Developmental, Block 4

A 22-year-old mother is referred to a perinatologist for evaluation of very little amniotic fluid at 16 weeks of gestation. Ultrasound reveals bilateral absence of the kidneys in the fetus. The perinatologist explains that the fetus is likely to develop other problems. All the anomalies listed below are usually associated with this condition EXCEPT A. Hypoplasia of the lungs B. Dry and wrinkly skin C. Flattened nose, low set ears D. Clubfoot E. Cleft palate

Cleft palate

While being evaluated for delayed puberty, a 16-year-old male is found to have a mutation in the Kal1 gene. Further workup in this patient is MOST LIKELY to reveal which one of the following? A. Decreased sense of smell B. Tracheoesophageal fistula C. Coarctation of the aorta D. Left sided colon

Decreased sense of smell

The stylopharyngeus muscle is innervated by which nerve? Oculomotor Trigeminal Glossopharyngeal Vagus Facial

Glossopharyngeal

Each pharyngeal arch is composed of an aortic arch artery, a muscle component, a nerve, and a cartilage bar. The cartilage bar of the 3rd arch develops into Greater horn of the hyoid bone Styloid process Thyroid cartilage Mandible Malleus

Greater horn of the hyoid bone

During your rotation in pediatrics you see a 4-year-old girl who is brought to the clinic for a routine well-child visit. The only finding your thorough physical exam reveals is a marking over the lumbar region similar to the one shown on the adjacent photograph. Further work-up might reveal an anomaly resulting from faulty sclerotome differentiation. What is this anomaly? A. Tethered cord B. Hydrocephalus C. Missing vertebral arch D. Neural tube defect

Missing vertebral arch

As the neural tube develops, a structure called the sulcus limitans forms and effectively divides the neural tube into a dorsal (alar) plate and a ventral (basal) plate. The basal plate represents which component of the spinal cord? Sensory Motor Motor and sensory Neural crest

Motor

During the cellular differentiation of the spinal cord which of the following transient zones (layers) will become the white matter? A: Ventricular zone B: Mantle layer C: Intermediate layer D: Marginal zone

Marginal zone

The cheeks are formed from which prominences? Maxillary Lateral nasal Medial nasal Frontal Mandibular

Maxillary

A newborn is found to have leakage of yellow fluid from his umbilicus. The structure whose faulty development is 1/1 responsible for this problem is associated with which of the following in the adult? A: Medial umbilical ligament B: Medial arcuate ligament C: Lateral umbilical ligament D: Median umbilical ligament E: Lateral arcuate ligament

Median umbilical ligament

1) What adult structure develops from the myelencephalon? a) Corpus striatum b) Cerebellum c) Thalamus d) Medulla e) Tegmentum

Medulla

The otic placode develops into which of the following structures? A: Auricle B: Stapes C: Tympanic membrane D: Membranous labyrinth

Membranous labyrinth

The cerebral aqueduct (aqueduct of Sylvius) differentiates from the central canal of which region of the brain? Telencephalon Diencephalon Mesencephalon Metencephalon Myelencephalon

Mesencephalon

The superior and inferior colliculi differentiate from which part of the developing brain? Metencephalon Mesencephalon Diencephalon Myelencephalon Telencephalon

Mesencephalon

A 45-year-old man develops Bell's palsy in which function of the facial (VII) cranial nerve is compromised. What specific level of the central nervous system does the facial nerve connect to? a) Telencephalon b) Diencephalon c) Myelencephalon d) Mesencephalon e) Metencephalon

Metencephalon

All except one of the cranial sutures normally close during the adult years. Which of the following is the suture that usually undergoes physiologic closure in childhood? A: Coronal B: Lambdoid C: Metopic D: Sagittal

Metopic

Teratogens are environmental substances capable of causing birth defects. Pregnant women who use alcohol have a higher frequency of fetal morbidity and mortality. Children born to women consuming alcohol during pregnancy may develop which of the following as a result of the teratogenic effects of alcohol? A. Microcephaly B. Gastroschisis C. Limb defects D. Meckel's diverticulum

Microcephaly

A 13-year-old girl develops a tumor of the anterior pituitary gland. What is the embryologic origin of the anterior pituitary gland? Laryngotracheal groove Pharyngeal pouch 1 Neural crest cells Rathke's pouch Infundibulum of diencephalon

