Fichas
Repro - embryology
Fichas del conjunto (19)
- 1—Within week 1
- hCG secretion begins around time of implantation of blastocyst (day 6)
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Within week 2
- bilaminar disc (epiblast, hypoblast)
*week 2 = 2 layers*
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Within week 3
- gastrulation:
(cells from epiblast invaginate through primitive streak --> endoderm, mesoderm, ectoderm)
- ^this forms trilaminar embryonic disc
*3 weeks = 3 layers*
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Weeks 3-8 (embryonic period)
- Neural tube formed by neuroectoderm --> closes by week 4
- organogenesis
- extremely susceptible to teratogens
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Week 4
- heart begins to beat
- upper and lower limb buds begin to form
(4 chambers + 4 limbs)
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Week 6
- fetal cardiac activity visible by transvaginal ultrasound
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Week 8
- fetal movements start
*Gait at week 8*
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Week 10
- genitalia have male/female characteristics - 2Ectoderm (what layers? what do they form?)-----Surface ectoderm-----
1. Epidermis
2. Adenohypohysis (anterior pituitary - Rathke pouch)
3. Lens of eye
4. Epithelial linings of oral cavity
5. Sensory organs of ear
6. Olfactory epithelium
7. Anal canal below the pectinate line
8. Parotid glands
9. Sweat glands
10. Mammary glands
-----Neuroectoderm-----
1. Brain (neurohypophysis, CNS neurons, oligodendrocytes, astrocytes, ependymal cells, pineal gland)
2. Retina
3. Spinal cord
-----Neural crest-----
1. PNS (dorsal root ganglia, cranial nerves, autonomic ganglia, Schwann cells)
2. Melanocytes
3. Chromaffin cells of adrenal medulla
4. Parafollicular cells of thyroid
5. Pia, arachnoid, bones of skull
6. Odontoblasts
7. Aorticopulmonary septum
8. Endocardial cushions - 3Mesoderm (what does it form? how does it interact w/ ectoderm? mesodermal defects?)1. Muscle + bone + connective tissue
2. Dermis
3. Serous linings of body cavities (i.e. peritoneum
4. Cardiovascular structures (i.e. blood vessels, heart)
5. Lymphatics
6. Blood
7. Spleen (from foregut mesentery)
8. Kidneys + Adrenal cortex
9. Wall of gut tube
10. Upper vagina
11. Testes + Ovaries
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12. Notochord
--> induces ectoderm to form neuroectoderm (neural plate) --> postnatal structure: nucleus pulposus
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Mesodermal defects = VACTERL
Vertebral defects
Anal atresia
Cardiac defects
Tracheo-Esophageal fistula
Renal defects
Limb defects - 4Endoderm1. Gut tube epithelium (anal canal above pectinate line)
2. Most of urethra + lower vagina (from urogenital sinus)
3. Luminal epithelial derivatives
a) lungs
b) liver
c) gallbladder
d) pancreas
e) eustachian tube (auditory tube)
f) thymus
g) parathyroid
h) thyroid follicular cells - 5Teratogens (ACE-i? Alkylating agents? Aminoglycosides? Antiepileptic drugs? Diethylstilbestrol? Folate antagonists?)ACE-i
1. Renal damage
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Alkylating agents
1. Absence of digits
(and multiple others)
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Aminoglycosides
1. Ototoxicity
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Antiepileptic drugs
(phenytoin, carbamazepine, valproate, phenobarbital)
1. Neural tube defects
2. Cardiac defects
3. Cleft palate
4. Skeletal abnormalities (nail hypoplasia, facial dysmorphism)
*recommended folate supplement*
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Diethylstilbestrol
1. Vaginal clear cell adenocarcinoma
2. Congenital Mullerian anomalies
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Folate antagonists
(trimethoprim, methotrexate, anti epileptic drugs)
1. Neural tube defects - 6Teratogen (isotretinoin? lithium? methimazole? tetracyclines? thalidomide? warfarin?)Isotretinoin
1. Multiple severe birth defects
(patients MUST be on contraceptives)
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Lithium
1. Ebstein anomaly (apical displacement of tricuspid valve - atrialization of right ventricle)
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Methimazole
1. Aplasia cutis congenita (no skin)
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Tetracyclines
1. Discolored teeth
2. Inhibited bone growth
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Thalidomide
1. limb defects (flipper limbs)
"thalimbdomide"
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Warfarin
1. Bone deformities
2. Fetal hemorrhage
3. Abortion
4. Ophthalmologic abnormalities - 7Effects on fetus? (alcohol? cocaine? smoking?)Alcohol --> fetal alcohol syndrome:
(leading cause of intellectual disability in the U.S.)
