Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
247 Cards in this Set
- Front
- Back
|
Cell-to-cell interactions between adjacent cells (tissues) of different properties and history via chemical signals that regulate development (morphogenesis and patterning) |
Inductive cellular interactions |
|
|
Differentiation of cells and tissues in the early embryo which results in the establishment of the form and structure of the various organs and parts of the body (Ex. formation of the shape of the tooth) |
Morphogenesis |
|
|
The processes occurring in early development that direct morphogenesis. They specify the basic body plan ensuring that cells will proceed to differentiate, grow, and diversify in size and shape at the correct relative position to each other and the surrounding tissues. (Ex. correct positioning of the tooth in the jaw) |
Patterning |
|
|
Types of Patterning |
Axial patterning, segmentation, compartment specification, limb position, organ boundary patterning, blood vessel patterning |
|
|
Formation of birth defects as a result of genetic mutations and/or environmental influences. May result from both malformations and deformations/disruptions |
Dysmorphogenesis |
|
|
Primary morphological defect resulting from an intrinsically abnormal developmental process (genetic and/or environmental) that mostly occur during organogenesis (weeks 3-8) (Ex. polydactyly) |
Malformation |
|
|
Secondary morphological defect of a normally developed body part resulting from physical forces (Ex. clubfoot - due to insufficient amount of amniotic fluid) |
Deformation |
|
|
Secondary morphological defect of a normally developed body part resulting from interruption of the blood supply (Ex. amniotic band syndrome causing constriction or amputation of digit or limb) |
Disruption |
|
|
Embryonic loose connective tissue (star shaped cells in extracellular matrix) that can arise from any germ layer |
Mesenchyme |
|
|
the signal leads to the initiation of new genes |
Instructive |
|
|
all the machinery for development is present and the tissue only needs the proper environment to develop |
Permissive |
|
|
the tissue is prevented to transform into its default fate |
Suppressive |
|
|
Type of signal transduction pathway where proteins synthesized by inducer cells diffuse into extracellular environment and affect nearby responder cells |
Paracrine |
|
|
Type of signal transduction pathway that does not involve diffusible proteins (signaling molecules) |
Juxtacrine |
|
|
Processes of Paracrine Signaling Pathway |
Signaling molecules, receptor molecules, signal transduction, transcription factors |
|
|
Intercellular molecules produced by inducer cells (also called Paracrine signaling factors or growth factors) |
Signaling molecules |
|
|
Cell surface (transmembrane) proteins or intracellular molecules of the responder cells that form complexes with signaling molecules |
Receptor molecules |
|
|
Transmits the signal from the receptor molecule to the nucleus of the responding cell via a molecular cascade |
Signal transduction |
|
|
Intracellular protein that binds to the regulatory regions of DNA |
Transcription factors |
|
|
4 Major Families of signaling molecules |
1) Hedgehog family 2) Transforming growth factor beta family 3) Wingless family (Wnt) 4) Fibroblast growth factor family (Fgf) |
|
|
Best known signaling molecule; it is involved in the establishment of boundaries within the embryo: patterning |
Sonic hedgehog (Shh) |
|
|
Defects of Sonic Hedgehog |
midline defects of brain, face (craniofacial defects), tracheoesophageal fistula, polydactyly |
|
|
Signaling molecule (in Hedgehog family) involved in postnatal development; present in Steroli cells and plays role in spermatogenesis |
Desert hedgehod (Dhh) |
|
|
Defects of Desert hedgehog |
gonadal dysgenesis (defective development) |
|
|
Signaling molecule (in Hedgehog family) involved in postnatal development; present in cartilage and used for postnatal bone growth |
