Anatomy of Urogenital Flashcards
At what spinal level are the kidneys positioned in the body?
T12-L3
Which kidney is lower than the other and why?
The right kidney due to the presence of the liver.
Under which ribs do the kidneys sit?
Ribs 11 and 12
What is the renal hilum?
An indentation in the kidney that leads to the renal sinus.
What structures are contained within the hilum?
Renal veins, arteries, nerves and lymphatic vessels. Ureters also exit the kidney.
What are the three levels of tissue that surround each kidney?
Superficial layer - renal fascia
Middle layer - Adipose capsule
Deep layer - Renal capsule
What does the renal fascia do?
Renal fascia anchors the kidney to it’s surrounding structures and to the abdominal wall.
What does the adipose capsule of the kidney do?
Fatty tissue that protects the kidney from trauma and holds it in place.
What does the renal capsule do?
Serves as a barrier against trauma and helps to maintain the shape of the kidney.
What are the two regions of the kidney?
Renal cortex
Renal Medulla
What do ureters do?
Transport urine from kidneys to bladder.
Where are nephrons in the kidney located?
Outer cortex and the juxtamedullary region.
How are cortical nephrons different to juxtamedullary nephrons?
Cortical nephrons have a short loop and their tubules extend only a short distance into the medulla.
Juxtamedullary nephrons have a long loop and extend deep into the medulla.
What are renal pyramids and where are they located?
Collections of tubules located in the medulla.
Explain the path of urine drainage in the kidneys.
Collecting duct > Papillary duct > Minor calyx > Major calyx > Renal pelvis > Ureter > Urinary bladder
What is the outer cortex comprised of?
Outer cortical zone and juxtamedullary zone
What comprises the inner medulla?
12 renal pyramids
On entering the kidney which is superior, the renal artery or the renal vein?
Renal artery is superior to the renal vein.
What is the glomerulus?
High pressure capillary bed between an afferent and efferent arteriole.
What surrounds the glomerulus and what is it’s function?
Bowman’s capsule which forms a lumen to capture and direct filtrate.
Explain the flow of fluid through the nephron.
Glomerulus > PCT > Descending limb of the loop of Henle > Ascending limb > DCT > Collecting Duct
Explain the blood flow through the kidney.
Aorta > Renal artery > Segmental artery > Interlobar artery > Arcuate artery > Cortical radiate artery > Afferent arteriole > Glomerulus capillaries > Efferent arteriole > Peritubular capillaries > Cortical radiate vein > Arcuate vein > Interlobar vein > Renal vein > Inferior vena cava
What is the blood supply to the ureters?
- Branches of the renal artery (upper ureter)
- Branches from the gonadal artery (middle ureter)
- Branches from the internal iliac artery (lower ureter)
What is the blood supply to the upper ureter?
Branches of the renal artery
What is the blood supply to the middle ureter?
Branches of the gonadal artery
Where do the three uteric constrictions occur?
- Pelviuteric junction.
- As the ureter cross the pelvic brim (common for kidney stones to be lodged here).
- As the ureter enters the bladder.
Where does the major calyx drain into?
Renal pelvis
What is the blood supply to the lower ureter?
Branches of the internal illiac artery.
Where are macula densa cells found?
The DCT and JGA
What do macula densa cells do?
Help to regulate GFR by altering blood pressure. They detect the concentration of Na+ in the distal convoluted tubule.
Where are mesangial cells located?
Glomerulus
What do mesangial cells do?
Remove trapped residues and aggregated protein from the basement membrane thus keeping the filter free of debris.
What do mesangial cells secrete?
Prostaglandins and cytokines
Where are podocytes located?
The bowman’s capsule
What do podocytes do?
The podocytes have filtration slits between them allowing substance to diffuse out of the blood into the filtrate.
When does kidney development begin?
Week 3
When do the kidneys become functional in the embryo?
3 months
What are the three kindeys that form in the embryological development of the kidneys?
Pronephros
Mesonephros
Metanephros
Describe the pronephros.
The first kidney to form, develops in week three. The pronephros has a pronephric duct which empties into the cloaca.
What germ layer are the kidneys formed from?
The mesoderm
Which of the three kidneys is functional in the adult?
Metanephros
What happens to the pronephros after it is formed?
The pronephros begins to degenerate in week 4 and is gone by week 6.
What replaces the pronephros?
The mesonephros
Describe the mesonephros.
The mesonephros has a mesonephric duct developed from the pronephric duct.
What happens to the mesonephros after it is formed?
The mesonephros begins to degenerate in the 6th week and is gone by the 8th week.
Explain the formation of the metanephros.
The metanephros forms in the 5th week, developing from a uteric bud.
What does the uteric bud form in the final kidney?
Collecting ducts, calyces, renal pelvis and ureter.
What makes up the majority of the amniotic fluid around the fetus?
Fetal urine
Explain what the cloaca forms.
The cloaca forms a urogenital sinus.
What develops from the urogenital sinus?
Urinary bladder and urethra.
Explain the ascension of the kidneys.
The kidneys form in the pelvis and then ascend into the abdomen. This leads to the kidneys having multiple blood vessels supplying them.
