Chapter 25

Front 1

Name the male reproductive structures.

Back 1

Male reproductive structures are the scrotum, two testes, two epididymides, a pair of ductus deferens, two ejaculatory ducts, a urethra, two seminal glands, a prostate gland, two bulbourethral glands, and a penis.

Front 2

Identify the complex network of channels that is connected to the seminiferous tubules.

Back 2

The complex network of channels that is connected to the seminiferous tubules is the rete testis.

Front 3

On a warm day, would the cremaster muscle be contracted or relaxed? Why?

Back 3

On a warm day, the cremaster muscle (as well as the dartos muscle) would be relaxed so that the scrotal sac could descend away from the warmth of the body, thereby cooling the testes.

Front 4

Define Spermatogenesis.

Back 4

Spermatogenesis is the production of spermatozoa and involves mitosis, meiosis, and spermiogenesis.

Front 5

How many spermatoza will eventually be produced from each primary spermatocyte?

Back 5

Four haploid spermatozoa will be produced from each diploid primary spermatocyte.

Front 6

Describe the functional anatomy of a typical spermatozoon.

Back 6

A typical spermatozoon has an acrosomal cap that contains enzymes essential to fertilization; a head that is packed with chromosomes; a neck that contains centrioles; a middle piece containing mitochondria to provide ATP for propulsion; and a flagellum, the whiplike structure that moves the cell.

Front 7

What is the function of interstitial cells?

Back 7

Interstitial cells produce male sex hormones, or androgens, the most important of which is testosterone.

Front 8

What is the role of nurse cells?

Back 8

Nurse cells provide nutrients to the developing sperm and form the blood-testis barrier that isolates sperm from the blood.

Front 9

List the order of development for a spermatid.

Back 9

Spermatogonia (stem cells) divide by mitosis to produce primary spermatocytes; through meiosis, primary spermatocytes give rise to secondary spermatocytes, which divide and differentiate into spermatids. Each spermatid matures into a spermatozoon.

Front 10

Define semen.

Back 10

Semen is sperm plus the secretions of the seminal, prostate, and bulbo-urethral glands.

Front 11

What are the functions of the secretion of the bulbourethral glands?

Back 11

The secretion of the bulbo-urethral glands lubricates the penis tip and neutralizes any urinary acids that may remain in the urethra.

Front 12

Trace the ductal pathway from the epididymis to the urethra.

Back 12

The tail of each epididymis connects with the ductus deferens, which passes through the inguinal canal as part of the spermatic cord. Near the prostate gland, each ductus defers enlarges to form an ampulla. The junction of the base of the seminal gland and the ampulla creates the ejaculatory duct, which empties into the urethra.

Front 13

Name the three columns of erectile tissue in the penis.

Back 13

The three columns of erectile tissue are the corpus spongiosum and the paired corpora cavernosa.

Front 14

List the three physiological phases of male sexual activity.

Back 14

The physiological phases of male sexual activity are arousal, emission, and ejaculation.

Front 15

An inability to contract the ischiocavernosus and bulbospongiosus muscles would interfere with which phase of male sexual activity?

Back 15

An inability of a male to contract the ischiocavernosus and bulbospongiosus muscles would interfere with the ejaculation phase, including the contractions that are part of the male orgasm.

Front 16

Identify important regulatory hormones in the establishment and maintenance of male sexual function.

Back 16

Important regulatory hormones in the establishment and maintenance of male sexual function are FSH (follicle-stimulating hormone), LH (luteinizing hormone), and GnRH (gonadotropin-releasing hormone). Testosterone is the most important androgen.

Front 17

Identify the sources of hormones that control male reproductive function.

Back 17

The testes, hypothalamus, and the anterior lobe of the pituitary gland secrete the hormones that control male reproductive functions.

Front 18

What effect would low FSH levels have on sperm production?

Back 18

Low FSH levels would lead to low levels of testosterone in the seminiferous tubules, reducing both the sperm production rate and sperm count.

Front 19

List the major organs of the female reproductive system.

Back 19

The major organs of the female reproductive system are the ovaries, uterine tubes, uterus, vagina, and external genitalia.

Front 20

Name the structures enclosed by the broad ligament, and cite the function of the mesovarium.

Back 20

The ovaries, uterine tubes, and uterus are enclosed within the broad ligament. The mesovarium supports and stabilizes each ovary.

Front 21

What roles do the ovaries perform?

Back 21

The ovaries produce immature female gametes called oocytes; secrete female sex hormones, including estrogens and progestins; and secrete inhibin, which is involved in the feedback control of FSH production.

Front 22

Define oocyte.

Back 22

An oocyte is an immature female gamete whose meiotic divisions will produce a single ovum and three polar bodies.

Front 23

What are the main differences in gamete production between males and females?

Back 23

Males produce gametes from puberty until death; females produce gametes only from menarche to menopause. Males produce many gametes at a time; females typically produce one or two per 28-day cycle. Males release mature gametes that have completed meiosis; females release secondary oocytes suspended in metaphase of meiosis 2.

Front 24

List the important events in the ovarian cycle.

