Male Reproduction Male Reproduction - PowerPoint Presentation

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Male Reproduction

Male ReproductionFunction:Produce and deliver fertile sperm to the female reproductive tractProduce the hormone Testosterone

Job:Fertilize the female egg

Important TermsFibroelastic Penis vs. Vascular PenisFibroelastic

: uses the sigmoid flexure and retractor muscle to become erectVascular: will fill with blood to become erectThermoregulation: regulation of the temperature of the testes to support fertile sperm productionCryptorchidism: when one or neither testes descend into the scrotum during the fetal stages

Convoluted: contains many veinsVasectomy: procedure to sterilize a maleSpermatogenesis: formation and growth of sperm

HormoneTestosteroneProduced by: Leydig Cells (found in the testicles)

Function:Promotes spermatogensisPromotes secondary sex characteristicsExample: horn growth or bright colored feathers in male birds

Male ReproductionImportant Organs:Scrotum

Tunica DartosSpermatic CordDuctus Deferens/Vas DeferensPampiniform PlexusCremaster Muscle

TesticlesEpididymisPenisFibroelastic vs. Vascular

ScrotumHouses the testesFunction:

ProtectionTemperature Regulation (thermoregulation)Movement of the testesLayers:SkinSweat Glands located hereThermal ReceptorsTunica Dartos

MuscleAssists in thermoregulation

Testes

Skin

Tunica

Dartos

Epididymis

Spermatic CordDescription: highly convolutedFunction:

Suspend the testes in the scrotumProvide heat cooling systemHouses:Ductus Deferens/Vas Deferens:Move fertile sperm from the tail of the epididymis to the penis for ejaculationThis is cut and causes a VasectomyPampiniform

PlexusComposed of a testicular artery and veins that cool the blood before circulating throughout the scrotumCremaster muscleSupports the testesMuscle that will pull testes up during a fight or flight situationHolds testes up for a

short period of time

Pampiniform

Plexus

TesticlesFunction:Produce Sperm

Produce the hormone TestosteroneProduce 1-25 Billion spermMust be 3-6 degrees cooler than the body to keep sperm aliveTakes 45-60 days to produce fertile sperm

Testicular Descent

In the Fetal stage the testes will descend into the scrotumThis is important for proper sperm production and temperature control

Gubernaculum:Pulls the testes through the Inguinal Ring into the scrotumInguinal Ring:Ring that is the opening between the body and scrotumCryptorchidism:Def

: Failure of one or both of the testes to descend through the inguinal ring into the scrotumUnilateral Cryptorchidism: one testis does NOT descend into the scrotumResults in reduced fertile sperm concentration

NOT

infertile

Bilateral Cryptorchidism:

Neither

testes descend into the scrotum

Results in

Sterility/Infertility

Inguinal Ring

EpididymisFunction:Sperm TransportSperm Maturation

Storage of Sperm3 Components:Head (Caput)Body (Corpus)Tail (Cauda)

Ductus

Deferens

Epididymis ContinuedHead (Caput)Entry point of produced sperm from the testes

Sperm are NOT motileSperm are NOT fertileBody (Corpus)Maturation of SpermSome expression of motilitySome expression of fertilityTail (Cauda

)Sperm StorageSperm are motileSperm are fertile5-10 ejaculations are storedSperm can bind to an egg

PenisOrgan of fertilization of the female2 Types:

Fibroelastic PenisSigmoid Flexure (S-curve)Rectractor Penis MuscleVascular PenisSpecies Differences:Fibroelastic Penis:

Boar, Bull, and RamVascular PenisStallion and Humans

Sigmoid Flexure

Retractor Penis

Muscle

Vascular Penis

Fibroelastic

Penis

Species DifferencesBullFibroelastic

PenisRamFibroelastic PenisFiliform AppendageBoarFibroelastic PenisNonpendulous

& Inverted testicles (tail of epididymis is above the head of the epididymis)Cork Screw Shape (match for the sows corkscrew cervix)StallionVascular PenisBell Shaped PenisNO Sigmoid Flexure

Penis ContinuedFibroelastic Penis:

Extends in length by a muscle to penetrate the femaleRetractor Muscle Helps with erectionSigmoid Flexure‘S curve’ that holds penis within the body when not erected or helps extend the penis when erectedExamples: Bull, Boar, and RamSpecies Differences:

Ram:Filiform Appendage: Sprays sperm within the vagina for better chance of fertilizationBoar:Corkscrew shaped penis: Matches the sows corkscrew shaped cervix

Filiform

appendage

Penis ContinuedVascular PenisPenis fills with blood to become erectDoes

NOT include sigmoid flexure Examples:Stallion Human

Sterilization TechniquesCastrationRemoval of the testicles

VasectomyCutting or severing of the Ductus DeferensShortening of Spermatic cordShortening of the spermatic cord to raise the testicles closer to the bodyRaising the testicles closer to the body will cause the temperature to become too hot causing sperm to die or become sterile

ThermoregulationThermoregulation is important for the survival of fertile spermSperm will die if:

Testes become too hotTestes need to be 3-6 degrees cooler than the bodyHeat will damage DNA within the spermHeat will cause lower levels of fertilityTestes become too coldCome in contact with bloodWays of thermoregulation

Thermoreceptors located on the scrotum sends messages to the brain when too hot or too coldWill cause panting to help dissipate heat from the bodySweat glands located on the scrotum will allow for cooling

Tunica Dartos Muscle:Muscle layer beneath the skin of the scrotum will expand when too hot and will

lift the testes up

towards the body

if too cold

Thermoregulation ContinuedHow Thermoreceptors and sweat glands communicate with the brain

SpermatogenesisDefinition: formation of Sperm

Sperm are formed and grow within the testesWithin the testes sperm are grown inside of the seminiferous tubules within the lobules2 Cell Types:Leydig Cells:Produce testosteroneLocated outside the seminiferous tubulesSertoli

Cells:Protect and aid in growing spermAid in SpermatogenesisLocated inside the seminiferous tubules

Testes

Ductus

Deferens

Sperm TransportSeminiferous TubulesEpididymis

HeadBodyTailVas Deferens

PenisInto the Female Tract

Penis

Sperm Anatomy

Head:Carries the DNA

Mid-Section (neck)StructureHolds the head to the tailTailMotorDrives the sperm throughout the male reproductive tract and female reproductive tract to the site of fertilization

Mid-Section

Head

Tail

Sperm MeasurementsSperm is measured by Volume (mL) and Concentration (x106/mL)Species differences:

Species

Volume (mL)Concentration (x106/mL)

Ram 12000Bull

10

1000

Stallion

100

500

Boar

200

250