Animal/Dairy Science 434 Learning Objectives
Male Reproductive Tract Anatomy • To be able to describe the male reproductive system in the stallion. – Structure – Function
Testis Epididymis Factory Finishing School Stallion Reproductive Tract • <1 - 25 X 109 sperm/day • Fluid Absorption • “Plant” must be air • 8-25 X 109 sperm Pelvic Tract conditioned – membrane changes – nuclear & flagellar stabilization – motility, fertility Penis – cytoplasmic droplet translocation Delivery System • Erection • Protrusion • Ejaculation Tail of Epididymis Warehouse and Delivery • Storage 10-50 X 109 sperm • Sperm for 5-10 ejaculates Testes • Smooth muscle contractions Accessory Sex Glands upon sexual stimulation Alterations & Packaging • Metabolic substrates • Surface coatings • Transport for sperm Penis
Reproductive Organs of the Stallion Reproductive Organs of the Stallion
Testis
Primary Sex Organ Tunica Vaginalis Tunica Albuginea Parietal Visceral
Scrotum Scrotal Cross Section - Stallion
• Thermosensor • Radiator • Protective sac
Scrotum
Scrotal Cross Section
Scrotal Longitudinal Section Equine Testis and Spermatic Chord a. Tunica Albuginea b. Seminiferous tubule c. Efferent Ducts d. Initial Segment e. Caput (head) f. Rete testis g. Corpus (body) h. Cauda (Tail) i. Vas Deferens
Varner and Johnson, 2007
Primary Sex Organ Mediastinum Rete Testis • Testes o Testosterone o Sperm
Seminiferous Secondary Sex Organs • Tubule Efferent Ducts • Epididymis o Caput o Corpus Interstitial Tunica Albuginea o Cauda Tissue • Vas Deferens
The Testis Varner and Johnson, 2007
Spermatic Chord Spermatic Chord Testicular Vas Deferens TV TA • Vascular, lymphatic and nerves Artery • Heat exchanger Testicular Vein • Houses cremaster muscle
Pampiniform Plexus EC VD Pampiniform Plexus • Counter Current Exchange Ø Arterial Blood 39C, 4.8 ng T/ml Ø Venus blood 34C, 70 ng T/ml External Cremaster Muscle Spermatic Chord Testis Arterial Pulse External Cremaster Muscle
Testicular Artery Testicular Artery In Spermatic Chord In Testes
Reproductive Organs of the Stallion Contraction of the Tunica Dartos
Testis Tunica Dartos • Smooth muscle
Tunica Dartos • Androgen dependent (Testosterone)
Reproductive Organs of the Stallion Reproductive Organs of the Stallion
Pelvic Genitalia
Gubernaculum Pelvic Genitalia of the Stallion The Stallion Bladder Seminal Cowper’s Body of Cowper’s Vesicles Gland Prostate Gland Seminal Bulbospongiosus Bulbospongiosus Vesicles Urethra Muscle Muscle Ampulla Vas Deferens Ampulla Crus Colliculus Seminalis Body of Penis Prostate Retractor Penis Muscle Pelvic Urethral No Disseminate Muscle Ischiocavernosus Vas Prostate Deferens Pelvic Urethral Muscle Muscle
Bulb of the Penis Reproductive Organs of the Stallion
Seminal Vesicles
Ampulla Prostate Rectum Cowpers Bladder Gland Vas Deferens Retractor Penis Muscle Gubernaculum
Cauda Caput Testis Glans Penis Scrotum
Cross Section of Stallion Penis Equine Penis Free Part Urethral Process Tunica Albuginea of Penis Corpus Cavernosum
Urethra Glans Penis
Bulbospongiosus Corpus Spongiosum Prepuce (Retracted) Muscle Retractor Penis Muscle Glans Penis
Urethral Process
Fossa Glandis (urethral sinus)