Chapter 26 - Urinary System

Question 1

Kidney functions (8)

Answer 1

**Regulation of: **

blood ionic composition, pH, volume, pressure, glucose level

**Maintenance of **blood osmolarity

**Production of **hormons (calcitrol & erythropoitin)

**Excretion of **wastes from metabolic reactions & foreign substances

Question 2

External Anatomy of Kidneys

Answer 2

**Renal Hilum **

**3 layers of tissue **

Question 3

Renal Hilum

(3) layers of tissue

Answer 3

• indent where ureter emerges along with blood & lymphatic vessels & nerves
  1) renal capsule
  2) adipose capsule
  3) renal fascia

Question 4

1) renal capsule
2) adipose capsule
3) renal fascia

Answer 4

1) deep layer - continous with coat of ureter, barrier against trauma & maintains kidney shape
2) mass of fatty tissue, protects kidney from trauma & holds it in place
3) superficial layer - thin layer of CT that anchors kidney to surrounding structures & abdominal wall

Question 5

Kidney - position, weight & size

Answer 5

retroperitoneal

level of T12 to L3

160g each

size of bar of soap

Question 6

Kidney shape

Answer 6

**lateral surface - **convex

**medial border- **concave: faces vertebral column

• renal hilum near center

Question 7

Connective tissue coverings

1) renal capsule (deep)
2) adipose capsule
3) renal fascia (superficial)

Answer 7

1) encloses kidney like cellophane wrap
2) cushions kidney
3) binds to abdominnal wall

Question 8

(2) distinct regions of kidney

Answer 8

superficial, light red - Renal cortex

deep, darker reddish-brown - **Renal medulla **

Question 9

**Renal Cortex **

extends from?

consists of

Answer 9

superficial

extends from renal capsule to bases of renal pyramids

divided into (2) zones

**renal columns **

Question 10

(2) zones of renal cortex

Answer 10

**Outer cortical zone **

Inner juxtamedullary zone

Question 11

Renal cortex

• renal columns

Answer 11

portions of renal cortex that extend between renal pyramids

Question 12

**Renal Medulla **- inner region

consists of?

Answer 12

several cone-shaped **renal pyramids **

base (wider end) faces renal cortex,

apex (narrow end) = **renal papilla **- points toward renal hilum

Question 13

Renal lobe

Answer 13

consists of **renal pyramid, **overlying area of **renal cortex **& ¹/₂of each adjacent renal column

Question 14

Parenchyma of kidneys = ?

Answer 14

FUNCTIONAL PORTION OF KIDNEYS

renal cortex + renal pyramids of renal medulla

Question 15

Nephrons

Answer 15

microscopic functional unit of kidney

Question 16

filtered fluid formed by **nephrons **drains into?

Answer 16

large **papillary ducts - **extend through renal papillae of renal pyramids

Question 17

Flow of filtered fluid from nephrons

Answer 17

→ papillary ducts → minor calyces (8-18) → major calyces (2-3) → renal pelvis → ureter → urinary bladder

Question 18

When does filtrate become urine? why?

Answer 18

once filtrate enters calyces

because no further reabsorption can occur

b/c simple epithelium of nephron & ducts becomes transitional epithelium in calyces

Question 19

Renal sinus

Answer 19

cavity within kidneys that hilum expands into

contains part of renal pelvis, calyces, branches of renal blood vessels & nerves

Question 20

Although kidneys constitute less than 0.5% of total body mass, they
receive 20-25 % of resting cardiac output via?

Answer 20

right & left **renal arteries **

Question 21

Within kidneys, **renal arteries **divide into…

Answer 21

segmental arteries →interlobar → arcuate → interlobular→ afferent arterioles → glomerulus → efferent arteriole→ peritubular capillaries + vasa recta → peritubular venules→ interlobular veins →arcuate → interlobar →renal vein

Question 22

each ___ recieves one **afferent arteriole, **which divides into tangled ball-shaped capillary network called ___?

