1 Flashcards
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?
Immediately prior to 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 1st 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 speematogenesis 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 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, 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. When 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 embryonic period is classified as weeks 1-8 after fertilization. Which major event categorizes week 2?
Implantation
How many chromosomes and how many copies of the DNA would be present in a human spermatid?
23 and 1N
How many chromosomes and how many copies of the DNA (N) would be present in a human secondary oocyte?
23 and 2N
When during the cell cycle does centriole replication occur?
S phase
Which structure is analagous to the corpus spongiosum of the male penis?
Clitoris
The primary site of spermatogenesis is the:
Seminiferous tubules
Which sequence best reflects the sperm pathway through the male reproductive system?
Semiferous tubules, rete testis, efferent ducts, epididymis, ductus deferens, ejaculatory duct, prostatic urethra, membranous urethra, penile urethra
Which male cell is the first to initiate meiosis?
Primary spermatocyte
Which cell type is haploid?
Secondary spermatocyte
What single feature is shared by primordial, early and late primary, secondary and tertiary (prior to the LH surge) follicles?
All include a primary oocyte
The primary target cells for LH in males is?
Leydig cells
Which cells or structures would not accompany the oocyte at ovulation?
Granulosa cells
Luteal phase ovarian production of which hormone primarily accounts for the secretory phase development of the endometrium?
Progesterone
Which area of the female reproductive tract is characterized by branched mucus secreting glands that shift mucus production from a thick, acidic secretion during most of the menstrual cycle to large volumes of a thin, watery alkaline secretion around the time of ovulation?
Cervix
Sperm-oocyte binding results in all of the following except?
Oocyte immediately hatches from the zona pellucida
Which major organelle is contributed to the zygote by the sperm cell during fertilization?
Centrioles
What is the fundamental mechanism by which the classic contraceptive pill prevents pregnancy?
Inhibits oocyte/follicle maturation and ovulation
Why is compaction important?
Seperates blastomeres into two distinct cell populations (embryoblast and trophoblast)
Which cells would not be present in a human blastocyst at the initiation of implantation (day 7) ?
Mesoderm
Where does the decidual reaction occur?
Functional zone of endometrium
95% of all ectopic pregnancies occur in which location?
Oviduct
What is the origin of the amniotic membrane?
Epiblast
The hypoblast layer is important because it contributes to?
Extraembryonic mesoderm formation
The end of the second week is marked by formation of the chorion and its organization into the primary chorionic villi. What is the correct order (from the chorionic cavity to the decidua) of the three layers that make up the chorionic membrane?
Extraembryonic somatic mesoderm, cytotrophoblast, syncytiotrophoblast
The primitive streak marks the beginning of gastrulation. What will be the fate of the second population of cells that pass through the primitive streak?
Will become intraembryonic axial mesoderm
A woman has a difficult time delivering an infant because of a large bulging mass in the posterior area of the infants buttocks. After delivery, gentle rectal palpation indicated that this tissue extended up into the pelvis. Biopsy of the tissue revealed the presence of skin, cartilage, bone, nervous tissue, cardiac and skeletal muscle, and intestinal epithelium. What is your diagnosis?
Sacrococcygeal teratoma
The neurenteric canal is a transient passageway that develops during?
Notochord formation
Why are neural crest cells important?
Essential to peripheral nervous system development
Why is the extraembryonic somatic mesoderm important to the developing embryo?
Basis for chorionic villus blood vessel formation
The correct sequence of structures would be:
Zygote, morula, blastocyst, gastrula, neurula
Why is the extraembryonic splanchnic mesoderm important to the developing embryo?
Basis for yolk sac blood island formation and vitelline circulation
Where does extraembryonic vasculogenesis begin?
Splanchnic mesoderm
The somites develop from which cell population?
Embryonic paraxial mesoderm
The first pair of somites develop from which pair of somitomeres?
8
Which event would not be considered a major accomplishment of the 4th week of development?
Chorion formation
The mesoderm derived epithelium that lines our closed body cavities is the?
Mesothelium
The visceral peritoneum derives from the?
Intraembryonic splanchnic mesoderm
Another name for the simple squamous epithelium that forms the lining of the cardiovascular system is the?
Endothelium
A major outcome of longitudinal folding is?
Foregut/hindgut formation
What layers make-up the intraembryonic somatopleure?
Surface ectoderm and somatic mesoderm
Genitourinary system
Intermediate mesoderm
Notochord
Axial mesoderm
Coelom formation
Lateral mesoderm
Somite development
Paraxial mesoderm
List three male secondary sex glands?
Prostate, bulbourethral gland, seminal vesicles
List three ectoderm derived cell populations that result from neurulation?
Neural crest cells, neuroepithelial cells, surface ectoderm
Why is the notochord important to the process of neurulation?
The notochord serves as the primary inducer in converting surface ectoderm into neural ectoderm
Why is longitudinal folding important to cardiovascular system development?
Cranial folding serves to position the heart tube in what will become the chest cavity
List three components that make up the chorion?
Extraembryonic somatic mesoderm, cytotrophoblast, syncytiotrophoblast
List the three components that make up the embryonic vascular system during the fourth week?
Aortic/cardinal circulation, vitelline circulation, allantoic/ umbilical circulation
Outline the process of spermiogenesis
Golgi phase
Cap phase
Acrosome phase
Maturation phase
Which cells produce human chorionic gonadotropin (hCG)? And why is hCG important to human pregnancy?
Syncytiotrophoblast
It does positive feedback on the ovary to maintain the corpus luteum which produces progesterone and estrogen to maintain the endometrium
Explain why meiosis is important
It reduces total number of chromosomes from 46 to 23
It also provides genetic variability through synapsis and crossing over and independent assortment
The epiblast gives rise to the three definitive embryonic germ layers. Identify the three layers and provide major derivatives of each.
Embryonic endoderm-primitive gut
Embryonic ectoderm-skin ectoderm, neural plate/fold ectoderm–neural tube cells, neural crest cells
Embryonic mesoderm-axial–prechordal plate and notochord,-paraxial–somites,-intermediate–genitourinary system,-lateral–somatic, splanchnic
