K01 Anatomy Urinary System
The kidneys have some essential function;
Conserve body fluid and electrolytes and remove metabolic waste
Regulate water- and electrolyte balance, tissue osmolality, blood pressure, acid-base
balance
Function also as an endocrine organ: synthesis and secretion of erythropoietin (bone
marrow erythropoieses) and renin (blood pressure), causes activation of vitamin D
(Ca2+ metabolism)
The kidneys are high in the upper abdomen. The left kidney is a little bit higher in the upper
abdomen than the right one. This is caused by the liver, which is also on the right side. The
kidneys have no other relationship with other organs; this is why they are primary
retroperitoneal. The kidneys are surrounded by:
Perinephric fat; perirenal fat capsule = structural adipose tissue
Renal fascia; enclosing membranous layer, open inferiorly; also encloses the
suprarenal gland
Paranephric fat; pararenal fat body = retroperitoneal adipose tissue
The left renal artery is shorter than the right renal artery. The opposite holds for the vein. The
renal vein on the left side is longer, than on the right side because the right kidney is much
closer to the vena cava inferior.
Left renal vein: receives the left suprarenal vein and gonadal (testicular/ovarian) vein.
Clinical: renal vein entrapment syndrome; compression of the left renal vein between
the superior mesenteric artery anteriorly and abdominal aorta posteriorly.
The kidneys have a bean shaped, multilobes structure. They concave medially and
have a renal hilum (entrance). The renal hilum contains the vein (anterior), artery
(middle) and the renal pelvis (posterior). The renal pelvis is the urine collection system,
which transfers into the ureter. It also has autonomic nerves and lymphatic vessels.
The suprarenal gland is a separate organ that produces corticosteroids.
The fibrous capsule has 2 layers
(fibroblast, myofibroblasts); aids in
resisting volume and pressure
variations.
The kidney receives 25% of the
Cardiac Output. It is branched in 5
segmental arteries which are divided
in interlobular arteries. In the
medulla, it has an arcuate artery. In
the cortex; 90-95% of the blood is
present in the renal cortex.
2
, Physiology Basic Concepts | Carlita Verhoef
The nephron is the structural and functional unit of the kidney. It is situated in the cortex and
the medulla. The renal corpuscle (of malpighi) has two components; clomerulus and
Bowman’s capsule. The general organization of the nephron is as followed;
Proximal thick segment;
Proximal convoluted tubule (TC I)
Proximal straight tubule (TR I)
Thin segment
Thin part of the loop of Henle
Distal thick segment
Distal straight tubule (TR II)
Distal convoluted tubule (TC II)
The collecting tubule is outside of the nephron and contains the ductus colligens and
ductus papillaris. The thin segment is followed by a distal thick segment. This part goes to
the duct. On the distal convoluted tubule, less microvilli are present
Renal corpuscles;
Always in the cortex (cortical labyrinth and renal columns); subcapsular, intermediate
and juxtamedullary
Juxtamedullary nephrons have long loops of Henle*
Loop of Henle
Pyramidal part proximal straight tubule (TR I)
Thin segment
Pyramidal part distal straight tubule (TR II)
3
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller ceverhoef. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $4.88. You're not tied to anything after your purchase.