Ch. 29, Human Development
Spanking a newborn is required to initiate the infant's first breaths.
false
The rate of senescence of different organ systems is relatively the same.
false
the sperm penetrates the egg
fertilization
the _____________ trimester extends from fertilization through 12 weeks gestation
first
Unstable molecules destroy cells and normal molecules to satisfy their own valence shells.
free radical theory
name the process that results in the formation of the primary germ layers
gastrulation
embryonic tissue layers
germ layers
blastocoel
hollow internal cavity
the granulosa cells surrounding an egg bound together by hyaluronic acid. name the enzyme released by the sperm that digests this compund
hyaluronidase
will be replaced with endoderm
hypoblast
the process by which a blastocyst attaches to the lining of the uterus is called ________________
implantation
explain why an infant loses heat easily
it has larger surface area to volume ratio than an adult
name the condition that involves a yellowing of the skin, corneas, mucous membranes, and body fluids due to an excessive concentration of bilirubin
jaundice
at the placenta, __________ blood s found within placental sinuses and _____________ blood is found within chorionic villi
maternal; fetal
at about 72 hours after conception, the conceptus is called a ________________, consisting of 16 or more cells and resembling a mulberry
morula
the failure of homologous chromosomes to separate during meiosis is known as _____________________
nondisjunction
the process of ______________________ is the differentiation of the primary germ layers into organ and organ systems
organogenesis
stiffness and joint pain are symptoms of the most common joint disease of older people. the disease is known as __________________
osteoarthritis
the loss of bone caused by reduced activity of osteoblasts is called ___________
osteopenia
source of nutrition for most of the prenatal period
placenta
name the condition involving the loss of flexibilty of lens of the eye
presbyopia
during the _________ trimester, the organs complete most of their development
second
newly ovulated cell
secondary oocyte
The degeneration that occurs in an organ system following a certain age is called __________.
senescence
the ____________ are blocks of mesoderm tissue that will give rise to vertebral column, dermis of the skin, and trunk muscles
somites
carries the father's DNA
sperm pronucleus
substances that cause birth defects are known as
teratogens
describe a telomere
the end cap on each chromosome
during which trimester does the fetus grow rapidly, becoming self sufficient outside the womb?
third
the ___________ period is the first six to eight hours after delivery
transitional
name the disorder associated with the presence of 3 X chromosomes
triplo X syndrome
The presence of one extra chromosome producing a triplet set is called ____________
trisomy
After implantation, the conceptus resorts to ____________ nutrition.
trophoblastic
describe the blood vessels found in the umbilical cord
two umbilical arteries, one umbilical vein
the internal iliac arteries of the fetus gives rise to the _____________ ______________
umbilical arteries
a common adage is that it "only takes one sperm" to fertilize an egg. As an anatomy student, describe your response
while only one sperm head enters the egg, thousands are needed to break through the egg's defenses
name the segment of the female reproductive system in which the sperm will encounter an egg that is viable (able to survive) and can be fertilized
within the distal one-third of uterine tube
embryonic membrane that surrounds the yolk
yolk sac
slow block
- calcium ions stimulate exocytosis - cortical granules - sperm are pushed away from the egg - fertilization membrane
Which of the following is a benefit of regular exercise that may help slow the rate of senescence?
- cells lose their capacity for mitosis - proteins fold differently in older tissues - the body's immune system begins to attack normal body cells - free radicals destroy healthy body tissues
mesoderm
- dermis - muscle - bones
indicate circulatory changes that occur just after birth
- ductus arteriosus collapses - foramen ovale is closed by flaps in the left atrium
list some structures that arise from the ectoderm
- epidermis - CNS - salivary glands
list some effects of the senescence on the integumentary system
- graying hair - loss of skin elasticity
list changes in the body as a result of an aging female reproductive system
- increased loss of bone mass - increased cardiovascular risk - decrease in estrogen production
list some reasons that muscles weaken with age
- reduced myoglobin content - reduced mitochondiral number - sacromere disorganization
list some causes of reduced nervous system function with aging
- thinning of cerebral cortex - less neurotransmitter produced - loss of receptors
why is it difficult for premature infants to ingest milk?
