Urinary System

Question 1

What is in the Urinary System?

Answer 1

2 Kidneys, Uriniferous tubule , 2Ureters, 1bladder, and 1Urethra

Question 2

What are the functions of the urinary system?

Answer 2

1. )Excretion
   - waste products of metabolism
   - foreign substances
2. ) Homeostasis
   - regulate total body water & extracellular fluid volume
   - Electrolyte balance (Na+)
   - Acid-base balance
3. ) Endocrine function
   - erythropoietin>increase RBC production in bone marrow
   - enzyme renin>regulate aldosterone secretion
   - vitamin D activation

Question 3

Kidney size and location

Answer 3

Kidney

• 300gm: 10-12cm x 3-4cm
• Level T12-L3
• Left Kidney slightly higher due to Liver being on the right side
• just anterior to psoas and Quadratus Lumborum
• Retroperitoneal

Question 4

3 capsules of the kidney

Answer 4

1. ) True = Fibrous CT (layer directly on kidney)
2. ) Adipose Capsule = Perirenal Fat (surrounds kidney, packaging)
3. ) Renal Fascia = subserous fascia (incases adipose capsule and connects it to the posterior wall)

Question 5

Hilus

Answer 5

Medial indentation where vessels and nerves enter and exit the kidney (entryway straight line from top to bottom)

Question 6

Sinus

Answer 6

thin concave slit within which we find pelvis and calyces, blood vessels, nerves and loose CT (at the base of each column)

Question 7

Pelvis and calyxes (major and minor)

Answer 7

-lined w/ transitional epithelium
-1 pelvis>3-4 major calyxes> 7-14 minor calyxes
(pelvis is before the ureter, major calyxes before pelvis, minor calyxes before major)

Question 8

Cortex

Answer 8

1. ) outer zone (layer towards outside wall)

2. ) renal columns (b/n pyramids)

Question 9

Medulla

Answer 9

Renal pyramids

• striaghted pyramidal regions
• apex projects into minor calyx

Question 10

Lobe of Kidney

Answer 10

lobe of kidney is the renal pyramid plus cortical matter, both outer cortex and within renal column

Question 11

Name the path of blood flow through the renal blood vessels

Answer 11

Aorta>Renal a.> (5)Segmental a.> Interlobar a.> Arcuate a.> Cortical Striate a.> Afferent glomerular arteriole>Glomerulus capillaries>Efferent Glomerular arteriole> peritubular capillaries and vasa recta> cortical radiate vein>Arcuate Vein>Interlobar Vein>Renal Vein>Inferior vena cava

Question 12

What is the functional unit of the kidney?

Answer 12

Uriniferous Tubule

1. ) Nephron
2. ) collecting duct

Question 13

Nephron

Answer 13

1. ) Renale Corpuscle
   - Glomerulus, tuft of capillaries
   - Bowman’s capsule, double walled cup surrounding the glomerulus
2. ) proximal convoluted tubule
3. ) Loop of Henle
4. ) Distal convoluted tubule

Question 14

What part of the Uriniferous tubule is in the cortex?

Answer 14

convoluted tubules and renal corpuscle

Question 15

What part of the Uriniferous tubule is in the pyramids?

Answer 15

loops of henle and collecting ducts

Question 16

Name the two types of Nephrons and differences?

Answer 16

1. ) Cortical -80% of nephrons short loops of henle

2. ) Juxtemedullary- 20% of nephrons and their loops of henle go deeper into the pyramids

Question 17

Urine is formed by what 3 processes?

Answer 17

1. ) Glomerular filtration of blood plasma
2. ) Tubular reabsorption (filtrate>plasma) (efferent artirioles before interlobular vein)
3. ) Tubular secretion (plasma>filtrate)(efferent artirioles before interlobular vein)

Question 18

Bowman’s Capsule 2 walls

Answer 18

1. ) parietal layer- simple squamous epithelium (outer layer)
2. ) Visceral layer-Podocytes (Tech. still simple squamos epithelium variation)

Question 19

Podocytes

Answer 19

branching processes interdigitate with processes of adjacent cells to totally coat the surface area of glomerular capillaries, interdigitating processes leave small slits=filtration Slits

Question 20

Filtration barrier

Answer 20

blood plasma filters from the glomerular capillary to the lumen of the Bowman’s capsule

