Chapter 28: Pregnancy

Which of the following serve(s) as the direct trigger to begin the more vigorous, rhythmic contractions of true labor? prostaglandins relaxin placental estrogen progesterone

prostaglandins

What is the name for the period of time that extends from the last menstrual period until birth, which is approximately 280 days? pregnancy the conceptus a gestation period an embryo

a gestation period

Which of the following epithelial layers arise(s) from the endoderm? alveolar cells of the lungs linings of the glomeruli in nephrons the epidermis the periosteum

alveolar cells of the lungs

Which of these is the innermost (closest) structure that completely surrounds the embryo? yolk sac placenta chorion amnion

amnion

When capacitated sperm a secondary oocyte, they are able to weave past granulosa cells of the with the aid of hyaluronidase enzymes present on their surface.

approach, corona radiata

As sperm travel through the , secretions of the cervix, uterus and uterine tubes capacitate the sperm by making their membranes more fragile and capable of releasing enzymes.

female reproductive tract

In humans, zonal inhibiting proteins are destroyed by sperm receptors when sperm bind with sperm receptors, preventing polyspermy. True False

False

Leads to the formation of the first cell of the new individual.

Fertilization

Leads to the establishment of the three primary germ layers.

Gastrulation

Her doctor wants to put delivery off as long as possible because premature babies have multiple problems. One possible problem is that the ductus arteriosus does not close. Why would this be a problem? If the ductus arteriosus doesn't close, blood will continue to perfuse the umbilical cord with a risk of fatal hemorrhage. If the ductus arteriosus doesn't close, the liver will not get an adequate blood supply. If the ductus arteriosus doesn't close, the lungs will continually receive too much blood. If the ductus arteriosus doesn't close, the right atrium will continually be overloaded with blood.

If the ductus arteriosus doesn't close, the lungs will continually receive too much blood.

Embedding of the blastocyst in the uterine wall

Implantation

Which of the following occurs 9-12 weeks into pregnancy, during the fetal period? Quickening occurs. The head of the fetus is nearly as large as the body. The distal limb bones are beginning to ossify Sex is readily detected by observing the genitals.

Sex is readily detected by observing the genitals.

A lack of _____ can, without treatment, lead to _____ in premature infants. surfactant; lung overinflation oxygen; suffocation surfactant; alveolar collapse oxytocin; pneumothorax

surfactant; alveolar collapse

What cellular area shown in the figure secretes human chorionic gonadotropin (hCG)? syncytiotrophoblast cytotrophoblast embryoblast the entire blastocyst

syncytiotrophoblast

Which of the following is the multicellular cytoplasmic mass formed from the outer layer of the trophoblast as it implants into the endometrium? syncytiotrophoblast inner cell mass blastocyst cytotrophoblast

syncytiotrophoblast

Which of the following is/are derived from somites? the liver vertebrae and ribs heart and blood vessels spinal cord

vertebrae and ribs

Zonal inhibiting proteins (ZIPs), enzymes from the cortical granules, cause the to harden and the to be clipped off.

zona pellucida, sperm receptors

A morula has approximately 16 cells. What is the rate of mitotic division that takes place between the 4-cell stage and the morula? 4 hours per cell division 12 hours per cell division 24 hours per cell division 2 days per cell division

12 hours per cell division

The 4-cell stage occurs 2 days after fertilization. How much time passes between the 4-cell stage and implantation? 36 hours 2 days 3 days 5 days

5 days

Which of the following is NOT a change in female anatomy or physiology during pregnancy? An increase in blood volume by as much as 40% A tightening of pelvic ligaments to help bear the extra weight of the growing fetus Decreased urine output because the fetus requires more fluid Nasal stuffiness and difficulty breathing

A tightening of pelvic ligaments to help bear the extra weight of the growing fetus

A couple undergoes a workup for infertility, which shows that the man has a low sperm count. The couple asks why this is a problem because "it only takes one sperm to fertilize an egg." How could you explain their problem? The corona radiata that surrounds the oocyte contains many macrophages that kill most of the sperm that reach the egg. The flagella of many sperm must beat against the zona pellucida of the oocyte to destroy it before a single sperm can penetrate. Many sperm must enter the egg before one is chosen to complete fertilization. Although a single sperm fertilizes the egg, many others prepare the egg for its entry.