Indian hedgehog (Ihh) |
|
|
Family of signaling molecules composed of over 30 members (including TGF-beta 1-5, the activins, nodal, and bone morphogenetic proteins); involved in regulating cell division and the formation of extracellular matrix |
Transforming Growth Factor Beta Family |
|
|
Defects of Tgf-beta family |
pulmonary hypertension, vascular and skeletal defect, cancer |
|
|
Family of signaling molecules composed of 19 members; involved in patterning the dorsal portion of the somites to form muscle, the development of the gut and urogenital system, and in limb formation |
Wingless family (Wnt) |
|
|
Defects of the Wingless family |
tetra-amelia (absence of limbs), osteoarthritis of hip, genitourinary anomalies, colon cancer |
|
|
Family of signaling molecules with 22 members; they bind to receptors with a Tyrosine kinase domain; important for limb development |
Fibroblast growth factor (Fgf) family |
|
|
Defects of Fibroblast growth factor family |
skeletal defects e.g. achondroplasia (most common form of dwarfism) |
|
|
Types of Juxtacrine cell-to-cell interactions |
1) Direct cell-to-cell interactions 2) Ligands in extracellular matrix 3) Gap junctions |
|
|
Proteins on the cell surface interact with receptors on another cell surface |
Direct cell-to-cell interactions |
|
|
Small channels between cells allow passage of small molecules from one cell to the other |
Gap Junctions |
|
|
Notch 1-4 receptor proteins bind to cells with a particular protein (e.g. Jagged) in their cell membrane |
Notch pathway |
|
|
Defects of Notch pathway |
cardiovascular, gastrointestinal, and skeletal defects |
|
|
Transmembrane receptors that link extracellular matrix molecules with the cytoskeleton. The resulting rearrangement of the cytoskeleton leads to changes in cell size, shape, etc. |
Integrins |
|
|
Vitamin A (the ligand in extracellular matrix) is converted to this in the cell, which then enters the nucleus and binds to its receptors that are transcription factors; acts in concentration dependent manner providing positional information |
Retinoic acid |
|
|
Defects of Integrins |
skin and connective tissue diseases, cancer of gut, breast |
|
|
Defects of Retinoic Acid |
environmental and pharmacological agents may affect this system; Accutane, a retinoid, is linked to craniofacial and limb anomalies when taken during pregnancy |
|
|
Domains of receptors on responding cells |
1) Extracellular 2) Transmembrane 3) Cytoplasmic |
|
|
Binding of the signaling molecule to the receptor induces a ______________ on the cytoplasmic domain that activates a _______________ |
conformational change; protein kinase |
|
|
Signal transduction ends in the phosphorylation of a _________ that activates or represses a particular set of genes |
transcription factor |
|
|
proteins that bind to enhancer or promoter regions of a particular gene and either activate or repress the transcription of that gene |
Transcription factors |
|
|
Domains of Transcription factors |
1) DNA binding domain 2) Trans-activating domain 3) Protein-protein interaction domain |
|
|
Domain of transcription factor that recognizes a sequence of DNA |
DNA binding domain |
|
|
Domain of transcription factor that either suppresses or activates the promoter |
Trans-activating domain |
|
|
Domain of transcription factor that allows the activity to be modulated by other transcription factors or transcription activating factors |
Protein-protein interaction domain |
|
|
Transcription factors are grouped together based on similarities in their ____________ |
DNA-binding sites |
|
|
Homeodomain proteins |
1) Hox proteins 2) Lim 3) Engrailed 4) Pax 5) POU |
|
|
Homeodomain protein involved in head/tail specification (segmentation) of the body axis |
Hox proteins |
|
|
Homeodomain protein involved with head development |
Lim |
|
|
