Chapter 25 The Reproductive System PDF

Human Anatomy, 7e (Marieb/Mitchell/Smith) Chapter 25 The Reproductive System 25.1 Multiple Choice Questions Figure 25.1 Use the diagram above to answer the following questions. 1) Identify the letter that indicates the ejaculatory duct. A) A B) B C) C D) D E) E Answer: A Diff: 2 Page Ref: 744 2...

Human Anatomy, 7e (Marieb/Mitchell/Smith) Chapter 25 The Reproductive System 25.1 Multiple Choice Questions Figure 25.1 Use the diagram above to answer the following questions. 1) Identify the letter that indicates the ejaculatory duct. A) A B) B C) C D) D E) E Answer: A Diff: 2 Page Ref: 744 2) Identify the letter that indicates the site of sperm maturation and storage. A) A B) B C) C D) D E) E Answer: C Diff: 2 Page Ref: 744, 747-748 1 Copyright © 2014 Pearson Education, Inc. 3) Identify the letter that indicates the organ that directs sperm toward the seminal vesicles during ejaculation. A) A B) B C) C D) D E) E Answer: E Diff: 2 Page Ref: 744, 748 4) Identify the letter that indicates the gland that secretes neutralizing mucus prior to ejaculation. A) A B) B C) C D) D E) E Answer: B Diff: 2 Page Ref: 744, 751 5) Identify the letter that indicates the organ that serves as common passageway for semen and urine in men. A) A B) B C) C D) D E) E Answer: D Diff: 2 Page Ref: 744,752 2 Copyright © 2014 Pearson Education, Inc. Figure 25.2 Use the diagram above to answer the following questions. 6) Identify the letter that indicates the cervix. A) A B) B C) C D) D E) E Answer: E Diff: 2 Page Ref: 756 7) Identify the letter that indicates the organ where fertilization normally occurs. A) A B) B C) C D) D E) E Answer: C Diff: 2 Page Ref: 756-757 3 Copyright © 2014 Pearson Education, Inc. 8) Identify the letter that indicates the region of the uterus known as the fundus. A) A B) B C) C D) D E) E Answer: B Diff: 2 Page Ref: 756 9) Identify the letter that indicates the tissue layer that is shed during menstruation. A) A B) B C) C D) D E) E Answer: D Diff: 2 Page Ref: 756, 759 10) Identify the letter that indicates the organ where ectopic pregnancies commonly occur. A) A B) B C) C D) D E) E Answer: A Diff: 2 Page Ref: 756, 758 4 Copyright © 2014 Pearson Education, Inc. Figure 25.3 Use the diagram above to answer the following questions. 11) Identify the letter that indicates the "neck" of the uterus. A) A B) B C) C D) D E) E Answer: A Diff: 1 Page Ref: 756, 758 12) Identify the letter that indicates the infundibulum. A) A B) B C) C D) D E) E Answer: D Diff: 2 Page Ref: 756 13) Identify the letter that indicates the female erectile tissue that is homologous to the penis. A) A B) B C) C D) D E) E Answer: E 5 Copyright © 2014 Pearson Education, Inc. Diff: 2 Page Ref: 756, 767 14) Identify the letter that indicates the gland that secretes lubricating mucus into the vaginal orifice. A) A B) B C) C D) D E) E Answer: C Diff: 2 Page Ref: 756, 767 15) Identify the letter that indicates the organ which is commonly referred to as the birth canal. A) A B) B C) C D) D E) E Answer: B Diff: 2 Page Ref: 756, 766 16) Tubular organ that is transected during a vasectomy. A) epididymis B) rete testis C) ductus deferens D) spermatic cord E) pampiniform plexus Answer: C Diff: 2 Page Ref: 749 17) The fluid-filled cavity in a mature ovarian follicle is known as A) zona pellucidum. B) antrum. C) corona radiate. D) theca folliculi. E) granulaosa cells. Answer: B Diff: 2 Page Ref: 763 18) This layer of the uterus contracts during parturition to expel the baby. A) perimetrium B) stratum functionalis C) stratum basalis D) myometrium E) endometrium Answer: D Diff: 1 Page Ref: 759 6 Copyright © 2014 Pearson Education, Inc. 19) The opening of the oviduct is surrounded by these structures. A) internal os B) external os C) fimbriae D) isthmus E) cardinal ligaments Answer: C Diff: 2 Page Ref: 757 20) Fertilization of the ovum normally occurs in this region of the oviduct. A) isthmus B) fimbriae C) infundibulum