Anatomy of the Renal System

Question 1

Components of the renal system

Answer 1

Kidney, ureter, bladder, urethra

Question 2

Kidney location

Answer 2

Lies behind the parietal peritoneum on posterior abdominal wall
Right kidney slightly lower than left
Lumbar vertebrae and rib cage partially protect the kidney - can be damaged through trauma

Question 3

External anatomy of the kidney

Answer 3

renal capsule, adipose tissue, renal fascia

Question 4

Renal capsule

Answer 4

fibrous connective tissue surrounding each kidney

Question 5

Adipose tissue

Answer 5

engulfs renal capsule, acts as cushioning

Question 6

Renal facia

Answer 6

thin layer loose connective tissue, anchors kidneys to posterior abdominal wall

Question 7

Internal anatomy of the kidney

Answer 7

Hilum, renal sinus, ureter, cortex, renal columns

Question 8

Hilum

Answer 8

renal artery and nerves enter, renal vein and ureter exit - most medial section
Hilum opens into renal sinus

Question 9

Renal artery

Answer 9

blood from heart to kidney

Question 10

Renal vein

Answer 10

blood from kidney to heart

Question 11

Renal sinus

Answer 11

Cavity filled with fat and loose connective tissue

Question 12

Ureter

Answer 12

exits at the hilum; connects to urinary bladder

Question 13

Cortex

Answer 13

outer area

Question 14

Renal columns

Answer 14

Part of cortical tissue that extends into medulla

Question 15

Internal Anatomy

Answer 15

Medulla, renal pyramids, renal papilla, major calyces, pelvis

Question 16

Medulla

Answer 16

inner area, surrounds renal sinus

Question 17

Renal pyramids

Answer 17

cone-shaped, base is boundary between cortex and medulla

Apex of pyramid is renal papilla, points towards sinus

Question 18

Major calyces

Answer 18

converge to form the renal pelvis

Question 19

Pelvis

Answer 19

Enlarged chamber formed by major calyces

Question 20

Nephron

Answer 20

Functional unit of the kidney; filter blood and produce urine

Question 21

Nephron - structure

Answer 21

Renal corpuscle, proximal tubule, loop of Henle, distal tubule

• Blood enters the nephron for filtration. Filtrate/urine is produced
• Urine continues from the nephron to papillary ducts, minor calyces, major calyces, renal pelvis and ureter

Question 22

Juxtamedullary nephron

Answer 22

• renal corpuscle located near the medulla

- Long Loops of Henle extending deep into medulla (15%)

Question 23

Cortical nephron

Answer 23

• renal corpscule located nearer to the periphery of the cortex
• Loops of Henle don’t extend deep into medulla (85%)

Question 24

Renal corpuscle

Answer 24

Bowman’s Capsule - enlarged end of the nephron, double walled chamber

• Filters blood/fluid which then enters the proximal convoluted tubule

Glomerulus - network/ball of capillaries

• Blood enters through afferent arteriole, exits through efferent arteriole
• Efferent arteriole is smaller than afferent; creates pressure

Question 25

Bowman's capsule

Answer 25

Parietal layer - outer layer - simple squamous - becomes cuboidal in PCT Visceral layer - inner layer - Specialised podocytes that wrap around the glomerular capillaries; facilitate filtration

Question 26

Filtration membrane

Answer 26

fenestrae, filtration slits, basement membrane

Question 27

Fenestrae

Answer 27

window-like openings in endothelial cells of glomerular capillaries

Question 28

Filtration slits

Answer 28

gaps between podocytes

Question 29

Basement membrane

Answer 29

between endothelial cells of glomerular capillaries and podocytes

Question 30

PCT

Answer 30

filtrate drains from Bowman's capsule into PCT - Simple cuboidal epithelium with many microvilli - Active reabsorption of sodium, potassium and chlorine

Question 31

Loop of Henle

Answer 31

ascending and descending limb - Thick parts - simple cuboidal; thin parts - simple squamous (for osmosis/diffusion)

Question 32

DCT

Answer 32

shorter than PCT - Simple cuboidal, few microvilli - Numerous mitochondria

Question 33

Collecting duct

Answer 33

extends through medulla towards renal papilla to ureter - Larger in diameter - Simple cuboidal epithelium

Question 34

Major renal arteries and veins

Answer 34

Blood enters kidney via abdominal aorta; left and right artery branch off Deoxygenated blood removed via right and left renal vein, exits through inferior vena cava

Question 35

Urine movement

Answer 35

Pressure forces urine through nephron Peristalsis moves urine from renal pelvis in kidney through ureters to bladder (smooth muscle) Ureters enter bladder obliquely through trigone Pressure in bladder compresses ureter, prevents backflow - important to prevent kidney infection

Question 36

Ureters

Answer 36

Bring urine from renal pelvis to bladder Lined by transitional epithelium transitional epithelium - mucosa - muscularis - adventitia

Question 37

Bladder

Answer 37

Hollow, smooth muscle; allows for temporary storage of urine Sits posteriorly to symphasis pubis Volume can increase/decreasae Transitional epithelium - lamina propria - submucosa - detrustor muscle

Question 38

Trigone

Answer 38

interior of urinary bladder | Triangular area between the entry of the ureter and the exit of the urethra

Question 39

Urethra

Answer 39

Transports urine from the bladder to outside the body Internal urinary sphincter - elastic connective tissue and smooth muscle prevent urine continuously flowing out of the bladder Transitional epithelium (top), stratified columnar epithelium (external opening) External urinary sphincter - skeletal muscle surrounds urethra; extends through pelvic floor. Acts as a valve that controls the flow of urine