Homeodomain protein involved with ventral ectoderm and brain development |
Engrailed |
|
|
Homeodomain protein involved in neural specification and eye development |
Pax |
|
|
The members of this family all contain this motif and are characterized by the muscle specific transcription factor (MyoD); involved in muscle development (myogenesis) |
Basic helix-loop-helix proteins |
|
|
The members of this family are dimers with subunits that contain a basic DNA binding domain followed by a region that is rich in leucine. |
Basic leucine zipper proteins |
|
|
Basic leucine zipper proteins involved in liver differentiation and fat cell development |
C/EBP and AP1 |
|
|
Zinc finger Proteins involved in the development of the kidney and gonads |
Engrailed, Krox-20, and WT1 |
|
|
Mutations of WT1 cases _______ |
urogenital malformations and Wilms tumor of the kidney |
|
|
Members of Nuclear Hormone receptors |
glucocorticoids, estrogen, testosterone, and retinoid acid receptors |
|
|
Bind to steroid hormones and enter nucleus where it is able to bind to specific DNA sequences; involved in secondary sex determination, craniofacial and limb development |
Nuclear Hormone receptors |
|
|
Branch of medicine concerned with the fetus from Week 26 to four weeks after birth |
Perinatology |
|
|
Used to determine fetal age, detect malformations |
Ultrasonography |
|
|
Used to detect anomalies of brain and GI tract and maturity of lungs (usually 2nd, 3rd trimester) |
MRI |
|
|
Types of sampling of fetal cells/blood for genetic analysis |
(1)Chorionic villus sampling (10-13 weeks gestation) (2) Amniocentesis (from 14 weeks gestation) (3) Percutaneous umbilical cord blood sampling |
|
|
Maternal serum screening is usually done in the _____________ combined with ultrasonography |
second trimester |
|
|
Triple Screen |
1) Alpha-fetoprotein (AFP) 2) Human chorionic gonadotropin 3) Estriol |
|
|
Chemicals tested that are produced by the placenta |
Human chorionic gonadotropin and estriol |
|
|
Quadruple Screen |
1) Alpha-fetoprotein (AFP) 2) Human chorionic gonadotropin 3) Estriol 4) Inhibin-A (produced by fetus and placenta) |
|
|
Alpha-fetoprotein (AFP) can be measured in _______ and ______ |
maternal serum (15-20 weeks gestation); amniotic fluid |
|
|
AFP is produced by ________ |
fetal liver, gut |
|
|
AFP is ____________ in neural tube defects (NTD's) and abdominal wall defects |
elevated |
|
|
AFP is ___________ in trisomy 18, 21, and sex chromosome abnormalities |
decreased |
|
|
Common indications for amniocentesis |
Advanced maternal age, previous birth with a genetic problem, chromosome abnormality in either parent, carriers of X-linked recessive disorders, history of neural tube defects, carriers of inborn errors of metabolism, or abnormal ultrasound or serum screening test |
|
|
Treatment options of the fetus |
Transfusion, medical treatment, surgery, stem cell transplantation, and gene therapy |
|
|
Refers to the number of copies of each chromosome (ex. haploid = one copy; diploid = two copies) |
Ploidy |
|
|
Refers to number of copies of each DNA molecule |
N number |
|
|
All cells of the organism except germ cells and stem cells. They are diploid and reproduce by mitosis. |
Somatic cells |
|
|
Diploid cells (46, 2N) that produce gametes by undergoing mitosis and meiosis. |
Germ cells |
|
|
Haploid reproductive cell -- ovum or sperm (23, 1N) |
Gamete |
|
|
A single, diploid cell from the union of the male and female gametes |
Zygote |
|
|
A specialized cell division that maintains stable chromosome counts in successive generations and allows for diversity of genotype and variations in phenotype. |
Meiosis |
|
|
Regularly recurring physiological changes in the uterus (endometrium) |
Menstrual cycle |
|
|
Physiological changes in the ovary associated with ovulation |
Ovarian cycle |
|
|
Two stages of Meiosis |
1) Meiosis I (reductional division) (46, 2N --> 46, 4N --> 23, 2N) 2) Meiosis II (sister chromatids of ds chromosomes separate; 23, 2N --> 23, 1N)