- due to failure of cell migration
1. Pre and postnatal developmental retardation
2. Microcephaly
3. Facial abnormalities
a) smooth philtrum
b) thin vermillion border (upper lip)
c) small eye openings
4. Limb dislocation
5. Heart defects
- severe forms: holoprosencephaly
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Cocaine
1. Low birth weight
2. Preterm birth
3. IUGR (intrauterine growth retardation)
4. Placental abruption
(since cocaine causes vasoconstriction)
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Smoking (nicotine, CO)
1. IUGR
2. Low birth weight
3. Preterm labor
4. Placental problems
5. Sudden infant death syndrome - 8Effects on fetus: (lack/excess of iodine? methylmercury? Vit A excess? X-rays?)Lack or Excess Iodine
- Congenital goiter or hypothyroidism (Cretinism)
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Methylmercury
1. Neurotoxicity
(highest in swordfish, shark, tilefish, king mackerel)
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Vit A excess
1. High risk for spontaneous abortions
2. High risk for birth defects (cleft palate, cardiac)
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X-rays
1. Microcephaly
2. Intellectual disability - 9Aortic arches and their derivativesAortic arches - vasculature of the pharyngeal arches
1st Aortic arch
- Part of maxillary artery (branch of external carotid)
- maxillary artery -->
1. Inferior alveolar artery --> mental artery
2. Myhyloid artery
3. Deep temporal arteries
4. Infraorbital artery
5. Buccal artery
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2nd aortic arch
- Stapedial artery
- hyoid artery
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3rd aortic arch
- common carotid artery
- proximal part of internal carotid artery
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4th aortic arch
- on left --> aortic arch
- on right --> proximal part of right subclavian artery
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6th aortic arch
- proximal part of pulmonary arteries
- ductus arteriosus - 10—Branchial apparatus/pharyngeal apparatus
- composed of branchial clefts, arches, pouches
1. branchial clefts
- derived from ectoderm
2. branchial arches
- derived from mesoderm (muscles + arteries) and neural crest (bones + cartilages)
3. Branchial pouches
- derived from endoderm
- 11Branchial cleft derivatives (1st? 2nd to 4th? persistent cervical sinus?)1st branchial cleft
- external auditory meatus
2nd-4th branchial cleft
- temporary cervical sinuses --> obliterated proliferation of 2nd arch mesenchyme
- persistent cervical sinus --> branchial cleft cyst within lateral neck anterior to sternocleidomastoid muscle
- immobile during swallowing - 12Derivatives of the 1st branchial arch (pharyngeal arch) Cartilages? Muscles? nerves?1st Branchial arch
Cartilage
1. Maxillary process -->
a) Maxilla
b) zygoMatic bone
2. Mandibular process -->
a) Meckel cartilage
b) Mandible
3. Malleus + incus
4. sphenoMandibular ligament
Muscles
1. Muscles of mastication (temporalis, masseter, lateral pterygoids (only abduction), medial pterygoids)
2. Mylohyoid (forms the floor of mouth)
3. Anterior belly of digastric (also forms the floor of the mouth)
4. Tensor tympani
5. Tensor veli palatini
Nerves
1. CN V2, CN V3 - 13Pierre Robin Sequence? Treacher Collins syndrome?Abnormalities assoc. w/ 1st and 2nd branchial arch derivatives
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1. Pierre Robin sequence -->
a) micrognathia
b) glossoptosis
c) cleft palate
d) airway obstruction
2. Treacher Collins syndrome
neural crest dysfunction --> mandibular hypoplasia + facial abnormalities - 14Derivatives of 2nd branchial arch (pharyngeal arch) Cartilages - muscles - nervesCartilage --> Reichert cartilage
1. stapes
2. styloid process
3. Lesser horn of hyoid
4. stylohyoid ligament
Muscles -->
1. muscles of facial expression
2. Stapedius
3. Stylohyoid
4. Posterior belly of digastric
Nerve
CN VII
- 15Derivatives of 3rd branchial arch cartilage - muscles - nervesCartilage
- Greater horn of hyoid
Muscles
1. Stylopharyngeus
Nerves
CN IX (glossopharyngeus)
- 16Derivatives of the 4th and 6th arches Cartilages - Muscles - NervesCartilage
1. Arytenoids
2. Cricoid
3. Corniculate
4. Cuneiform
5. Thyroid
(ACCCT)
Muscles - 4th arch
1. Most pharyngeal constrictors (superior, middle, inferior constrictor muscles, palatopharyngeus, etc)
2. Cricothyroid
3. Levator veli palatini
Muscles - 6th arch
All intrinsic muscles of larynx except cricothyroid:
1. Posterior cricoarytenoid
2. Lateral cricoarytenoid
3. Transverse arytenoid
4. Oblique arytenoid
5. Thyroarytenoid
Nerves
4th arch: CN X (superior laryngeal branch) - swallowing
6th arch: CN X (recurrent laryngeal branch) - speaking
- 17Branchial pouch derivatives (Pharyngeal pouch) (1st? 2nd? 3rd? 4th? DiGeorge Syndrome?)1st Branchial pouch
- contributes to endoderm-lined structures of ear
1. Middle ear cavity
2. Eustachian tube
3. Mastoid air cells
2nd Branchial pouch
- epithelial lining of palatine tonsil
3rd Branchial pouch
- Dorsal wings --> inferior parathyroids
- Ventral wings --> thymus
4th Branchial pouch
- Dorsal wings --> superior parathyroids
- Ventral wings -->
1. Ultimobranchial body
2. Parafollicular cells of thyroid
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DiGeorge Syndrome
- Chromosome 22q11 deletion
- aberrant development of 3rd and 4th pouches -->
1. Thymic aplasia --> T-cell deficiency
2. Hypocalcemia (no parathyroids)
- assoc. w/ conotruncal anomalies of the heart - 18Cleft lip and cleft palateCleft lip
- failure of fusion of maxillary and medial nasal processes (formation of 1* palate)
Cleft palate
- failure of fusion of the two lateral palatine shelves OR
- failure of fusion of lateral palatine shelves w/ the nasal septum and/or median palatine shelf
(2* palate formation)
*the often occur together*
- 19Sudden infant death syndrome (what is it? risk factors?)Death of a healthy infant (1 mo to 1 yr old) w/o obvious cause --> usually during sleep
Risk factors:
1. Sleeping on stomach
2. Exposure to cigarette smoke
3. Prematurity
Información
- Descripción
- Organ modules Fichas sobre Repro - embryology, creado por Eric Zhang el 11/04/2017.
- Creado por
- Eric Zhang
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