Anatomy of urinary tract system Flashcards
List the components of urinary system
- right and left kidney
- urinary bladder
- urethra
- ureter
- left and right suprarenal glands
(around: diaphragm, oesophagus, IVC, abdominal aorta, right and left renal arteries and veins, uterus/ovary/testes, rectum)
Detail the functions of the structures of the urinary system
Kidneys:
- Regulate body fluid, electrolyte balance, and acid-base balance (homeostasis).
- Remove metabolic waste and toxins (uric acid, nitrogenous wastes).
- Perform endocrine functions (EPO, Vitamin D).
Ureters:
- transports urine from the kidneys to the bladder
Bladder:
- stores urine
Urethra:
- discharges urine from body
Hilum
- where vessels and ducts enter and exit the organ, roughly located at L1
- kidney rule of three : homeo, waste, endocrine: HEW
What is the hilum?
Hilum
- where vessels and ducts enter and exit the organ, roughly located at L1
Describe the functions of kidney or what can go wrong e.g. in chronic kidny disease
- Acid-base balance: metabolic acidosis
- Water removal: pulmonary oedema
- Erythropoiesis: anaemia
- Toxin removal: uraemia
- Blood pressure control: hypertension
- Electrolyte balance: hyperkalaemia
- Vitamin D activation: bone-mineral disorder of chronic kidney disease (CKD-BMD)
What are the indications e.g. for dialysis?
- Acidosis
- Electrolyte abnormalities
- Ingested toxins
- FluidOverload
- Uraemia
What are some surface anatomy markers that are relevant for identifying the kidneys?
- superior and inferior angles of the scapulae
- C7 spinous process
- pubic symphysis
- can construct Morris’ parallelogram to locate kidney
- midline identified by c7 spinous process
- bordered at top by inferior angles of scapulae
- the middle line at T11 is the transpyloric plane
- kidneys sit between two longitudinal lines,
Describe kidney in terms of its relations to other structures
The kidneys are related to various organs superiorly, inferiorly, posteriorly, and anteriorly.
* Left kidney is located higher than right kidney, because the right sits just under the liver
- Superiorly, kidneys are related to the diaphragm and suprarenal glands
- Inferiorly, the posterior surface of the kidney is related to the quadratus lumborum muscle
- Posterior aspect of the kidney:
- Subcoastal nerve and vessels
- Ilio-hypogastric n
- Ilio-inguinal n
- Anterior aspect of the R kidney is related to:
- liver (sup)
- Duodenum (sup, ant)
- Ascending colon
- Anterior aspect of the L kidney is related to:
- Stomach
- Spleen
- Pancreas tail
- Jejunum
- Descending colon
Describe the coverings of the kidney
The kidney is covered by three layers: fibrous capsule (renal capsule), adipose capsule (perirenal fat), and renal fascia, going from inside to out.
FAR
True or false: kidneys are intraperitoneal
FALSE
recall SADPUCKER
How is the renal vasculature organised at the hilum?
The renal vasculature, including the renal vein, renal artery, and ureter, is observed from superior to inferior and anterior to posterior.
Note the mnemonic: VAD
mainly ant to post
Describe the division of the kidneys
- kidney is divided into renal lobes
- can be persistently lobulated, as a consequence of development
- can function normally like this
A single kidney contains 7-9/18 renal lobes, each of which include a renal pyramid and renal cortex.
