Chapter 11 Flashcards
Genital organs
Male internal and external genitalia
Genitourinary system
The structures of the genitourinary system include the external genitalia and the internal genitalia. The genitourinary system shares some structures with the urinary system and is also known as the urogenital system.
Corpora cavernosa
Two columns of erectile tissue along the upper surface of the penis. They fill with blood during sexual arousal.
Corpus Spongiosum
Column of erectile tissue along the underside of the penis. It fills with blood during sexual arousal.
Epididymis
Long, coiled structure of the outer wall of each testis. It receives spermatozoa fro the seminiferous tubules, adds a cap-like layer of enzymes to them, and destroys defective spermatozoa.
Glans penis
Enlarged tip at the end of the penis
Gonads
The male sex glands
Inguinal canal
Opening in the abdominal wall muscle of a fetus. Each testis and its spermatic cord pass through the inguinal canal on their way to the scrotum.
The opening of the inguinal canal usually closes before age 2.
Interstitial cells
Cells between the seminiferous tubules of the testes. They secrete testosterone when stimulated by luteinizing hormone (LH).
Lumen
Central open area throughout the length of a tube or duct (such as the seminiferous tubule, vas deferents, ejaculatory duct, or urethra)
Penis
Organ that contains three columns of erectile tissue that fill with blood during sexual arousal to make an erection. At other times, the penis helps urine to be removed from the body via the penile urethra.
Penile urethra
Part of the urethra that is within the penis. It is the passageway for semen and for urine. The urethral meatus is at the tip of the glans penis.
Perineum
Area on the outside of the body between the posterior scrotum and the anus.
Prepuce
In uncircumcised males, the prepuce is a fold of skin that covers the glans penis.
Also known as the foreskin.
Scrotum
Pouch of skin behind the penis that holds each testis, epididymis, and part of each vas deferns. Muscles in the wall of the scrotum move it closer to or farther away from the body to control the temperature of the scrotum for sperm production.
Seminiferous tubules
Small, tightly coiled tubes within each testis that produce spermatozoa.
Spermatic cord
A tube that, before birth, contains the vas deferents as well as arteries, veins and nerves for each testis.
In the fetus, each testis and its spermatic cord pass through the inguinal canal and into the scrotum.
There the spermatic cord separates into the vas deferens and the other structures.
Spermatozoon
An individual mature sperm. Each spermatozoon has a head and a tail (flagellum) that propels it forward.
A spermatozoon is a gamete because it is a cell whose nucleus of 23 chromosomes can unite with another cell nucleus of 23 chromosomes (the egg of the female) to form a new cell of 46 chromosomes.
Testis
Egg-shaped gland in each side of the scrotum. Also known as a testicle.
It contains interstitial cells that secrete testosterone and seminiferous tubules that produce spermatozoa.
The testis is an endocrine gland because it secretes testosterone; it also secretes a small amount of the female hormone estradiol.
Testosterone
Most abundant and most biologically active of the male sex hormones.
It is secreted by the interstitial cells of the testes. It stimulates spermatozoa to mature. It stimulates the development of secondary sexual characteristics in the male.
Vas deferens
Long duct that receives spermatozoa from the epididymis and stores them.
As each vas deferens travels superiorly, it becomes part of the internal genitalia in the pelvic cavity.
Bulbourethral gland
Small, bulb-like gland on the side of the urethra after the urethra leaves the prostate gland.
Each gland produces thick mucus that makes up part of the semen.
The duct of the gland empties into the urethra.
Ejaculatory duct
Collecting duct that holds spermatozoa from each vas deferens and fluid from each seminal vesicles. The ejaculatory duct enters the prostate gland and joins with the prostatic urethra.
Prostate gland
Doughnut-shaped gland at the base of the bladder. The prostatic urethra goes through its center.
The prostate gland produces prostatic fluid, a milky fluid that becomes part of the semen.
Prostatic urethra
Part of the urethra that goes through the center of the prostate gland.
Semen
Fluid expelled from the penis during ejaculation. Semen contains spermatozoa, seminal fluid, prostatic fluid, and mucus from the bulbourethral glands.