- underdeveloped sucking and swallowing reflexes - small stomach volume
outermost membrane enclosing all the embryonic membranes
chorion
fingerlike outgrowths of the chorion are called
chorionic villi
choose the term that means present at birth. Examples include an anatomical defect, a syphilis infection, or a hereditary disease
congenital
in some neonates the foramen ovale does not close to form the fossa ovalis. this is an example of
congenital anomaly
the _____________ and _____________ are two features of the fetal circulation that allow blood to bypass the non- \functional lungs
ductus arteriosus foramen ovale
carries the mother's DNA
egg pronucleus
the _______________ system degenerates less with aging than any other organ system
endocrine
replaces the hypoblast, gives rise to the most mucosal epithelium
endoderm
tissue that replaces the original hypoblast
endoderm
will eventually become ectoderm
epiblast
indicate the 3 major processes that occur during the preembryonic stage of gestation
- embryogenesis - implantation - cleavage
aging, but not senescence
- endochondral ossification - differentiation of stem cells - appearance of secondary sec characteristics - getting taller
endoderm
- epithelium of the GI tract - thyroid - thymus - urinary bladder
occurs by end of week 8
- eyes form - digital rays form - major blood vessels form - bone calcification begins - brain waves are detectable - nostrils are evident
aging and senescence
- heart disease - decreased insulin sensitivity - visibility of blood vessels through the skin of the cheeks and nose - replacement of muscle tissue with adipose tissue - presbyopia - decrease in the number of nephrons
Which of the following is true regarding sperm migration?
- less than 1 % of ejaculated sperm cells reach the egg - vaginal acids destroy many sperm cells
occurs by the end of week 4
- neural plate appears - limb buds form - heart beat - vertebral column begins to form
functions of the amniotic fluid
- protect fetus from temperature fluctuations - allow development of the lungs - protect fetus from trauma
Which of the following can cause birth defects?
- radiation exposure - drinking one alcoholic beverage per day while pregnant - cigarette smoking - infectious disease - prescription meds
sign of fetal alcohol syndrome
- small head - malformed facial features - hyperactivity
Which of the following statements is true regarding the fetal circulation?
- the foramen ovale allows blood to bypass the lungs - the ductus venosus allows the blood to bypass the liver - the umbilical vein carries blood from the placenta to the fetal circulation
Which of the following adaptations of the circulatory system occurs shortly after birth?
- the foramen ovale closes and seals, blocking blood between the atria from mixing - the ductus arteriosus collapses and stops pulmonary trunk blood from mixing with aortic arch blood - several vessels close off and form fibrous cords or ligaments
buried in the endometrium
implanted blastocyst
in the egg, ______________ begins before ovulation, but will only complete if fertilization occurs
meiosis II
gives rise to muscle tissue
mesoderm
third layer of embryonic tissue made of migrating epiblast cells
mesoderm
The lack of a chromosome, leaving one without a match, is called ____________
monosomy
the condition of having only one member of a homologous pair of chromosomes is known as ______________
monosomy
16 or more cells within the zona pellucida
morula
an infant up to 6 weeks old is classified as a
neonate
In ____________ , a pair of chromosomes fails to separate.
nondisjunction
Disruptions occur with the way polypeptides are folding and/or binding to carbohydrates.
other protein abnormalities
throphoblast
outer layer of cells
Trophoblastic nutrition wanes as ____________ nutrition takes over and ceases entirely by week ____________ .
placental; 12
The egg can utilize a rapid depolarization of the membrane or the secretion of an impenetrable fertilization membrane to prevent __________.
polyspermy
describe the primary cause of infant respiratory distress syndrome
prematurity and the lack of sufficient surfactant
midline structure making the embryo bilaterally symetrical
primative streak
midline structure making the embryo bilaterally symetrical
primitive groove
following fertilization, the genetic material of each gamete, prior to them combining, is contained within the
pronuclei
Cells lose their capacity for division and begin to die out.
replicative senescence
fast block
- Na ion channels open - membrane depolarization
Which of the following is a result of senescence?
- The loss of pigment in the hair due to dying out of melanocytes - The degeneration of the hyaline cartilage that lines the femoral head - The stiffening of the hyaline cartilage that connects the ribs to the sternum
Which of the following signs and/or symptoms in a premature infant is/are due to a poorly developed liver?
- a hypotonic enviroment in the blood plasma causing a net filtration pressure resulting in systemic tissue edema - a difficulty inhaling due to lack of surfactant - a yellowing of the skin and sclera - an inability to properly dispose of bilirubin
ectoderm
- anterior pituitary - outer ear - sensory neurons
name the stages of developing organism that occur during the preembryonic stage
1) zygote 2) cleavage 3) morula 4) blastocyst
When this occurs, one cell will receive ____________ chromosomes and the other will receive 22.
