Urological Anatomy and Physiology Mr Andrew Sinclair

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Urological Anatomy and Physiology

• Mr Andrew Sinclair
• Consultant Urological Surgeon
• Stockport NHS Foundation Trust

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Overview

• Introduction
• Anatomy and clinical relevance
• Kidney
• Ureter
• Bladder
• Urethra
• Prostate
• Scrotum
• Physiology
• Renal
• Bladder Function
• Erection and Ejaculation

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Introduction

• Need to know the BASICS only
• Broad knowledge base
• Identify life threatening problems
• Dont harm the patient

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Surface markings of the kidneys

• 2 Kidneys
• Retroperitoneal Organs
• Each side of vertebral column
• From T12 to L3
• Right slightly lower because displaced inferiorly
  by the liver
• Hilum at L1

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Anatomy of the Kidneys Renal Vein
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Anatomy of the Kidneys Renal Artery
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Anatomy of the Kidneys

• Longer left renal vein crosses anterior to the
  Aorta
• From Anterior to Posterior
• Vein, Artery, Renal Pelvis
• Left gonadal vein drains into Left renal vein
• Right gonadal vein drains directly into IVC

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Microanatomy of the kidney

• 1.Renal Vein
• 2. Renal Artery
• 3. Renal Calyx
• 4.Medullary Pyramid
• 5.Renal Cortex
• Vasculature
• 6.Segmental Artery
• 7.Interlobar Artery
• 8.Arcuate Artery
• 9.Arcuate Vein
• 10.Interlobar Vein
• 11. Segmental Vein
• 12.Renal Column
• 13.Renal Papillae
• 14.Renal Pelvis
• 15.Ureter

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Anatomy of the Ureter
adrenal

• Ureters continue from the renal pelvis at L1
• 25 cm long
• Run inferomedially along the transverse processes
  of lumbar vertebrae
• Crosses pelvic brim at the SIJ anterior to the
  origins of the external iliac artery
• Runs anterior to the internal iliac artery in the
  pelvis
• Passes towards the ischial spine before turning
  towards the pubic tubercle and entering the
  bladder

kidney
ureter
bladder
urethra
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Relevance of Anatomy
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Anatomy of the Bladder
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Anatomy of Lower Male GU Tract
Prostatic Urethra
Membranous Urethra
Bulbar Urethra
Penile urethra
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Anatomy of the prostate
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Relevance of anatomy
Female catheterisation
Suprapubic catheterisation
Digital Rectal Examination
Male catheterisation
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Anatomy of the scrotum
Embryology

• Important area for medical students
• Chronic conditions
• Easily palpable
• Limited diagnoses
• Therefore easy to bring to exams

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Spermatic cord

• Runs through Inguinal canal
• The coverings of the cord arise from the layers
  from the inguinal canal
• Internal spermatic fascia from transversalis
  fascia
• Cremasteric fascia and muscle from transversus
  abdominis internal oblique
• External spermatic fascia from external oblique
  aponeurosis

• Contents of spermatic cord
• Ductus deferens (45cm)
• Testicular artery
• Artery to the ductus deferens
• Cremasteric artery
• Pampiniform plexus
• Sympathetic nerves
• Parasympathetic nerves
• Genital branch of genitofemoral nerve
• Lymphatics

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Layers of the spermatic cord and scrotum

• Peritoneum
• Transversalis fascia
• Transversus abdominis internal oblique
• External oblique
• Subcutaneous fat
• Skin
• CV Cavity of tunica vaginalis
• T Testis
• E Epididymis

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Scrotal Contents

• Testis covered by visceral layer of tunica
  vaginalis except where the testis is attached to
  the epididymis and spermatic cord.
• Parietal layer attached to internal spermatic
  fascia
• Fluid between layers allows movement

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Relevance of AnatomyIdentify origins of scrotal
lumps

• Is it attached / part of the testicle
• Is it separate from testicle
• Is it transilluminable
• Can you feel the testicle
• Can you get above it

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Relevance of AnatomyIdentify origins of scrotal
lumps
Epididymal cyst
Inguinal Hernia
Hydrocele
Testicular cancer
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Physiology
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Renal Physiology

• General understanding
• Complex physiology
• General principles

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Loop of Henle

• Countercurrent multiplier
• Relies on a concentration gradient between the 2
  limbs of the loop
• Requires energy
• Relatively small gradient BETWEEN the 2 limbs is
  magnified by the countercurrent to a relatively
  large gradient ALONG the limb of the loop
  involved
• Thick ascending limb
• continuous active transport of NaCl into
  interstitium
• Impermeable to H2O
• Descending loop
• Tonicity in equilibrium with the interstitium

Impermeable to H2O
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Salt and water balance
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Physiology of Micturition
Lateral corticospinal tract
Sympathetic T10-L2
Parasympathetic
S2, 3, 4
Intermediolateral column parasympathetic
Pelvic nerve Onufs nucleus - rhabdosphincter Ante
rior Horn Cell Nucleus pudendal nerve
periurethral striated muscle
somatic
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Physiology of erections and ejaculation.Central
erectile stimulation
Inhibitory stimuli anxiety fear
depression
Cerebralcortex
PVN
Spinal cord
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Neural input to erections

• In the flaccid state sympathetic dominance keeps
  arterioles and smooth muscle contracted
• Erections are primarily vascular in nature BUT
  from parasympathetic stimulation
• This leads to arteriolar dilation and trabecular
  smooth muscle relaxation.
• Pudendal nerve also has an input causing
  ischiocavernosus muscle contraction further
  increasing intracavernosal pressure

NB Nervi erigentes now called pelvic splanchnic
nerves NB The 2 Inferior hypogastic plexuses make
up the pelvic plexus
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Trabecular smooth muscle relaxation

• Dominant mediator is Nitric oxide NO released
  from parasympathetic nerve terminals
• Parasympathetic nerve terminal also releases Ach
  which stimulates vascular endothelium to also
  release NO

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Peripheral erectile stimulation
Parasympathetic and Sympathetic nerves from the
pelvic plexus pass within the cavernous nerve to
the penis
PDE5 Inhibitors Phosphodiesterase 5 Inhibitors
Examples of PDE5 inhibitors are Viagra, Cialis
and Levitra
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Physiology and anatomy of Erection
Erect State
Flaccid State
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Physiology of Ejaculation

• Ejaculation has 3 processes
• Closure of bladder neck (sympathetic)
• Emission (sympathetic)
• 1stly prostatic secretions
• Then seminal vesicle emptying
• Antegrade ejaculation (sympathetic and somatic)
• Somatic is the pudendal nerve causing contraction
  of the bulbocavernosus muscle.

Inferior mesenteric plexus
Superior hypogastric plexus
(sympathetic)
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Thank you