The Urinary System Flashcards Preview

Anatomy MD3002 > The Urinary System > Flashcards

Flashcards in The Urinary System Deck (25)
Loading flashcards...
1
Q

What are the main functions of the urinary system?

A
  • Stabilization of blood pH,
  • Regulates fluid balance,
  • Regulates electrolyte balance,
  • Blood pressure control,
  • Metabolism of toxic waste products and drugs,
  • Stimulates RBC production,
  • Required for absorption of calcium
2
Q

Describe the epithelium of the urinary system

A
  • The ureter and upper urethra are lined by urothelium which are capable of stretching.
  • Distal urethra is lined by a protective stratified squamous epithelium.
3
Q

Where are the locations of the kidneys?

A
  • Retroperitoneum.
  • Left Kidney is found in the left hypochondrium, epigastric, left lumbar and umbilical.
  • Right kidney is found in right hypochondriac, epigastric, right lumbar and umbilical.
4
Q

Explain the layers of tissue that surround the kidneys

A

Renal capsule, perinephric fact, renal fascia, paranephric fat, parietal peritoneum and the anterolateral abdominal wall muscles

5
Q

Explain the structure of the kidneys

A

It consists of an outer cortex and an inner medulla (renal pyramids and renal columns which are extensions of the cortex around pyramids) The apex of the pyramids (renal papillae) empty into the minor calyces which empty into major calyces, these then empty into the renal pelvis which continues as the ureter

6
Q

Describe the structure of a nephron

A
  • Renal corpuscle (bowmen’s capsule and glomerulus) - RC,
  • Proximal convoluted tubule (RC)
  • Loop of henle (RM)
  • Distal convoluted tubule (RC)
  • Collecting duct (RM)
7
Q

What is Nutcracker syndrome?

A

Compression of the left renal vein by the SMA. In males this results in varicocele in left spermatic cord

8
Q

Name the branches of the renal artery

A
  • Segmental artery,
  • Interlobar artery,
  • Arcuate artery (anastomosis between interlobar arteries),
  • Interlobular artery,
  • Afferent arterioles then to glomerulus.
9
Q

Explain the abdominal path of the ureter

A

In passes anterior to psoaj major and the branches of the lumbar plexus. It has a close relationship to gonadal vessels and crosses common iliac artery at its bifercation

10
Q

Explain the pelvic cource of the ureter

A

Females - Crosses umbilical artery, obturator neurovascular. Forms the posterior boarder of ovarian fossa. Crossed superiorly by uterine artery.
Males - Crosses umbilical artery, obturator neurovascular. Cross the ductus deferences

11
Q

Explain features of intramural ureter

A

It passes into the bladder obliquely creating a valve flap. The pressure of urine in the full bladder forces the valve closed which prevents ureteric reflux

12
Q

name the three ureteric constrictions

A

1) Pelvi-ureteric junction,
2) Ureter crossing the iliac vessels at the pelvic inlet,
3) Uretic orifice as it passes through the bladder wall

13
Q

Explain the innervation of the ureter

A
  • Nerve supply is derived from the renal, abdominal aortic and superior hypogastric plexuses.
  • Visceral afferent fibres to T11 to L2 so referred pain is mainly to loin, groin and scrotum/labia. Afferents in vagus can cause N/V
14
Q

Describe the blood supply to the ureter

A

It receives multiple arterial branches from;

  • Renal arteries,
  • Gonadal arteries,
  • Aorta,
  • Common iliac arteries
15
Q

What is the lymphatic drainage of the kidneys and ureter

A

Kidneys - Lateral aortic (lumbar) LNs,

Ureter - Lateral aortic, common and internal iliac LNs

16
Q

In males what sits between the bladder and rectum?

A

Seminal vesicles and the retrovesical septum

17
Q

Describe the clinical correlations of catheters and child birth with the bladder

A

Catheters can be places urethrally or suprapubically.

Repeated childbirth may weaken pelvic floor allowing for bladder drop which affects uriniary continence

18
Q

Describe features of the detrusor muscle

A

It is 3 layered smooth muscle which is internally lined by mucosa, it is involuntary (PSNS)

19
Q

Describe internal features of the bladder

A

Trigone - area between ureteric orifices and urethral orifice.
Urothelium - Urine proof and allows distention
Internal urethral sphincter (males) - involuntary and contracts to prevent passage of semen into the bladder

20
Q

Name the supportive structures of the bladder

A

Fascial condensations - eg, puboprostatic and pubovesical ligaments

21
Q

Name the different parts of the male urethra

A
  • Pre-prostatic urethra,
  • Prostatic urethra,
  • Membranous urethra,
  • Spongy (penile) urethra
22
Q

Describe the vasculature of the bladder and urethra

A

Arterial supply - Branches of internal iliac artery and internal pudendal.
Venous - Vesical (and prostatic) plexuses converging on internal iliac veins.
Lymph - Internal and external iliac nodes

23
Q

Describe the innervation of the bladder and urethra

A

From the inferior hypogastric (pelvic) plexus.
PSNS from S2-4 via pelvic splanchnic nerves (contracts detrusor muscle and relaxes internal urethral sphincter in males)
Sympathetics from T11-L2 (contract internal urethral sphincter in males)
Somatic motor from pudendal nerve (control of external urethral sphincter)

24
Q

Explain the first stage of micturition

A

Storage phase;

1) PSNS supply to detrusor muscle ‘off’ to allow for relaxation and filling.
2) When urine volume reaches {400-500m} then stretch receptors are activated.
3) afferents sent to S2-4) Inhibition lifted
5) Preganglionic OSNS fibres synapse with postganglionic fibres in walls of bladder = contraction of detrusor muscle

25
Q

Describe the second stage of micturition

A

Voiding;

1) Contraction of detrusor muscle by PSNS,
2) Relaxation of external urethral sphincter by pudendal nerve,
3) Contraction of abdominal wall,
4) Sensation of urine in urethra maintains the reflex