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60 Cards in this Set
- Front
- Back
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Gametes (sex cells) |
produced by each parent |
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Zygote (fertilized egg) |
has combination of both parents’ genes |
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Our cells contain pairs of chromosomes |
23 |
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Crossing Over |
Exchange of genetic material between non-sister chromatids of homologous chromosomes |
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Circumcision |
Removal of the prepuce |
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Spermatic cord |
bundle of fibrous connective tissue containing the ductus deferens, blood and lymphatic vessels, and testicular nerve |
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The human testes reside in the scrotum because |
they need this cooler environment |
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Scrotum has three mechanisms to regulate temperature of the testes |
Cremaster muscle: Dartos muscle Pampiniform plexus |
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Cremaster muscle |
strips of the internal abdominal oblique muscle In cold temperatures, contracts and draws testes upward toward body |
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Dartos muscle |
subcutaneous layer of smooth muscle Contracts when cold, wrinkling the scrotum, holding testes against warm body |
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Pampiniform plexus |
: an extensive network of veins from the testes that surrounds the testicular artery and spermatic cord |
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Pampiniform plexus |
Countercurrent heat exchanger—without the pampiniform plexus, warm arterial blood would heat the testis and inhibit sperm productionRemoves heat from the descending arterial bloodBy the time it reaches the testis, the blood is 1.5° to 2.5°C cooler |
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Testes (testicles |
combined endocrine and exocrine glands that produce sex hormones and sperm |
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Seminiferous tubules |
One to three in each lobuleEach tubule lined with a thick germinal epithelium for sperm generation |
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Interstitial (Leydig) cells between tubules produce |
testosterone |
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Sustentacular cells in between germ cells |
Protect the germ cells, and promote their development Germ cells depend on them for nutrients, waste removal, growth factors, and other needs |
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Blood–testis barrier (BTB)— |
formed by tight junctions between sustentacular cells Separates sperm from immune system Germ cells are immunologically different from body cells and would be attacked by the immune system |
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Spermatic ducts from testis |
to the urethra |
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Efferent ductules |
Transport sperm to epididymis |
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Duct of the epididymis (head, body, and tail |
Site of sperm maturation and storage (fertile for 40 to 60 days) Contains a single coiled duct, 6 m long, adhering to posterior of testis Sperm mature as they travel through the duct If not ejaculated, they disintegrate and epididymis reabsorbs them |
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Ductus (vas) deferens |
Muscular tube, 45 cm (18 inches) long, passing up from scrotum through inguinal canal to posterior surface of bladder |
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Ejaculatory duct |
2 cm duct formed from ductus deferens and seminal vesicle; passes through prostate to empty into urethra |
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Three sets of glands in male reproductive system |
Seminal vesicles Prostate gland Bulbourethral (Cowper) glands |
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Seminal vesicles |
Forms 60% of semen |
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Prostate gland |
Thin milky secretion forms 30% of semen |
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Bulbourethral (Cowper) glands
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Near bulb of penis During sexual arousal, they produce a clear slippery fluid that lubricates the head of the penis Protects the sperm by neutralizing the acidity of residual urine in the urethra |
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Benign prostatic hyperplasia (BPH |
noncancerous enlargement of the prostate Compresses urethra and obstructs flow of urine Promotes bladder and kidney infections |
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Prostate cancer |
Second most common cancer in men after lung cancer Diagnosed from elevated levels of serine protease (PSA) and acid phosphatase in the blood |
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Reproductive system remains dormant for several years after birth |
10 to 12 years in most boys; 8 to 10 years in most girls Surge of pituitary gonadotropins awakens the reproductive system, leading to onset of puberty |
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As hypothalamus matures it produces |
gonadotropin-releasing hormone (GnRH |
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GnRH stimulates anterior pituitary cells to secrete
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Follicle-stimulating hormone (FSH) Luteinizing hormone (LH) |
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Follicle-stimulating hormone (FSH) |
Stimulates sustentacular cells which stimulates spermatogenesis |
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Luteinizing hormone (LH) |
Stimulates interstitial cells to produce testosterone |
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Decline in testosterone secretion |
Peak secretion at 7 mg/day at age 20 Declines to one-fifth of that by age 80 Decline in the number and activity of interstitial cells (testosterone) and sustentacular cells (inhibin) |
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Rise in FSH and LH secretion after age 50 produces male climacteric (andropause) |
Most have little or no effect Some experience mood changes, hot flashes, “illusions of suffocation” |
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Erectile dysfunction (impotence)— |
the inability to produce or maintain an erection sufficient for intercourse |
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Spermatogenesis |
}processof sperm production in seminiferous tubules |
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Two forms of cell division |
Mitosis Meiosis |
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Mitosis |
a body cell doubles its DNA and then divides to produce two genetically identical daughter cells Basis for division of the single-cell fertilized egg, growth of an embryo, all postnatal growth, and tissue repair |
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Meiosis |
produces four gametes (haploid cells), each with only half the DNA of the diploid body cells |
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Once the primary spermatocyte undergoes meiosis, it |
becomes genetically different and needs to be protected from the immune system |
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Spermiogenesis—changes that transform spermatids into |
spermatozoa |
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Spermatozoon have two parts |
head and tail |
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Spermatozoon Head |
contains the nucleus, acrosome, and basal body of the tail flagella |
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Spermatozoon Nucleus |
contains haploid set of chromosomes |
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Spermatozoon Acrosome |
enzyme cap over the apical half of the nucleus that contains enzymes that penetrate the egg |
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Two requirements for sperm motility: |
elevated pH and an energy source |
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Chlamydia: |
may cause urethral discharge and testicular pain |
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Bacterial STDs |
Chlamydia Gonorrhea Syphilis |
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Gonorrhea |
pain and pus discharge; may result in sterility from pelvic inflammatory disease |
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Syphilis: |
hard lesions (chancres) at site of infection Disappearance of chancres ends first stageSecond stage is widespread pink rashNeurosyphilis is third stage with cardiovascular damage and brain lesions |
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Viral STDs |
Genital herpes |
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Genital herpes |
most common STD in United StatesBlisters and pain |
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Genital warts |
warts on perineal region, cervix, anusHepatitis B and C: inflammatory liver disease |
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Syphilis Bacterial infection transmitted sexually or contracted congenitallyInfected fetuses are stillborn or die shortly after birth |
Infection is asymptomatic for 2–3 weeksA painless chancre appears at the site of infection and disappears in a few weeks |
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Syphilis If untreated, secondary signs appear several weeks later for 3–12 weeks, and then disappear: pink skin rash, fever, and joint pain |
The latent period may or may not progress to tertiary syphilis, characterized by gummas (lesions (soft granulomas) of the CNS, blood vessels, bones, and skin) Treatment: penicillin |
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HIV |
50%The risk gay men in America face for contracting HIV.Overall for Americans, the risk is 1%. |
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Chlamydia Most common bacterial STD in the United StatesResponsible for 25–50% of all diagnosed cases of pelvic inflammatory disease |
Symptoms: urethritis; penile and vaginal discharges; abdominal, rectal, or testicular pain; painful intercourse; irregular menses Can cause arthritis and urinary tract infections in men, and sterility in women Treatment: tetracycline |
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Genital warts Caused by human papillomavirus (HPV) |
Second most common STD in the United StatesIncrease the risk of cancers in infected body regions |
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Genital herpes Caused by human herpes virus type 2 |
Characterized by latent periods and flare-upsCongenital herpes can cause malformations of a fetus Treatment: acyclovir and other antiviral drugs |
