A&P 2 Human Development
What is the primary function of the reproductive system?
- Nurturing and transporting of ova and sperm
- Secretion of hormones
- The female reproductive system has two functions: The first is to produce egg cells, and the second is to protect and nourish the offspring until birth.
- The male reproductive system has one function, and it is to produce and deposit sperm.
The prenatal period extends from?
Conception to birth
The inner cell mass of the blastocyst will form the?
The testes are housed in the _________ , outside the abdominal (which lowers sperm so that the testes are slightly cooler. This difference in temperature helps sperm production.)
The postnatal period extends from?
Birth to death
What metabolic effect would you expect if someone developed an autoimmune disease in which the person’s interstitial cells were destroyed?
Testosterone production would plummet
The______ of the penis fill(s) with blood during sexual arousal, causing an erection?
Which part of blastocyst forms the embryo?
Inner cell mass “ICM” or embryoblast
The penetration of the endometrium by the blastocyst is referred to as?
Which components in semen stimulates the uterus to contract in reverse peristalsis?
Unlike females, males produce gametes throughout life due to the presence of _____________ in their seminiferous tubules
The period of gestation when organs and organ systems complete most of their development and the fetus looks distinctly human is the ______ trimester
A man and his wife have been unable to conceive a child. When examined, the man’s sperm are viable, swim unidirectionally, and are present in higher than average quantities. What could explain the inability of his sperm to penetrate an egg?
- The acrosomal cap is deficient in the enzymes necessary to penetrate the egg
What is the function of Progesterone?
- it targets the uterine endometrium to prepare for implantation causes it to be thick, glandular and vascular
- inhibits the release of LH and FSH
What is the function of Human Placental Lactogen (hPL)?
- Regulation of metabolism
- decreases use of glucose by mother so fetus can have more
- releases fatty acids from fat deposits to provide alternative source of energy for the mother.
Labor is regulated by ______feedback control?
In a female, which structures houses the oocytes?
The _______ layer of the uterus receives the embryo and provides nourishment until the placenta is formed?
During which stage of development the organ systems are mostly formed, although immature?
The pH of the vagina is normally acidic, which keeps bacterial growth in check, but the vagina is still home to many bacteria and yeast in balance with each other. Occasionally, when a female takes antibiotics for a bacterial infection, a secondary yeast infection results. Why might this happen?
The removal of bacteria from the vagina allows yeast to grow at a faster rate than normal.
Compared to adult hemoglobin, fetal hemoglobin binds oxygen?
It has greater affinity for oxygen, and there is a larger concentration
Separation of the inner cell mass from the trophoblast forms the?
- amniotic cavity
In females, the _______ is (are) the homologous structure to the glans penis in males?
What is the major difference between spermatogenesis and oogenesis?
- Spermatogenesis produces small, motile spermatozoa
- Oogenesis the ovum is spherical, not motile and is much larger with more food reserves and cytoplasm
Differentiation during the first few days of development is the result of?
An unequal distribution of regulatory molecules in the cytoplasm of the egg
A woman who wants to ensure conception might buy an “ovulation predictor” kit. Which of the following hormones, when detected by the kit, would be the best indicator of imminent ovulation: Estrogen, GnRH, LH, FSH? Why?
List hormones produced by the placenta?
What percentage of sperm carry the Y chromosome?
The process of cell division that occurs after fertilization is called?
________ is the stage of life in females when reproductive hormones decline and menstrual cycles become erratic?
The stage of labor during which the fetus emerges from the vagina is called the ________ stage?
What is the function of Estrogens?
- development of secondary sex characteristics of females.
-Enlarging of breasts, buttocks, thighs, etc
During fertilization of the oocyte, ______ spermatozoa create a puncture of the ______. Then ___ spermatozoa contact(s) the membrane of the oocyte for activation?
-Many; corona radiate; one
The hormone oxytocin aids the birth process by stimulating?
uterine wall contractions
Which enzyme is involved in the penetration of the oocyte during fertilization?
Improper development of which of the extraembryonic membranes affects the cardiovascular system?
During gestation, powerful uterine contractions are suppressed by elevated levels of?
The head is disproportionately large compared to the rest of the body at the beginning of which stage of development?
-fetal stage of development
- What is (are) the important function(s) of the placenta?
Serves to maintain the fetus: oxygen and nutrients diffuses from maternal blood to fetal blood, carbon dioxide and wastes diffuses from fetal blood to maternal blood, a protective barrier against most microorganisms, serves to maintain pregnancy via secretion of hormones.
The foramen ovale is an opening that allows fetal blood to pass from the?
- R atrium to the L atrium
What are the important roles of hCG in maintaining pregnancy?
Stimulates continued secretion of estrogen and progesterone by corpus letrum
The external genitalia of the fetus can be distinguished as male or female by about ___ weeks after fertilization?
