Developmental Bio Flashcards
How many pharyngeal/branchial arches are in the developing embryo?
6
Which pharyngeal arches contribute to adult structures?
1, 2, 3, 4, 6
Which embryologic structure contributes to muscular and vascular elements?
Mesoderm
Which embryologic structure forms bony and cartilagenous structures of pharyngeal arches?
Neural crest cells
What is the nerve associated with 1st pharyngeal arch?
5
What are the bony derivatives of 1st pharyngeal arch
zygoma, maxilla, mandible, incus, malleus
What are the muscular derivatives of 1st pharyngeal arch?
Muscles of mastication (temporalis, masseter, etc)
What is the nerve affiliated with 2nd pharyngeal arch?
Facial, 7
Bony derivatives of second pharyngeal arch
Styloid process of temporal bone, lesser horn of hyoid, stapes
Muscular derivatives of 2nd arch
muscles of facial expression
What is Treacher-Collins syndrome?
Abnormal development of 1st and 2nd pharyngeal arches
Bony derivatives of 4th and 6th arches
Cartilagenous structures of larynx (cricoid and thyroid cartilages)
Nerve derived from 3rd arch
Glossopharyngeal (9)
Nerve associated with 4th and 6th arches
Vagus (10)
Dysfunction of vagus nerve results in
laryngeal and pharyngeal paralysis and autonomic dysfunction (esophageal motility, gastric acid secretion, heart rate variability)
Which blood test checks for neural tube defects
AFP and ACh levels
Which blood test checks for erythroblastosis fetalis?
Amniotic bilirubin levels
Fetal adrenal dysfunction can be detected via
17-hydroxyprogesterone levels, gene linkage analysis involving HLA on chromosome 6
Why are pts with CF likely to present with hyponatremia?
They cannot reabsorb sodium through their sweat glands, so excess sodium is lost through sweat (especially on hot summer days)
Which electrolyte abnormalities are common in pts with CF?
Hypochloremia and Hyponatremia
The bulbis cordis forms which structures?
Smooth portions of left and right ventricles
From which structure is the ductus arteriosus derived?
6th embryonic aortic arch
Which structure is derived from the first aortic arch?
Part of maxillary artery
Which two structures are derived from second aortic arch?
Hyoid artery and stapedial artery
Which structures are derived from third aortic arch
Common carotid and proximal internal carotid arteries
Which structures are derived from fourth aortic arch?
Left–>aortic arch; Right–> proximal right subclavian
Which structures are derived from sixth aortic arch?
Proximal pulmonary arteries and ductus arteriosus
