AnimalDairy Science 434 Male Reproductive Tract Anatomy Learning

Animal/Dairy Science 434 Male Reproductive Tract Anatomy

Learning Objectives • To be able to describe the male reproductive system in the bull. – Structure – Function

Testis Factory • 1 -25 X 109 sperm/day • “Plant” must be air conditioned Penis Delivery System • Erection • Protrusion • Ejaculation Epididymis Finishing School • Fluid Absorption • 8 -25 X 109 sperm – membrane changes – nuclear & flagellar stabilization – motility, fertility – cytoplasmic droplet translocation Tail of Epididymis Warehouse and Delivery Accessory Sex Glands Alterations & Packaging • Metabolic substrates • Surface coatings • Transport for sperm • Storage 10 -50 X 109 sperm • Sperm for 5 -10 ejaculates • Smooth muscle contractions upon sexual stimulation

Bull Reproductive Tract

Reproductive Organs of the Bull

Reproductive Organs of the Bull Primary Sex Organ Testis

Bull Testis

Bull Tract • • • Thermosensor Radiator Protective sac Scrotum

Bull Tract Longitudinal Section Cross Section

Scrotal Cross Section

Scrotal Longitudinal Section

Structure of the Testis Seminiferous Tubule Tunica Albuginea Rete Testis (within the mediastinum)

Mediastinum Rete Testis Seminiferous Tubule The Testis

Structure of the Testis Seminiferous Tubule Tunica Albuginea Rete Testis (within the mediastinum)

Structure of the Testis Secondary Sex Organs Caput Epididymis Spermatic Cord Vas Deferens • Vasectomy Vas Efferentia 6 -12 tubules Corpus Epididymis Cauda Epididymis

Structure of the Testis Caput Epididymis Spermatic Cord Vas Deferens • Vasectomy Vas Efferentia 6 -12 tubules Seminiferous Tubule Tunica Albuginea Corpus Epididymis Rete Testis (within the mediastinum) Cauda Epididymis

Spermatic Chord • Vascular, lymphatic and nerves Pampiniform Plexus • Heat exchanger • Houses cremaster muscle Testicular Artery Pampiniform Plexus • Counter Current Exchange Ø 39°C - 34°C Ø 70 ng T/ml - 4. 8 ng T/ml

Testis Arterial Pulse Spermatic Artery Pampiniform Plexus Testicular Artery

Spermatic Chord Pampiniform Plexus

Bull Tract Tunica Dartos

Contraction of the Tunica Dartos Testis Tunica Dartos • Smooth muscle • Androgen dependent (Testosterone)

Bull Tract Gubernaculum

Bull Tract Pelvic Genitalia

Pelvic Genitalia of the Bull Pelvic Urethra Muscle

Bull

Bulb of the Penis

Reproductive Organs of the Bull Rectum Prostate Cowpers Gland Seminal Vesicles Ampulla Bladder Retractor Penis Muscle Vas Deferens Sigmoid Flexure Glans Penis Caput Epididymis Scrotum Testis Gubernaculum Cauda Epididymis

Cross Section of Bull Penis

Penis Cross Section

Glans Penis of the Bull Free Part of Penis Urethral Process Raphe Prepuce (Retracted) Glans Penis

Urethral Process Glans Penis Raphe Free Part of Penis Prepuce (Retracted)

Arterial Supply

Reproductive Organs of the Bull Rectum Prostate Cowpers Gland Seminal Vesicles Ampulla Bladder Retractor Penis Muscle Vas Deferens Sigmoid Flexure Glans Penis Prepuce Caput Epididymis Scrotum Testis Gubernaculum Cauda Epididymis