Rathke's pouch

1) Several days following a routine delivery a young mother brings her baby girl into the emergency room. The child is distressed, will not stop crying and has a very bloated abdominal region. The mother relates that the child has a healthy appetite but has not had a good bowel movement since coming home. The infant has normal looking anal opening and an abdominal X-ray with contrast media confirms that the child has Hirschsprung's disease (Congenital megacolon). This defect is caused by the a) failure of neural crest cells to innervate the gut wall b) failure of somatic afferents to innervate the gut c) failure of somatic motor neurons to innervate the gut d) failure of sympathetic neurons to innervate the gut

failure of neural crest cells to innervate the gut wall

The general sensory innervation of the mucosa of the anterior 2/3 of the tongue provides evidence that it develops from the A: second pharyngeal arch B: first pharyngeal arch C: fourth pharyngeal arch D: occipital somites

first pharyngeal arch

Treacher Collins syndrome is an inherited autosomal dominant condition whose symptoms may include hypoplasia of the mandible and facial bones, malformation of the external and middle ears, cleft palate and faulty dentition. All of these defects are associated with the fourth pharyngeal arch third pharyngeal arch second pharyngeal arch first pharyngeal arch

first pharyngeal arch

The cerebellum develops from the roof of the metencephalon and is said to reflect its phylogenetic development. The oldest part of the cerebellum (archicerebellum) is involved in vestibular function and is represented as the vermis posterior lobe flocculonodular lobe anterior lobe

flocculonodular lobe

Development of the primary sensory neurons of the olfactory system is dependent on the formation of the olfactory placode formation of the olfactory bulb formation of the otic placode interactions between neural crest cells and the floor of the telencephalon

formation of the olfactory placode

The sensory innervation of the mucosa of the base of the tongue and the epiglottis by the superior laryngeal nerve provides evidence that these structures develop from the A. second pharyngeal arch B. third pharyngeal arch C. fourth pharyngeal arch D. occipital somites E. endoderm not associated with a pharyngeal arch

fourth pharyngeal arch

A 24-year-old Rh-negative female's second baby is born severely jaundiced (yellow discoloration of the skin). Which of the following characteristics most likely describes her first child? A: male B: female C: Rh-negative D: Rh-positive

Rh-positive

Which of the following muscles is associated with the 3rd pharyngeal arch? Cricothyroid Stylohyoid Stylopharyngeus Medial Pterygoid Tensor tympani

Stylopharyngeus

Which of the following muscles is associated with the 3rd pharyngeal arch? Stylopharyngeus Medial Pterygoid Stylohyoid Tensor tympani Cricothyroid

Stylopharyngeus

Salivary glands develop from invaginations of the epithelium, a process dependent on epithelial-mesenchymal interactions. Which one(s) of the three main salivary glands develop(s) from endoderm of the oral cavity? A. Submandibular B. Parotid C. Sublingual and submandibular D. Submandibular and parotid E. Sublingual and parotid

Sublingual and submandibular

The 2nd pharyngeal pouch contributes to what adult structure? Parathyroid gland Thymus gland Thyroid gland Auditory tube Supratonsillar fossa

Supratonsillar fossa

The roof plate of the neural tube is induced by the secretion of BMP2 and 4 from the Surface ectoderm Amnion Yolk sac Notochord Paraxial mesoderm

Surface ectoderm

1) The cerebral cortex arises from the a) Telencephalon b) Mesencephalon c) Metencephalon d) Diencephalon e) Rhombencephalon

Telencephalon

Which muscle(s) are associated with the ear ossicles? Lateral pterygoid Stylopharyngeus Medial pterygoid Tensor tympani and stapedius Stylohyoid

Tensor tympani and stapedius

The caudal part of the prosencephalon develops into several structures that surround the third ventricle. One of these marked "A" on the adjacent diagram acts as a relay center to the cerebral cortex. What is the name of this structure? A. Epithalamus B. Thalamus C. Hypothalamus D. Infundibulum E. Hippocampus