|
|
|
Gametes are formed from __________ |
primordial germ cells (PGC's) |
|
|
PGC's (46, 2N) originate from ________ and move to the ______ |
epiblast; yolk sac |
|
|
From the yolk sac, PGC's migrate to the _______ during Week ______ |
genital ridge; week 5-6 |
|
|
In the genital ridge, PGC's undergo several rounds of mitosis yielding ________ in males and _______ in females (both 46, 2N) |
spermatogonia; oogonia |
|
|
In females, PGC's enter ________ but arrest after crossing over occurs in prophase as _______ (46, 4N) until ______ |
meiosis I; primary oocytes; puberty |
|
|
In males, PGC's do not enter meiosis until _______ |
puberty |
|
|
Spermatogenesis is initiated at _________ by _____________ |
puberty; testosterone |
|
|
Testosterone is produced by ________ in the ________ and triggers growth of the testes and maturation of seminiferous tubules |
Leydig cells; testes |
|
|
Spermatogenesis takes about _______ days |
64 |
|
|
Two stages of spermatogenesis |
1) Spermatogonia -> primary spermatocytes -> secondary spermatocytes -> spermatids
2) Spermatids -> spermatozoa (spermiogenesis) |
|
|
Spermatogenesis takes place in the testis in the _________________ |
seminiferous tubules |
|
|
Cells in testis that produce testosterone and are located between seminiferous tubules |
Leydig Cells |
|
|
Cells in testis that play a role in support and nourishment of the gametes, removal of cytoplasm during spermiogenesis; they line the seminiferous tubules and form intimate relationship with germ cells within them |
Sertoli cells |
|
|
Spermatogenesis is initiated by the mitosis of ______ which takes _____ days |
Primordial germ cells; 16 days |
|
|
Spermatogonia migrate between _______ from the basal to the luminal side of seminiferous tubules as they undergo Meiosis I and II |
Sertoli cells |
|
|
Meiosis I takes ____ days |
8 days |
|
|
Stages of Meiosis I |
spermatogonium (46, 2N) -> primary spermatocyte (46, 4N) -> two secondary spermatocytes (23, 2N) |
|
|
Meiosis II takes ____ days |
16 days |
|
|
Stages of Meiosis II |
two secondary spermatocytes -> four spermatids (23, 1N) |
|
|
Spermiogenesis is the conversion of ________ to _________ |
spermatids; spermatozoa |
|
|
During spermiogenesis, the ______ is removed while shape and organization change |
cytoplasm |
|
|
Spermiogenesis takes about _____ days |
24 days |
|
|
Parts of a spermatozoon |
head, mid piece, and tail |
|
|
Capacitation of spermatozoa occurs in the ____________ and prepares the sperm for fertilization |
female reproductive tract |
|
|
Changes in the _________ allows it to penetrate the zone pellucid of the oocyte |
acrosome |
|
|
Spermatozoa retain their ability to fertilize for ______ days |
1-3 days |
|
|
Capacitation of spermatozoa takes about ____ hours |
7 hours |
|
|
Oogenesis begins ______ and is completed after ____ until _____ |
before birth; puberty; menopause |
|
|
______ primary oocytes at birth, ______ at puberty, and only _____ will become secondary oocytes |
2,000,000 ; 40,000 ; 400 |
|
|
The ovarian cycle is controlled by these hormones |
follicle stimulating hormone (FSH), estrogen, and luteinizing hormone (LH) |
|
|
Oogenesis prior to birth |
PGC's undergo mitotic divisions and differentiate into oogonia. Oogonia then enter meiosis I and become primary oocytes (46, 4N) |
|
|
The primordial follicle is composed of |
a transparent layer of glycoprotein (zone pellucida) and a single layer of follicular cells |
|
|
At puberty, rising levels of ____ and ____ initiate follicular matruation |
FSH and LH |
|
|
Beginning each cycle, several primordial follicles become _________ |
primary follicles |
|
|
Only one primary follicle continues to grow into a _________ |
mature follicle |
|
|
In response to hormonal surge just before ovulation, the primary oocyte completes meiosis I to become a __________ |