Although a single sperm fertilizes the egg, many others prepare the egg for its entry.

Which of the following occurs 21 to 30 weeks into pregnancy, during the fetal period? The head of the fetus is nearly as large as the body. Sex is readily detected by observing the genitals. Blood cell production in the bone marrow. Quickening occurs

Blood cell production in the bone marrow.

Entry of the sperm's contents causes in the oocyte's cytoplasm to rise, triggering the cortical reaction.

Ca2+ levels

Leads to enhancement of sperm motility and increasing membrane fragility to enable enzyme release from acrosomes.

Capacitation

Leads to the development of a morula and then a blastocyst.

Cleavage

Cortisol prompts the fetal lungs to begin synthesizing surfactant. Why is this important? Surfactant is necessary to protect the cells lining the respiratory tract from drying out. Surfactant attracts white blood cells into the lungs to protect them against pathogens. Surfactant reduces surface tension in the alveoli, allowing the alveoli to inflate. Surfactant causes vasodilation, allowing blood to flow through the lungs.

Surfactant reduces surface tension in the alveoli, allowing the alveoli to inflate.

Which of the following statements about the acrosomal reaction is correct? The acrosomal enzymes released from many sperm digest holes through the zona pellucida. The decrease of Ca2+ levels within the sperm triggers the acrosomal reaction. The acrosomal reactions of many sperm expose the sperm membrane. Binding of sperm to the sperm-binding receptors in the corona radiata causes the Ca2+ levels within the sperm to increase.

The acrosomal enzymes released from many sperm digest holes through the zona pellucida.

involves the exocytosis of cortical granules near the oocyte plasma membrane.

The cortical reaction

Which of these statements regarding the embryo is FALSE? The extraembryonic coelom lies between the chorion and the amnion. Blood from the fetus travels to and from the placenta via vessels in the umbilical cord. The yolk sac is the source for the earliest blood cells and blood vessels. The embryo's blood supply mixes with that of the mother.

The embryo's blood supply mixes with that of the mother.

Select the correct statement about the special fetal blood vessels. The umbilical vein becomes the ligamentum teres. The distal parts of the umbilical arteries form the superior vesical arteries. The hepatic portal vein forms from the umbilical artery. The fossa ovalis becomes the foramen ovale.

The umbilical vein becomes the ligamentum teres.

Which statement best describes the result of binding and fusion of the sperm's membrane to the oocyte plasma membrane? They allow the contents of the sperm to enter the oocyte cytoplasm. They make the sperm's membrane more fragile. They cause an increase in Ca2+ levels within the sperm. They block multiple sperm from entering the oocyte.

They allow the contents of the sperm to enter the oocyte cytoplasm.

Implantation begins six to seven days after ovulation. True False

True

Which of the following implants in the mucosa of the endometrium? oocyte morula blastocyst zygote

blastocyst

The occurs as a result of the cortical reaction, by detaching any sperm bound to the receptors and preventing additional sperm from entering.

block of polyspermy

Once sperm are deposited into the vagina, the sperm's motility must be enhanced and they must be prepared to release hydrolytic enzymes from their acrosomes. What is this process called? acrosomal reaction capacitation cortical reaction fertilization

capacitation

Which term, by definition, includes all the other terms? fetus zygote conceptus embryo

conceptus

Which of the following is the first barrier that must be penetrated by the sperm in order to fertilize an oocyte? oocyte plasma membrane zona pellucida extracellular space corona radiata

corona radiata

What reaction prevents more than one sperm from binding to an oocyte during fertilization? cortical reaction acrosomal reaction capacitation gestation

cortical reaction

In humans, after a single sperm enters the cytoplasm, further sperm entry is prevented., further sperm entry is prevented.