D) ampulla E) intrauterine portion Answer: D Diff: 2 Page Ref: 757 21) Involuntary contraction of this smooth muscle layer wrinkles and thickens the walls of the scrotum to prevent heat loss. A) tunica albuginea B) tunica vaginalis C) dartos muscle D) cremaster muscle E) internal spermatic fascia Answer: C Diff: 2 Page Ref: 745 22) Tubules that connect testicular lobules with the efferent ductules of the epididymis. A) seminiferous tubules B) rete testis C) pampiniform plexus D) ductus deferens E) straight tubules Answer: B Diff: 2 Page Ref: 746 23) This multinucleate embryonic structure invades the uterus, digesting cells and maternal blood vessels to make way for development of the placenta. A) syncytiotrophoblast B) morula C) inner cell mass D) decidua basalis E) decidua capsularis Answer: A Diff: 3 Page Ref: 770 7 Copyright © 2014 Pearson Education, Inc. 24) Type of cell in the testes that produces testosterone. A) spermatogonium B) primary spermatocyte C) spermatid D) interstitial E) sustentocytes Answer: D Diff: 2 Page Ref: 747 25) Fingerlike placental structures where oxygen and nutrients from the maternal blood supply diffuse into the embryonic blood. A) syncytiotrophoblast B) allantois C) amnion D) chorionic villi E) extraembryonic membrane Answer: D Diff: 2 Page Ref: 772 26) The usual site of embryo implantation is the A) uterus. B) peritoneal cavity. C) vagina. D) uterine tube. Answer: A Diff: 1 Page Ref: 770 27) A factor that propels an oocyte through the uterine tube is A) pressure exerted by ovarian fluid. B) smooth muscle contraction (peristalsis). C) secretions of the nonciliated cells. D) amoeboid motion of the oocyte. Answer: B Diff: 2 Page Ref: 757 28) Sperm become motile in the A) ductus deferens. B) epididymis. C) seminiferous tubules. D) prostate. Answer: B Diff: 1 Page Ref: 748 8 Copyright © 2014 Pearson Education, Inc. 29) Which of the following is the primary sex organ in the male? A) the prostate B) the testis C) the epididymis D) the penis Answer: B Diff: 1 Page Ref: 744 30) The correct sequence of sperm-transporting tubules that transport spermatozoa to the epididymis is the A) seminiferous tubule to efferent ductule to straight tubule to rete testis. B) seminiferous tubule to rete testis to straight tubule to efferent ductule. C) seminiferous tubule to rete testis to efferent ductule to straight tubule. D) seminiferous tubule to straight tubule to rete testis to efferent ductule. Answer: D Diff: 2 Page Ref: 746 31) The female homologue of the male scrotum is the A) ovary. B) labia majora. C) penile urethra. D) bulb of the vestibule. Answer: B Diff: 2 Page Ref: 767 32) A woman's sex cells (germ cells) originate embryologically A) in the innermost part of the gonad. B) from the germinal epithelium of the ovary. C) from the follicular cells of the follicles. D) from yolk sac endoderm. Answer: D Diff: 2 Page Ref: 777 33) In cows, the nipples (teats) are in the groin region, not in the midthorax as in humans. What is the most logical reason for this difference between cows and people? A) Cows' mammary glands have entirely different embryonic origins from human ones. B) Male cows do not produce milk. C) Cows are more likely to develop inguinal hernias, and their mammary glands protect against that. D) Cows' mammary glands arise from a different part of the milk line. Answer: D Diff: 3 Page Ref: 767 9 Copyright © 2014 Pearson Education, Inc. 34) The function of the pampiniform plexus of veins is to A) help prevent hernias. B) help cool blood. C) form the outer wall of the spermatic cord. D) form hydroceles. Answer: B Diff: 1 Page Ref: 747 35) At what point during fetal development is the decidua basalis/chorionic villi collectively referred to as the placenta? A) the first month B) the ninth month C) the start of fourth month D) the end of second month Answer: C Diff: 2 Page Ref: 772 36) A woman has developed a cancerous lump in each breast, and the skin of the breasts is dimpled. What