Kidney is also divided into segments
- renal artery splits into segments e.g. apical, upper, middle, lower, posterior in order to provide the different segments of the kidney
- it divides even further until it reaches the level of the glomerulus
- note: there are no segmental veins
Describe the internal featurs of the kidney
- renal cortex
- medulla
- column
- renal sinus
- renal papilla
- renal capsule
- nephron
- renal pyramid
- minor and major calyx
- renal pelvis
- ureter
- renal artery
- renal vein
Describe the flow of urine
- collecting duct
- papillary duct in renal pyramid
- minor calyx
- major calyx
- renal pelvis
- ureter (passing pelviureteric junction — one of three constriction points)
- urinary bladder
Describe some devlopmental issues
- horseshoe: occurs when moving kidneys into position during development (ascending from pelvis); more common in males; symptoms include UTIs
- pancake: completely fused, results in frequent UTIs
Describe ther arterial and venous supplies and drainage
renal arteries located at L1
- just above superior mesenteric artery
- note the arm of right renal artery is longer than left
- longer left arm of renal vein
- note that gonadal vein on left drains directly
- this increases chance of varicoceles on left side, as there are no valves between the veins
Aorta– splits of into renal arteries – splitting into segmental – interlobar – arcuate – interlobular – afferent arterioles, breaks into glomerular capillaries, draining into efferent arterioles, which split into either peritubular capullaries and into interlobular veins, or straight into vasa recta and interlobular veins, into arcuate veins, interlobar veins, renal veins and IVC
Describe the ureters
clinicallyrelevant bladder expands and pushes on ureter, to prevent backflow
The ureters play a crucial role in transporting urine from the kidneys to the bladder. The ureters are lined with smooth muscle; this enables transport of the urine in peristaltic motion.
Three constrictions:
- junction of renal pelvis with ureter (ureteropelvic junction)
- crossing iliac blood vessels at pelvic brim
- ureters enter bladder (oblique course, functions like a valve)
The abdominal part of the ureters is retroperitoneal and has specific vasculature.
The abdominal part of the ureters are retroperitoneal, running inferomedial beyond the
bifurcation of the common iliac artery
Vasculature of ureters:
- Arterial supply: renal artery, testicular/ovarian arteries, abdominal aorta (in lower aspects)
- Venous drainage: drain into renal and testicular/ovarian veins
- nervous supply from T12-L2
constrictions – site of stone formation
Compare and contrast male and female ureters
- males: ureters lie posterolateral to ductus deferens
- females crossed superiorly by uterine artery
Describe bladder
The bladder is responsible for storing urine.
It is a hollow midline organ.
It holds urine pre-expulsion.
It is also lined with smooth muscle: detrusor muscle.
Note the rugae: these increase the surface area.
More rugae adds to expansive capacity.
Note the three orifices, forming the trigone region:
- two ureteric orifices
- internal urethral orifice
Compare and contrast male and female bladders
Males and females have different features and locations.
. In women, the bladder is located in front of the vagina and below the uterus. In men, the bladder sits in front of the rectum and above the prostate gland
![[Pasted image 20230730125012.png]]
Five components
- apex
- base (posterior surface)
- superior surface (covered with peritoneum)
- inferolateral surfaces (two)
- neck
-
- typically sits above pubic symphysis, so can insert suprapubic catheter
- position depends on amount of filling
- extraperitoneal
- intra-abdominal, above the pubis in children (new born male)
Female
- note that bladder sits anterior and inferior to uterus
- reduced capacity in pregnancy
Note the internal and external sphincters (these are also present in male bladders).
The urethra is the small tube connecting the bladder to the outside of the body. The male urethra is about 20 centimetres long, while the female urethra is shorter, about four centimetres.
The detrusor is thicker in men than women, as greater voiding pressure is needed to empty the bladder through the longer urethra of males [7].
Males supposedly have larger capacity although there is limited evidence on this topic
What is the bladder composed of?
transitional cells
Describe urethra between males and females
Males
There are four parts:
- prostatic urethra
- membranous urethra
- bulbar urethra
- penile urethra
Two sphincters:
- internal sphincter: bladder neck sphincter (smooth muscle)
- external sphincter: prostatomembranous sphincter (striated muscle)
Note other nearby structures: seminal vesicles, scrotum ,testes, penis, epididymis, vas deferens
Females:
nOTE: pubic symphysis, vagina, ovaries, fallopian tubes
Risk of UTIs greater because urethra is straighter, wider and shorter