secondary oocyte (23, 2N) |
|
|
During ovulation, there is rupture and release of the _____________ |
secondary oocyte |
|
|
Upon ovulation, the mature follicle of the secondary oocyte is converted into the __________ |
corpus luteum |
|
|
The corpus luteum secretes __________, and it degenerates after _____ days and becomes _________ |
progesterone and estrogen; 14 days; corpus albicans |
|
|
After fertilization, the ovulated secondary oocyte arrested in metaphase completes meiosis II yielding the ___________ and a __________ |
definitive oocyte (23, 1N) and a second polar body |
|
|
Phases of the Menstrual Cycle |
1) Menstrual phase (5 days) 2) Proliferative phase (9 days) 3) Secretory phase (13 days) 4) Ischemic phase (1 day) 5) Prenancy phase if fertilization occurs |
|
|
Phase of menstrual cycle in which there is sloughing off of the endometrium due to a drop in progesterone from the corpus luteum |
Menstrual phase (5 days) |
|
|
Phase of menstrual cycle in which the endometrium begins to thicken due to the release of FSH and estrogen |
Proliferative phase (9 days) |
|
|
Phase of menstrual cycle in which progesterone secreted by the corpus luteum causes the glandular epithelium to secrete glycogen rich material and the spiral arteries to enlarge |
Secretory phase (13 days) |
|
|
Phase of menstrual cycle where if fertilization does not occur the rapidly dropping hormone levels from the degenerating corpus luteum cause the spiral arteries to start falling apart and pieces of the endometrium are shed into the uterine cavity |
Ischemic phase (1 day) |
|
|
Phase of menstrual cycle where if fertilization does occur, hormone levels remain high and the endometrial lining is maintained |
Pregnancy phase |
|
|
Pathway of Sperm: from the ______, it passes through the ______ to the ______ and finally into the ______ before being deposited in the vagina around the _________ |
epididymis; ductus deferens; ejaculatory duct; urethra; external os of the cervix |
|
|
Pathway of Oocyte: after release into the abdominal cavity, the secondary oocyte is swept into the _______ of the uterine tube by the sweeping action of the ______. The oocyte then passes into the _______ by peristalsis. |
infundibulum; fimbria; ampulla |
|
|
The process in which two sex cells fuse together to create a new individual, the zygote, with genetic potential from both parents. |
Fertilization |
|
|
Sperm must pass from the cervix to the ____________ to meet the egg |
ampulla of the uterine tube |
|
|
Of the 200 million - 600 million sperm deposited in the vagina, only about 200 make it to the ampulla because of these barriers |
1) Vaginal pH is acidic 2) Cervical mucus is thick |
|
|
Cervical mucus becomes more watery in the days surrounding ________ |
ovulation (days 9-16 of cycle) |
|
|
Steps of Fertilization |
1) Passage through the corona radiata (follicular cells surrounding the egg) 2) Penetration of the zone pellucida |
|
|
_______, a glycoprotein receptor in the zone pellucida binds sperm, initiating _______ enzyme release |
ZP3; acrosomal |
|
|
_________ protein on the sperm cell membrane binds to an ______ on the egg surface, and the two membranes fuse |
Fertilin beta protein; integrin |
|
|
Fusion of the egg and sperm plasma membranes initiates release of ________ and activation of _______ |
cortical granules; egg metabolism |
|
|
Prevents penetration by other sperm (polyspermy) |
cortical granules |
|
|
During the fusion of genetic material, the _______ of sperm and oocyte fuse |
pronuclei (swollen nuclei) |
|
|
Consequences of fertilization |
Restoration of diploid number, variation of the species through a mingling of paternal and maternal chromosomes, determination of genetic sex, and metabolic activation of the oocyte which results in the initiation cleavage |
|
|
Cleavage occurs within the bounds of the _______, so the overall size of the zygote cannot increase despite growing number of cells |