structure(s) is (are) causing the dimpling? A) pectoralis major muscle B) pectoralis minor muscle C) smooth muscle cells around the ducts of the large glands in the breast D) suspensory ligaments of the breast Answer: D Diff: 2 Page Ref: 767, 775 37) All of the following are adaptations for keeping the testes cool except the A) descent of the testes into the scrotum before birth. B) pampiniform plexus of veins. C) cremaster and dartos. D) testicular artery. Answer: D Diff: 3 Page Ref: 745, 747 38) The seminal vesicles A) store sperm. B) are glands that secrete most of the volume of the semen. C) secrete digestive enzymes when cancerous. D) empty into the epididymis. Answer: B Diff: 1 Page Ref: 750 10 Copyright © 2014 Pearson Education, Inc. 39) In breast cancer, the cancer cells usually originate from the A) lactiferous ductules. B) cuboidal acinar cells. C) fat cells in the breast. D) endothelium of the lymph vessels in the breasts. Answer: A Diff: 1 Page Ref: 775 40) Which testicular cells help deliver sperm to the epididymis by contracting rhythmically? A) interstitial B) myoid C) sustentocytes D) type A spermatocytes Answer: B Diff: 2 Page Ref: 747 41) In the early fetus, all of the following are parts of the chorionic villi except the A) syncytiotrophoblast. B) cytotrophoblast. C) extraembryonic mesoderm. D) decidua. Answer: D Diff: 3 Page Ref: 770, 772 42) Inguinal hernias A) always reach the scrotum. B) always enter the inguinal canal. C) occur with equal frequency in males and females. D) are signs of old age and almost never congenital. Answer: B Diff: 2 Page Ref: 749 43) Hypospadias A) never occurs in females. B) is characterized by the absence of a urethra. C) cannot be detected through an examination of the outside of a baby's body. D) has no effects until puberty, when males start producing sperm. Answer: A Diff: 1 Page Ref: 777 44) The function of the cremaster muscle is to A) squeeze semen from the urethra during ejaculation. B) maintain erection in both sexes. C) increase intra-abdominal pressure during childbirth. D) alter the position of the testes in the scrotal sac with increases in ambient temperature. Answer: D Diff: 1 Page Ref: 745 11 Copyright © 2014 Pearson Education, Inc. 45) By undergoing meiosis, each primary spermatocyte ultimately gives rise to how many sperm cells? A) two B) four C) eight D) billions Answer: B Diff: 2 Page Ref: 754 46) Of the following tubes, which is the only one that lies partly outside the testis? A) tubulus rectus B) seminiferous tubule C) rete testis D) efferent ductule Answer: D Diff: 1 Page Ref: 746 47) Which of the following anchors the uterus into an anteverted position in the pelvis? A) broad ligament B) ovarian ligament C) round ligament D) suspensory ligament Answer: C Diff: 2 Page Ref: 759 48) The ovarian cortex consists of A) follicles and connective tissue. B) the largest blood vessels of the ovary. C) the hilus of the ovary. D) the mesovarium. Answer: A Diff: 1 Page Ref: 761-763 49) The female uterine cycle begins A) at ovulation. B) on the first day of menstruation. C) at the end of menstruation. D) every six weeks. Answer: B Diff: 2 Page Ref: 763 12 Copyright © 2014 Pearson Education, Inc. 50) In addition to remaining granulosa cells, which of the following cell types make up the corpus luteum? A) oocyte B) theca cells C) cells of the corona radiata D) interstitial cells Answer: B Diff: 2 Page Ref: 763 51) The largest macroscopic region of the uterus is its A) fundus. B) body. C) cervix. D) fornix. Answer: B Diff: 1 Page Ref: 758 52) The zona pellucida A) is the portion of the placenta in which maternal blood contacts fetal tissues. B) is a protective shell around the oocyte that sperm must penetrate for fertilization to occur. C) is the region of the uterine tube where fertilization occurs. D) is the remnant of the vesicular follicle that becomes the corpus luteum. Answer: B Diff: 2 Page Ref: 763 53) The prepuce of the clitoris is formed