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
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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
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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
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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
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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
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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
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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.
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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
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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
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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
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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
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Anatomy of the male Testis
Structure
Seminiferous tubule
Convoluted portion (spermatogenesis)
Straight portion (excretion)
Anatomy of the male Testis
1) Interstitial
2) Basal
3) Adluminal
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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
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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)
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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
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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
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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
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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
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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
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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
bulbo-urethral glands
Anatomy of the male
Accessory sexual glands
Different features in different species
Vesicular glands
Stallion Conglomerated prostate
Bulbourethral glands
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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
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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
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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
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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
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Anatomy of the male
Penis
fibroelastic
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