zona pellucida |
|
|
During cleavage, each division results in smaller and smaller daughter cells or _________ |
blastomeres |
|
|
After about 4 days of fertilization, the zygote consists of ____ blastomeres and is referred to as a _______ |
16-32; morula |
|
|
The formation of intercellular junctions converts the loose arrangement of _________ into a tight compact ball of cells. |
blastomeres |
|
|
On Day 4, the embryo develops the ability to control the flow of ions via an _______ in _______ |
Na/K pump in trophoblast |
|
|
As embryo pumps ions, water follows into its interior and the blastomeres are rearranged into fluid-filled ball with _________ |
blastocyst |
|
|
The blastomeres segregate into ________ and _________ |
Inner cell mass and outer cell mass |
|
|
The inner cell mass is the _______ and becomes the ________ |
embryoblast; embryo |
|
|
The outer cell mass is the ______ and becomes the _______ |
trophoblast; placenta |
|
|
At the end of day 4, the blastocyst enters the __________ |
uterine cavity |
|
|
On day 5, the blastocyst hatches from _________ to interact directly with _________ |
zona pellucida; endometrium |
|
|
On day 6, the embryo attaches to the wall of the uterus, adjacent to the ________ |
embryonic pole |
|
|
Trophoblast differentiates into two layers, an inner _______ and an outer _______ |
cytotrophoblast; syncytiotrophoblast |
|
|
Embryoblast differentiates to form the _______ and ______ (primary endoderm) |
epiblast; hypoblast |
|
|
Endometrial stroma shows _________ |
decidual reaction |
|
|
PGC's get stranded or strayed during migration |
Forms tereatoma |
|
|
Issues during gametogenesis |
1) Meiosis-nondisjunction (trisomy, monosomy) 2) Meiosis-structural changes in chromosome 3) Meiosis-gene mutations |
|
|
What structural changes in chromosomes may occur? |
Translocation, deletion, duplication, or inversion |
|
|
Issues during fertilization |
1) Maternal pronucleus is lost 2) Oocyte fertilized by two sperm |
|
|
Issues during cleavage |
1) Loss of chromosome from a set of cells (mosaics) 2) gene mutation |
|
|
Issues during implantation |
ectopic pregnancy (embryo implants outside of uterine cavity) |
|
|
____ of fertile couples (35 and under) will conceive within 12 months of trying |
90% |
|
|
The chance of conceiving within each cycle is __ |
25% |
|
|
_ out of _ couples have difficulty in achieving pregnancy |
1 out of 6 |
|
|
Female factors for infertility |
1) Endocrine disorders 2) Tubal damage/obstruction resulting mostly from pelvic inflammatory disease (PID) |
|
|
Male factors for infertility |
1) Endocrine disorders 2) Abnormal spermatogenesis 3) Obstruction of genital ducts |
|
|
_____ of in vitro fertilization (IVF) results in live birth |
30% |
|
|
Steps in IVF |
1) Stimulation of gamete production 2) Capturing and storing gametes 3) Fertilization and storage 4) Embryo transfer |
|
|
Methods of stimulating gamete production |
1) Clomiphene citrate -- nonsteroidal antiestrogen 2) Human menopausal gonadotrophins (hMGs) 3) Gonadotropin-releasing hormone (GnRH) |
|
|
Methods in capturing and storing gametes |
-Female: eggs harvested by laproscopy -Male: sperm donation -stored indefinitely in liquid nitrogen and glycerin |
|
|
Methods in fertilization and storage |
-immature eggs cultured for a short time to reach maturity -spermatozoa are separated form seminal fluid -eggs checked next day for pronuclei -embryos grown to the 2-8 cell stage then implanted or stored |
|
|
Method of embryo transfer |
3 embryos injected into the uterus by way of a catheter |
|
|
Tumors of disputed origin that often contain a variety of tissues, such as bone, hair, muscle, gut, etc. PGC's that have strayed from normal path may result in these. |
Teratoma |
|
|
Chromosomal abnormalities account for ____ of major birth defects, and gene mutations account for another ____ |
10%, 8% |
|
|