by A) the fourchette. B) the hymen of the vagina. C) the labia minora. D) the mons pubis. Answer: C Diff: 1 Page Ref: 767 54) The milk-producing cells in the breast are A) adipose cells (because milk contains 4% fat). B) columnar epithelial cells in lobules. C) simple cuboidal epithelial cells in alveoli. D) endocrine cells. Answer: C Diff: 2 Page Ref: 768 13 Copyright © 2014 Pearson Education, Inc. 55) In females, the paramesonephric ducts give rise to A) the ovaries. B) the vestibule in the vulva. C) the corpora cavernosa (erectile bodies). D) the uterine tubes and uterus. Answer: D Diff: 2 Page Ref: 777 56) The epithelium lining the vagina is A) simple columnar. B) stratified squamous. C) pseudostratified columnar. D) simple squamous. Answer: B Diff: 1 Page Ref: 766 57) The most common site of ectopic pregnancy is the A) uterus. B) peritoneal cavity. C) vagina. D) uterine tube. Answer: D Diff: 1 Page Ref: 758 58) Which of the following events occurs when the testes do not descend before birth? A) Male sex hormones will not circulate in the body. B) Sperm will have no route of exit from the body. C) Inadequate blood supply will retard the development of the testes. D) Viable sperm will not be produced. Answer: D Diff: 2 Page Ref: 778 59) Which of the following organs does not contribute secretion(s) during the male sexual response? A) prostate B) seminal vesicles C) bulbourethral glands D) corpus cavernosum Answer: D Diff: 2 Page Ref: 750-751 14 Copyright © 2014 Pearson Education, Inc. 60) During the proliferative phase of the uterine cycle, these vessels grow and proliferate. A) arcuate arteries B) radial arteries C) spiral arteries D) straight arteries Answer: C Diff: 2 Page Ref: 759 61) Which female structure is homologous to the corpus spongiosum of the penis? A) clitoris B) crura C) bulb of the vestibule D) labia minora Answer: C Diff: 3 Page Ref: 767 62) Erection is caused by A) a jointed bone in the penis that unfolds. B) the penis filling up with semen that is about to be ejaculated. C) erectile bodies filling with blood. D) impulses from the sympathetic nervous system. Answer: C Diff: 2 Page Ref: 752 63) Sperm are moved into the epididymis from the testis by A) swimming under their own power. B) gravity. C) suction. D) testicular fluid moved by cilia and smooth muscle cells. Answer: D Diff: 2 Page Ref: 747 64) The deep inguinal ring is formed by A) extension of the external oblique muscle. B) extension of the internal oblique muscle. C) fascia layer deep to the transversus abdominis muscle. D) cremaster muscle. Answer: C Diff: 2 Page Ref: 749 65) A hydrocele A) occurs in females only. B) is a series of varicosities of the pampiniform plexus. C) is a sac filled with intestines that have pushed through the abdominal wall. D) is excess serous fluid in the scrotum. Answer: D Diff: 1 Page Ref: 780 15 Copyright © 2014 Pearson Education, Inc. 66) A difference between a primary follicle and a primordial follicle is that A) one has an antrum and the other does not. B) the oocyte is larger in the primordial follicle. C) the primary follicle is an earlier stage than the primordial follicle. D) the primordial follicle has only a single layer of flat follicular cells, whereas the primary follicle is comprised of cuboidal follicle cells. Answer: D Diff: 2 Page Ref: 763 67) The acrosomal reaction occurs A) just before fertilization. B) during meiosis of the sperm. C) during spermiogenesis. D) during placentation. Answer: A Diff: 2 Page Ref: 769 68) Which structure develops into the umbilical cord? A) body stalk B) chorionic villi C) decidua capsularis D) placenta Answer: A Diff: 1 Page Ref: 772 69) The placenta consists of which two structures? A) chorionic villi and amnion B) chorionic villi and decidua basalis C) cytotrophoblast and syncytiotrophoblast D) decidua basalis and decidua capsularis Answer: B Diff: 3 Page Ref: 772 70) Which of the following pairs of structures is not derived from the same embryonic