Animal / Dairy Science 434Animal / Dairy Science 434Lec 4: Comparative Male AnatomyLec 4: Comparative Male Anatomy
TestisSpecies 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
Cowpers Gland
Caput Epididymis
Cauda EpididymisTestis
Scrotum
GlansPenis
Bladder
Ampulla
Seminal Vesicles
ProstateRectum
Vas Deferens
Gubernaculum
SigmoidFlexure
Retractor Penis
Muscle
Prepuce
Ram
Boar
Dog
Stallion
Human
Testis Orientation
Tail Head
Bull
TestisSpecies 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
Ram
No Body of the Prostate
Ampulla
SeminalVesicles
Prostate
BulbospongiosusMuscle
Cowper’s
Gland
Bladder
Vas Defere
ns
Pelvic Urethral Muscle
No AmpullaLarge Cowper’s
No DisseminateProstate
Human
No DisseminateProstate
Dog Pelvic TractProstate
Vas Defere
ns
Bladder
Pelvic Urethral Muscle
BulbospongiosusMuscle
Cat (Tom) Reproductive Tract
ProstateCowper’s Gland
Glans Penis
Corpus Cavernosum
Crus Penis
Vas Deferens
Ampulla
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 GlandsSpecies Seminal Prostate Cowper's
Vesicles body disseminate
bull ++ + + +
ram + - + ++
boar +++ + + +++
stallion +++ ++ - (+) +
dog - ++ - -
Cat - ++ - ++
human + ++ - +
Accessory Gland SecretionsSpecies Seminal
VesiclesProstate
Body+ DisseminateCowper’s
bull 30 6ram 8 6boar 30 40 30
stallion 30dog 70
human 70 25
GelGel
Clot Clot Enzyme
Penis TypesMuscular-Vascular Fibroelastic
Human Penis Cross Section
InternalPrepuce Raphe
UrethralProcess
Free End of Penis GlansPenis
FiliformAppendage
Bull
Ram
Boar
Stallion
Human
Cat
Comparison of Penis Types
Human
Sigmoid Flexure
Bull
Boar
Fibroelastic Penis
Muscular-Vascular
Penis Type
Stallion
The Penis
Erection and Ejaculation Characteristics
Species Speed of Ejaculate Semen Sperm SpermErection Time Volume Conc. Number
bull rapid short medium medium- mediumhigh
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 numbersLarge accessory glands = large volume of the ejaculate with lower concentration of sperm
»Support spermatogenesis
»Testosterone synthesis
PrimarySpermatocyte
Sertoli Cells
Leydig Cells
Capillary
BasementMembrane
Spermatids
Round Spermatids
SecondarySpermatocyte
Myoid Cells
SeminiferousTubule
SeminiferousTubule
Seminiferous Tubules
Seminiferous Tubule
Sertoli CellSertoli Cell
Leydig Cell
Capillary
Capillary
LeydigCells
Basal CellPrincipal Cell Stereo-Cillia
Epididymis
Cauda Epididymis near Vas Deferens
Vas Deferens
Smooth Muscle
Sperm
Urethra
LumenLumen
MuscleMuscle
CorpusSpongiosum
CorpusSpongiosum