Nondisjunction during mitosis in an embryonic cell during the earliest cell divisions produces _________ |
mosaicism |
|
|
47, XXY disorder |
Klinefelter Syndrome |
|
|
45, X disorder |
Turner Syndrome |
|
|
Syndrome caused by partial deletion of the short arm of chromosome 5 |
Cri-du-chat syndrome |
|
|
Syndrome caused by micro deletion on maternal chromosome 15 |
Angelman's Syndrome |
|
|
Syndrome caused by micro deletion on paternal chromosome 15 |
Prader-Willi syndrome |
|
|
regions of chromosomes that demonstrate a propensity to separate or break under certain cell manipulations; usually consist of CGG repeats |
fragile sites |
|
|
Syndrome caused by damage to FMRI gene on the long arm of the X chromosome |
Fragile X syndrome |
|
|
________ produced by the hypothalamus, acts on cells of the anterior lobe of the pituitary gland, which in turn secrete gonadotropins |
Gonadotropin-releasing hormone (GnRH) |
|
|
Gonadotropins |
Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) |
|
|
Slight pain felt during ovulation |
Mittelschmerz |
|
|
Ovulation is also generally accompanied by a rise in ______________, which can be monitored to aid couples in becoming pregnant or preventing pregnancy. |
Basal temperature |
|
|
Hormonal methods of contraception provide ________ and/or ________ . These inhibit ovulation by preventing the release of FSH and LH. |
estrogen and/or progestin |
|
|
In a vasectomy, the _______ is blocked, preventing transport of sperm from the testis to the penis. |
ductus deferens |
|
|
In preparation for implantation, the uterus undergoes a __________ reaction in which the endometrial lining _______ to provide suitable cellular and nutritional environment |
decidual; thickens |
|
|
The ___________ secretes trypsinlike enzymes that digest hole in zona pellucida |
trophoblast |
|
|
For the _______, development is regulated by maternal genes |
embryoblast |
|
|
For the ________, development is regulated by paternal genes |
trophoblast |
|
|
Currently known imprinted genes are clustered on chromosomes ___ and ____ |
11 and 15 |
|
|
One of the X chromosomes in females is inactivated and becomes condensed to a ________ |
Barr body |
|
|
X inactivation requires expression of the _____ gene on the inactive X, which inactivates genes by __________ |
Xist gene; DNA methylation |
|
|
X inactivation affects the inheritance of certain genetic diseases such as _________ |
Duchenne muscular dystrophy |
|
|
Duchenne muscular dystrophy is an ________ disorder where there is a mutation of the gene for _______ |
X-linked recessive; dystrophin |
|
|
Implantation begins on Day _____ |
6 |
|
|
The blastocyst attaches to endometrium at _____ wall of uterus at the _______ of blastocyst |
posterior wall; embryonic pole |
|
|
Endometrium induces trophoblast proliferation and differentiation into ________ (inner layer) and _______ (outer layer) |
cytotrophoblast; syncytiotrophoblast |
|
|
The ______ produces proteolytic enzymes to break down ECM |
Cytotrophoblast |
|
|
The _______ penetrates endometrium with finger-like projections, and lucanae form |
Syncytiotrophoblast |
|
|
The endometrial stromal cells accumulate nutrients, lipids, glycogen and become _____ |
decidual cells |
|
|
The decidual cells and highly vascularized endometrium are collectively called ______ |
decidua |
|
|
The decidua contributes to the formation of the __________ |
placenta |
|
|
The embryoblast divides into two layers, and the ________ of the embryo is established |
dorsal-ventral axis |
|
|
The embryoblast divides into two layers: the _________ (primitive ectoderm) and the ______ (primitive endoderm) |
epiblast; hypoblast |
|
|
The hypoblast forms the roof of the ________ |
blastocyst cavity (exocoelomic cavity) |
|
|
The epiblast gives rise to the _______ on its dorsal aspect |
amniotic cavity |
|
|
The roof of the amniotic cavity is lined by ______ that are connected to the edge of the embryo |
amnioblasts |
|
|