tissues? A) ductus deferens, uterine tube B) penis, clitoris C) spongy urethra, labia minora D) testes, ovaries Answer: A Diff: 3 Page Ref: 777 16 Copyright © 2014 Pearson Education, Inc. 71) Which structure is not derived from the embryonic paramesonephric ducts? A) cervix B) clitoris C) upper vagina D) uterine tube Answer: B Diff: 2 Page Ref: 777 72) The structural basis of the blood-testis barrier is A) the basal lamina around the seminiferous tubules. B) the endothelial cells of the continuous (nonfenestrated) capillaries that supply the seminiferous tubules. C) the tight junctions between sustentocytes. D) the thick basal lamina around the capillaries that supply the seminiferous tubules. Answer: C Diff: 1 Page Ref: 755 73) In the late stages of pregnancy, the placental barrier of the chorionic villi consists only of which two layers? A) decidua capsularis and decidua basalis B) syncytiotrophoblast and cytotrophoblast C) syncytiotrophoblast and capillary endothelium D) cytotrophoblast and extraembryonic mesoderm Answer: C Diff: 3 Page Ref: 772 74) An episiotomy during childbirth is performed to A) save the baby's life. B) minimize tearing of the central tendon and muscles of the pelvic floor. C) prevent the anal canal from being crushed. D) eliminate the pain to the mother. Answer: B Diff: 1 Page Ref: 767 75) Which of the following statements about pelvic inflammatory disease is incorrect? A) It can lead to sterility. B) It is usually caused by chlamydia or gonorrhea. C) It includes salpingitis. D) It inhibits ovulation. Answer: D Diff: 2 Page Ref: 758 17 Copyright © 2014 Pearson Education, Inc. 76) All of the following are functions of the sustentocytes in the seminiferous tubules except A) secretion of androgen-binding protein. B) secretion of testicular fluid. C) secretion of testosterone. D) phagocytosis of excess cytoplasm from spermatids during spermiogenesis. Answer: C Diff: 2 Page Ref: 747 77) The typical (diploid) cells of the body have 46 chromosomes; how many chromosomes does each gamete have? A) 23 B) 46 C) 46 pairs D) 184 Answer: A Diff: 2 Page Ref: 754, 760 78) All of the following are located within the spermatic cord except the A) superficial inguinal ring. B) ductus deferens. C) pampiniform plexus. D) testicular artery. Answer: A Diff: 2 Page Ref: 747, 749 79) The embryonic urethral folds develop into the female A) bulb of the vestibule. B) labia majora. C) labia minora. D) urethra. Answer: C Diff: 2 Page Ref: 777 80) The cells that secrete estrogens in females are A) oocytes. B) cells in the pituitary gland. C) granulosa cells. D) germinal epithelium of the ovary. Answer: C Diff: 2 Page Ref: 763 18 Copyright © 2014 Pearson Education, Inc. 81) Technically, the theca folliculi is not part of the ovarian follicle, although it is associated with it. Instead, the theca folliculi arises from the A) zona pellucida. B) basal lamina around the follicle. C) connective tissue that fills the area between follicles. D) ovarian medulla. Answer: C Diff: 2 Page Ref: 763 82) In which part of the uterine tube does fertilization usually occur? A) ampulla B) isthmus C) infundibulum D) It doesn't occur in the uterine tubes. Answer: A Diff: 1 Page Ref: 757 83) Most support of the uterus is provided by the A) mesometrium. B) round ligament. C) cardinal ligament. D) muscles of the pelvic floor. Answer: D Diff: 1 Page Ref: 759 84) The vaginal fornix A) is in the superior part of the vestibule. B) surrounds the tip of the cervix. C) is in the middle layer of the vaginal wall. D) surrounds the external vaginal orifice. Answer: B Diff: 1 Page Ref: 766 85) In an adult woman who has never been pregnant, the breasts have poorly developed or no A) lobules of acini/alveoli. B) lactiferous sinuses. C) suspensory ligaments. D) areolar glands. Answer: A Diff: 2 Page Ref: 768 19 Copyright © 2014 Pearson Education, Inc. 86) The capillaries within a chorionic villus of the placenta contain blood A) from the fetus. B) from