Lec 4: Comparative Male Anatomy Animal / Dairy Science 434 Lec 4: Comparative Male Anatomy

Testis Species Testis Wt. % Of Orientation (grams) Body Wt. bull 300+ .03 vertical ram 250 .3 vertical boar 350 .2 oblique stallion 200 .03 horizontal dog 25 .2 oblique rabbit 2.5 .1 vertical human 25 .03 vertical

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

Reproductive Organs of the Bull Vertical

Vertical Ram

Oblique Boar

Dog Oblique

Horizontal Stallion

Human Vertical

Testis Orientation Bull Tail Head

Testis Species Testis Wt. % Of Orientation (grams) Body Wt. bull 300+ .03 vertical ram 250 .3 vertical boar 350 .2 oblique stallion 200 .03 horizontal dog 25 .2 oblique rabbit 2.5 .1 vertical human 25 .03 vertical

Pelvic Urethral Muscle Bulbospongiosus Muscle Seminal Vesicles Ram Pelvic Urethral Muscle Cowper’s Gland Ampulla Prostate Bladder Vas Deferens Bulbospongiosus Muscle No Body of the Prostate

Bulbospongiosus Muscle Pelvic Urethral Muscle Cowper’s Gland Seminal Vesicles Prostate No Ampulla Large Cowper’s Vas Deferens Bulbospongiosus Muscle Pelvic Urethral Muscle

Bulbospongiosus Muscle Pelvic Urethral Muscle Prostate Cowper’s Gland Seminal Vesicles Ampulla Bulbospongiosus Muscle No Disseminate Prostate Pelvic Urethral Muscle Vas Deferens

Human No Disseminate Prostate

Pelvic Urethral Muscle Dog Pelvic Tract No Seminal Vesicles or Disseminate Prostate Pelvic Urethral Muscle Prostate Bladder Vas Deferens Bulbospongiosus Muscle

Cat (Tom) Reproductive Tract Cowper’s Gland Vas Deferens Prostate Corpus Cavernosum Glans Penis Crus Penis Ampulla No Seminal Vesicles or Disseminate Prostate

Cat (Tom) Reproductive Tract Note how close the cowper’s gland is to the penis in the cat.

Cat Glans Penis

Feline Anatomy: Erection and Mating

Accessory Glands Species Seminal Prostate Cowper's Vesicles body disseminate bull ++ + + + ram + - + ++ boar +++ + + +++ stallion +++ ++ - (+) + dog - ++ - - Cat - ++ - ++ human + ++ - +

Accessory Gland Secretions Gel Clot Clot Enzyme

Penis Types Muscular-Vascular Fibroelastic

Human Penis Cross Section Blood Vessels Corpus Cavernosum Large Veins Urethra Corpus Spongiosum

Stallion Bull Human Ram Cat Boar Internal Urethral Prepuce Raphe Process Stallion Raphe Bull Free End of Penis Glans Penis Human Filiform Appendage Ram Cat Boar

Comparison of Penis Types

Human

Sigmoid Flexure Boar Bull Fibroelastic Penis

Muscular-Vascular Penis Type Stallion

The Penis

Erection and Ejaculation Characteristics Species Speed of Ejaculate Semen Sperm Sperm Erection Time Volume Conc. Number bull rapid short medium medium- medium high ram rapid short small high medium boar rapid long large low high stallion slow moderate large low medium dog slow long large low low human slow moderate medium low low Large Testes = high sperm numbers Large accessory glands = large volume of the ejaculate with lower concentration of sperm

Seminiferous Tubule Primary Spermatocyte Spermatogonium Sertoli Cells Support spermatogenesis Myoid Cells Secondary Spermatocyte Leydig Cells Testosterone synthesis Round Spermatids Spermatids Basement Membrane Capillary

Seminiferous Tubules

Seminiferous Tubule

Sertoli Cell Sertoli Cell

Interstitial Tissue (space) Capillary Leydig Cell

Capillary Leydig Cells

Epididymis Principal Cell Basal Cell Stereo-Cillia

Cauda Epididymis near Vas Deferens

Sperm Smooth Muscle Vas Deferens