Urinary Anatomy Study Guide

Question 1

What are the major organs of the urinary system

Answer 1

kidneys, ureters, urinary bladder, urethra

Question 2

kidneys

Answer 2

major excretory organs, create urine

Question 3

Ureters

Answer 3

transport urine from kidneys to bladder

Question 4

Urinary bladder

Answer 4

temporarily stores urine

Question 5

Urethra

Answer 5

transports urine out of the body

Question 6

How do the kidneys maintain homeostasis

Answer 6

Regulate total water volume 1and solute concentration
Regulating ion concentrations in extracellular fluid
Ensuring long term acid base balance
Excreting metabolic wastes, toxins, drugs
Producing erythropoietin
Producing renin
Activating vitamin d
Carrying out gluconeogenesis (production of glucose)

Question 7

Renin

Answer 7

regulate blood pressure

Question 8

erythropoietin

Answer 8

regulate rbc function

Question 9

What structures enter/exit the renal hilum?

Answer 9

Ureters, blood vessels, lymphatics, nerves

Question 10

3 layers surrounding the kidney

Answer 10

renal fascia (superficial), perirenal fat capsule (middle), fibrous/renal capsule (deep)

Question 11

Renal ptosis

Answer 11

1 or both kidneys drop to a lower position
- Caused by loss of surrounding fatty tissue (emaciation/rapid weight loss)
- Can lead to kink in ureter and back up of urine into kidney

Question 12

Hydronephrosis

Answer 12

backup of urine into the kidney because of ureteral obstruction or infection (like UTI) – can cause kidney damage, tissue death, renal failure

Question 13

Pyelonephritis

Answer 13

inflammation or infection of the kidney, usually extensions of UTIs (can cause kidney to swell, abscesses form, and pelvis fills with pus)

Question 14

dialysis

Answer 14

Process of removing waste and extra fluid from the body when the kidneys are unable to

Question 15

order of urine flow from origination in the nephrons to exiting the body through the external urethral orifice.

Answer 15

Urine is created in the nephron and drains continuously through the renal papillae
Renal pyramid
Minor calyx
Major calyx
Renal pelvis
Ureter
bladder
urethra

Question 16

order of arterial blood flow into the kidney starting with the aorta.

Answer 16

Aorta → renal artery → segmental artery → interlobar artery → arcuate artery → cortical radiate (interlobular) artery

Question 17

Memorize the order to venous blood flow out of the kidney starting with the cortical radiate veins.

Answer 17

Cortical radiate (interlobular) veins → arcuate veins → interlobar veins → renal vein → IVC *no segmental veins

Question 18

function of a nephron

Answer 18

Structural and functional unit of the kidney, it forms urine
- Makes cell-free and protein-free filtrate from blood
- Chemicals are either added/subtracted from filtrate
- Filtrate is emptied into collecting ducts where it becomes urine

Question 19

What are the 2 parts of a renal corpuscle?

Answer 19

• Glomerulus: tuft of capillaries
• glomerular/bowman’s capsule: hollow structure that surrounds glomerulus and is continuous with renal tubule, has parietal and visceral layer, and filtrations slits (filtration slits: clefts/openings between foot processes. Filtrate passes through these slits and into the capsular space)

Question 20

type of endothelium that makes up the glomerulus

Answer 20

Fenestrated endothelium - highly porous, allowing efficient formation of filtrate

Question 21

podocytes

Answer 21

Branching epithelial cells in the visceral layer of the glomerular capsule. They terminate in foot processes. they function in protection of filtrate

Question 22

3 parts of the renal tubule

Answer 22

Proximal convoluted tube: closest to the renal corpuscle
Nephron loop: u-shaped, hairpin turn, has ascending and descending limbs Distal convoluted tube: furthest from the renal corpuscle, drains into collecting duct

Question 23

PCT structure

Answer 23

cuboidal cells with dense microvilli that form a brush border
- Increased surface area
- Large mitochondria

