small volume of high concentration
-varies with hormones hydration

Front 2

Urinary System part 2:

Back 2

Metabolism produces wastes
-toxic if allowed to accumulate in tissues and blood

Nitrogenous wastes
-Urea:
NH2 produced during protein synthesis
Liver converts to urea, starts as ammonia
Uric acid:
Produced during nucleic acid synthesis(replicating DNA, and making mRNA)




Kidneys remove these wastes via urine production

Front 3

kidney functions:

Back 3

Filter plasma

Regulate blood volume, pressure and osmolarity
Regulate electrolyte and acid-base balance

Secrete erythropoietin

Clear hormones and drugs from body

Front 4

urinary system anatomy:

Back 4

Kidneys filter blood and
produce urine

-each kidney drained by one ureter, end in urinary bladder where urine is stored
Leaves body through urethra
Bean shaped

Right is slightly lower-croweded by liver

Size=bar of soap

Partially protected by the 12th pair of ribs

Front 5

kidney:external anatomy:

Back 5

Renal fascia
-Function-=anchor

2. Perirenal fat capsule
functions=cushion
3. Fibrous capsule
function= protection from infection, “syran wrap” around kidney

Front 6

kidney: inner anatomy:

Back 6

Inner Anatomy
Outer cortex
-highly vascularized
-majority of nephrons

2. Inner medulla
-same nephrons
-renal pyramids
-striped appearance
-due to collecting ducts
3. Renal Pelvis
-collecting ducts empty into renal pelvis
-remove urine into ureter

Front 7

Renal blood flow:

Back 7

Kidneys receive 1.2 liters of blood per minute
Receive 21% of total cardiac output

Blood flow
-Aorta-->renal artery=enters kidney
-Afferent arteriole-->glomerulus-->efferent arteriole-->peritubular capillaries
-leaves kidney=renal vein-->inferior vena cava

Front 8

urine production:

Back 8

Functional unit =nephron
Function =filter blood and produce urine

- Several nephrons empty into one collecting duct
- Thousands of collecting ducts empty into renal pelvis
- Urine carried through ureters to bladder for storage
- Emptied from body through urethra

Front 9

Nephron structure:

Back 9

Renal corpuscle
-glomerulus-specialized capillary, where filtration occurs, area of blood being squeezed into nephron
-glomerular capsule-end of nephron where the filtrate is collected.
-2 layers, visceral (around/clinging to glomerulus, also where filtration occurs) and out parietal (no interaction with glomerulus, provides structure and support)
2. Renal tubule
-proximal convoluted tubule (PCT)
-loop of henle
2 parts:
-descending limb(comes first)
-ascending limb
-distal convoluted tubule
-collecting duct
3. Renal pelvis

Front 10

Nephron types:

Back 10

Cortical:
-85% of all nephrons
-loop of henle in cortex only
Juxtamedullary:
-15% of all nephron
-longer loop of henle dips into medulla
-produce concentrated urine