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37 Cards in this Set
- Front
- Back
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What are the embryological origins of skin and CNS?
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Ectoderm
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What are the embryological origins of muscle, CT, BVs and notochord?
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Mesoderm
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What are the embryological origins of the Lungs, respiratory tract and GIT?
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Endoderm
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Name the vesicles in the 3 vesicle stage
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Prosencephalon (forebrain)
Mesencephalon Rhombencephalon (hindbrain) |
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What does the prosencephalon give rise to in the 5 vesicle stage?
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Telencephalon
Diencephalon |
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What does the mesencephalon turn into in the 5 Vesicle stage?
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Stays as mesencephalon
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What vesicles come from the rhombencephalon in the 5 vesicle stage?
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Metencephalon
Mylencephalon |
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What does the telencephalon give rise to?
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Cerebral cortex
Amydala Hippocampus Striatum Olfactory bulb |
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What structures does arises from the diencephalon?
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Thalamus
Hypothal. Epithal. Subthal. Retina |
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What arises from the mesencephalon?
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Midbrain
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What does the metencephalon give rise to?
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Pons
Cerebellum |
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What comes from the mylencephalon?
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Medulla
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There are 4 verticals, name their embryological origins in relation to the 5 vesicle stage.
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Lateral ventricles: Telencephalon
3rd ventricle: Diencephalon 4th ventricle Meten- and Mylen- cephalon |
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What embryological tissue does the cerebral aqueduct come from?
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Mesencephalon
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What is the function of the zona pellucid during early pregnancy?
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1. prevent polyspermy
2. prevent premature implantation 3. prevents two zygotes from sticking together 4. keeps blastomeres together until compaction |
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When does differentiation start after fertilisation?
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compact 8 cell stage -> morula
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What features are seen in a uterus receptive to implantation?
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apical protrusions absorb uterine fluid -> decrease volume of uterine cavity
loss of negative charge microvilli shorten glycocalyx shorten |
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What day after fertilisation does the attachment occur?
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Day 6
trophoblast |
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Describe the prices of the trophoblast attachment
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Zona broken down by proteases
increase vascular permeability in stroma underlying contact point Change in stromal morphology (new capillaries) Few days after initial attachment -> formation of new capillaries in stroma spreads to larger area |
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When does implantation for a trophoblast occur?
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Day 9
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Describe the process of implantation
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some trophoblasts fuse to form syncytium
Others proliferate -> cytotrophoblast Uterine glandular and decidual tissue is destroyed |
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What hormone/cytokines influences endometrium to be receptive to attachement?
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Oestrogen acts on uterus:
endometrial glands -> LIF -> epithelium and stroma Oestrogen acts of blastocyst: Blastocyst signals (?) endometrium -> heparin binding EGF like GF -> zona dissolution and hatching |
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How does trophoblast and decidual cells suppress inflammatory response to the embryo implantation thus preventing rejection?
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Trophoblast and decimal cells secrete CRH (corticotrophin releasing hormone) and express Fas ligand -> kills activated T cells
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How does the trophoblast prevent luteolysis thus ensuring that the endometrium does not shed?
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hCG secreted by trophoblast (then by syncytiotrophoblast) binds to LH receptors on corpus lutuem and prevents luteolysis hence maintain progesterone production.
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How long does morning sickness usually last?
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12 weeks gestation
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What is the severe form of morning sickness?
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hyperemesis gravidarum
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How would you manage morning sickness?
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dry, bland food
adequate hydration decrease FA intake high protein diet vitamin B6 antimetics ginger and other herbal remedies |
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What day is corpus lutuem no longer needed to sustain the embryo?
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Day 40
because trophoblasts produce progesterone and embryo produce oestrogen |
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What hormones are secreted for foetal growth and when does this start?
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Week 6-7
syncytiotrophoblasts start to secrete somatomammatrophins including placental lactogen (variant of GH) |
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Conventionally when do you date a pregnancy?
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since 1st day of last menstural period (40 week gestation)
38 weeks gestation if counting from ovulation which is approx 14 days after LMP |
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When can you measure foetal heart rate?
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4-5 weeks
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What is the heart rate at 4 weeks and what is the heart rate again at 7-8 weeks?
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75 beats/min
130 beats/min |
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What does a low foetal heart rate (<90) indicate?
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indicator of developmental failure and predictor of spontaneous miscarriage
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What defines a miscarriage?
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spontaneous abortion before week 20
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List some maternal causes for miscarriages
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Febrile illness
Septicaemia with infection of foetus Severe HT or renal disease Diabetes Hypothyroidism Trauma Drugs Uterine fibroids Congenital malformation of uterus Hormone deficiency (progesterone) |
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List some foetal causes of miscarriages
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Genetic abnormalities
Congenital malformations Faulty implantations |
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What defines recurrent miscarriages?
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>3 times consecutively prior to 20 weeks gestation
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