Disorders of the Male Reproductive System PDF

American University of Iraq – Baghdad College of Arts & Sciences Chapter 39 Disorders of the Male Genitourinary System BIO 218 – Pathophysiology Dr. Colette Kabrita-Bou Serhal...

American University of Iraq – Baghdad College of Arts & Sciences Chapter 39 Disorders of the Male Genitourinary System BIO 218 – Pathophysiology Dr. Colette Kabrita-Bou Serhal spring 2024 Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins 1  Male Reproductive Anatomy Testes: production of androgens & sperm. Ductile system: storage, maturation, & transport of sperm. Accessory genital organs: produce seminal fluid. Penis: urine elimination & sexual function. Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Histology: - Tunica vaginalis (derived from the peritoneum) - Tunic albuginea (dense connective capsule that forms the speta around the lobules inside the. Testis) - Seminiferous tubules: contain spermatogonia and Sertoli cells - Connective tissue stroma: contains Leydig cells 2 Testicular Function 2 main function: 1. Steroidogenesis 2. Spermatogenesis Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins 3  Androgens Testosterone – Main testicular hormone Dihydrotestosterone – Formed from testosterone in peripheral tissues – Produced by the enzyme 5-alpha reductase Androstenedione Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Estrogen is produced in small amounts. 4  Physiologic role of testosterone Anabolic effects: Increases protein synthesis (influences musculoskeletal growth) Promotes spermatogenesis Stimulates erythropoiesis Induces differentiation of male genital tract during fetal development (inlc. descent of the testes) Induces development of primary & secondary sex characteristics Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Testosterone: - Metabolized in the liver; excreted by the kidneys. - It circulates in the free (3% of the hormone) or bound forms. The bound form (major fraction) of the hormone is bound to albumin or sex hormone binding protein (SHBP). - In many tissues, it is converted into DHT (DHT is important to many tissues, such as the prostate gland). - Physiol. action: in fetus -> development of internal and external genitalia, as well as the descent of the testis; in aults -> protein synthesis, anabolic agebts and growth. 5 Spermatogenesis and semen production Role of Sertoli cells: - supply nutritional and physical support for germ cells - form a blood-testis barrier - help transport sperm along the tubule toward the lumen & release of mature sperm into the lumen - phagocytose damaged germ cell - secrete androgen binding protein (ABP) in response to FSH & testosterone Also secrete inhibin & plasminogen activator Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins 6 Ductile transport Transport of sperm from lumen into rete testis into epididymis. Epididymis: a reservoir for sperm (storage for several months) & a final site of sperm maturation. Ductus Deferens ends in the pelvic region with the ampulla (stores sperm for up to 5 weeks). Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins 7 Accessory genital glands Paired seminal vesicles: Secrete fructose, prostaglandins, proteins,.. Prostate gland: secretes milky alkaline fluid: citric acid, calcium, acid phosphate, a clotting enzyme, profibrinolysin. Paired bulbourethral glands: produce mucus-like secretions Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins 8  Hypothalamus Negative GnRH feedback Pituitary LH FSH Inhibin Interstitial cells Sertoli of Leydig cells ABP Plasminogen Testosterone Spermatogenesis activator, inhibin Maturation of sperm Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins ABP + testosterone → initiate spermatogenesis, promote maturation of spermatozoa, acts in epididymis. PA → detachment of mature spematoxoa from Sertoli cells Inhibin B → suppresses FSH only (-ve feedback regulation of FSH secretion). 9  Erection—Vasodilation Fills Spongy Tissue with Blood Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Neural innervation: - Sensory nerves in penis: mostly concenrated in the glans. - Motor nerves: - ANS (caverous nerves): control erection, ejaculation, and detumescence - somatic nerves (pudendal nerve): control sensation and contraction of muscles. Shaft: 3 masses of erectile tissue that are cavernous sinuses: - 2 corpora cavernosa (dorsal) - corpus spongiosum (ventral): encircles the urethra The male sex act involves interactin between spinal cord 10 reflexes (ANS), higher neural centers, and the vascular system: - erection: controlled by the PNS - emission - ejaculation: controlled by SNS - detumesence: controlled by the SNS 10 Neural Control of Male Sexual Function Physiology of male sex is a neurovascular process: involves the interaction between autonomic nervous system (mediated by spinal reflexes & higher neural control via the cavernous nerves), somatic nervous system (by way of pudendal nerve), the vascular system, and the sinusoidal spaces of the corpora cavernosa (trabecular smooth muscle). Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins 11  Erection is under parasympathetic control: mediated by NO which acts to activate cGMP -→ trabecular smooth muscle relaxation Ejaculation & detumescence (penile relaxation) are under sympathetic control: caused by cessation of neurotransmitter release, breakdown of cGMP, & contraction of trabecular smooth muscles Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Erection, - cotrolled by the PNS - a neurovascular process: neural: mediated by the ANS (PNS) & release of NO; vascular: mediated by venous costriction & the release of endothelial factors which cause relaxation of the vascular smooth muscles of blood vessels (arteries) and trabecular smooth muscles of the sinusoids -> engorgement of sunuses with blood. Smooth muscle relaxants include: NO PGE1 analogs alpha-2-adrenergivc antagonists 12  papaverine PDE-5 inhibitors Detumescence: - controlled by SNS - happens because of degradation of cGMP (by PDE- 5) and contraction of trabecular smooth muscles => blood outflow through the veins. 12 Disorders of the Male Reproductive System A. Erectile Dysfunction B. Testicular disorders C. Childhood Disorders Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins 13 A. Erectile dysfunction Inability to achieve and maintain an erection Causes: - psychogenic: performance anxiety, strained relationship, depression, schizophrenia, therapeutic drugs,.. - organic: most common can be neurogenic, hormonal, vascular, drug- induced, penile-related etiologies. - mixed (psycho.+org.) Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins 14 Treatment Psychosexual counseling Androgen replacement therapy Oral and intracavernous drug therapy Surgery Drugs: phosphodiesterase-5 (PDE-5) inhibitors PGE1 analogs a-2 adrenergic receptor antagonist smooth muscle relaxants Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins 15 B. Testicular Disorders Varicocele Hydrocele Testicular torsion (refer to the textbook) Inflammations – Epididymitis – Orchitis Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins 16 Testicular Torsion Twisting of the spermatic cord. Can be 1- Extravaginal (less common type): occurs only in prenatals or neonates during testicular descent. 2- Intravaginal (more common type) Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins 17 Intravaginal Torsion The testis rotates on its long axis in the tunica vaginalis (about the distal spermatic cord). Can be caused due to loose attachment between the epididymis & testis or the connective tissue. Occurs between ages 8-18 yrs Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins 18 Symptoms of Intravaginal Torsion Nausea Vomiting Tacchycardia Large tender testis (the affected one) Pain radiating to the inguinal area Thickening of the spermatic cord Scrotal swelling Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins 19 Clinical Manfestations of Testicular Torsion Testis high in the scrotum with abnormal orientation Scrotal swelling Absence of the Cremasteric reflex (i.e. no retraction of the testis upon streaking the mid aspect of the thigh). Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins 20 Treatment of Testicular Torsion Surgery (effective within 6 hrs): involves detorsion or orchiectomy. Prophylactic fixation of the unaffected testis. Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins 21 C. Childhood Disorders Hypospadias Epispadias Phimosis Paraphimosis Cryptorchidism (refer to the textbook) Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins 22 Embryonic Development and Descent of Testes Testes develop from embryonic kidneys Descend into scrotum through inguinal canal Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins 23