renal anatomy

Question 1

where are the kidneys positioned

Answer 1

• retroperitoneal
• posterior abdominal wall
• vertebral levle T12- L3
• left kidney higher than right kidney

Question 2

right kidney associations

Answer 2

• Liver is closely associated
• Ascending part of duodenum
• Right colic flexure of large intestine
• Parts of the small intestine
• Suprarenal gland at the top

Question 3

left kidney associations

Answer 3

• Stomach
• Spleen
• Pancreas
• Left colic flexure
• Descending colon
• Parts of small intestine

Question 4

what muscles are associated with the kidneys

Answer 4

• Posterior abdominal wall muscles
  o Psoas major > from lumbar vertebrae to femur
  o Quadratus lumborum > square shaped in lumbar region
  o Transversus abdominus > flat abdominal wall muscle
• Ribs > sit in line with ribs 11 and 12

Question 5

whats located at the superior pole of the kidneys

Answer 5

suprarenal gland

Question 6

whats located at the medial margin of the kidney

Answer 6

• Beginning of the ureter
• Ureter exits the kidney here at the hilum
  o Renal pelvis (wide beginning of the ureter)
  o Entrance of Renal artery
  o Exit of Renal vein

Question 7

describe the renal cortex and medulla

Answer 7

• the outer area of the kidney is the cortex
• the more inward area is the medulla
• there are pyramids in the medulla (triangular shape)
• extensions of the cortex form inside the kidney towards the central portion known as the renal columns

Question 8

drainage of urine via the kidneys

Answer 8

• urine drains via renal pyramids
• flows into renal papilla at the tip of each pyramid
• then flows into the minor calyx
• these join together to form the major calyx’s (2-3 in each kidney)
• these exit at the hilum into the renal pelvis

Question 9

blood supply to the right kidney

Answer 9

• Supplied by the right renal artery
  o Direct branch of abdominal aorta
  o Just below coeliac trunk at about same level as coeliac artery
• Drains through the right renal vein directly into the inferior vena cava

Question 10

blood supply to the left kidney

Answer 10

• supplied by left renal artery
  o branch of abdominal aorta
• drains through the left renal vein directly into inferior vena cava

Question 11

why are the left and renal veins/ arteries different lengths and state which ones longer of each

Answer 11

• left renal veins passes anteriorly over the aorta
• it’s vv long in comparison to the right renal vein
• right renal artery much longer than the left as it travels posterior to the inferior vena cava to reach right kidney

Question 12

splitting of the renal artery

Answer 12

• as it goes into the hilum you get interlobar arteries
  o these flow within the renal columns
  o renal columns = extensions of the cortex that sit within the pyramids
• then become arcuate arteries in the cortex region
• then become intralobular arteries

Question 13

where about in a kidney is the nephron

Answer 13

crosses over between the renal pyramid and renal cortex

Question 14

whats the bowman’s capsule

Answer 14

• the area where filtrate first goes

Question 15

whats the pathway of filtrate through the kidney

Answer 15

• Filtered blood then passes into proximal convoluted tubule
• Then into the Loop of Henle
• Then into the distal convoluted tubule
• Then, the straight collecting duct into the main collecting duct

Question 16

the pathway of blood through the kidney

Answer 16

It’s the filtrate going through the nephron not the blood itself
- Blood comes into kidney via renal artery
- Then goes through afferent arteriole
- Then forms a glomerular structure
- Then during filtration, it goes through a membrane
o Due to pressure differences
- Then rest of the blood that has been filtered comes through efferent arteriole
o This is where there’s diff. blood vessels that supply the kidney itself
o Called peritubular capillaries
- This is where there is exchange of nutrients/ deoxygenation of blood to the kidney
- Then vessels come together again into the renal vein to drain blood out of the kidneys

Question 17

what are the components of the renal corpuscle

Answer 17

glomerulus + bowman’s capsule

Question 18

renal tubules structure

Answer 18

single layer of epithelium

Question 19

ureters - structure, function, what artery do they cross and at what point

Answer 19

• 2 muscular tubes – smooth muscle
• Take urine from kidneys to bladder (in pelvis)
• Via peristalsis and gravity
• Cross the external iliac artery just beyond the bifurcation of the common iliac artery

Question 20

what are the 3 sites of constriction in the ureter and why are these sites significant

Answer 20

• Uteropelvic junction
• Pelvic inlet
• Entrance to bladder
  These are the sites where kidney stones get stuck

Question 21

blood supply and veinous drainage to the ureters

Answer 21

Arterial blood supply
- Ureters receive branches from 3 main sources
o Renal arteries
o Gonadal arteries
o Abdominal arteries
- Variable due to what happens during development – start in pelvic cavity and descend
Venous Drainage
- Veins of the ureters drain into the renal veins and gonadal veins

Question 22

histology of the ureter

Answer 22

• Highly muscular
• Epithelial lining
  o Known as transitional epithelium only found in urinary system (ureter and bladder)

Question 23

bladder - structure, internal anatomy

Answer 23

• Hollow muscular organ
• For storage of urine
• Made of smooth muscle
  o Smooth muscle called – detrusor muscle
• In the centre there’s a smoothened region called the trigone
  o Found between the openings of the 2 ureters
• One outlet – the urethra
  o Starts as the internal urethral orifice

Question 24

position of the bladder in both sexes

Answer 24

• In females – shorter urethra than in males
• Empty bladder = lesser pelvis
• Full bladder = ascends into the greater pelvis

Question 25

blood supply of the bladder

Answer 25

• Through 2 branches of the internal iliac artery
  o Superior vesicle arteries (anterior and superior parts)
  o Inferior vesical arteries (males) (fundus and neck)
  o Vaginal arteries (females)

Question 26

histology of the bladder

Answer 26

• LOTS OF LAYERS OF SMOOTH MUSCLE
• Transitional epithelium again
  o Stratified epithelium
  o Found in areas that need to be a change of shape/ expansion
  o Protective layer also – protect from chemical nature of urine

Question 27

the urethra - structure in males and females

Answer 27

In males
-	~20cm long
-	3 diff parts
o	Prostatic
o	Intermediate 
o	Spongy
In females
-	~3-4cm long
-	Terminates between the clitoris and vagina

Question 28

male urethra - divisions and where these lie

Answer 28

• Urethra passes through the prostate gland
  o This area is called prostatic
• Passes through the perineal membrane
  o This area is called the membranous part – short
• Passes through the spongy part of the penis
  o Called the spongy part

Question 29

common abnormalities of the ureters and kidneys

Answer 29

Bifed Ureters
- 2 ureters from bladder to pelvis joining into 1 or remaining as 2
- Doesn’t necessarily cause problems – function not impaired
- Can predispose people to formation of renal stones/ drainage problems
Kidney fusion- Horseshoe Kidney
- During descent to lumbar region in development kidneys normally separate at inferior poles
- In some cases inferior poles remain fused together
- Kidneys snagged on branch of abdominal aorta
o Kidney much lower down
o Fused together
- Can be asymptomatic or same probs as above