Chapter 21 Flashcards
What do organisms that utilize sexual reproduction must produce?
Gametes.
What are gametes?
Haploid sex cells united in fertilization.
Where is sperm produced and matured?
Produced in the testes and matures in the epididymis. Maturation involves gaining motility.
Describe the male genital tract.
Sperm passes through the vas deferens where they can be stored. Each vas deferens empties into an ejaculatory duct which connects to the urethra.
What 3 glands contribute to semen?
Seminal vesicles, prostate gland, and bulbourethral glands.
Describe seminal vesicles.
Paired, and contribute to most fluid of semen. Vitamins, proteins, and fructose in fluid for sperm nourishment.
Describe prostate gland.
Single, secretes a slightly alkaline fluid which helps sperm motility and looks milky. Muscles of prostate push semen into urethra.
Describe bulbourethral glands.
Pea-sized organs. Lubricates distal urethra. Neutralizes remaining urine in urethra.
Describe the penis.
Male organ of sexual intercourse. Long shaft and enlarged tip called glans penis. At birth, glans penis covered by foreskin.
Describe erection and orgasm in males.
Spongy, erectile tissue containing distensible blood space extends through penis shaft. Arousal increases blood flow to penis causing an erection. Autonomic nerves release nitric oxide.
What are some causes of ED (erectile disfunction)?
Poor blood flow, certain medications, and many illnesses.
What happens when sexual stimulation intensifies?
Sperm enters from the vas deferentia, and glands contribute secretions to the semen. Semen is ejaculated followed by refractory period.
Describe the testes.
Produce sperm and male sex hormones. Located outside of the abdominal body cavity. Scrotum helps regulate temperature of the testes. Have lobules.
What is contained in a lobule in the testes?
1-3 tightly coiled seminiferous tubules.
What happens in the seminiferous tubules?
Spermatogenesis.
What are sertoli cells?
Found in seminiferous tubules, function is to support, nourish, and regulate spermatogenic cells.
What are interstitial cells?
Secrete male sex hormones, the androgens. Cells lie between the seminiferous tubules.
What is the most important androgen?
Testosterone.
What are the three main parts of the sperm?
Head: acrosome contains enzymes needed to penetrate an egg.
Middle piece: many mitochondria to provide energy for movement.
Tail: structured like flagellum.
What does the hypothalamus do for hormonal regulation in males?
Has control of the testes’ sexual function.
What happens in males when puberty is reached?
GnRH will be released, and will cause two other hormones to be released: Follicle-stimulating hormone, and luteinizing hormone.
What does Follicle stimulating hormone do? (FSH)
Targets seminiferous tubules to stimulate sperm production.
What does Luteinizing hormone do? (LH).
Stimulates interstitial cells of the testes to produce testosterone.
What is testosterone essential for?
Normal development and function of the male reproductive organs. Responsible for male bone and muscle mass and body hair.
What are the female gonads?
Ovaries.
What is the production of an egg or oocyte?
Oogenesis.
What is ovulation?
The process by which an oocyte bursts from ovary and enters a uterine tube.
What are the 4 parts in the female genital tract?
Uterine tubes, uterus, cervix, vagina.
What extends from the uterus to the ovaries?
Oviducts/fallopian tubes.
What are fimbriae?
On oviducts, finger-like projections that sweep oocytes into the oviduct during ovulation. When in the oviduct, oocyte is propelled slowly towards the uterus.