Seminal vesicles
Elongated gland that forms a V-shaped pair along the posterior wall of the bladder and merges into the ejaculatory duct.
Each seminal vesicle produces seminal fluid, which makes up most of the volume of semen and contains fructose (sugar) as a source of energy for spermatozoa.
Vas deferens
Long duct that continues from the external genitalia into the pelvic cavity.
Each vas deferens goes behind the urinary bladder and ends as it merges with the seminal vesicle.
Coitus
Action in which the male deposits semen in the female’s vagina.
Also known as Sexual intercourse.
Ejaculation
Sudden spelling of semen from the penis during sexual arousal of the male.
Erection
The corpora cavernosa and corpus spongiosum become distended with blood during sexual arousal. Begins constrict to keep the blood in the penis and maintain the erection.
Follicle-stimulating hormone (FHS)
Hormone secreted by the anterior pituitary gland during puberty. It causes the seminiferous tubules of the testes to enlarge during puberty and stimulates spermatocytes in the seminiferous tubules to begin dividing.
Gamete
A cell (male spermatozoon or female egg) that has 23 chromosomes instead of the usual 46 chromosomes like other body cells.
Luteinizing hormone (LH)
Hormone secreted by the anterior pituitary gland during puberty. It stimulates the interstitial cells of the testes to begin secreting testosterone.
Meiosis
Process by which an spermatocyte reduces the number of chromosomes in its nucleus to 23, or half the normal number, to create gametes.
Mitosis
Process by which most body cells divide. The 46 chromosomes in the cell nucleus duplicate and then divide to create two identical cells, each with 46 chromosomes.
Puberty
Beginning of sexual maturity when FSH and LH from the anterior pituitary gland begin to stimulate the testes to produce testosterone.
Testosterone stimulates the development of male secondary sexual characteristics, and there is a growth spurt.
Also known as Adolescence. The period of time between 11 and 19 years of age when sexual maturity occurs.
Semen
A combination of spermatozoa and fluids from the seminal vesicles, prostate gland, and bulbourethral glands. It is expelled through the urethral meatus during ejaculation.
Spermatocyte
Immature, round cell in the seminiferous tubules that obtains 46 chromosomes.
Spermatogenesis
Process of producing mature sperm or spermatozoa
Testosterone
Causes the development of the male secondary sexual characteristics.
Enlargement of the external genitalia; development of large body muscles; deepening of the voice; growth of body hair on the face, chest, axillae, and genital area; and development of the sexual drive.
FSH
Follicle-stimulating hormone
LH
Luteinizing hormone
GU
Genitourinary
Gynecomastia
Enlargement of the male breast. It is caused by an imbalance of testosterone and estradiol.
This occurs during puberty or aging or it can occur because of surgical removal of the testes or from a female hormone drug used to treat prostate cancer.
Treatment: Androgen (male hormone) drug; plastic surgery to decrease the breast size.
Cryptorchidism
Failure of one or both testes to move through the inguinal canal and descend into the scrotum.
This causes a low sperm count and male infertility because spermatozoa need the lower temperature of the scrotum to develop properly.
Also known as cryptorchism
Epididymitis
Infection or inflammation of the epididymis. It is caused by a bacterial infection in the urinary tract or by a sexually transmitted disease such as gonorrhea or chlamydia.
Treatment: antibiotic drug
Infertility
Inability of a male to impregnate a female after 1 year of regular sexual intercourse.
This can be caused by a hormone imbalance of FSH or LH, undescended testes, a varicocele, damage to the testes from a childhood infection of the mumps, infection in the testes, too few spermatozoa, or abnormal spermatozoa.
Treatment: Correct the underlying cause.
Oligospermia
Fewer than the normal number of spermatozoa are produced by the testes.
This is the most common reason fro male infertility. It is caused by a hormone imbalance or undescended testes.
Treatment: Correct the underlying cause.
Orchitis
Infection or inflammation of the testes.
Caused by a bacterial or viral infection, a childhood infection of the mumps, or trauma to the testes.