Fetal Development of the Heart and Head Flashcards
What vessel takes blood from the placenta to the fetus?
umbilical v. (v. because it is heading TOWARDS the fetal heart)
What condition occurs as a result of the spiral septum failing to correctly divide the the truncus arteriosus? What is the consequence?
Transposition of the great vessels
Right ventricle pumps to the aorta
Left ventricle pumps to the pulmonary trunk
The nerve developing in the hyoid arch (pharyngeal arch II) will eventually innervate what mm.?
mm. of facial expression
What is the name of the opening at the rostral and caudal end of the neural tube?
neuropores
What is the name of the second pharyngeal arch?
Hyoid arch
A chieloschisis occurs as a result of tissues failing to fuse. What are the two ways this condition can occur?
- failure of medial nasal prominence and maxillary prominence to fuse (more common)
- failure of left and right medial nasal prominences to fuse (less common)
The lateral palatine processes will give rise to what?
- most of the hard palate
- all of the soft palate
The intermaxillary segment will grow inward into the stomodeum to become the , which then becomes the .
- median palatine process
- primary palate
The fetal nasal cavity is separated from the pharynx by what structure?
oronasal membrane
What is agnathia?
Failure of the mandibular prominence to form, means “no jaw”
During early cardiogenesis, the cardiac tube forms from the fusion of what structures?
2 endocardial tubes from mesoderm
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Failure of the palatal structures to fuse is called what?
palatoschisis
What embryonic structures give rise to the structures of the head?
Pharyngeal arches (mesodermal)
Some contribution from the neural crest (from ectodermal neural plate)
What n. arises from the hyoid arch (pharyngeal arch II)?
facial n.
This is an example of what condition?
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eyelid agenesis
Failure of the oronasal membrane to break down is called what?
choanal atresia
What skeletal structures will arise from the hyoid arch (pharyngeal arch II)?
Most of the hyoid apparatus
tympanic bulla
stapes of the ear
The nerve developing in pharyngeal arch III will eventually innervate what mm.?
some pharyngeal mm.
The notochord induces what embryonic layer (endoderm, mesoderm, ectoderm) to form the neural plate?
ectoderm
What skeletal structure will arise from pharyngeal arch III?
Parts of the hyoid apparatus (basihyoid and thryohyoid)
What n. arises from pharyngeal arch III?
glossopharyngeal n.
What fetal structure is identified by the red overlay? This structure will become the future oral cavity.
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stomodeum
Where does the neural tube first close?
occipital region
Nerves developing in the mandibular arch (pharyngeal arch I) will eventually innervate what mm.?
Masticatory mm. (only from mandibular n.)
What is the name of the temporary fissure along the ventral side of the optic cup?
choroid fissure
Does the dorsal portion of the spinal cord contain sensory or motor neurons?
sensory
After it begins to fold, the cardiac tube becomes known as what?
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Cardiac loop
What is the name of the outer most layer of the developing spinal cord?
marginal layer
The sixth LEFT aortic arch will become what fetal structure?
ductus arteriosus
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This (red arrow) is an example of what condition?
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palatoschisis
What are the 4 regions of the cardiac tube?
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From top to bottom:
truncus arteriosus
ventricle
atrium
sinus venosus
A Persistent Right Aortic Arch (PRAA) occurs when the fourth RIGHT aortic arch becomes the mature aorta instead of the fourth LEFT aortic arch. Considering that the sixth LEFT aortic arch still becomes the ductus arteriosus, what structure becomes compressed when the ductus arteriosus contracts after birth?
esophagus
PRAA common to dogs. Puppies usually okay until transition to solids at weaning.
The truncus arteriosus will divide to become what 2 adult structures?
aorta
pulmonary truck
What is the name of the inner most layer of the developing spinal cord? This is where neuroblast mitosis orginates.
germinal layer
What n. arises from pharyngeal arches IV and VI?
vagus n.
What structure divides the truncus arteriosus?
spiral septum
Diverticula of the fetal nasal cavity become what adult structures?
paranasal sinuses
What is the difference between pharyngeal grooves and pharyngeal pouches?
Both are considered part of the pharyngeal arch.