cytoplasm

During a cesarean section, an incision is made through all EXCEPT which of the following? linea alba perimetrium superficial fascia decidua basalis

decidua basalis

The dermatome is one of the three derivatives of a somite. What does the dermatome form? kidneys and gonads skeletal muscles dermis of the skin vertebrae and ribs

dermis of the skin

Which germ layer gives rise to the nervous system? ectoderm endoderm sclerotome mesoderm

ectoderm

Which of the following tend(s) to initiate Braxton Hicks contractions, or "false labor"? prostaglandins surfactant protein A (SP-A) estrogens oxytocin

estrogens

Because of the increased bulkiness of the anterior abdomen and the change in a pregnant woman's center of gravity, what type of spinal curvature do many pregnant women develop? kyphosis of the cervical spine kyphosis of the thoracic spine excessive lordosis of the lumbar spine scoliosis of the thoracic spine

excessive lordosis of the lumbar spine

Which fetal vascular shunt directly connects the right atrium to the left atrium so as to bypass the nonfunctional lungs? ductus venosus ductus arteriosus ligamentum arteriosum foramen ovale

foramen ovale

Sperm

freshly deposited in the vagina are incapable of penetrating an oocyte.

Which of the following refers to the transfer of sperm and harvested oocytes together into the woman's uterine tubes in the hopes that fertilization will take place there? gamete intrafallopian transfer (GIFT) in vitro fertilization (IVF) zygote intrafallopian transfer (ZIFT) rhythm method

gamete intrafallopian transfer (GIFT)

Which of the following is NOT one of the primary germ layers? mesoderm ectoderm gastroderm endoderm

gastroderm

Based on the function of the extraembryonic membranes, which of the problems would likely develop if there were a deficiency in the yolk sac? lack of umbilical cord formation and umbilical attachment to the urinary bladder loss of amniotic fluid lack of blood cells for the early embryo lack of development of the embryo

lack of blood cells for the early embryo

Which of the following is the primary germ layer that forms the basis for the musculoskeletal system? ectoderm mesoderm gastroderm endoderm

mesoderm

Polyspermy occurs when sperm enter the oocyte. Monospermy occurs when a single sperm enters the oocyte. sperm enter the oocyte.

multiple

Teratogens may cause anatomical abnormalities in an embryo, but they do not cause anatomical abnormalities in a pregnant woman because ______. organogenesis does not occur in an adult a woman's kidneys remove all teratogens from the blood a woman's immune system is mature and can therefore provide defense against teratogens None of the listed responses is correct.

organogenesis does not occur in an adult

Together, what do the decidua basalis and the chorionic villi form? chorion placenta amnion yolk sac

placenta

During what stage is the afterbirth delivered? expulsion stage engagement dilation stage placental stage

placental stage

A dangerous complication of pregnancy called __________ results in an insufficient placental blood supply, which can starve a fetus of oxygen. The pregnant woman becomes edematous and hypertensive, and proteinuria occurs. dystocia dyspnea preeclampsia parturition

preeclampsia

The foramen ovale and the ductus arteriosus are both examples of __________. cells of the somatic mesoderm, which help to form the dermis of the skin venous shunts, which serve to bypass the liver sinusoids pulmonary bypass shunts, which serve to bypass the lungs cells of the mesoderm that form the heart and blood vessels

pulmonary bypass shunts, which serve to bypass the lungs

Which body system of a pregnant woman shows the most dramatic physiological changes during pregnancy? the respiratory system the cardiovascular system the urinary system the digestive system

the cardiovascular system

During which of the following stages does the amnion rupture, an event also known as the mother's "water breaking"? the dilation stage crowning the placental stage engagement

the dilation stage

A pregnant woman with preeclampsia becomes edematous and hypertensive. An effective way to treat these symptoms might be ______. to use drugs that increase capillary permeability to use drugs that increase albumin secretion by the liver to use drugs that cause systemic vasodilatation All of the listed responses are correct.

to use drugs that cause systemic vasodilatation

Which fetal vessels or shunts will become the medial umbilical ligaments in the newborn? ductus venosus umbilical vein ductus arteriosus umbilical arteries

umbilical arteries

Which of the following takes oxygenated blood to the liver from the placenta? ductus venosus umbilical vein umbilical artery hepatic vein

umbilical vein