Animal Dairy Science 434 Lec 4 Comparative Male

Animal / Dairy Science 434 Lec 4: Comparative Male Anatomy

Testis Species Testis Wt. (grams) % Of Body Wt. bull 300+ . 03 vertical ram 250 . 3 vertical boar 350 . 2 oblique stallion 200 . 03 horizontal 25 . 2 oblique . 1 vertical . 03 vertical dog rabbit human 2. 5 25 Orientation

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

Ram

Boar

Dog

Rectum Ampulla Seminal Vesicles Ureter Prostate Gland Vas Deferens Cowper’s Gland Spermatic Cord Retractor Penis Muscle Cauda Epididymis Caput Epididymis Gubernaculum Glans Penis Testis Stallion Corpus Epididymis

Human

Testis Orientation Bull Tail Head

Testis Species Testis Wt. (grams) % Of Body Wt. bull 300+ . 03 vertical ram 250 . 3 vertical boar 350 . 2 oblique stallion 200 . 03 horizontal 25 . 2 oblique . 1 vertical . 03 vertical dog rabbit human 2. 5 25 Orientation

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

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

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

Human No Disseminate Prostate

Dog Pelvic Tract Prostate Pelvic Urethral Muscle Bladder Vas Deferens Bulbospongiosus Muscle

Cat (Tom) Reproductive Tract Vas Deferens Prostate Cowper’s Gland Corpus Cavernosum Crus Penis Ampulla Glans Penis

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

Accessory Gland Secretions Gel Clot Enzyme

Penis Types Muscular-Vascular Fibroelastic

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

Internal Prepuce Raphe Urethral Process Stallion 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 Erection Ejaculate Time Semen Volume Sperm Conc. Sperm Number bull rapid short mediumhigh medium rapid short small high medium boar rapid long large low high stallion slow moderate large low medium dog slow long large low human slow moderate medium 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 Basement Membrane Capillary

Seminiferous Tubules

Seminiferous Tubule

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