Which stage of development is the first and second stage of development?
Embryonic stage, Fetus
Why is it more detrimental for a pregnant woman to be exposed to teratogens, alcohol, or drugs during the first trimester than later in pregnancy?
Can cause congenital malformations by affecting the embryo during its periods of rapid growth and develeopment
Sperm cannot fertilize an egg until they undergo?
The hormones that maintain the uterine wall during the last 5 to 6 months of pregnancy are?
Placental estrogen and progesterone
Neural tissue is formed from which germ layer?
- Colostrum contains ____ than breast milk?
High protein, low carbs and fat. Contains protective antibodies, IgA
Which embryonic layer is considered loosely organized connective tissue?
Use the key choices to identify the embryonic stage or process described below: blastula, cleavage, fertilization, gastrulation, morula, zygote
- fusion of male and female pronuclei?
- solid ball of embryonic cells?
- process of rapid mitotic cell division without intervening growth periods?
- combination of egg and sperm?
- process involving cell rearrangements to form the three primary germ layers?
- embryonic stage in which the embryo consists of a hollow ball of cells?
fusion of male and female pronuclei?
solid ball of embryonic cells?
process of rapid mitotic cell division without intervening growth periods?
combination of egg and sperm?
process involving cell rearrangements to form the three primary germ layers?
embryonic stage in which the embryo consists of a hollow ball of cells?
a diploid cell resulting from the fusion of two haploid gametes; a fertilized ovum.
The period of gestation that is characterized by rapid fetal growth is the ________ trimester?
The ectoderm forms which tissue type?
- nervous system
What is the importance of cleavage in embryonic development?
First round of cell division. From a zygote to morula. Increase cell number
How is cleavage different from mitotic cell division, which occurs later in life?
mitosis: cells grow and divide
Cleavage: Keeps dividing and becomes smaller
The first stage of labor is the ________ stage?
The cells of the human blastula (blastocyst) have various fates. Which blastocyst structures have the following fates?
Use the following key once or more than once: yolk sac, trophoblast, allantois, inner cell mass
- produces the embryonic body?
- becomes the chorion and cooperates with uterine tissues to form the placenta?
- produces the amnion, yolk sac, and allantois?
- produces the primordial germ cells?
- an embryonic membrane that provides the structural basis for the body stalk or umbilical cord?
- produces the embryonic
- inner cell mass
- becomes the
chorion and cooperates with uterine tissues to form the placenta?
- produces the
amnion, yolk sac, and allantois?
- inner cell mass
the primordial germ cells?
- Yolk sac
- an embryonic
membrane that provides the structural basis for the body stalk or
What is the function of the amnion and the amniotic fluid?
- Protective membrane
- encases the embryonic body
- shock absorber
- help regulate fetal temp
- prevents adhesion between skin of fetus and other tissues
A major difference between fetal blood flow and adult blood flow is that in the fetus the?
Fetus: Vena cava is oxygenated
- The hormone measured in a pregnancy test is?
hCG, it is secreted when implantation occurs by the corpus luteum, supporting endometrium lining thus maintaining pregnancy.
- Explain the process and importance of gastrulation?
Development of three distinct primary germ layers. Where all the body tissues will develop from. Develops from ICM of blastocyst. Top layer will proliferate and form amnion and amniotic cavity. Ectoderm will become the skin and nervous system tissues. Endoderm will become the inner lining (internal organs). Endoderm will also form a yolk sac. Mesoderm will develop as connective tissue between endo and ectoderm and will form muscles and bones.
- Describe the process of implantation, noting the role of the trophoblast cells?
Blastocysts will adhere to the endometrium after the zona pellucida disintegrates. The trophoblast will develop into two layers. Cytotrophoblast is composed of distinct boundary cells. Syncytiotrophoblast will secrete enzymes that break down the endometrium for implantation.
- How many days after fertilization is implantation generally completed?
- Day( 7 -14)then attachment and penetration of implantation
- The proliferation phase where a new functional layer is produced in the uterus
- Which two organ systems are extensively developed in the very young embryo?
- Nervous system and cardio system
- The cells of a blastocyst that give rise to the body of the developing offspring constitute the?
inner cell mass
- When does the human embryo come to be called a fetus?
8th week until birth
- Fertilization of the ovum usually occurs where in the uterine tube?
Upper portion of fallopian tube.
Germ layers are formed during which period?
- Muscle contractions of the uterine walls and ________ in the semen aid sperm cell movement through the uterus and uterine tubes?
- The solid ball of cells that is formed after several rounds of cell division following fertilization is called a?
What is the usual and most desirable fetal position in utero?
During gastrulation which layers are formed?
3 distinctive germ layers, ecto, endo and mesoderm