Thalamus

The lumbar segment of the spinal cord develops as a result of which of the following processes? A: primary neurulation B: secondary neurulation C: body folding D: gastrulation

primary neurulation

The final signal for the induction of the otic placode comes from the paraxial mesoderm lateral plate mesoderm rhombencephalon notochord mesencephalon

rhombencephalon

A pregnant woman in her 1st trimester is referred to your prenatal clinic because of a previous child born with spina bifida. You recall that neural tube defects A. are very rare, affecting only 1 in 600,000 births B. are associated with decreased levels of maternal α-fetoprotein C. can be prevented by daily administration of Vitamin A D. are the result of abnormal neurulation

are the result of abnormal neurulation

Abnormal development of the scleral venous sinuses leads to congenital glaucoma. This condition is present in children born to mothers who A: suffer from diabetes B: contract rubella during pregnancy C: develop vitamin A deficiency D: abuse alcohol during pregnancy

contract rubella during pregnancy

The intrinsic muscles of the larynx and the pharyngeal muscles are derived from the pharyngeal arches and are innervated by cranial nerve IX cranial nerve XII cranial nerve XI cranial nerve VIII cranial nerve X

cranial nerve X

During secondary development, the tail bud (caudal eminence) gives rise to which segments of the spinal cord? sacral and coccygeal thoracic and lumbar lumbar and sacral lumbar and coccygeal

sacral and coccygeal

Which of the following muscles is associated with the 3rd pharyngeal arch? tensor tympani medial pterygoid stylohyoid stylopharyngeus cricothyroid

stylopharyngeus

All the following muscles develop from pharyngeal arches EXCEPT A. buccinator B. superior rectus C. stylopharyngeus D. tensor veli palatini

superior rectus

During spinal cord development the formation of the roof plates, the structures that later develop into the dorsal horns, are induced by the alar plates notochord surface ectoderm intermediate layer

surface ectoderm

The most caudal part of the prosencephalon develops into several structures that act as a relay center between the cerebral cortex and other regions of the brain and spinal cord. Included in these structures is the pons thalamus medulla oblongata cerebellum caudate nucleus

thalamus

As part of your M3 surgical rotation you elect to do ENT. You and the resident team you're assigned to examine and evaluate several patients with hearing loss and later present their cases for discussion with Dr Carron for possible cochlear implant surgery. Which one of the following patients is NOT a candidate for a cochlear implant? A. 1-year-old male with bilateral profound sensorineural hearing loss B. 12-year-old male with bilateral absence of the cochlea and CNVIII C. 62-year-old female with postlingual deafness induced by gentamycin, an ototoxic antibiotic D. 5-year-old female with profound sensorineural hearing loss with poor language progress

12-year-old male with bilateral absence of the cochlea and CNVIII

The pharyngotympanic tube is a derivative of which of the following? 1st pharyngeal pouch Occipital somites 3rd pharyngeal arch 2nd pharyngeal cleft

1st pharyngeal pouch

A 17-year-old female sprinter is caught up in a fight about her gender after doping officials have found that her testosterone levels are much higher than expected in a female. Gender verification test shows a 46, XY karyotype. Physical exam reveals the absence of the uterus, a vagina that ends in a blind pouch and gonads in the labial region.The breasts are well developed. This condition would be best classified as which of the following? A. Persistant Müllerian duct syndrome B. Androgen insensitivity syndrome C. Klinefelter syndrome D. Turner syndrome

Androgen insensitivity syndrome

As the brain develops a series of commissures develop that connect one area of the forebrain with its component on the other side. The commissure that connects the two olfactory regions is called Lamina teriminalis Anterior commissure Corpus callosum Internal capsule hippocampal commissure

Anterior commissure

The developing myelencephalon has a functional organization similar to that of the spinal cord with an expanded central canal forming the 4th ventricle. Using the adjacent figure identify the motor nuclei that project to structures derived from the 3rd pharyngeal arch. A B C D E F

B

The endodermal lining of the pharyngeal pouches gives rise to important organs in the head and neck. On the diagram attached, identify the pharyngeal pouch that forms the bed of the palatine tonsil. A. A B. B C. C D. D