Pharyngeal groove = indentation from outside the embryo, ectoderm
Pharyngeal pouch = outpocketing from inside the embryo, endoderm
Does the ventral aspect of the spinal cord contain sensory or motor neurons?
motor
What skeletal structures will arise from the mandibular arch (pharyngeal arch I)?
Mandibular prominence –> mandible
Maxillary prominence –> maxilla, zygomatic bone, parts of temporal bone
What vessels takes blood from the fetus to the placenta?
umbilical aa. (paired) (aa. because it is heading AWAY from the fetal heart)
What fetal structure is identified by the green and blue overlays?
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mandibular arch (maxillary + mandibular prominences)
Through what fetal structure does blood from the GI tract and umbilical vein bypass hepatic capillary beds?
ductus venosus
What is the name of the fetal structure that forms from the ectoderm of the frontonasal prominence which will become the future nose?
nasal placodes
What two fetal structures will fuse to form the hard palate?
median palatine process + lateral palatine processes
What embryonic structure is located where the optic vesicle remains connected to the portion of the diencephalon from which it arose? What will this structure eventually become?
optic stalk
optic nerve
The nerve developing in pharyngeal arches IV and VI will eventually innervate what mm.?
mm. of the larynx and esophagus
Which aortic arch normally gives rise to the aorta?
Fourth LEFT aortic arch
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What adult structure of the head arise from the neural crest?
bones of the face
ganglia of cranial nn.
parts of teeth
mm. of mastication
What adult structure forms from the fusion of the lateral nasal prominence and the maxillary prominence?
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nasolacrimal duct
The third aortic arches and dorsal aortae will eventually become what adult structures?
common carotid arteries
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What is the term given to a “cleft lip”?
chieloschisis
Through what fetal structure does blood bypass the lungs (pulmonary trunk to aorta)?
ductus arteriosus
What is the name given to the developmental defect that results from failure of the choroid fissure of the eye to fully close? This condition is typically seen as asymmetry of the pupil.
coloboma
What is the name given to vertebrae that have incomplete fusion of the vertebral arch?
spina bifida
What is the name given to the fused medial nasal prominences?
intermaxillary segment
The optic vesicle will form what mature structure of the eye?
retina
This is an example of what condition?
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chieloschisis
What is a menigocele?
a protrusion of the meninges through a gap in the spine (due to incomplete closure of the neural tube)
What is the name of the rostral-most prominence (unpaired) of an embryo? This structure will become parts the forehead and dorsum of the nose.
frontonasal prominence
What is anencephaly?
failure of the brain to form
What developmental defect occurs as the result of failure of the brain to split?
cyclopia
What n. arises from the mandibular arch (pharyngeal arch I)?
Trigeminal n.
Mandibular prominence –> mandibular br. of trigeminal n.
Maxillary prominence –> maxillary br. of trigeminal n.
The adult conchae are formed from outgrowths of what bones?
maxilla and nasal bones
What is the name given to the indentation on the nasal placode that will become the future nostril?
nasal pit
Through what fetal structure does blood pass from the right atrium to the left atrium?
foramen ovale
The fourth RIGHT aortic arch normally becomes what adult structure?
right subclavian artery
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The swellings adjacent to the first pharyngeal groove that later become the auricle are called what?
auricular hillocks
What connective tissue structures will eventually arise from pharyngeal arches IV and VI?
laryngeal cartilages
What is the name given to where the spinal cord ends in a bundle of individual nerves?
cauda equina
This is an example of what condition?
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chieloschisis
What is the name of first pharyngeal arch? What are the name of its two prominences?
Mandibular arch
Maxillary and mandibular prominences
What vessel enters through the choroid fissure? This will become the blood supply for the interior of the eye.
hyaloid a.
What is the name of the middle layer of the developing spinal cord? This layer contains young neurons and supporting glia.
mantle layer
The ductus arteriosus becomes known as what structure after its collapse at birth?
ligamentum arteriosum
What embryonic structure forms where the optic vesicle contacts with ectoderm? What will this structure mature into?
lens placode
lens of the eye
What is the name of the condition where the ductus arteriosus does not close after birth?
Patent Ductus Arteriosus (PDA)