Foundations Flashcards
2 Cell Groups of a Blastocyst
Inner Cell Mass, Trophoblast
Placental development
trophoblast —> inner cytotrophoblast & outer syncytiotrophoblast (invade the endometrium, secrete hCG)
The inner cell mass becomes the bilaminar disc in which week? What are the two layers?
Week 2; Hypoblast & Epiblast
The inner cell mass becomes the trilaminar disc in which week? Through a process called? What are the three layers?
Week3; Gastrulation
Epiblast—-> endoderm, ectoderm, mesoderm
Hypoblast —> endoderm, yolk sac
Notochord is derived from which cell type
Mesoderm
Neural plate is derived from which cell type
Ectoderm
Neural plate gives rise to
neural tube & neural crest cells
Organogenesis occurs during which weeks?
Weeks 3-8
Heart is formed during which week?
Week 4
Limb buds are formed during which week?
Week 4
Fetal movement begins during which week?
Week 8
Sex-specific characteristics appear during which week?
Week 10
Epidermis, hair, nails are derived from?
Surface Ectoderm
Mammary glands, sweat glands, & salivary glands are derived from?
Surface Ectoderm
Retina is derived from?
Neural tube
Cornea, sclera, ciliary m., iris pigment cells are derived from?
Neural crest cells
Melanocytes are derived from?
Neural crest cells
The inner ear is derived from?
Surface Ectoderm
The ossicles of the middle ear are derived from?
Neural crest cells
The odontoblasts are derived from?
Neural crest cells
Tooth enamal is derived from?
Surface Ectoderm
The lens is derived from?
Surface Ectoderm
The posterior pituitary is derived from?
Neural tube
The anterior pituitary is derived from?
Surface Ectoderm
The anal canal proximal to the pectinate line is derived from?
Endoderm
The anal canal distal to the pectinate line is derived from?
Surface Ectoderm
PNS is derived from?
Neural crest cells
The parenchyma of the thyroid is derived from?
Endoderm
The parafollicular cells of the thyroid are derived from?
Neural crest cells
The liver and pancreas are derived from?
Endoderm
The CNS is derived from?
Neural tube
The pineal body is derived from?
Neural tube
The aorticopulmonary septum is derived from?
Neural crest cells
The chromaffin cells of the adrenal medulla are derived from?
Neural crest cells
The olfactory epithelium is derived from?
Surface Ectoderm
The respiratory epithelium is derived from?
Endoderm
The enteric nervous system & celiac ganglion are derived from?
Neural crest cells
The kidneys & gonads are derived from?
Mesoderm
Craniofacial structure arises from?
Neural crest cells
The parathyroids are derived from?
Endoderm
The tonsils are derived from?
Endoderm
The vertebral bodies & IV discs are derived from?
Mesoderm (somites)
The meninges are derived from?
Neural crest cells
The muscles are derived from?
Mesoderm
The bladder & urethra are derived from?
Endoderm
The cardiovascular system is derived from?
Mesoderm
The tympanic cavity & auditory tube are derived from?
Endoderm
The lymphatic system is derived from?
Mesoderm
The thymus is derived from?
Endoderm
Describe the relationship between the notochord, neural plate, neural tube and neural crest cells?
notochord is derived from mesoderm, it induces neural plate formation in the overlying ectoderm, neural plate gives rise to the neural tube & neural crest cell
The yolk sac is derived from?
Hypoblast
What embryonic structure is a reservoir of nonspecialized stem cells?
endodermal yolk sac
Teratogenic effects of ACE-I & ARBs?
Renal malformation
Teratogenic effects of Aminoglycosides?
Ototoxicity (CN8 damage)
Teratogenic effects of Fluoroquinolones?
Cartilage damage
Teratogenic effects of Tetracyclines?
Discolored teeth in children
Teratogenic effects of Cyclophosphamide?
Ear/facial anomalies, limb hypoplasia, absence of digitis
Teratogenic effects of Methotrexate?
Neural tube defects, abortion
Teratogenic effects of Carbamazepine?
Neural tube defects
Teratogenic effects of Valproic Acid?
Neural tube defects
Teratogenic effects of Phenytoin?
Fetal hydantoin syndrome (intrauterine growth restriction, microcephaly and develop minor dysmorphic craniofacial features and limb defects)
What drug may be used to terminate an ectopic pregnancy?
Methotrexate
Teratogenic effects of Lithium?
Ebstein Anomaly
Teratogenic effects of Statins?
CNS & limb abnormalities
Teratogenic effects of Warfarin?
Facial/limb/CNS anomalies, spontaneous abortion
Teratogenic effects of Isotretinoin?
Spontaneous abortion, birth defects
Teratogenic effects of Diethylstilbestrol?
Clear cell vaginal adenocarcinoma
Teratogenic effects of Thalidomide?
Phocomelia (limb deformity)
Which anticoagulant is safe during pregnancy?
Heparin
HOX genes
determines skeletal layout (limb positioning)
Teratogens other than pharmaceuticals?
radiation, excessive Vitamin A, maternal diabetes, iodine deficiency, cocaine, tobacco, EtOH
Vitamin A excess (teratogen) causes
failure of the neural crest cells to migrate (spontaneous abortion, birth defects)
Mutation of HOXD-13 causes
synpolydactyly (extra fused digit b/w 3-4)
SHH
detemines A/P axis ZPA
Mutation in SHH
holoprosencephaly
Wnt7
organizes D/V axis
FGF
limb lengthening
FGF mutation
achondroplasia
Most common cause of neural tube defects
folic acid derivative
most common preventable cause of congenital malformations in the US
EtOH use
Proteins with a nuclear localization signal may enter the nucleus, this signal is rich in?
Proline, Arginine, & Lysine
Cyclin/CDKs are degraded by
ubiquitin protein ligase
p21, p27, & p57 act to
bind and inactivate cyclin-CDK complexes
What cyclin-CDK complexes are required for the progression from G1–>S?
Cyclin D + CDK4
Cyclin E + CDK2
What cyclin-CDK complexes are required for the progression from G2–>M?
Cyclin A + CDK2
CyClin B + CDK1
Describe the MOA of Cyclin D - CDK4 complex
phosphorylates Rb –> Rb is unbound to E2F –> unbound E2F is a TF that causes synthesis of components for DNA replication
Mutation in Rb is seen in
Retinoblastoma & Osteosarcoma
cdc25
activates Cyclin B - CDK2 complex —> breakdown of nuclear lamins
RER function
synthesize proteins for secretion outside the cell
Free ribosomes function
synthesize proteins that remain in the cytosol
Nissl Bodies
RER in neurons (not in axon)
SER function
steroid synthesis & detoxification
SER is most abundant in what cells
adrenal cortex & hepatocytes
COP-II
coat protein necessary for anterograde trafficking (RER –> GA)
COP -I
coat protein necessary for retrograde trafficking (GA –> RER)
Clathrin
traffics hydrolase to lysosomes (trans-GA side)
GA protein modifications
N-oligosaccharide on Aspargine
O-oligosaccharide on Serine & Threonine
Glycosylates core proteins to form proteoglycans
GA + Clathrin send enzymes to the lysosomes by adding what molecule?
Mannose-6-Phosphate
I-cell Disease Pathogenesis
AR inherited lysosomal storage disorder caused by deficient mannose phosphorylation; enzymes are secreted out of the cell instead of into lysosomes
I-cell Disease Sx
Corneal clouding, coarse facies, HSM, skeletal abnormalities, restricted joint movement, MR
3 Methods of breaking down proteins?
Proteasomal degradation (Ubiquitin), Lysosomal degradation, Calcium-dependent enzymes
Chaperone proteins
assist in folding and transporting polypeptides
Heat shock proteins
HSP70 & HSP90 “rescue” shock-stressed proteins from misfolding, if unsuccessful they add ubiquitin to rage for degradation
Peroxisomes synthesize
plasmalogens (found in myelin)
Peroxisomes catalyze the breakdown of
very long chain fatty acids & branched chain fatty acids via beta-oxidation, & oxidases/catalases for toxic substance metabolism
Sarcoplasmic reticulum
specialized SER found in mm. cells, stores Ca2+ & regulates mm. contraction
What is the primary chorionic villi?
develops in week 2, and consist of a cytotrophoblast surrounded by syncytiotrophoblast.
What is the secondary chorionic villi?
develops in week 3 and consist of extraembryonic mesoderm core surrounded by cytotrophoblast and syncytiotrophoblast
What is the tertiary chorionic villi?
develops at the end of week 3 and will become the villous chorion, the fetal component of the placenta. It consists of a core of villous (fetal) capillaries surrounded by cytotrophoblast and syncytiotrophoblast
The chorionic villi are
finger-like projections of the developing placenta composed of trophoblasts, interspersed by blood-filled sinuses called “intervillous spaces”