the mother. C) from both the fetus and the mother. D) that doesn't belong to the fetus or the mother. Answer: A Diff: 3 Page Ref: 772 87) In males, the paramesonephric (Müllerian) ducts A) give rise to the penile urethra. B) give rise to the prostate gland. C) give rise to the vas deferens. D) degenerate and don't form any structures in males. Answer: D Diff: 2 Page Ref: 777 25.2 True/False Questions 1) The spermatic cord is another name for the ductus deferens. Answer: FALSE Diff: 1 Page Ref: 748-749 2) Breast milk collects in the lactiferous sinus when a woman breastfeeds her infant. Answer: TRUE Diff: 2 Page Ref: 768 3) Primordial follicles develop into primary oocytes within the germinal epithelium of the ovary. Answer: FALSE Diff: 2 Page Ref: 761-763 4) Although the ovaries and uterine tubes are retroperitoneal, oocytes are ovulated into the peritoneal cavity. Answer: TRUE Diff: 3 Page Ref: 763 5) The ductus deferens and uterine tube are homologous structures, each deriving from the same embryonic duct. Answer: FALSE Diff: 2 Page Ref: 777 6) Sustentocytes support developing sperm and form a blood-testis barrier. Answer: TRUE Diff: 2 Page Ref: 747 7) Spermatogonia are located near the lumen of seminiferous tubules. Answer: FALSE Diff: 2 Page Ref: 752-754 20 Copyright © 2014 Pearson Education, Inc. 8) The ejaculatory ducts are formed by the union of the ductus deferens and urethra. Answer: FALSE Diff: 2 Page Ref: 748, 750 9) Granulosa cells of a maturing ovarian follicle convert androgens to estrogens that will stimulate proliferation of the endometrium. Answer: TRUE Diff: 2 Page Ref: 763 10) Breast milk production and secretion follows the following sequence: lactiferous sinus, alveoli, lactiferous ducts, nipple. Answer: FALSE Diff: 2 Page Ref: 767-768 11) Seminiferous tubules are the site of sperm storage. Answer: FALSE Diff: 2 Page Ref: 745-746, 752 12) Cryptorchidism is a congenital condition in which one or both testes fail to descend into the scrotum. Answer: TRUE Diff: 2 Page Ref: 778 13) Oogenesis takes years to complete. Answer: TRUE Diff: 2 Page Ref: 760 14) The epididymis, ductus deferens, and seminal vesicles are all derived from mesonephric (Wolffian) ducts. Answer: TRUE Diff: 3 Page Ref: 776-777 15) Lobules and alveoli of the breast develop during puberty. Answer: FALSE Diff: 3 Page Ref: 768 25.3 Short Answer Questions 1) The ________ is formed by the union of the ductus deferens and seminal vesicles. Answer: ejaculatory duct Diff: 2 Page Ref: 748, 750 2) The ________ of the female genitalia is a central space surrounded by the labia minora. Answer: vestibule Diff: 2 Page Ref: 767 21 Copyright © 2014 Pearson Education, Inc. 3) The bulb of the vestibule and the ________ are female erectile bodies. Answer: clitoris Diff: 2 Page Ref: 767 4) The uterus consists of the fundus, body, cervix, and ________. Answer: isthmus Diff: 2 Page Ref: 758 5) Ovarian follicles contain ________ and thecal cells that, after ovulation, differentiate into the corpus luteum Answer: granulosa cells Diff: 2 Page Ref: 763 6) An ovulated oocyte swept into the oviduct via fimbriae moves from the ________ of the oviduct to the ampula, then the isthmus, and finally into the uterus. Answer: infundibulum Diff: 2 Page Ref: 757 7) Contraction of the ________ in the wall of the spermatic cord raises the testes closer to the body cavity. Answer: cremaster muscle Diff: 2 Page Ref: 745 8) The uterus is composed of three basic layers. The inner layer is the ________. Answer: endometrium Diff: 2 Page Ref: 759 9) The first menstruation is called ________. Answer: menarche Diff: 2 Page Ref: 779 10) Testes descend through the ________ into the scrotum. Answer: inguinal canal Diff: 2 Page Ref: 777-778 11) Contraction of the fibromuscular ________ of the prostate squeezes prostatic secretions into the urethra during ejaculation. Answer: stroma Diff: 2 Page Ref: 750-751 12) During the menstrual phase of the uterine cycle, the