Back 24

Important events in the ovarian cycle are (1) the fomation of primary follicles from primordial follicles in an egg nest, (2) the formation of secondary follicles, (3) the formation of a tertiary folicle, (4) ovulation, and (5) the formation and degeneration of the corpus luteum. A corpus albicans forms if fertilization does not occur.

Front 25

Name the regions of the uterus.

Back 25

The regions of the uterus are the fundus, body (ending at the isthmus), and cervix.

Front 26

Describe the three layers of the uterine wall.

Back 26

The perimetrium is the incomplete serosal layer; the myometrium is the outer, muscular layer; and the endometrium is the inner, glandular layer.

Front 27

How do recently released secondary oocytes reach the uterine tube?

Back 27

Recently released secondary oocytes reach the uterine tube with the aid of the beating action of cilia on the inner surfaces of the fimbriae of the infundibulum.

Front 28

Name the zones of the endometrium.

Back 28

The emdometrium contains the deeper basilar zone and the more superficial functional zone.

Front 29

Differentiate between menses and menstruation.

Back 29

Menses is the first phase of the uterine cycle and is marked by degeneration of the functional zone of the uterus; menstruation is the process of endometrial sloughing that occurs during menses.

Front 30

Describe the phases of the uterine cycle.

Back 30

The uterine cycle begins with menses, the destruction of the functional zone. After menses, the proliferative phase begins, during which the functional zone undergoes repair and is thickens. Following the proliferative phase is the secretory phase, during which uterine (endometrial) glands enlarge. The uterine cycle first begins at menarche and continues until menopause.

Front 31

List the functions of the vagina.

Back 31

The vaginal (1) serves as a passageway for the elimination of menstrual fluids; (2) receives the penis during sexual intercouse, and holds spermatozoa prior to their passage into the uterus; and (3) forms the inferior portion to the birth canal, through which the fetus passes during delivery.

Front 32

Describe the anatomy of the vagina.

Back 32

The vaginal is a muscular tube extending between the uterus and external genitalia; its lining forms folds called rugae. The proximal portion of the vagina is marked by the cervix, which dips into the vaginal canal, and the shallow recess known as the fornix. The hymen, a thin epithelial fold, partially blocks the entrance to the vagina until physical distortion ruptures it.

Front 33

Cite the similarities that exist between certain structures in the reproductive systems of females and males.

Back 33

The greater vestibular glands in females are similar to the bulbo-urethral glands in males, and both the penis and the clitoris have characteristic erectile tissue (and a glans as well).

Front 34

Define lactation.

Back 34

Lactation is the secretion of milk by the mammary glands.

Front 35

Explain whether the blockage of a single lactiferous sinus would or would not interfere with the delivery of milk to the nipple.

Back 35

Blockage of a single lactiferous sinus would not interfere with the delivery of milk to the nipple, because each breast generally has 15-20 lactiferous sinuses.

Front 36

Trace the route of milk from its site of production to outside the female.

Back 36

Route of milk flow: secretory alveoli of the secretory lobules-> ducts within a lobe-> lactiferous sinus-> surface of the nipple

Front 37

What event in the uterine cycle occurs when the levels of estrogens and progesterone have declined?

Back 37

Completion of the decline in the levels of estrogens and progesterone signal the beginning of menses and the start of a new uterine cycle.

Front 38

What changes would you expect to observe in the ovarian cycle if the LH surge did not occur?

Back 38

If the LH surge did not occur during an ovarian cycle, ovulation and corpus luteum formation could not occur.

Front 39

Summarize the roles of the hormones in the ovarian and uterine cycles.

Back 39

The hypothalamic secretion of GnRH triggers the pituitary secretion of FSH and LH. FSH initiates follicular development, and activated follicles and ovarian interstitial cells produce estrogens. High estrogen levels stimulate LH secretion and increase anterior pituitary gland sensitivity to GnRH, causing the release of LH. Progesterone is the principal hormone of the luteal phase. Changes in estrogen and progesterone levels are responsible for the maintenance of the uterine cycle.

Front 40

Define vasectomy.

Back 40

A vasectomy is the surgical removal of a segment of each ductus deferens and the tying or cauterizing of the cut ends, preventing spermatozoa from reaching the distal portions of the male reproductive tract.

Front 41

Which birth control method(s) provide some protection against sexually transmitted diseases?

Back 41

Condoms provide some protection against sexually transmitted diseases.

Front 42

The use of which birth control method often results in the cessation of the uterine cycle?

Back 42

Depo-Provera injections (a progesterone-only form of birth control) results in the cessation of the uterine cycle in 50 percent of women using this product. (Uterine cycles eventually resume after use of the product is discontinued).

Front 43

Define sexually transmitted disease.

Back 43

A sexually transmitted disease is a disease that is transferred form one individual to another primarily or exclusively through sexual contact.

Front 44

From which cell type does ovarian cancer usually arise?

Back 44

Ovarian cancer usually arises from epithelial cells.

Front 45

Which pathogen is associated with most cases of cervical cancer?

Back 45

The human papillomaviruses (HPV) cause most cases of cervical cancer.