Question 24

Nephron loop structure

Answer 24

u shaped structure with two limbs

Question 25

DCT structure

Answer 25

cuboidal cells with very few microvilli

Question 26

PCT function

Answer 26

reabsorption of water + solutes and secretion of substances, confined to renal cortex

Question 27

DCT function

Answer 27

secretion, less absorption, confined to renal cortex

Question 28

Nephron loop function

Answer 28

- Descending limb: proximal part is continuous with PCT; distal part (descending thin limb) is simple squamous epithelium - Ascending limb: typically thicker, cuboidal and columnar cells, right side

Question 29

Collecting ducts

Answer 29

run side by side through medullary pyramids and receive filtrate from many different nephrons

Question 30

Fused collecting ducts

Answer 30

deliver urine through the renal papillae to the minor calyces

Question 31

two major types of cells within collecting ducts

Answer 31

Principal cells Intercalated cells

Question 32

Principal cells

Answer 32

more plentiful, sparse, short microvilli, maintain the body’s water/Na+ balance

Question 33

Intercalated cells

Answer 33

cuboidal cells with abundant microvilli, exist in types A and B – both help maintain the acid base balance of blood

Question 34

two classes of nephrons

Answer 34

cortical (85%) and juxtamedullary (15%)

Question 35

cortical nephrons

Answer 35

Almost entirely in the cortex Peritubular capillaries

Question 36

Juxtamedullary nephrons

Answer 36

Originate near the cortex - medulla junction Have long nephron loops that deeply invade the renal medulla Important for the production of concentrated urine Vasa recta

Question 37

Glomerulus

Answer 37

- Its capillaries are specialized for filtration - 99% of filtration will be absorbed - Glomerular Capillaries are fed and drained by arterioles - O2 is not dropped off

Question 38

afferent arterioles

Answer 38

enter the glomerulus Arises from the cortical radiate arteries

Question 39

Efferent arterioles

Answer 39

leave the glomerulus Feeds into the peritubular capillaries/vasa recta

Question 40

Peritubular capillaries

Answer 40

- Lower pressure, porous capillaries adapted for reabsorption of water solutes from the filtrate within the renal tubule - arise from efferent arterioles and cling to any adjacent renal tubules in the cortex - Empty into into venules → cortical radiate veins

Question 41

What keeps the pressure high within a glomerulus?

Answer 41

The afferent arteriole is larger than the efferent arteriole, so blood pressure in the glomerulus is high – increased filtration

Question 42

Memorize the order to venous blood flow out of the kidney starting with the cortical radiate veins.

Answer 42

Cortical radiate (interlobular) veins → arcuate veins → interlobar veins → renal vein → IVC *no segmental veins

Question 43

Where do the nephron’s glomerulus, peritubular capillary, and afferent + efferent arterioles fit into the pathway of blood flow that you memorized above?

Answer 43

(first five steps) → Cortical radiate arteries → afferent arteriole → glomerulus → efferent arteriole → peritubular capillaries → venules → cortical radiate veins → (next 4 steps)

Question 44

JGC

Answer 44

Juxtaglomerular complex, Found in each nephron, region where the most distal portion of the ascending limb of the nephron loop lies against the afferent arteriole feeding the glomerulus - Both structures are modified at the point of contact - Plays important role in regulating the rate of filtrate formation and systemic blood pressure

Question 45

3 cell populations of the JGC

Answer 45

macula densa, granular cells (juxtaglomerular cells), extraglomerular mesangial cells

Question 46

Macula densa

Answer 46

- Tall, closely packed cells in the ascending limb of the nephron loop - Chemoreceptors that sense the NaCl content of filtrate entering the DCT

Question 47

Granular cells (juxtaglomerular cells)

Answer 47

- enlarged smooth muscle cells in the afferent arteriole wall - Act as mechanoreceptors to sense blood pressure in the afferent arteriole - Contain secretory granules for the enzyme renin

Question 48

Extraglomerular mesangial cells

Answer 48

- Located between the arteriole and tubule cells - Interconnected by gap junctions - May pass regulatory signals between macula densa and granular cells