inner ________ of the endometrium is shed. Answer: functional layer Diff: 2 Page Ref: 759 22 Copyright © 2014 Pearson Education, Inc. 13) The crura are extensions of the ________, the paired erectile bodies of the penis, and attach the penis to the pubic arch. Answer: corpora cavernosa Diff: 3 Page Ref: 752 14) The secretory phase of the uterine cycle corresponds to the ________ phase of the ovarian cycle. Answer: luteal Diff: 2 Page Ref: 763-764 15) The most effective way to detect cervical cancer in its earliest stage is by a(n) ________. Answer: Papanicolaou (Pap) smear Diff: 2 Page Ref: 775 25.4 Essay Questions 1) Describe the structures involved in the descent of the testes. Answer: The testes descend from the lumbar region of the abdominal cavity to the pelvic region. The vaginal process, an extension of the parietal peritoneum protrudes through an opening in the muscles of the anterior abdominal wall to create the inguinal canal. The testes descend through this canal into the scrotum during the seventh month of fetal development. The mechanism for the descent of the testes is not known, however their movement from the abdominopelvic cavity is guided by a fibrous cord called the gubernaculum. This cord connects from the scrotal floor to the testis. As it shortens, the testes move through the inguinal canal. Diff: 2 Page Ref: 777-778 2) Describe the mechanisms of propulsion by which sperm are transported from the seminiferous tubules to the epididymis and, during ejaculation, from the epididymis out of the body. Answer: Sperm are carried to the epididymis on a current of testicular fluid that is continuously produced by sustentocytes. The positive pressure of the fluid production forces the nonmotile sperm forward. Additionally, myoid cells that surround the seminiferous tubules rhythmically contract, helping to squeeze the sperm out of the testes. During ejaculation, smooth muscle cells in the epididymis and ductus deferens propel sperm by strong peristaltic contractions. Finally, the bulbospongiosus muscle covering the bulb of the penis contracts, propelling semen through the spongy urethra. Diff: 2 Page Ref: 747-748, 752 3) Identify the space into which an oocyte is ovulated, and describe the structures and mechanisms involved in transporting it to the uterus. Answer: The oocyte is ovulated into the peritoneal cavity. Currents, created by the motion of the fimbria of the oviduct, draw the oocyte into the infundibulum. Ciliated columnar cells lining the oviduct create currents that move the oocyte through the ampulla, to the isthmus, and into the uterus. The journey of the oocyte is assisted by peristaltic contractions of the smooth muscle in the oviduct walls. Diff: 2 Page Ref: 757 23 Copyright © 2014 Pearson Education, Inc. 4) Menstruation occurs as a result of the absence (or low level) of a particular hormone. Identify (a) this hormone, (b) the specific arteries of the uterine lining that collapse/fracture, and (c) the specific layer of the uterus that is shed. Answer: Menstruation, or shedding of the endometrium, occurs due to the rapid decline of progesterone. Without progesterone, the spiral arteries of the endometrium (located in the functional layer) spasm, collapse, and degenerate. Diff: 3 Page Ref: 759 5) Describe the structures involved in the transfer of nutrients and wastes between the fetal and maternal bloodstreams. Answer: Nutrients and wastes cross the placenta, which consists of both embryonic and maternal tissues. Extensions of the embryonic tissue are called chorionic villi. These extensions protrude into lacunae, or cavities in the endometrium, which contain maternal blood. Adjacent to these lacunae are maternal blood vessels located in a region called the decidua basalis. Together, the decidua basalis and chorionic villi, when fully established at the fourth month of fetal development, are called the placenta. Diff: 3 Page Ref: 772 24 Copyright © 2014 Pearson Education, Inc.