Anatomy: Urinary System Flashcards
Identify the main functions of the urinary system.
- Regulation of fluid balance
- Regulation of electrolyte concentration
- Production of renin
- Removal of end-products of protein metabolism and drug metabolism
- Re-absorption of glucose and amino acid
- Stabilization of blood pH
- Production of erythropoietin
- Vitamin D metabolism
Describe the anatomical location of the kidney.
- Retroperitoneal
- On the posterior abdominal wall, below the diaphragm
- Kept in place by the renal vessels and renal fascia
- Between upper borders of T12 and L3 vertebrae
- Deep to last 2 ribs
Describe the location of the R kidney relative to the L. Also describe the movement of both kidneys with deep inspiration.
Right kidney is 1 cm inferior due
to liver
May descend 1-2 cm with deep inspiration
Identify the layers which encapsulate the kidney.
From inside out:
- Fibrous capsule
- Perirenal (perinephric) fat
• Fills renal sinus as well - Renal fascia
• Covers suprarenal gland as well - Pararenal fat
Identify the main components of the kidney.
1) Renal cortex
2) Renal medulla
• Renal pyramids: x8-10
• Renal papilla: Project into minor calyx
• Renal columns of Bertin: Extensions of the cortex around pyramids
3) Renal sinus, filled with perirenal fat
4) Hilum (A to P: VAAAPA)
• Renal vein
• Renal arteries
• Renal pelvis
Identify the main differences between the renal cortex and medulla.
1) Renal cortex
• Outer
• Made up of nephrons + Numerous capillaries
2) Renal medulla
• Inner
• Contains collecting tubules + Arteries and veins
What are the main functions of nephrons ?
Ultrafiltration and re-absorption
What is the functional unit of the kidney ? What are the main components of this unit ?
Nephron
• Renal corpuscle
- Glomerulus
- Bowman’s capsule
- Proximal convoluted tubule
- Loop of Henlé
- Distal convoluted tubule
- Collecting duct
What are the main functions of the nephron ?
Ultrafiltration and re-absorption
Describe the components of the juxtaglomurular apparatus, and its function.
Components of the juxtaglomerular apparatus: Distal convoluted tubule and the glomerular afferent arteriole
Function: Regulate blood pressure and the filtration rate of the glomerulus.
Describe the response of the juxtaglomerular apparatus to elevated sodium.
The macula densa is a collection of specialized epithelial cells in the distal convoluted tubule that detect sodium concentration of the fluid in the tubule. In response to elevated sodium, the macula densa cells trigger contraction of the afferent arteriole, reducing flow of blood to the glomerulus and the glomerular filtration rate. The juxtaglomerular cells, derived from smooth muscle cells, of the afferent arteriole secrete renin when blood pressure in the arteriole falls. Renin increases blood pressure via the renin-angiotensin-aldosterone system.
Describe the main anatomical relations of the kidney.
- The upper pole of the kidney is covered by the suprarenal gland.
- Anteriorly, the right kidney is related to the liver, duodenum, ascending colon or right colic flexure, and small intestine. The left is related to the spleen, stomach, pancreas, descending colon or left colic flexure, and small intestine.
- Posteriorly, the kidneys are related to rib 12 and the diaphragm, psoas major, quadratus lumborum, and transversus abdominis
-The upper part of the kidney is usually separated by the diaphragm from the pleura and lung. In the vertebrocostal trigone, however, the kidney and pleura may be separated only by connective tissue
Distinguish between the main structures on slide 13 of lecture slides.
Refer to lecture slide 13.
Describe the path of renal arteries.
From abdominal aorta (at L1/2)
Posterior to renal veins
Divide at hilum
Where do renal veins drain ?
IVC
Define nutcracker syndrome.
“Vascular compression disorder and refers to the compression of the left renal vein between the superior mesenteric artery (SMA) and aorta. This can lead to renal venous hypertension, resulting in rupture of thin-walled veins into the collecting system with resultant hematuria.”
What is the arterial supply of the kidneys ?
Renal arteries, from the abdominal aorta
What is the veinous supply of the kidneys ?
Renal veins, into IVC
Describe the main divisions of the renal arteries.
• Each renal artery usually divides into 5 segmental arteries that enter the kidney at its hilum
• Lobar arteries arise from each segmental artery (1 for each renal pyramid)
• Before entering the renal substance, each lobar artery gives off 2 or 3
interlobar arteries
• The interlobar arteries run towards the cortex on each side of the pyramids
• At the junction of the cortex & medulla the interlobar arteries give off the arcuate arteries that arch over the bases of the pyramids
• The arcuate arteries give off several interlobular arteries that ascend in the cortex
• The afferent glomerular arterioles (that give blood directly into the renal corpuscle) arise as branches of the interlobular arteries
Describe the lymphatic drainage of the kidneys.
Lymph drainage to lateral aortic (lumbar) lymph nodes
Describe the nerve supply of the kidneys, including where referred pain takes place and any associated symptoms with this pain.
- Sympathetics from T11-L1
- Referred pain to the back & lumbar region (costovertebral angle) as well as loin to groin
- Afferents in the vagus nerve (CN X) may cause the nausea and vomiting associated with such pain
Define glomerular filtrate.
The fluid that passes from the blood through the capillary walls of the glomeruli of the kidney
Describe the path of the filtrate.
1) The filtrate coming from the collecting tubules empty through the renal papillae into minor calyces
2) Minor calyces empty, in turn, into two or three major calyces
3) Renal pelvis is the upper dilated portion of the ureter where major calyces empty into
4) Renal pelvis fills most of the renal sinus and continues as the ureter
5) Ureter empties into bladder
6) Urethra
State the dimensions (width, length) of ureters.
- 25-30 cm long
- 1-10 mm wide
- Right ureter is 1 cm shorter than left