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

Prostate Rectum Reproductive Cowpers Reproductive Seminal Vesicles Gland Organs of the Ampulla Organs of the Bull Bladder Bull

Vas Deferens Retractor Penis Glans Muscle Penis Sigmoid Flexure

Caput Epididymis Scrotum Vertical Prepuce Testis Cauda Epididymis Gubernaculum

Ram Boar

Vertical

Oblique Dog Stallion

Horizontal Oblique

Testis Orientation

Bull

Tail Head

Human Vertical

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 Seminal Ram Pelvic Vesicles Urethral Muscle Ampulla Cowper’s Gland

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

Human

Prostate Seminal Cowper’s Gland Vesicles

Ampulla No Disseminate Prostate No Disseminate Bulbospongiosus Muscle Prostate Pelvic Urethral Muscle Vas Deferens

Dog Pelvic Tract No Seminal Vesicles or Pelvic Disseminate Prostate Urethral Prostate Muscle

Bladder

Vas Deferens Bulbospongiosus Muscle Cat (Tom) Reproductive Tract Cat (Tom)

Cowper’s Gland Reproductive Vas Deferens Prostate Corpus Cavernosum Tract

Note how close the Crus Penis Glans Penis cowper’s gland is to the penis in the cat. Ampulla No Seminal Vesicles or Disseminate Prostate

Feline Anatomy: Cat Glans Penis Erection and Mating

Accessory Glands Accessory Gland Secretions

Species Seminal Prostate Cowper's Species Seminal Prostate Cowperʼs Vesicles Body+ Disseminate Vesicles body disseminate bull 30 6 ram 8 6 bull ++ + + + boar 30 40 30 Gel ram + - + ++ stallion Gel 30 dog 70 boar +++ + + +++ human 70 Clot 25 Clot Enzyme stallion +++ ++ - (+) + dog - ++ - - Cat - ++ - ++ human + ++ - + Penis Types Muscular-Vascular Fibroelastic Human Penis Cross Section Blood Vessels

Corpus Cavernosum

Large Veins

Urethra Corpus Spongiosum

Internal Urethral Raphe Comparison of Penis Types Prepuce Process Stallion

Bull

Free End of Penis Glans Penis

Human Filiform Appendage Ram

Cat Boar

Human Sigmoid Flexure

Boar Bull Fibroelastic Penis Muscular- The Penis Vascular Species Sigmoid Type Erectile Glans Penis Type Flexure Tissue

bull yes FE + Glans ram yes FE + Glans boar yes FE + not distinct stallion no MV +++ Large Glans dog no MV +++ Large Glans human no MV +++ Large Glans

Stallion

Seminiferous Erection and Ejaculation Tubule Characteristics Species Speed of Ejaculate Semen Sperm Sperm Primary Spermatocyte Erection Time Volume Conc. Number Spermatogonium bull rapid short medium medium- medium high Sertoli Cells Myoid Cells » Support ram rapid short small high medium spermatogenesis Secondary boar rapid long large low high Spermatocyte Leydig Cells stallion slow moderate large low medium » Testosterone Round Spermatids dog slow long large low low synthesis Spermatids human slow moderate medium low low

Large Testes = high sperm numbers Basement Large accessory glands = large volume of the ejaculate with lower Membrane concentration of sperm Capillary

Seminiferous Tubules Seminiferous Tubule Interstitial Tissue (space)

Capillary

Leydig Cell Sertoli Cell Sertoli Cell

Capillary Leydig Cells

Epididymis

Principal Cell Basal Cell Stereo-Cillia Cauda Epididymis near Vas Deferens Sperm

Smooth Muscle

Vas Deferens