1. ) Fenestrated Capillaries-cells and platelets cannot pass
2. ) Basement membrane- Large proteins (>160,000) cannot pass
3. )filtration slits-small proteins(>40,000) cannot pass

Question 21

Proximal convoluted tubule

Answer 21

Simple cuboidal epithelium w/ brush border and basal striations.
f(x) 1.) reabsorb glucose, NaCl, water, protein, amino acids; about 80% of filtration (first absorption in digestion) 2.) Secrete H+, foreign substances

Question 22

Distale Convoluted Tubule

Answer 22

Simple cuboidal epithelium w/ basal striations.
f(x) 1.) reabsorb Na+ controlled by aldosterone to regulate blood volume
2.) Acid base balance

Question 23

Loop of Henle

Answer 23

Simple cuboidal and simple squamous epithelium
f(x) Counter current multiplyer, increases hypertonicity of medullary interstitum to allow reabsorption of water in excess of sodium to regulate plasma osmolarity, ascending limb pumps NaCl to interstitium

Question 24

Collecting Ducts

Answer 24

Simple cuboidal epithlium to simple columnar epithelium (distinct cell boundaries)
f(x) concentrate urine to regulate plasma osmolarity, water is reabsorbed by osmosis as CD passes through hypertonic interstitium
-regulated by ADH, which increases water permeability increasing water reabsorption
-decreased ADH decreases water reabsorption
-Lack of ADH-Diabetes insipidus

Question 25

Peritubular Capilaries

Answer 25

After efferent arterioles, capillaries surround tubule; special area; around loop

Question 26

Vasa Recta

Answer 26

capillary network of medulla= counter-current exchanger, capillaries loop in and out of pyramids= a portal system

Question 27

JG apparatus

Answer 27

Juxtaglomerular apparatus 1. ) Macula Densa 2. ) Juxtaglomerular cells

Question 28

JG cells

Answer 28

Specialized smooth muscle of afferent arteriole 1. ) Act as baroreceptors 2. ) secretory granules- secrete renin Decreased blood pressure>increased secretion of renin

Question 29

Macula Densa

Answer 29

tall narrow, simple columnar epithlial cells in wall of Distal convoluted tubule, - Adjacent to JG cells - sense NaCl content of filtrate - Decreased NaCl>increased renin secretion

Question 30

Renin > Increased BP

Answer 30

- Decreased blood pressure>increased renin - Renin=enzyme from JG cells - Catalyzes: Angiotensinogen (from liver)>Angiotensin 1 ``` Converting enzyme (in lung): -Catalyzes; Angiotensin 1> Angiotensin 2 ```

Question 31

Angiotensin 2

Answer 31

Leads to increased BP 1. ) Vasoconstriction 2. ) Increased secretion of aldosterone> increased Na+ reabsorption in DCT primarily 3. ) Thirst

Question 32

Ureters

Answer 32

- 25-30cm by 4-5cm - Retroperitoneal - urine moves via peristalsis

Question 33

Walls of calices, pelvis, ureter, bladder, 1st part of urethra: histology

Answer 33

1. ) Mucosa- transitional epithelium CT 2. ) Lamina Propria 3. ) Muscularis- inner longitudinal, outer circular, outermost longitudenal in last 1/2 ureter and bladder 4. ) Adventitia- CT

Question 34

Bladder

Answer 34

- 300 ml up to 1000ml storage capacity - within true pelvis - inferior to peritoneal cavity - posterior to symphysis pubis, anterior to uterus in female, anterior to rectum in male

Question 35

Trigone of Bladder

Answer 35

3 openings 2 Ureters and 1 Urethra -about 2 cm oblique path through posterior wall of bladder, no backflow

Question 36

Bladder wall structure and sphincters

Answer 36

1. )mucosa-rugae with transitional epithelium 2. ) Muscularis- several layers; detrusor 3. ) Adventitia: ct, superiorly peritoneum sphincters- Internal-smooth muscle at the base of bladder External-Skeletal muscle or urogenital diaphram

Question 37

Male Urethra and 3 regions

Answer 37

20cm long epithelium: transitional>pseudostratified>stratified squamous (Same as female) region 1. )Prostatic-though prostate 2. )membranous-through urogenital diaphram 3. )Penile or Cavernous or Spongy-through shaft of penis

Question 38

Female Urethra

Answer 38

3-5cm long | epithelium: transitional>pseudostratified>stratified squamous (same as male)