B

A 25-year-old woman is referred to your gynecology clinic because of several miscarriages over the past years. After the first round of testing for hormone levels comes back normal, you order a series of images (X-ray, CT, and MRI). The results of these show the condition pictured on the adjacent diagram. Which of the following faulty processes is most likely responsible? A. Incomplete fusion of the mesonephric duct during development B. Incomplete fusion of the paramesonephric duct during development C. Incomplete fusion of the vaginal plate during development D. Incomplete division of the cloaca during development E. Incomplete fusion of the labioscrotal swellings during development

B. Incomplete fusion of the paramesonephric duct during development

During surgery for removal of the parathyroid glands only three glands were found associated with the thyroid gland. Of the following sites which of the following is NOT a possible location for the missing gland? a) Along the trachea in the neck b) Superior mediastinum c) Lateral and inferior to the hyoid bone d) Base of the tongue

Base of the tongue

A 3-year-old boy with spina bifida develops hydrocephalus. What is the likely cause of this? Constriction of the foramen magnum Blockage of the median or lateral apertures Degeneration of the choroid plexus Blockage of the subarachnoid space Enlargement of the choroid plexus

Blockage of the median or lateral apertures

Development of the floor and roof plates of the spinal cord is directed by inductive signals from the notochord and the surface ectoderm, respectively. Which of the following signals, secreted by the surface ectoderm, directs the formation of the roof plate? A. Bmp B. Shh C. Tbx1 D. Treacle

Bmp

A 4-year-old girl is diagnosed with DiGeorge (22q11.2 deletion) syndrome following multiple episodes of recurrent infections. Patients with this condition are most likely to also have which of the following? A. Congenital heart defects B. Holoprosencephaly C. Polydactyly D. Horseshoe kidney

Congenital heart defects

A 4-year-old girl presents with multiple episodes of recurrent infections. You notice facial anomalies including low set ears, underdeveloped mandible and wide-set eyes. You discuss with the parents that patients with this combination of medical problems might also suffer from which of the following? A: Congenital heart defects B: Holoprosencephaly C: Polydactyly D: Horseshoe kidney

Congenital heart defects

What are the key protein constituent(s) of the lens? Myosins Keratins Melanin Crystallins Actins

Crystallins

The optic vesicle emerges from what portion of the neural tube? Anterior neuropore Diencephalon Mesencephalon Metencephalon Rhombencephalon

Diencephalon

A surgeon operates on the lumbar nervous system to relieve intractable pain in a terminal cancer patient. What specific part of the nervous system would be cut? Spinal nerve Dorsal root Basal plate of the spinal cord Ventral root Visceral root

Dorsal root

The developing myelencephalon has a functional organization similar to that of the spinal cord with an expanded central canal forming the 4th ventricle. Using the adjacent figure identify the sensory nuclei that receive taste information from the tongue. A B C D E F

E

Derivatives of the second pharyngeal arches are innervated by which nerve? Facial nerve Cervical spinal nerve Trigeminal nerve Vagus nerve Glossopharyngeal nerve

Facial nerve

A new mom takes her baby son on an airplane trip. On descent, the child begins to cry vociferously, and does not quiet down until a few minutes after landing. At the next well-baby visit, the pediatrician explains that the eustachian tube in infants is very short and horizontally oriented, resulting in difficulty in clearing pressure from the middle ear. The eustachian tube forms from a persisting portion of a pharyngeal pouch that remains connected to the pharynx. Which pharyngeal pouch forms the eustachian tube? Fourth Second Fifth Third First

First

The muscles of mastication, excluding the tongue muscles, arise from the mesoderm of which structure(s)? Second pharyngeal arches Occipital somites Notochord Neural crest cells First pharyngeal arches

First pharyngeal arches

The site of origin of the thyroid gland can be seen as an opening on the tongue. What is the name of this opening? A. Laryngotracheal groove B. Rima glottis C. Stomodeum D. Foramen cecum B. Rathke's pouch

Foramen cecum

The forehead of the embryo develops from the a) Lateral nasal process b) Maxillary prominence c) Frontonasal prominence d) Medial nasal process e) Mandibular prominence

Frontonasal prominence

During development, the nasal and oral cavities are separated by a membrane that eventually breaks down. What is the name of this membrane? Buccopharyngeal membrane Foramen cecum Nasal pit Nasal choana Oronasal membrane

Oronasal membrane

Innervation of the mucosa of the tongue by the trigeminal and glossopharyngeal nerves reflects that these areas of the tongue take origin from which pharyngeal arches? I and IV I and III III and IV II and IV I and II

