Midterm 2 - Lecture 13 Flashcards
5 components of the semen manufacturing complex
- manufacturing center = testes
- finishing shop = excurrent ducts (forward section)
- warehouse shipping = excurrent ducts (hind section)
- final alteration & shipping = accessory sex glands
- delivery system = penis
2 primary functions of the scrotum
- houses and supports the testes
- temperature control of testes
What is the scrotum composed of
- scrotal skin - rich in sweat glands
- tunica dartos - smooth muscle that responds to temp
- scrotal lining - scrotal fascia & parietal vaginal tunic (connective tissue)
- gubernaculum - connective tissue attaching the testes to the base of the scrotum
What do the testes produce?
- spermatozoa
- androgens (ex. testosterone)
What are the testes composed of?
- Testicular Capsule
- visceral vaginal tunica and tunica albuginea (connective tissue) - Parenchyma
- functional layer of testis (making sperm)- contains seminiferous tubules - Mediastinum
- inner layer of connective tissue - house the ReteTubules which drain the seminiferous tubules
Testicular Parenchyma
- makes up the majority of the testicular tissue & is composed primarily of seminiferous tubules (site of spermatogenesis)
- also contains: (1) sertoli cells (within seminiferous tubules) (2) leydig cells (between seminiferous tubules)
Efferent ducts
drains rete tubules
Epididymus (head, body, tail)
- concentrates sperm (removes fluid)
- matures sperm
- stores sperm until ejaculation
Ductus Deferens
- connects the epididymus with the urethra - traverses the spermatic cord
Testicular “plumbing”
- seminiferous tubules
- rete tubules
- efferent ducts
- epididymus
- ductus deferens
What are the excurrent ducts?
Efferent Ducts, Epididymus, Ductus Deferens
What is the spermatic cord?
Tubular cord-like tissue that extends through the inguinal canal (passage btw the scrotal sac and abdominal cavity)
What does the spermatic cord contain?
- Testicular artery & vein = Pampiniform Plexus
- Lymphatic & Nervous Tissue
- Cremaster Muscle
- Ductus Deferens
What are the fxns of the spermatic cord?
- supports and maintains the testes
- temperature regulation
What are accessory sex glands?
- glands of the male repro tract that contribute the seminal plasma (fluid) to semen
*semen = sperm + seminal plasma
What are the 4 accessory sex glands?
- ampulla - enlargement of the ductus deferens that connects to urethra
- vesicular gland - contributes fluid, energy substrates and buffers to semen
- prostate - contributes fluid and inorganic ions (for buffering) to semen
- bulbourethral - flushes urine residues from the urethra and/or produce gel-fraction (sticky and produced at the end) of semen (first gland to produce pre-ejaculate)
What is the penis?
- organ of copulation on the males; forms around the urethra from the point where the urethra leaves the pelvis
What is the penis composed of?
- base - attached to the penile muscles
- shaft - main portion
- glans penis - specialized, highly enervated, shape varies dramatically btw species
Two types of penis common to livestock
- Vascular (stallion)
- Fibroelastic (bull, ram, buck, boar, tom, dog)
Vascular penis
- penis composed primarily of erectile tissue
- unstimulated penis is flacid and erection is caused by engorgement of erectile tissue with blood
Fibroelastic penis
- penis is rigid and often possesses a sigmoid flexure that permits the penis to retract completely into the body; less erectile tissue, more connective tissue
- retractor muscles relax to permit extension of the penis and contract to draw the penis back into the body