Answer 22

**glomerulus **

Question 23

LOCATION OF:

1) segmental arteries →
2) interlobar →
3) arcuate →
4) interlobular →
5) afferent arterioles →
6) glomerulus

Answer 23

1) within kidney
2) in parenchyma, through renal columns, b/w renal pyramids
3) base of renal pyamid, arch b/w medulla & cortex
4) pass b/w renal lobules
5) renal cortex
6) nephron recieves 1 afferent arteriole which divides into **glomerulus **

Question 24

**Glomerular **capillaries reunite to form **efferent arterioles **which divide to form → __ __ → __ _→_ _→___→__→__ ___ → __ ___ __

extending from some **efferent arterioles **are ___ ___

Answer 24

efferent arteriole → peritubular capillaries (surround tubular part of nephrons in cortex)→ peritubular venules → interlobar veins → arcuate → interlobar → renal vein → exits through renal hilum → **inferior vena cava **

**vasa recta **- long loop-shaped capillaries that support tubular portions of nephron in medulla

Question 25

Renal nerves are part of the ___ \_\_\_ nervous system most are __ nerves regulating?

Answer 25

sympathetic autonomic **vasomotor **- regulate blood flow through kidney by vasodilation/constriction of renal arterioles

Question 26

**Nephron** - (2) parts

Answer 26

1) Renal **corpuscle ** 2) Renal **tubule **

Question 27

Parts of **Nephron:** 1) Renal **corpuscle** ​ 2) Renal **tubule**

Answer 27

1) where blood plasma is filtered 2) into which filtered fluid passes

Question 28

**Nephron** (2) components of renal **corpuscle**

Answer 28

a) **glomerulus ** b) **glomerular (Bowman's) capsule**

Question 29

Nephron: renal **corpuscle ** **a) glomerulus ** **b) glomerular (Bowman's) capsule**

Answer 29

a) capillary network b) double-walled epithelial cup that surrounds glomerular capillaries

Question 30

Blood plasma is filtered in **golumerular capsule, **then passed into **renal tubule.** (3) main sections of RENAL **TUBULE** - *in order that fluid passes through them *

Answer 30

1) **proximal convulated tubule (PCT)** 2) **loop of Henle (nephron loop) ** 3) **distal convulated tubule**

Question 31

**renal corpuscle **& both **convulated** **tubules** lie within ____ \_\_\_ **Loop of Henle **extends into __ \_\_ but returns to renal cortex

Answer 31

renal cortex renal medulla

Question 32

**Distal convoluted tubule **of several nephrons empty into?

Answer 32

a single **collecting duct **

Question 33

**Urine flow:** Distal convoluted tubules → ? → ? ....

Answer 33

**collecting duct **→ converge into 100s of **papillary ducts → minor calyces **

Question 34

**collecting ducts & papillary ducts **extend from? through? to?

Answer 34

renal **cortex** through **medulla** to renal **pelvis**

Question 35

**Loop of Henle **in nephron connects? (2) parts of **Loop of Henle **

Answer 35

proximal & distal convoluted tubules. into renal medulla as 1) **descending** limb makes hairpin turn and returns to renal cortex as 2) **ascending **limb

Question 36

(2) types of Nephrons

Answer 36

1) Cortical 2) Juxtamedullary

Question 37

1) Cortical Nephron location of **renal corpuscles** **Loop of Henle **structure

Answer 37

80-85% of nephrons **renal corpuscles **lie in outer portion of renal cortex **(cortical zone)** short loops of Henle - mainly in cortex, penetrate only into outer region of renal medulla

Question 38

the short **Loops of Henle **in **Cortical Nephrons **recieve blood supply from..?

Answer 38

**peritubular capillaries **that arise from **efferent arterioles **

Question 39

**Juxtamedullary **nephrons location of **Renal corpuscle ** **Loop of Henle **structure - **ascending limb**

Answer 39

15-20% of nephrons **renal corpuscles **lie deep in cortex (**juxtamedullary zone)** long **Loop of Henle - **extends into deepest region of medulla (2) portions off **ascending limb **- thin & thick

Question 40

Long **loops of Henle **in **Juxtamedullary Nephrons **recieve blood supply from?