I and III

The inner ear arises from which structure? First pharyngeal pouch Otic placode First pharyngeal cleft Hindbrain

Otic placode

The adjacent photograph shows a patient suffering from multiple anomalies. Based on the anomalies seen, which of the following is the most likely structure that might also be affected in this patient? A: Incus B: Stapes C: Cricoid cartilage D: Hyoid bone

Incus

A 42-year-old male presents to your clinic with a history of urinary tract infections. Intravenous urography (IVU) 1/1 reveals that the kidneys are positioned lower than normal and fused at their inferior poles (horseshoe kidney). A horseshoe kidney is lower than normal because it gets caught during its ascent by the: A: Celiac artery B: Middle colic artery C: Portal vein D: Inferior mesenteric artery E: Lesser omentum

Inferior mesenteric artery

A 20-year-old woman suffers a stroke after a drug overdose that causes localized damage to the brain stem special somatic afferent column on one side. Sensation from which structure(s) will be compromised? Taste buds Skin Somatic striated muscle Nonstriated muscle Inner ear

Inner ear

The birth defect shown on the adjacent photograph is caused by failure of which of the following facial processes to fuse? A. Medial and lateral nasal processes B. Two medial nasal processes C. Lateral nasal and maxillary processes D. Intermaxillary and maxillary processes

Intermaxillary and maxillary processes

Projection fibers from the cortex to other brain regions divide the corpus striatum into the caudate and lentiform nuclei. The fibers are referred to as the Anterior commissure hippocampal commissure Corpus callosum Lamina teriminalis Internal capsule

Internal capsule

What is the correct position of the end of the spinal cord in a newborn? S1 L4 L2 L3

L3

The rostral end of the forebrain (neural tube) is referred to as the Sulcus limitans Lamina terminalis Corpus striatum Corpus callosum Internal capsule

Lamina terminalis

Which of the following structures does NOT derive from the optic cup? Lens Neural retina Pigmented epithelium of the retina Ciliary body

Lens

Which of the following muscles DOES NOT develop from pharyngeal arches? Tensor veli palatini Stylohyoid Levator palpabrae superioris Cricothyroid

Levator palpabrae superioris

A 9-month-old female infant is scheduled to undergo repair of a cleft palate. Repair of which of the following intravelar (palatine) muscles is necessary to achieve adequate postoperative velopharyngeal competence (separation of the oral and nasal cavities) in this patient? A. Levator veli palatini B. Palatopharyngeus C. Palatoglossus D. Superior constrictor E. Tensor veli palatini

Levator veli palatini

A 20-month-old boy with a known mutation of the FGFR3 gene on chromosome 4 is being evaluated for difficulty hearing. He is very short for his age with very short limbs, a large head and prominent forehead. Initial work-up suggests conductive hearing loss associated with structures in the middle ear. The affected structures most likely responsible for the hearing deficit in this patient develop from which of the following? A. Neural crest cells B. 3rd pharyngeal pouch C. Otic placode D. Auricular hillocks

Neural crest cells

Your patient who has a BMI of 36 becomes pregnant. Maternal obesity increases the risk of which of the following? A: Microcephaly B: Gastroschisis C: Annular pancreas D: Neural tube defects

Neural tube defects

Salivary glands develop from invaginations of the epithelium, a process dependent on epithelial-mesenchymal 1/1 interactions. Which one(s) of the three main salivary glands develop(s) from ectoderm? A: Submandibular B: Parotid C: Sublingual D: Submandibular and parotid E: Sublingual and parotid

Parotid

A newborn is found to have leakage of yellow fluid from the umbilicus. The pediatric surgeon anticipates to find which one of the following? A. Patent urachus B. Patent vitelline duct C. Patent umbilical artery D. Hypospadias E. Meckel's diverticulum

Patent urachus

In the presence of BMP the ectoderm is induced to form epidermis. Inhibiting BMP promotes a neural pathway in the ectoderm. Which of the following structures induces neurulation by producing BMP antagonists? Somites Endoderm Primitive node Stomodeum

Primitive node

Which of the following induces the formation of the neural tube in the ectoderm by secreting Bmp inhibitors that suppress the development of surface ectoderm in the region overlying the notochord? Stomodeum Paraxial mesoderm Primitive node Endoderm

