Male Reproductive System Flashcards
(32 cards)
What are the organs of the male reproductive system?
Testes
System of Ducts (epidydimitis, ductus deferens, ejaculatory ducts, bulbourethral glands)
Supporting structures (scrotum, penis)
What are the testes?
Paired oval glands that produce sperm and secrete hormones.
Develop in the abdominal activity and descend into the scrotum in the seventh month of the fetal development.
Lobules
Covered by a dense white capsule that divides each teste into lobules
Each of the 200-300 lobules contains 1-3 tightly coiled seminiferous tubules
Tubules are lined with sperm forming cells called spermatogenic cells
After a sperm cell is formed it is released into the lumen of the seminiferous tubule.
What are Sertoli cells?
Nourish sperm cells and release the hormone inhibin.
What are the leydig cells?
Secrete testosterone
What is the most important androgen?
Testosterone
Promotes libido and male characteristic development
What is the scrotum?
Pouch that supports the testes.
Septum divides the strum into two sacs each containing a single teste.
Production and survival of sperm is optimal 2-3 degrees Celsius below body temp.
Maintained with scrotum outside pelvic cavity.
Cremasteric muscle raises and lowers the teste to adjust temperature.
Where does sperm production occur?
In the testes and consists of meiosis 1, meiosis 2, and spermatogenesis.
Results in the formation of four haploid sperm cells from a primary spermatocyte.
Begins during puberty and continues throughout life.
From onset until release is 65-75 days.
Spermatogonia contain the diploid number of chromosomes 2N=46
Spermatogonia undergo mitosis
One stays in tubule as stem cell spermatagonia
Other turns into primary spermatocyte
Which spermatocyte undergoes meiosis 1?
Primary, resulting in two haploid secondary spermatocyte
Which spermatocyte undergoes meiosis 2?
Secondary, resulting in four haploid secondary spermatids
What is the final stage of spermatogenisis?
One spermatocyte creating four sperm.
At what rate is sperm produced?
300 million a day
Most don’t survive 48 hrs once ejaculated
What are the major parts of sperm?
Head- DNA and Acrosome
Tail-mitochondria and flagellum
What is the epidydimis?
Tightly coiled ductus epidydimis. Stores sperm and helps propel them during sexual arousal to the vas deferens.
This is where spermat mature and acquire motility and ability to fertilize an egg
Can remain in storage for several months
What makes up the spermatic cord?
Ascending with the vas are blood vessels, nerves, lymphatic vessels and cremasteric muscle.
What are the ejaculatory ducts?
Formed by the Union of the duct of the ductus deferens and the seminal vesicles. Carry sperm to the urethra.
What is the urethra?
Terminal duct of the male reproductive system. Passes through prostate, deep perineal muscles and penis.
What do the accessory sex glands do?
Secrete most of the liquid portion of semen.
Seminal vesicles
Prostate
Bulbourethral glands
What are the seminal vesicles?
Pouch like structures sitting posterior to the base of the urinary bladder.
Secrete an alkaline viscous fluid.
Secrete most of the liquid portion of semen and contain fructose, prostaglandin and clotting proteins.
Helps neutralize acidic nature of urethra and female reproductive tract.
60% of semen volume
What is the prostate?
Single doughnut shaped gland about the size of a golf ball.
Inferior to bladder, surrounds the upper portion of the urethra.
Secretes a milky, slightly acidic fluid 6.5 that contains citric acid, phosphatase, and protein digesting enzymes.
25% of semen volume
What are the bulbourethral glands?
Inferior to the prostate on either side of the urethra.
Secrete an alkaline substance into the urethra which protects the passing sperm by neutralizing acids from urine in the urethra.
Mucus that lubricators the end of the penis and lining of the urethra decreasing sperm damage.
What is semen?
Mixture of sperm and the secretions of the seminal vesicles, prostate,, and bulbourethral glands.
Volume of semen in a typical ejaculation is 2.5-5mL, with 50-150 million/mL.
Slightly alkaline ph of 7.2 to 7.7 due to higher ph and other volume of fluid from the seminal vesicles.
Prostatic secretion is what gives it a milky appearance.
Fluids from the seminal vesicles and bulbourethral glands give it a sticky consistency.
What is the penis?
Contains the urethra, root, body, and gland penis and serves as the passageway for ejaculation of semen and excretion of urine.
Root-attached portion
Body- two corpus cavernosa, one corpus spongiosum(spongiousum contains urethra)
Distal end of spongiosum is glans penis.
What is an erection?
Enlargement and stiffening of the penis.
Parasympathetic impulses
Dilation of penile arteries
Volume compresses veins and drainage is slowed
What is ejaculation?
Powerful release of semen from the urethra to the exterior. A sympathetic reflex.
