GU anatomy Flashcards
structures of the urinary system
2 kidneys, Ureters, 1 urinary , 1 urethra
appearance of the kidneys
- The kidneys are ‘ bean-shaped’
- The kidneys extend from T12-L3
- The right kidney is lower than the left, due to the liver sitting superior to it - They are Retroperitoneal – outside/behind the peritoneum
3 supportive tissue layers that surround the kidney
- Fibrous capsule
- Peri-renal fat capsule
- Renal fascia
Fibrous capsule of kidney
Is a transparent layer that covers the outer surface of the kidney. It helps to support kidney mass and protects the vital tissue from injury/infection.
Peri-renal fat capsule of kidney
Attaches the kidney to the posterior body
Renal fascia of the kidney
- An outer layer of dense fibrous connective tissue
- Anchors the kidney and the adrenal glands to surrounding structures
Kidney internal structures
cortex Medulla medullary (renal) pyramids renal columns renal pelvis hilum
Cortex of kidney
- Reddish-brown tissue layer, located immediately below the outer fibrous capsule
- It also surrounds the renal pyramids in the medulla
medulla of kidney
is the innermost layer comprised of renal pyramids
Appearance of Medulla
- striped appearance- due to being made of parallel budnles of microscopic collecting tubules and capillaries
- each pyramid constitutes a lobe of the kidney
Renal columns
- Separates the pyramids
- ## they are an extension of the cortex
Renal pelvis
- Funnel shaped tube
- continuous with the ureter
- extensions of the renal pelvis branch into major and minor calyces
renal pelvis (calyces)
- collect urine, which drain from the papilla and empties into the renal pelvis
Hilum of Kidneys
- concave medial border of the kidney where the renal blood vessels, lymph vessels and nerve enter and leave
VUJ abbreviation
Vesico-ureteric junction
Kidney Blood Supply: Arterial
- Aorta
- Renal artery
- 5 segmental arteries
- lobar arteries
- interlobar arteries
- arcuate arteries
- cortical radiate arteries (interlobular arteries)
Kidney blood supply: Venous
- interlobular veins
- arcuate veins
- interlobar veins
- renal vein
- IVC
kidney nerve supply: renal plexus
- A network of the autonomic nervous system
- Arises from the celiac plexus
- surrounds the renal artery
- Accompanies the …..into the kidney which it innervates (supply a body part with nerves)
position of the ureters
- From the renal pelvis (level of L2)
- lies behind the peritoneum
- enters the posterior bladder wall
Structure of ureters
they are tri-layered
- inner layer- made of transitional epithelium
- middle layer consists of smooth muscle for persistalsis
- outer layer - made of fibrous connective tissue
function of ureters
- transports urine
- bladder pressure prevents backflow…..
structure of the urinary bladder
- 12cm long
- holds 500 mls
- thin walled and muscular- smooth
- lined with epithelium
- rugae
- retroperitoneal
- interior openings - into the ‘trigone’ of the bladder
urinary bladder 3 layers of wall
- inner layer - muscosa
- middle layer - muscularis (detrusor muscle)
- outer layer - Adventita
Urethra
extends from the neck of the bladder to external
bladder meets the urethra
- internal urethral sphincter
- thickening of muscle
- involuntary sphincter
involuntary sphincter
keeps the urethra closed
prevents leakage of urine
Urethra: passing through the pelvic floor
- external urethral sphincter
- skeletal muscle
- Voluntary control
Urethra differences in males and females
Males - is substantially longer (20cm) and has 3 regions (prostatic urethra, membranous urethra and the spongy/penile urethra
females - 3-4cm in length
Nephron - functions
- filters the blood
- Balances water and electrolytes in the body
- produces urine containing metabolic waste products ……
types of Nephron
cortical and juxtamedullary
cortical nephron
- 85% of nephrons in kidney
- Located entirely in the cortex
- LoH (loop of Henle) ‘dips’ into medulla
juxtamedullary nephrons
- originate close to cortex/medulla junction
- LoH descends into the medulla portion of the kidney
component parts of the Nephron
- Glomerular/Bowmans capsule (glomerulus)
- Proximal convoluted tubule
- Loop of Henle ( Descending and Ascending limbs)
- Distal convoluted tubule
- collecting ducts
Glomerular/Bowmans capsule
- located at the end of the renal tubule
- cup shaped
- encloses the glomerulus
Glomerulus
- a tuft (a network of blood vessels) of capillaries, which bring unfiltered blood in to be filtered.
- Arises from arterial blood supply, which enter the kidney via the renal artery
parietal layer of Glomerular/Bowmans capsule
simple squamous epithelium - a single layer of flat scale-shaped cells
inner layer of Glomerular/Bowmans capsule
- This layer lines the capsule
- composed of podocytes…..
Gomerulus - afferent arterioles
These being blood to the Nephron …..
Glomerulus - efferent arterioles
these take blood away from the nephron ….
The Nephron - capillary beds and renal processes
