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Male Reproductive System. Veterinary anatomy. Male Reproductive System. The male reproductive system consists of the Scrotum Testes Spermatic cord Excurrent duct system Epididymis Ductus deference Urethra Accessory sex glands Penis. Scrotum. Functions Thermoregulation - PowerPoint PPT Presentation
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Male Reproductive System
Veterinary anatomy
Male Reproductive System
The male reproductive system consists of the
Scrotum Testes Spermatic cord Excurrent duct system
EpididymisDuctus deferenceUrethraAccessory sex glandsPenis
Scrotum
Functions Thermoregulation
Sweat glands Thermosensetive nerves
Protection and support of testis
- The scrotum is a two lobed sack. It protects and supports
the testes and is required for proper temperature regulation.
- The scrotum consists of four major layer. They are: 1) the skin. 2) the tunica dartos
Smooth muscleElevate testes for a sustained period of time in
response to temperature or stress3) the scrotal fascia 4) parietal tunica vaginalis
- The scrotal skin is heavily populated with sweat glands. These sweat glands are required for maintenance of proper testicular temperature. Sweating allows the scrotum to be cooled by evaporative heat transfer.
Scrotum
Descent of testes into scrotumTiming:
Sheep / cattle = midgestation Humans / horses = just before or after
birth
Testes
FunctionsProduce male germ cells (spermatozoa) Produce testosterone, inhibin and estrogen
Testes Structure:Structure:
1. Testicular capsule
2. Parenchyma
3. Mediastinum
4. Rete tubules (rete testis)
5. Efferent ductules
Testes - Structure
1- Testicular capsule
1)Tunica vaginalis Visceral Parietal
2) Tunica albuginea
TestisTestis
Testes - Structure
2- Parenchyma
A- Tubular compartmentSeminiferous tubules
B- Interstitial compartmentLeydig cellsCapillariesLymphatic vesselsConnective tissue
Testes - Structure
3- MediastinumCentral connective tissue core that houses
rete tubules
4- Rete tubules (rete testis)Tiny channels thru which spermatozoa
transported out of testis
Testes - Structure
5. Vasa efferentia (efferent ductules)
a. Collect sperm from rete testis
b. Carry sperm out of testis proper
Testes
Seminiferous tubulesSite of sperm productionConsists of 2 cell types:
Germ cells (eventual sperm cells) Sertoli or nurse cells
Testes
Sertoli cells Surround developing germ cellsProvide structural & metabolic support to
spermatogenic cellsProduces:
Androgen binding protein (ABP) Inhibin Sulfated glycoprotein
Testes
Blood-testis Barriers
a. Cells surrounding seminiferous tubules
b. Prevent autoimmune reaction from destroying developing germ cells
Testes
Leydig cellsLocated between seminiferous tubulesProduce androgens (testosterone)
Epididymis
Three partsHead (caput)Body (corpus)Tail (cauda)
Epididymis - Functions
Sperm Transport MaturationMotilityConcentrationStorageGains ability of fertilization
Vas Deferens
Ductus deferens or deferent ductPaired ducts
Ampulla Wide end of vas deferens
Function Sperm transport from epididymis to pelvic
urethra
Spermatic Cord
- spermatic cord extends from the inguinal ring to it’s attachment on the dorsal pole of the testis. It suspends the testis in the scrotum.
- The function of the spermatic cord is provides the pathway to and from the body for testicular vasculature, Lymphatic and nerves.
Spermatic Cord
- The spermatic cord also houses the ductus deferent, cremaster muscle and specialized vascular network called the pampiniform plexus.
- The pampiniform plexus is a vascular structure
consisting of an intimately intertwined artery and vein and this structure is important for proper temperature control of the testis
Spermatic Cord - Functions
Suspends testis in scrotumPathway to blood vessels, lymphatics, & nervesThermoregulation mechanism
Pampiniform plexus Cremaster muscle
Pulse pressure eliminator
Spermatic CordSpermatic Cord
Accessory Sex Glands
Vesicular glands (seminal vesicles)Prostate glandBulbourethral glands (Cowper’s gland)Ampulla of ductus deference
Vesicular Glands
Paired glandsLocated at junction of urethra & vas deferensRough structureContribute large amount of fluid
Fructose & sorbitol: energy sourcesPhosphate & bicarbonate: buffers
Seminal vesicle
• Absent in camel, dog and cat.• Lobulated type in ox and pig• Vesicular type in horse.
• Shape:• Pyramidal in pig• Elongated and lobulated in ox, sheep and goat• Elongated sac in horse
Prostate Gland
Located caudal to seminal vesicles and close proximity to pelvic urethra
Bilobed in bull
Diffuse in ram
Surrounds urethra in dogs & humans
Function = cleanse & lubricate and secretes just prior during ejaculation
Only accessory gland in dog
Prostate Gland
• The prostate gland of the dog is spherical, smooth and divided into right and left lobes which completely surrounded the urethra.
• In the cat the prostate gland has an uneven surface and covers the urethra dorsally and laterally only.
Bulbourethral Glands
Paired glandsBuried under bulbospongiosus muscleFunction:
Cleanse urethra prior to ejaculation Produce gel fraction Adds considerable volume
Colliculus Seminalis
Region of urethra where sperm mixes with
seminal vesicle secretions
Mixing incomplete in stallion
Sperm-free fraction & Sperm-rich fraction
Comparative of accessory sex gland
AnimalsSeminal vesicle
Ext. prostate Int. prostate
Bulbourethral Ampulla
Horse ++-++
Ox +++++
Sheep&goat +-+++
Camel -++++
Dog -+--+
Cat -++++
Pig ++++-
Penis
Male copulatory organ Consists of
BaseShaftGlans penis
Penis
Cavernous bodies:Corpus spongiosumCorpus cavernosum
Penis
Sigmoid flexure Ram, buck, bullAllows penis to be retracted inside body until
erection occurs
Penis
Retractor penis musclePair of smooth muscleDorsally attached to tail vertebrae Holds penis inside sheath
Glans Distal end of penis, contains sensory nerves
SheathCovers penis
Penis
Two Types1. Fibroelastic
Bull, buck, ram, dog2. Vasomuscular
Stallion, human
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