Flashcards in Embryo Deck (44):
Mutation in sonic hedghog
Mutations in homeobox genes
Appendages in the wrong location
What day is implantation?
When does the neural tube close?
When does the heart begin to beat?
What is derived from surface ectoderm?
Lens of the eye
Epi linings of oral cavity, sensory organs of the ear, olfactory epithelium
Anal canal below the pectinate line
Parotid, sweat and mammary glands
What is derived from neuroectoderm?
What is derived from the neural crest?
Chromaffin cells of adrenal medulla
Para follicular cells of thyroid
Bones of skull
What is derived from mesoderm?
Muscle, bone, CT, serous linings of body cavities
Wall of gut tube and bladder
What is derived from endoderm?
Gut tube epithelium
Thyroid follicular cells
Failure of fusion of the neuropores
Increased AFP and AchE
What is the urachus?
A duct between the bladder and yolk sac
What happens when the urachus fails to obliterate?
Urine discharge from umbilicus
Outpouching of the bladder
What is the vitelline duct?
Duct between yolk sac and midgut lumen
What comes from the 1st aortic arch?
Part of the maxillary artery (external carotid)
What comes from the 2nd aortic arch?
Stapedial artery and hyoid artery
What comes from the third aortic arch?
Common carotid artery
Proximal part if the internal carotid
What comes from the fourth aortic arch?
Proximal part of right subclavian
What comes from the sixth aortic arch?
Proximal part of pulmonary arteries
What are the branching clefts derived from?
What is derived from the 1st bronchial cleft?
External auditory meatus
What happens with failure of obliteration of branchial clefts?
A persistent cervical sinus in the lateral neck
What comes from the branchial arches?
Mesoderm and neural crest
What comes from the 1st branchial arch?
Meckel's cartilage: mandible, malleus, mandibular ligament
Muscles of mastication
What is the anomaly associated with the first branchial arch?
Treacher-Collins syndrome: first arch neural crest fails to migrate
So you get mandibular hypoplasia, facial abnormalities
What comes from second branchial arch?
Reichert's cartilage: stapes, stylohyoid, stapedius, facial muscles
What comes from the 3rd branchial arch?
Greater horn of hyoid cartilage
Stylo pharyngeal muscle
What is a congenital pharyngocutaneous fistula?
Failure of 3rd branchial arch to obliterate
Get mass in the lateral neck from fistula in the tonsillar area
What is derived from the 4th-6th branchial arches?
4th arch - all pharyngeal constrictors except cricothyroid and levator veli palatini, superior laryngeal branch of CN X (swallow)
6th - all intrinsic muscles of the larynx except cricothyroid, recurrent laryngeal branch of vagus (speak)
What is derived from the first branchial pouch?
Middle ear, Eustachian tube, mastoid air cells
What is derived from the second branchial pouch?
Develops into epithelial lining of palatine tonsil
What happens with a failure of the second pouch to regress?
A pharyngeal fistula - lateral anterior neck mass
What is derived from the 3rd pouch?
What is derived from the 4th pouch?
Parafollicular cells of the thyroid
What happens from incomplete fusion of the paramesonephric ducts?
What structures are derived from the mesonephric duct?
What structures come from the paramesonephric duct?
Fallopian tubes, uterus, upper portion of vagina
What comes from telencephalon?
Cerebral hemispheres and 4th ventricle
What comes from diencephalon?
Midbrain and aqueduct
Pons, cerebellum, and upper part of 4th ventricle
Lower part of 4th ventricle
What does the ureteric bud give rise to?
Pelvises and collecting ducts