24
Over the course of gestation, the conceptus is nourished in ____________ different ways
3
after ejaculation and during sperm migration, changes occur in the sperm that allow it to penetrate the egg.
capacitation
embryoblast
cell mass within blastocyst
Klinefelter syndrome results from what genotype?
XXY
___________ causes more birth defects than any other drug
alcohol
the term __________ refers to an abnormal number of chromosomes
aneuploidy
the stage of ______________ is complete when the blastomeres form 3 primary germ layers
embryogenesis
Collagen is disrupted by disulfide bridges and becomes stiff and less soluble.
cross linking theory
Which of the following is an existing scientific theory regarding the mechanism of senescence?
cross linking theory
Which of the following is a legitimate reason why a neonate's first few breaths are relatively difficult?
- upon birth, the alveoli are collapsed and the initial inflating requires a relatively large amount of force to generate the required pressure
Which of the following is a function of the placenta?
-The placenta allows the building blocks of proteins to diffuse from maternal to fetal blood. -The placenta helps the fetus dispose of metabolic waste that would normally be excreted by its own kidneys. -The placenta allows for gas exchange.
chronological regarding the development of the placenta
1)At implantation, extensions of the syncytiotrophoblast penetrate deep into the nourishing endometrium. These extensions are known as the chorionic villi. 2)The placenta begins to develop approximately 11 days after conception. 3)The placenta becomes a dominant mode of nutrition at the begninning of week 9. 4)By the end of week 12 the placenta is the sole mode of nutrition until birth. 5)Blood flows between the fetus and the mother by way of umbilical arteries and veins, attached to the placenta.
accurate explanation of fertilization
1)The sperm encounters the egg and undergoes an acrosomal reaction. 2)This reaction releases enzymes from the acrosome of the sperm cell, which then digest a path through the granulosa cells and the zona pellucida. 3)After the sperm contacts the egg, the sperm head and midpiece enter the egg. 4)At this point, the haploid set of chromosomes from each gamete combine to produce a full diploid set. 5)Finally, the egg blocks all other sperm from entering, in order to prevent a triploid cell.
sperm remain viable for ________ days after ejaculation
6
Trophoblastic nutrition remains the dominant mode of nutrition until the end of week ____________ .
9
A premature infant has an accelerated respiratory and heart rate, fatigue, and blood shows low oxygen levels. From which of the following conditions might the infant be suffering?
Patent Ductus Arteriosus: The ductus arteriosus failed to close Patent Foramen Ovale: The foramen ovale failed to seal.
becomes part of the urinary bladder
allantois
begins as an outpocketing of the yolk sac and forms the foundation of the umbilical cord
allantois
eventually encloses the embryo and is penetrated only by the umbilical cord
amnion
transparent sac that develops from cells of the epiblast
amnion
name the narrow space between embryoblast (inner cell mass) and the trophoblst during early embryogenesis
amniotic cavity
narrow space between the embryoblast and trophoblast
amniotic cavity
helps regulate fetal temperature
amniotic fluid in amniotic cavity
Lymphocytes begin to attack the body's own tissues.
autoimmune theory
dividing cells
blastomeres
outpocketing of the outermost membrane
chorionic villus
dividing of blastomeres
cleavage
Both chromosomes will then be passed to the ____________ cell.
daughter
In trophoblastic nutrition, the conceptus consumes ____________ of the endometrium
decidual cells
name the transport process by which oxygen, CO2, and nutrients cross the placenta
diffusion
the remaing epiblast after the first two layers have formed
ectoderm
the implanting of the blastocyst somewhere other than the uterus is known as a _____________ pregnancy
ectopic
blood flows into the fetus via these vessels
umbilical arteries
attaches the placenta to the uterus
umbilical cord
blood returns to the fetus via this vessel
umbilical vein
contains vessels used for gas exchange between mother and embryo
umbillical cord
hollow sphere with outer layer of squamous cells
unimplanted blastocyst
Shortly after conception, the conceptus absorbs ____________ while in the uterine tube and free floating in the uterus.
uterine milk
the ____________ ______________ arises from cells of the hypoblast. it contributes to the formation of the digestive tract and is the site of production of the first blood cells
yolk sac
susceptible to the acrosome's digestive enzymes
zona pellucida
a single-celled, fertilized egg is known as a
zygote
the fertilized egg cell
zygote
