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Anatomy and Physiology of the Male

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Anatomy and Physiology of the Male 12/03/2019 Reproductive Biotechnologies – Andrology I Anatomy and physiology of the male Prof. Alberto Contri Anatomy of the male Glands of the reproductive tract Excurrent duct system Structures for the copulation Testis and membranes of the testis 1 12/03/2019 Anatomy of the male Gonads localization Perienal Inguinal What is common? Suspended outside the abdomen Anatomy of the male Scrotum - layers Integument Superficial Dartos Spermatic fascia superficial deep Cremaster muscle Deep Vaginal tunic parietal visceral 2 12/03/2019 Anatomy of the male Cremaster muscle Integument Dartos Scrotum Vaginal tunic parietal visceral Superficial Spermatic fascia Deep spermatic fascia Anatomy of the male Layers derived from the absominal wall Integument and subc. tissue Scrotum and dartos Superficial abdominal fascia Superficial vaginal (spermatic) fascia Muscles of the abdomen Cremaster muscle Deep abdominal fascia – Deep vaginal transversalis fascia (spermatic) fascia Peritoneum Vaginal tunic 3 12/03/2019 Anatomy of the male Scrotum – skin and dartos • Skin pouch • Suspension and protection of the testis • Involved in the termoregulation Anatomy of the male Cremaster muscle • Striated muscle • Voluntary muscle • Connected with the inguinal ring 4 12/03/2019 Anatomy of the male Spermatic fascia Component of the inguinal canal Aid movement of the testis Anatomy of the male Vaginal tunic Derived from the peritoneum Superficial Deep Form a vaginal cavity Follow the testes during the descent 5 12/03/2019 Anatomy of the male Testis Two crucial functions 1 - Gametogenic 2 - Endocrine Anatomy of the male Testis Different orientation in different species cranial caudal caudal cranial Stallion – ventrocaudal major axis Ruminants – vertical major axis caudal Dog and boar – dorsocaudal major axis cranial 6 12/03/2019 Anatomy of the male Vessels of the testis Spermatic cord Within the vaginal canal - deferent duct - testicular artery - testicular venous Evaluation – gap fill test ____ cremastermuscle ____ vaginaltunic ____ incomplete ____ cavity ____ spermaticfascia ____ complete ____ dartos ____ subcutaneoustissue ____ skin pouch ____ layers The scrotum is a __________(1)skin pouch containing the testis and it is made of a series of _________(2).layers The superficial _________(layers 2) are the integument and the ____________(3).dartos The deep ______layers __(2) are _____________(4),spermatic fascia followed by the ___________(5).vaginal tunic Between them, the _______________cremastere muscle (6) is incomplete in most mammals and attachs to the spermatic fascia. 7 12/03/2019 Physiology of the male Descent of the testis Original position near the kidney Moves at different ages – fetus Drived by the gumernaculum testis Physiology of the male Descent of the testis Residuals of the gubernaculum testis testicular proper ligament ligament of the epididymis tail scrotal ligament 8 12/03/2019 Physiology of the male Thermoregulation Working temperature lower (2-6°C) than body temperature Increased temperture affect sperm production Relative common cause of infertility in some species Physiology of the male Thermoregulation Mechanisms of thermoregulation: Mechanic: crematere muscle – tunica dartos Thermic exchange: pampiniferous plexus 9 12/03/2019 Physiology of the male Thermoregulation Evaporation at the scrotal surface Reduced temperature Reduced temperature of the arterial blood of the venous blood Thermal exchange between V and A at the pampiniferous plexus Physiology of the male 10 12/03/2019 Physiology of the male Thermoregulation Crucial effect of the temperature Transient temperature of 40.5 °C for 2 h Increased requirement of metabolic support Cellular suffering and apoptosis (primary spermatocytes; spermatogonia B; spherical spermatids) Physiology of the male Thermoregulation Thermography in normal and abnormal bull testes 11 12/03/2019 Anatomy of the male Testis Structure Deep vaginal tunic Albuginea tunic Testicular capsule Connective supports to the lobuli (200-300) testicular mediastinum