Male Reproductive System (Ch. 28) Flashcards
What do the testes produce?
Sperm
The Testes and Scrotum
Testes are housed in scrotum (external sac, outside body cavity), divided into 2 compartments by a septum.
Cremaster muscle elevates or releases testes to maintain optimal temperature for sperm development (internal body temp. too high)
Average ~3 degrees cooler than body temp.
Spermatic Cord
Spermatic cord = ductus deferens, fascia, testicular vessels and nerves
Extends from scrotum to inguinal canal.
Medial opening = superficial inguinal ring; Deep inguinal ring is where ductus deferens and testicular vessels enter abdomen
Testes: Descent
Gubernaculum (fibrous tissue cord) extends form caudal end of developing testes through body wall and into skin of future scrotum.
Testes follow this path towards scrotum.
Spermatic cord (blood vessels, nerves, and sperm duct) follow testes
The Testes: Tunica Vaginalis and Tunica Albuginea
Inside scrotum, each testis is surrounded by a Tunica Vaginalis.
Deep to tunica vaginalis is fibrous Tunica Albuginea.
Seminiferous Tubules
Located within testes. Seminiferous tubules contain support cells (Sertoli cells) and dividing germ cells (future sperm).
Seminiferous tubule surrounded by CT that contains cells called Leydig’s cells. Leydig’s cells secrete testosterone.
Spermatogenesis
Takes ~75 days to create mature sperm
Begin as spermatogonia then primary and secondary spermatocytes, spermatids, and sperm.
~400 million sperm produced per day from puberty to death
Anatomy of a Mature Sperm Cell
Head contains a nucleus
Head is surrounded by an Acrosome - this has enzymes that will enable the sperm to penetrate the egg.
Mid-piece contains mitochondria for energy to propel the sperm
Tail is a flagellum for movement
The Epididymis
The epididymis is the site of sperm maturation and storage: protein secretions nourish the sperm and help maturation.
Ejaculation: smooth muscle in walls of epididymis contract, expel sperm into ductus deferens.
Ductus Deferens
aka Vas Deferens; transports sperm during ejaculation.
Extends form epididymis into pelvic cavity.
Vasectomy
Surgical method of birth control where ductus deferens is cut and ends are tied off.
Female version is tubal ligation (uterine tubes).
Urethra
Carries both urine and sperm
Includes prostatic urethra, intermediate [or membranous] urethra, and spongy urethra
Accessory Glands: Seminal Vesicles
Seminal vesicles (posterior to bladder) produce portion of seminal fluid. Join with ductus deferens to form ejaculatory duct.
The Penis
Penis delivers sperm into the female reproductive tract.
Erectile Tissue
Spongy CT filled w/ vascular spaces
Erection = filling of erectile tissues with blood (parasympathetic control).
- -corpus spongiosum = ventral
- -corpora cavernosa = dorsal (paired)
The scrotum is homologous to the ____ ____.
Labia majora
The scrotal midline is homologous to the ____ ____.
Labia minora
The glans penis is homologous to the ____ ____.
Glans clitoris
The corpus spongiosum is homologous to the ____ ____ ____.
Bulb of vestibule
The corpora cavernosa is homologous to the ____ ____.
Corpora cavernosa
The testes are homologous to the ____.
Ovaries
Accessory Glands: Prostate
Prostate (inferior to bladder) also produces some of seminal fluid. Holds prostatic urethra.
Secretions from seminal, prostate, and bulbourethral glands + sperm cells = ____.
Semen
The Ductus Deferens joins duct of seminal gland to form ____ ____, then passes through ____ and into urethra.
Ejaculatory Duct; Prostate
The root of the penis is the ____ - where it attaches to the pelvis. The ____ is the free portion.
Base; Body
The glans penis is the ____ end.
Enlarged
Skin covering penis is loose. Where it extends around the glans is ____ (foreskin).
Prepuce
Where do sperm travel (NOT the accessory organs)?
Sperm travel through epididymis, ductus deferens, ejaculatory duct, and out via the urethra.
Along the way sperm pass what accessory sex glands?
Seminal vesicle, prostate gland, and bulbourethral glands.
The Testes: Seminiferous Tubules
Testes are subdivided into 250-300 lobules containing seminiferous tubules.
Seminiferous tubules converge to straight tubule that carries sperm to Rete Testes.
The Testes: Rete Testes
Rete Testis leads through efferent ductules to epididymis
Hernia
Inguinal hernia when high pressure cause intestine to extrude through the deep inguinal ring
–very painful but easily repaired surgically
Sertoli cells are ____ ____.
Support cells
Leydig’s cells secrete ____.
Testosterone.
Erectile Tissue: During sexual stimulation, arteries dilate and blood flow ____.
Increases
Erectile Tissue: What maintains the erection?
Corpus cavernosum and spongiosum expand, compress veins that normally drain them…this maintains the erection.
Erectile Tissue: Ejaculation under Sympathetic Control
Smooth muscle contraction squeezes semen to urethra; bulbospongiosus muscle at base of penis squeezes semen out of urethra.