Primitive node

A 2-year-old boy is referred to the pediatric surgeon by his pediatrician for scrotal swelling. The swelling was first noticed six months ago and has been slowly increasing in size since. The surgeon finds a painless, fluid filled sac in the scrotum on the left. The testis is not palpable on that side. What is the name of the structure that failed to close, resulting in this condition? A. Vitelline duct B. Connecting stalk C. Allantois D. Processus vaginalis E. Gubernaculum

Processus vaginalis

A 4-month-old boy has congenital midline neck anomalies, including a reddened, atrophic skin defect in the central anterior neck, shown on the adjacent photograph.These anomalies are a result of the incomplete fusion of which of the following paired branchial (pharyngeal) arches? A. First B. Second C. Third D. Fourth E. Fifth

Second

The muscles of facial expression arise from the mesoderm of which structure(s) First pharyngeal arches Second pharyngeal arches Neural crest cells Notochord Occipital somites

Second pharyngeal arches

What is the origin of the cells that form the cochlear hair cells? The rhombencephalon The cranial neural crest The otic vesicle The first pharyngeal arch The second pharyngeal arch

The otic vesicle

Where is the origin of the cells that form the cochlear hair cells? The cranial neural crest The second pharyngeal arch The otocyst The rhombencephalon The first pharyngeal arch

The otocyst

The third pharyngeal pouches lie between which pharyngeal arches? Third and fourth Second and third Fourth and Sixth First and second

Third and fourth

The infant pictured on the adjacent photo suffers from Pierre Robin sequence. Which one of the following features these patients have appears first that sets off a sequence of events before birth that causes the other signs and symptoms in these patients? A. Respiratory distress B. Underdeveloped mandible (micrognathia) A. Cleft palate B. Posteriorly displaced tongue (glossoptosis)

Underdeveloped mandible (micrognathia)

As a result of abnormal development of the 1st pharyngeal arch, you would expect Treacher Collins syndrome to include which of the following? A. Underdeveloped zygomatic bone B. Malformation of the stapes C. Absent inferior parathyroid gland D. Malformation of the hyoid bone

Underdeveloped zygomatic bone

One of the factors that determine the effect of teratogens is the developmental stage at the time of exposure. The risk of developing birth defects as a result of exposure to teratogens is the highest in which of the following periods? A: Weeks 3-8 B: Weeks 9-11 C: Weeks 12-24 D: Weeks 25-38

Weeks 3-8

During the cellular differentiation of the neural tube the cells divide rapidly and form three zones. One of these, the marginal zone, is located away from the lumen, at the abluminal aspect of the tube and will become which of the following? White matter Gray matter Glioblasts Neural crest cells Ependymal layer

White matter

While examining a young child you notice the unusual appearance of the right eye as shown on the adjacent picture. This defect is a A. congenital glaucoma B. coloboma of the retina C. remnant of the papillary membrane D. coloboma of the iris

coloboma of the iris

Which of the following structures does NOT derive from the optic cup? unpigmented ciliary epithelium lens pigment epithelium of the retina neural retina

lens

Which of the following is most likely associated with an abnormality of the middle ear? malformed mandible limb abnormalities liver abnormalities pyramidal lobe of the thyroid gland parathyroid abnormalities

malformed mandible

Your new patient has an oblique facial cleft running from the upper lip to the medial corner of the eye, pictured below. This defect results from failure of the lateral nasal process to fuse with which of the following? mandibular process maxillary process medial nasal process intermaxillary segment lateral palatine shelf

maxillary process

Which of the following congenital defects associated with spina bifida involves the spinal cord? cranioschisis meningomyocele meningocele spina bifida occulta encephalocele

meningomyocele

A young mother brings her baby into your office with concerns about the shape of the infant's forehead pictured on the adjacent photograph. You suspect that the child is affected by premature fusion of which one of the following sutures? A. squamous B. metopic C. coronal D. lambdoid

metopic

DiGeorge syndrome is associated with a large deletion in chromosome 22 that can encompass several genes. It is characterized by hypocalcemia and a history of recurrent infections resulting from hypoplasia of the parathyroid glands and the thymus, respectively. