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104 Cards in this Set
- Front
- Back
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Ovaries are controlled by...
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hormones of the pituitary gland
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LH peak induces
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ovulation
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name hormone pathway involved in ovulation
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FSH --> estrogen --> LH
pituitary --> FSH --> follicle grows follicle releases --> estrogen estrogen accumulates --> causes pituitary to release LH LH --> ovulation |
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corpus luteum
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remaining follicle cells after ovultation
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corpus luteum (CL) produces...
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progesterone
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what does progesterone do?
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promotes growth of uterine lining, not menstruation
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what happens if no fertilization occurs?
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CL becomes white and degenerates
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the egg, once ovulated, is surrounded by
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zona pelucida = protein shell
corona radiata = granulosa cells |
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what happens when one sperm penetrates zona pelucida?
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egg expels cortical granules --> makes zp impermeable
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morula
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16 cells
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timeline of 1st wk after fertilization
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fertilization --> cleavage --> blastocyst --> implantation
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describe blastocyst (3)
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1) inner cell mass = embryo
2) outer cell mass = trophoblast (embryonic membranes) 3) blastocyst cavity |
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where do totipotent embryonic stem cells come from?
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inner cell mass of blastocyst
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what happens if you remove the ovary that ovulated, during pregnancy?
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lose pregnancy if before 3-4 months...after 3-4 months placenta produces enough progesterone on it's own
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what does RU-486 do?
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abortion pill...inhibits progesterone receptors
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what does embryo do when it implants?
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starts making loads of HCG
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what does HCG do?
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goes to LH receptors in ovaries and uterus, tells CL to keep making progesterone
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what happens in week 2 of pregnancy?
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week of 2s:
1) embroyblast (inner cell mass) becomes: * epiblast * hypoblast 2) trophoblast becomes: * cytotrophoblast * syncytiotrophoblast 3) 2 cavities: * amniotic cavity * yolk sac |
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what happens in week 3?
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gastrulation = results in 3 germ layers
1) endoderm 2) mesoderm 3) ectoderm |
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what regulates gastrulation?
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organizing centers (cells with morphogenic properties)
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what initiates gastrulation?
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the primitive node/streak
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what happens as cells encounter the primitive node/streak
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involute through --> epi to mesenchymal transition --> move more freely and form the 3 layers
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mesoderm becomes what 4 parts?
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axial = notochord
paraxial = somites intermediate = future kidney and UT lateral plate = 1) parietal = future body wall 2) visceral = future gut |
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what tumors can originate from gastrulation?
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if primitive streak persists
i.e. sacrococcygeal teratomas |
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name a gastrulation defect of the posterior primitive streak
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sirenomelia (mermaid fused limbs)
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3 types of monozygotic twins
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separate at
1) 2 cell stage (week 1) 2 amnions, 2 placenta 2) inner cell mass stage (week 2) 2 amnion, 1 placenta 3) gastrulation stage (week 3) 1 amnion, 1 placentaa |
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what happens in weeks 4-8
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body plan and organogenesis
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when, in development, is the most sensitive to teratogenesis?
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weeks 3-8 (organ development)
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what does paraxial mesoderm become?
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skeleton except skull
muscles of trunk dermis connective tissue |
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intermediate mesoderm becomes
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urogenital system
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what does lateral mesoderm become (4)?
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1) cardiovascular system
2) muscles and connective tissue of limbs 3) serous membranes 4) spleen |
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what does ectoderm become?
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1) neuroectoderm --> CNS & PNS
2) surface ectoderm --> epidermis, hair, lens, some glands |
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what does endoderm become?
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epithelium of GI tract
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what's the last part to close during neurulation?
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caudal pore
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pharyngeal arches become
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facial features
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what do somites become (in relation to neurulation)?
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vertebral column
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what do pharyngeal arches become?
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facial features
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brain formation happens in 3 vesicles:
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1) forebrain
2) midbrain 3) hindbrain |
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hindbrain consists of
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8 rhombomeres --> become cranial nerves
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what happens if anterior neural tube closure defect?
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anencephacly --> baby dies
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what happens if posterior neural tube closure defect?
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spina bifida
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how detect spina bifida?
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level of AFP in mom's blood
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how prevent spina bifida
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folic acid
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in official terms, paraxial mesoderm gives rise to (3):
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1) sclerotome
2) myotome 3) dermatome |
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what is segmented innervation?
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each sclerotome and myotome is innervated by a corresponding spinal nerve
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how does heart develop?
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blood islands in visceral plate --> become tubes --> fuse together
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where do neural crest cells come from?
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epi to mesenchymal transition from top of neural tubes as they close
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what do neural crest cells form?
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dorsal root ganglia
pharyngeal arches melanocytes schwann cells PNS |
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what happens to bones after week 9
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ossification
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vernix caseosa
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greasy skin covering
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lanugo
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fine, downy body hair
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what happens in week 24?
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surfactant secreted by alveoli = you could survive outside womb
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hematopoesis in fetus
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spleen until week 28 --> then bone marrow
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length of full-term pregnancy
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38 wks after conception
40 wks after LNMP |
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what happens in cases of maternal diabetes?
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large fetuses
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endocrine
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secretes into bloodstream
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paracrine
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secretes to cells adjacent
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how do hydrophobic chemical messengers communicate their message?
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they can go straight through membrane into cytoplasm
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how do hydrophillic chem messengers communicate their message?
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interact with protein receptors on the plasma membrane
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why are ligand-receptor curves sigmoidal, not linear?
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because of cooperative binding (its affinity for its ligand changes with the amount of ligand already bound)
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a ligand having tons of spare receptors means...
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the more sensitive the body is to a low concentration of that ligand
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agonist
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binds to a receptor and activates the same signaling
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antagonist
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binds to a receptor but doesn't activate the same signaling we're talking about
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name the 3 signaling pathways we know about
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cAMP --> PKA
DAG --> PKC Ca --> CAMK |
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what happens if Ga subunit can't cleave GTP
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the signaling pathway stays turned on --> i.e. cholera toxin
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quick summary DAG pathway
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receptor --> ligand --> g protein --> PPI-PDE instead of cyclase --> makes DAG --> activates PKC
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quick summary Ca pathway
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Ca binds to ligand-gated ion channel --> Ca flows in --> binds to CAM --> CAM with Ca binds to CAMK
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morphogen
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signaling molecule that can diffuse in the embryo, inducing distinct cell fates at different concentrations
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what do organizing centers do in embryo development?
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secrete growth factor/morphogen
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what is the largest family of growth factors in humans?
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TGFB, includes BMP
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how does BMP gradient work in mesoderm?
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most = lateral plate
middle = somites least = notochord |
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how does BMP gradient work in ectoderm?
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most = epidermis
middle = neural crest least = CNS |
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what are BMP antagonists?
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chordin and noggin
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what are chordin and noggin gradients like?
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opposite of BMP
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what controls anterior-posterior patterning?
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hox genes
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what controls dorsal-ventral patterning?
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morphogen gradients
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how many hox complexes do we have?
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4
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how are hox genes arranged?
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in the same order as expressed in the body: temporal and spatial colinearity
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what are anterior hox genes activated by?...how?
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retinoic acid
RA --> binds to RAR --> bound to RARE --> tranx on |
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normally, anterior border of Hox gene expression is
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rhombomere 3
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when embryo's treated with RA
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hox gene expression borders move into more anterior regions = posteriorization (ectopic expression)
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how were hox genes discovered?
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by researching homeotic mutations
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homeotic
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transformation of one body part to another
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concentrations in a typical cell
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more K on inside, more Ca, Cl, and Na on outside
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cathode
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negative
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anode
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positive
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driving force
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V-E
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resting membrane potential of a typical neuron
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-65mV
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direction of current
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direction in which positive charges move
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outward current
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positive
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inward current
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negative
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Na/K ATPase moves
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2 K in and 3 Na out
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electric potential
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voltage at which net ion flow (and electrochemical gradient) = zero
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Goldman-Hodgkin Katz equation
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nernst for multiple ions at once
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what happens when membrane depolarizes?
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m gate of Na gate opens --> Na into cell --> inward current --> h gate closes --> meanwhile K opens via n gate --> repolarizes --> K takes longer to close
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malformation
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from abnormal formation of a structure usually during embryogenesis
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deformation
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from the impact of mechanical forces on a normally-formed structure (usually in fetal period)
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disruption
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from the destruction of a previously normally formed structure
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dysplasia
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when normal structures are made out of abnormal tissues
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dandy-walker
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extra fluid in cerebellum
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more cigarettes =
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smaller baby
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thalidomide
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limb defects --> hands attached to shoulder girdle
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Fetal Alcohol Syndrome symptoms
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growth deficiency
no fat very hyperactive thin upper lip no philtrum |
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do any diagnostic tests cause radiation harm to the fetus?
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no
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