Urological Anatomy and Physiology

1. Urological Anatomy and Physiology Mr Andrew Sinclair Consultant Urological Surgeon Stockport NHS Foundation Trust

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

3. Introduction • Need to know the BASICS only • Broad knowledge base • Identify life threatening problems • Don’t harm the patient

4. 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

5. Anatomy of the Kidneys: Renal Vein

6. Anatomy of the Kidneys: Renal Artery

7. 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

8. 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

9. 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

10. Relevance of Anatomy

11. Anatomy of the Bladder

12. Anatomy of Lower Male GU Tract Prostatic Urethra Membranous Urethra Bulbar Urethra Penile urethra

13. Anatomy of the prostate

14. Relevance of anatomy Female catheterisation Suprapubic catheterisation Digital Rectal Examination Male catheterisation

15. Anatomy of the scrotum Embryology • Important area for medical students • Chronic conditions • Easily palpable • Limited diagnoses • Therefore easy to bring to exams

16. 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 Spermatic cord

17. 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

18. 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

19. Relevance of Anatomy:Identify 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

20. Relevance of Anatomy:Identify origins of scrotal lumps Epididymal cyst Inguinal Hernia Hydrocele Testicular cancer

21. Physiology

22. Renal Physiology • General understanding • Complex physiology • General principles

23. 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

24. Salt and water balance

25. Physiology of Micturition Lateral corticospinal tract Sympathetic T10-L2 Parasympathetic S2, 3, 4 Intermediolateral column – parasympathetic – Pelvic nerve Onuf’s nucleus - rhabdosphincter Anterior Horn Cell Nucleus – pudendal nerve – periurethral striated muscle somatic

26. Erectogenic stimuli– erotic imagery – audiovisual – tactile – olfactory Site of action – dopamine receptors in PVN PRO-ERECTILEneural signalling Physiology of erections and ejaculation.Central erectile stimulation Inhibitory stimuli– anxiety – fear – depression Cerebralcortex PVN Spinal cord

27. 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

28. 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

29. 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

30. Physiology and anatomy of Erection Erect State Flaccid State

31. 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)

32. Thank you