The amniotic cavity and the amnioblasts collectively make up the ________ |
amnion |
|
|
The first wave of migration of cells from the hypoblast on day 8 converts the exocoelomic cavity into the ____________ |
primary yolk sac |
|
|
On day 10, the hypoblast and primary yolk sac produce cells forming the ____________ that takes up residence between the cytotrophoblast, the yolk sac, and the amnion |
extraembryonic mesoderm |
|
|
The extra embryonic mesoderm and the surrounding trophoblast make up the ______ |
chorion |
|
|
On day 12, lacunae form in the extra embryonic mesoderm, splitting it and forming the _______ |
chorionic cavity (extraembryonic coelem) |
|
|
The second wave of migration of hypoblast cells on days 12-13 displaces the primary yolk sac, forming the smaller _________ |
secondary (definitive) yolk sac |
|
|
Functions of the definitive yolk sac (important in the first 4 weeks) |
Blood cell production, primordial germ cells, nutrition, and disappears before birth |
|
|
The secondary yolk sac may persist as _______ in the distal ileum |
Meckel's diverticulum |
|
|
The embryo, with its associated amnion and secondary yolk sac, remain tethered to cytotrophoblast by the __________ |
connecting stalk |
|
|
The connecting stalk later becomes the ______ |
umbilical cord |
|
|
The formation of the chorionic cavity divides the extra embryonic mesoderm into two layers: |
1) extraembryonic somatic mesoderm 2) extraembryonic splanchnic mesoderm |
|
|
The extra embryonic somatic mesoderm is the layer associated with the ________ |
cytotrophoblast and amnion |
|
|
The extra embryonic splanchnic mesoderm is the layer associated with the ________ |
yolk sac |
|
|
The trophoblastic lacunae coalesce and anastomose with expanded ________ |
maternal capillaries (maternal sinusoids) |
|
|
The maternal sinusoids have an inlet (______) and an outlet (_______) and represent the origin of the uteroplacental circulatory system |
spiral artery; uterine vein |
|
|
Secretion of _________ maintains the corpus luteum |
human chorionic gonadotrophin (hCG) |
|
|
The Primary Villi develop on days _______ |
11-13 |
|
|
To form primary villi, the ________ expands into the blood-filled lacunae. These columns are lined with __________ |
cytotrophoblast; syncytiotrophoblast |
|
|
The Secondary Villi develop on day ____ |
16 |
|
|
To form the secondary villi, the _______ grows into a column |
extraembryonic mesoderm |
|
|
The Tertiary Villi develop on day _____ |
21 |
|
|
To form the tertiary villi, the mesodermal core differentiates into _______ and ________ |
blood vessels and connective tissue |
|
|
_______ is central to diversifying cells into new tissues and establishing the body plan in the embryo |
epithelial-mesenchymal transformation (EMT) |
|
|
Gastrulation converts the ________ embryonic disk into a ________ disk |
bilaminar; trilaminar |
|
|
Gastrulation defines the _________ axis and the ________ axes |
cranial-caudal; medial lateral and left-right |
|
|
On day 15, epiblast cells migrate to the midline of the embryonic disc and for the _________ |
primitive streak |
|
|
Components of the primitive streak |
1) Primitive groove 2) Primitive node 3) Primitive pit |
|
|
The ________ is the midline groove in the primitive streak where cells move into the interior of the embryo |
primitive groove |
|
|
The ________ is the expanded anterior end of the streak |
primitive node |
|
|
The ________ is the continuation of the primitive groove into the primitive node |
primitive pit |
|
|
The primitive streak is induced by cell-cell interactions in the caudal end of the embryo, involving the ____ and ____ families |
Tgf-beta; Wnt |
|
|
The definitive endoderm and prechordal plate are formed from cells around the _______ end of the primitive streak during the early primitive streak stage |
cranial |
|
|
The prechordial plate later contributes to the future ________ |
oral opening |
