renal anatomy Flashcards
where are the kidneys positioned
- retroperitoneal
- posterior abdominal wall
- vertebral levle T12- L3
- left kidney higher than right kidney
right kidney associations
- Liver is closely associated
- Ascending part of duodenum
- Right colic flexure of large intestine
- Parts of the small intestine
- Suprarenal gland at the top
left kidney associations
- Stomach
- Spleen
- Pancreas
- Left colic flexure
- Descending colon
- Parts of small intestine
what muscles are associated with the kidneys
- 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
whats located at the superior pole of the kidneys
suprarenal gland
whats located at the medial margin of the kidney
- 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
describe the renal cortex and medulla
- 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
drainage of urine via the kidneys
- 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
blood supply to the right kidney
- 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
blood supply to the left kidney
- supplied by left renal artery
o branch of abdominal aorta - drains through the left renal vein directly into inferior vena cava
why are the left and renal veins/ arteries different lengths and state which ones longer of each
- 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
splitting of the renal artery
- 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
where about in a kidney is the nephron
crosses over between the renal pyramid and renal cortex
whats the bowman’s capsule
- the area where filtrate first goes
whats the pathway of filtrate through the kidney
- 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
the pathway of blood through the kidney
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
what are the components of the renal corpuscle
glomerulus + bowman’s capsule
renal tubules structure
single layer of epithelium
ureters - structure, function, what artery do they cross and at what point
- 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
what are the 3 sites of constriction in the ureter and why are these sites significant
- Uteropelvic junction
- Pelvic inlet
- Entrance to bladder
These are the sites where kidney stones get stuck
blood supply and veinous drainage to the ureters
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
histology of the ureter
- Highly muscular
- Epithelial lining
o Known as transitional epithelium only found in urinary system (ureter and bladder)
bladder - structure, internal anatomy
- 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
position of the bladder in both sexes
- In females – shorter urethra than in males
- Empty bladder = lesser pelvis
- Full bladder = ascends into the greater pelvis
blood supply of the bladder
- 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)
histology of the bladder
- 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
the urethra - structure in males and females
In males - ~20cm long - 3 diff parts o Prostatic o Intermediate o Spongy In females - ~3-4cm long - Terminates between the clitoris and vagina
male urethra - divisions and where these lie
- 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
common abnormalities of the ureters and kidneys
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
