Exam 1 Flashcards
Oocytes are produced by what and expelled during what?
Ovaries, expelled during ovulation
What sweeps the oocyte where it may be fertilized?
Fimbria of the uterine tube
Where are oocytes fertilized?
Ampulla of the uterine tube
Sperm are produced where and are stored where?
Testes,
Epididymis
After a oocyte is penetrated by sperm it soon becomes what? As it passes along the uterine tube towards uterus it undergoes what process?
Zygote,
Cleavage (mitotic cell divisions)
A ball of about 12 blastomeres is called what?
Morula
A cavity forms in an morula making it a blastocyst consisting of what two things?
Embryoblast (a cavity) and
Trophoblast (encloses embryoblast)
The blastocyst is implanted where At the end of the first week after fertilization?
Endometrium
Chromosomes and DNA copies in prophase of mitosis, completion of mitosis?
46 chrom. 4N copies DNA
46 chrom. 2N copies DNA
Chromosomes and DNA copies in prophase of meiosis 1, after first meiotic division, and after second meiotic division?
46 chrom. 4N
23 chrom. 2N
23 chrom. 1N
Which two ovarian cells are responsible for estrogen/progesterone production?
Theca cells and granulosa cells
During the process of ovulation, what is actually ejected from the ovary?
Secondary oocyte
During the average menstrual cycle LH and FSH levels are highest during which phase?
Before ovulation
During spermatozoa maturation protamines replace histones to facilitate chromatin condensation. When or where are sperm DNA protamines removed and replaced by histones?
In the oocyte after fertilization
The first polar body is produced during which stage of human development?
Tertiary Graafian follicle
When does Zona pellucida hatching occur?
Blastocyst stage
The amniotic cavity is formed when:
A cavity forms in the epiblast
GnRH regulates FSH and FSH supports both spermatogenesis and oogenesis by acting on which cells?
Sertoli and granulosa cells
During human gastrulation which definitive germ layer forms first?
Endoderm
Placental villi primarily derive from which tissue?
Trophoblast of the blastocyst
The chorionic cavity or extraembryonic coelom forms between which two layers?
Somatic extraembryonic mesoderm and splanchnic extraembryonic mesoderm
The oropharyngeal membrane (oral plate) is a combination of which layers?
Ectoderm and endoderm
Why is the notochord referred to as the “primary inducer”?
Induces ectoderm to form the neural plate and induces paraxial mesoderm to form somites
The intraembryonic coelom forms during week 3 and is defined by horizontal folding during week 4 of embryonic development. Where does this occur?
Between somatic and splanchnic mesoderm
A primary outcome of caudal embryonic longitudinal folding is formation of the?
Hindgut
What is the source of the mesothelium that makes up the parietal peritoneum?
Lateral somatic mesoderm
The trophoblast differentiates into two layers called?
The sycytiotrophoblast and cytotrophoblast.
What glandular structure maintains pregnancy with secretions of estrogen and progesterone in the blastocyst?
Corpus luteum
What appears in the syncytiotrophoblast that provides nutrients to the embryo?
Blood filled lacunae
Outer surface of the yolk sac and amnion is?
Splanchnic mesoderm
What produces hCG?
Syncytiotrophoblast
The extraembryonic mesoderm surrounds?
The amnion and umbilical vesicle
Somatic mesoderm covers ______ while splanchnic covers what?
Somatic mesoderm covers the amnion; splanchnic mesoderm covers the umbilical vesicle
The first sign of gastrulation is the formation of the ________ on the surface of the ___________
Primitive streak;
Epiblast
What forms somites?
Paraxial mesoderm
Mesenchymal cells organize to become ?
Intraembryonic mesoderm
The primitive streak produces what?
Mesenchymal cells
A thickening of embryonic ectoderm creates the?
Neural plate
Mesenchymal cells form the?
Notochordal process