Answer 40

**peritubular capillaries & ****vasa recta **that arrise from efferent arterioles

Question 41

Histology of **Glomerular capsule** (2) layers

Answer 41

1) parietal layer 2) visceral layer

Question 42

**Glomerular Capsule** 1) parietal layer 2) visceral layer

Answer 42

1) simple squamous epithelium - **outer wall ** 2) modified simple squamous epithelium = **podocytes **that wrap projections around single layer of endothelial cells of **glomerular capillaries ** **- inner wall**

Question 43

Fluid filtered from **glomerular** **capillaries** enters...

Answer 43

**Glomerular (Bowman's) space - **space between 2 layers of glomerular capsule (lumen of urinary tube)

Question 44

Histology of **Renal Tubule & Collecting duct** ## Footnote **- PROXIMAL CONVOLUTED TUBULE**

Answer 44

simple cuboidal epithelial cells prominent brush borderof microvilli on surface facing lumen

Question 45

Histology of** Renal Tubule & Collecting duct** **DESCENDING & **1ST PART OF **ASCENDING LIMB OF LOOP OF HENLE (THIN)**

Answer 45

**descending & thin ascending - **simple squamous epithelium **thick - **simple cuboidal to low columnar epithelium

Question 46

Macula densa

Answer 46

area of closely packed specialized cells lining the wall of the distal convoluted tubule/final part of ascending loop of henle

Question 47

Juxtamedullary cells

Answer 47

modified smooth muscle fibers in walls of afferent (& sometimes efferent) arterioles alongside macula densa

Question 48

Juxtamedullary Apparatus

Answer 48

macula densa + juxtamedullary cells - help regulate blood pressure in kidney

Question 49

In the last part of the **Distal Convoluted Tubule** & continuing into **collecting ducts, ** (2) different types of cells are present

Answer 49

1) **principal cells - **receptors for antidiuretic hormone (ADH) & aldosterone (2 hormones that regulate their functions) 2) **intercalated cells - **play a role in homeostasis of blood pH

Question 50

(3) basic processes performed by **nephrons & collecting ducts **to produce urine

Answer 50

**1) GLOMERULAR FILTRATION** **2) TUBULAR REABSORPTION ** **3) TUBULAR SECRETION**

Question 51

**1) GLOMERULAR FILTRATION ** **2) TUBULAR REABSORPTION** **3) TUBULAR SECRETION**

Answer 51

1) water & solutes in blood plasma move across wall of **glomerular capillaries**, filtered → move into **glomerular** **capsule** → **renal** **tubule** 2) as filtered fluid flows through **renal tubules → collecting ducts **- tubule cells reabsorb 99% of filtered water & other solutes which return to blood as it flows through **peritubular capillaries & vasa recta ** 3) as filtered fluid from **renal tubules + collecting ducts, **renal tubule & duct cells secrete other materials (waste, drugs, xs ions) into fluid

Question 52

solutes in fluid that drain into renal pelvis remain in fluid and are ___ as \_\_\_

Answer 52

excreted as urine

Question 53

Excretion of any solute = ?

Answer 53

glomerular filtration - reabsoprtion + secretion

Question 54

Urinary bladder

Answer 54

hollow ditensible muscular organ capacity: 700-800 mL

Question 55

Micturition

Answer 55

discharge of urine from urinary bladder aka **urination**

Question 56

**Urination/Micturition **involves combination of?

Answer 56

voluntary & involuntary muscle contractions

Question 57

When volume of urine in urinary bladder exceeds 200-400 mL, pressure increases &...

Answer 57

stretch receptors in wall transmit nerve impulses into spinal cord → **micturition** **center **in S2 & S3 → trigger (spinal reflex) **micturition reflex → parasympathetic** impulses to **urinary bladder & internal urethral sphincter → **contraction of **detrusor**, relaxation of **internal urethral sphincter + **inhibition of somatic motor neurons in **external urethral sphincter**

Question 58

External urethral orifice

Answer 58

between clitoris & vaginal orifice

Question 59

Internal urethral sphincter

Answer 59

detrusor muscle thickened, smooth muscle, involuntary control