CH 28 HW, A&P 28
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
Which body system of a pregnant woman shows the most dramatic physiological changes during pregnancy?
the cardiovascular system
The neonatal period refers to ________.
the first month after birth
A blastocyst is a hollow ball of cells, while the morula is a solid ball of cells.
true
An episiotomy is an incision made to widen the vaginal orifice, aiding fetal expulsion.
true
The chorionic villi of the placenta develop a series of capillaries that are immersed in lacunae of the mother's blood for exchange into the embryo's blood during placentation.
true
The period from fertilization through week eight is called the embryonic period.
true
Which of the following takes oxygenated blood to the liver from the placenta?
umbilical vein
Site of early blood cell production, and forms part of the gut (digestive tube).
yok sac
Which of the following incorrectly matches an embryonic structure with its function?
yolk sac: provides nutrients to developing embryo
What destroys the zona pellucida sperm-binding receptors?
zonal inhibiting proteins
The part of the endometrium destined to be a part of the placenta.
Decidua basalis
The part of the endometrium that surrounds the uterine cavity face of the implanted embryo.
Decidua capsularis
Relaxin promotes the widening and increased flexibility of the pelvic ligaments and pubic symphysis.
What does the hormone relaxin promote? -Relaxin promotes enlargement of the breasts. -Relaxin promotes increased pigmentation of the facial skin of the nose and cheeks. -Relaxin imparts a purplish hue to the vagina. -Relaxin promotes the widening and increased flexibility of the pelvic ligaments and pubic symphysis.
a gestation period
What is the name for the period of time that extends from the last menstrual period until birth, which is approximately 280 days? the conceptus a gestation period an embryo pregnancy
cortical reaction
What reaction prevents more than one sperm from binding to an oocyte during fertilization? capacitation acrosomal reaction gestation cortical reaction
Oxytocin stimulates the uterus to contract.
What role does oxytocin play in promoting labor? -Oxytocin stimulates the uterus to contract. -Oxytocin promotes the formation of gap junctions between the uterine smooth muscle cells. -Oxytocin stimulates the myometrial cells of the uterus to form oxytocin receptors. -Oxytocin antagonizes progesterone's quieting influence on uterine muscle.
alveolar collapse
What would happen in a premature infant if insufficient surfactant were available? alveolar collapse lung overinflation pneumothorax lung hyperinflation
foramen ovale
Which fetal vascular shunt directly connects the right atrium to the left atrium so as to bypass the nonfunctional lungs? foramen ovale ductus arteriosus ligamentum arteriosum ductus venosus
hCG
Which hormone is required to maintain the corpus luteum and prevent menstruation? estrogen human placental lactogen hCG progesterone
blastocyst
Which of the following implants in the mucosa of the endometrium? morula blastocyst zygote oocyte
dilation stage
Which of the following is the longest stage of labor, lasting 6-12 hours or more? expulsion stage placental stage dilation stage delivery stage
prostaglandins
Which of the following serve(s) as the trigger to begin the vigorous, rhythmic contractions of true labor? prostaglandins relaxin oxytocin progesterone
amnion
Which of these is the innermost (closest) structure that envelops the embryo? amnion chorion placenta yolk sac
conceptus
Which term, by definition, includes all the other terms? conceptus zygote embryo fetus
What is the name for the period of time that extends from the last menstrual period until birth, which is approximately 280 days?
a gestation period
Which of these is the innermost (closest) structure that completely surrounds the embryo?
amnion
Protective water-filled sac surrounding the embryo.
amnionic sac
Drinking alcohol during pregnancy is ________.
associated with microencephaly and intellectual disorders of the fetus
Which of the following implants in the mucosa of the endometrium?
blastocyst
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?
capacitation
The placenta, a vitally important metabolic organ, is made up of a contribution from mother and fetus. Which portion is from the fetus?
chorion
Leads to the development of a morula and then a blastocyst.
cleavage
Which of the following is the correct sequence of development from zygote to embryo?
cleavage, morula, blastocyst, gastrula
Prior to the let-down reflex, the mammary glands secrete a yellowish fluid called ________ that has less lactose than milk and almost no fat.
colostrum
What reaction prevents more than one sperm from binding to an oocyte during fertilization?
cortical reaction
During a cesarean section, an incision is made through all EXCEPT which of the following?
decidua basalis
Forms the mother's part of the placenta.
decidua basalis
What structures ultimately form the placenta?
decidua basalis and chorionic villi
Surrounds the uterine cavity face of the implanted embryo.
decidua capsularis
The prefix ----- means skin, covering, or integument.
derm-
Which of the following is the longest stage of labor, lasting 6-12 hours or more?
dilation stage
Which of the following is NOT a correct matching of a fetal structure with what it becomes at birth?
ductus arteriosus-ligamentum teres
At what stage of labor is the baby essentially facing sideways (in reference to the mother)?
early dilation
Neural tissue is formed by the ________.
ectoderm
Which of the following refers to the stage of the conceptus when organogenesis is occurring?
embryo
Derivatives of the endoderm include ________.
epithelial lining of the respiratory tract
The corpus luteum prevents loss of the implanted embryo through menstruation by secreting ________.
estrogens and progesterone
During which stage of labor is the fetus delivered?