Anatomy of the male Testis Structure Each testicular lobule scaffold of connective tissue capillar network compaction of the seminuferous tubules 12 12/03/2019 Anatomy of the male Testis Structure Seminiferous tubule Convoluted portion (spermatogenesis) Straight portion (excretion) Anatomy of the male Testis C. Seminiferous tubule 1) Interstitial 2) Basal 3) Adluminal 13 12/03/2019 Anatomy of the male Cells of the testis Interstitial compartment Loose connective tissue– myoid cells Blood vessels Leydig cells in small clusters Anatomy of the male 14 12/03/2019 Anatomy of the male Cells of the testis Leydig cells Close proximity to the vessels Secretion of steroid hormones Regulation of the spermatogenesis Control of the reproductive endocrine axis Activity of accessory sexual glands Anatomy of the male Cells of the testis Basal compartment Sertoli cells Germinal cells (Spermatogonia) 15 12/03/2019 Anatomy of the male Cells of the testis Sertoli cells Rest on the lamina propria Extensive cytoplasma to the lumen Pivotal role in the spermatogenesis Anatomy of the male Cells of the testis Sertoli cells 1) blood-testis barrier 2) support and nutrition of germinal cells 3) movement of germinal cells to the lumen 4) discharge of mature spermatids 5) phagocytosis of degenerated cells 6) secretion of fluids 7) cell-to-cell comunication 16 12/03/2019 Anatomy of the male Cells of the testis Germinal cells Spermatogonia Basal c. Spermatocytes different types Spermatids Adluminal c. Spermatozoa for different develpmental stages Evaluation – match Sertoli cells Interstitial comparment Spermatozoa Spermatids Myoid cells Basal compartment Spermatogonia Spermatocytes Adluminal compartment Leydig cells 17 12/03/2019 Anatomy of the male Excurrent duct system Straight portion of the seminiferous tubule Rete testis – a network of small cannals Efferent ducts Epididymis Deferent duct Urethra Anatomy of the male Epididymis Continuates the efferent ductules Unique high-convoluted canal with different regions 18 12/03/2019 Anatomy of the male Epididymis 1) Sperm maturation 2) Synchronization Spermatogenesis Ejaculation Anatomy of the male Epididymis Macroscopic-based classification of the portion of the epididymis 19 12/03/2019 Anatomy of the male Epididymis Microscopic-based classification of the portion of the epididymis Functional point of view region 1: resorption and secretion region 2: maturation region 3 storage Anatomy of the male Ampulla Deferent duct Deferent duct Bladder Continuation of the epididymis Thick wall of smooth muscle Limited role in the maturation Movement of spz to urethra In some species, modified distal portion - ampulla 20 12/03/2019 Anatomy of the male Accessory sexual glands Liquid component of the semen Part related to the reproductive system vesicular glands Part related to the urethra prostate bulbo-urethral glands Anatomy of the male Accessory sexual glands Different features in different species Vesicular glands Stallion Conglomerated prostate Bulbourethral glands 21 12/03/2019 Anatomy of the male Accessory sexual glands Large vesicular glands Large disseminated prostate Bull Small conglomerated prostate Bulbourethral glands Anatomy of the male Accessory sexual glands Different features in different species Dog Conglomerated prostate 22 12/03/2019 Anatomy of the male Accessory sexual glands Large vesicular Boar glands Prostate Large bulbourethral glands Anatomy of the male Penis Structure for the deposition of the semen in the female genital tract Wide functional differences at reproductive rest at reproductive stimulation 23 12/03/2019 Anatomy of the male Penis Structural composition urethra erectile strucures skin pouch (at rest) Anatomy of the male Penis Erection modification of the blood balance Increase in arterial imput Decrease in venous output accumulation of blood in cavernous tissue 24 12/03/2019 Anatomy of the male Penis Structural classification different feature of the erectile structures cavernous fibro-elastic Anatomy of the male Penis Structural classification different feature of the erectile strucures cavernous 25 12/03/2019 Anatomy of the male Penis fibroelastic 26.
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