expulsion stage
At what point is meiosis II completed for the female gamete?
fertilization
Embedding of the blastocyst in the uterine wall.
implantation
Becomes the embryonic disc.
inner cell mass
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 blood cells for the early embryo
The prefix ----- means milk or lactose.
lact(i)-
What does the ductus arteriosus become at birth?
ligamentum arteriosum
As pregnancy continues, the increasing bulkiness of the anterior abdomen changes the woman's center of gravity, possibly causing an accentuated lumbar curvature called ________.
lordosis
Muscle tissue is formed by the ________.
mesoderm
A solid sphere of undifferentiated cells.
morula
Relaxin is a hormone produced by the placenta and ovaries. The function of this hormone is to ________.
relax the pubic symphysis
Sperm move to the uterine tube through uterine contractions and the energy of their own flagella. What other factor is involved in sperm movement?
reverse peristalsis of the uterus and uterine tubes
The prefix ----- means hard or dry.
sclero-
A lack of _____ can, without treatment, lead to _____ in premature infants.
surfactant; alveolar collapse
Which of the following is NOT assessed as part of the Apgar score?
temperature
Which embryonic structure produces human chorionic gonadotropin (hCG)?
the syncytiotrophoblast
Forms the chorion.
trophoblast
Select the correct statement about fertilization.
Millions of sperm cells are destroyed by the vagina's acidic environment.
Which hormone is required to maintain the corpus luteum and prevent menstruation?
hCG
The result of polyspermy in humans is ________.
a nonfunctional zygote
The prefix ---- means embryo.
embry-
How long is the secondary oocyte viable and capable of being fertilized after it is ovulated?
12-24 hours
Which of the following is NOT a change in female anatomy or physiology during pregnancy?
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?
Although a single sperm fertilizes the egg, many others prepare the egg for its entry.
Leads to enhancement of sperm motilityand increasing membrane fragility to enable enzyme release from acrosomes.
Capacitation
Extraembryonic membrane that develops from the trophoblast and some extraembryonic mesoderm, and forms part of the placenta.
Chorionic villus
Premature infants often need to be placed on a ventilator because their undeveloped lungs produce excess surfactant.
False
Leads to the formation of the first cell of the new individual.
Fertilization
The acrosomal enzymes released from many sperm digest holes through the zona pellucida.
Focus your attention on part (2) of Focus Figure 28.1. Which of the following statements about the acrosomal reaction is correct? -The acrosomal reactions of many sperm expose the sperm membrane. -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. -Binding of sperm to the sperm-binding receptors in the corona radiata causes the Ca2+ levels within the sperm to increase.
They allow the contents of the sperm to enter the oocyte cytoplasm.
Focus your attention on parts (3) and (4) of Focus Figure 28.1. Which statement best describes the result of binding and fusion of the sperm's membrane to the oocyte plasma membrane? -They cause an increase in Ca2+ levels within the sperm. -They allow the contents of the sperm to enter the oocyte cytoplasm. -They make the sperm's membrane more fragile. -They block multiple sperm from entering the oocyte.
Leads to the establishment of the three primary germ layers.
Gastrulation
What role does oxytocin play in promoting labor?
Oxytocin stimulates the uterus to contract.
The cardiovascular system of a newborn must be adjusted after the infant takes its first breath. Which of the following is also true?
The ductus arteriosus constricts and is converted to the ligamentum arteriosum.
Which of these statements regarding the embryo is FALSE?
The embryo's blood supply mixes with that of the mother.
pulmonary bypass shunts, which serve to bypass the lungs
The foramen ovale and the ductus arteriosus are both examples of __________. -venous shunts, which serve to bypass the liver sinusoids -cells of the somatic mesoderm, which help to form the dermis of the skin -cells of the mesoderm that form the heart and blood vessels -pulmonary bypass shunts, which serve to bypass the lungs
Select the correct statement about the special fetal blood vessels.
The umbilical vein becomes the ligamentum teres.
placenta
Together, what do the decidua basalis and the chorionic villi form? placenta amnion chorion yolk sac
The foramen ovale and the ductus arteriosus are both examples of __________.
pulmonary bypass shunts, which serve to bypass the lungs
Which fetal vascular shunt directly connects the right atrium to the left atrium so as to bypass the nonfunctional lungs?
foramen ovale
The presence of endoderm, ectoderm, and mesoderm is first seen in the ________ stage.
gastrula
Which of the following would be the best method for delaying the onset of labor?
giving the mother antiprostaglandin drugs
Which hormone maintains the viability of the corpus luteum?
human chorionic gonadotropin
Milk ejection (the letdown reflex) is stimulated by which of the following hormones associated with pregnancy?
oxytocin
Which hormone is NOT produced by the placenta?
oxytocin
Together, what do the decidua basalis and the chorionic villi form?
placenta
At which stage of labor is the "afterbirth" expelled?
placental
The trophoblast is mostly responsible for forming the ________
placental tissue
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.
preeclampsia
Gastrulation begins when a groove with raised edges called the ________ appears on the dorsal surface of the embryonic disc.
primitive streak
Which of the following serve(s) as the direct trigger to begin the more vigorous, rhythmic contractions of true labor?
prostaglandins
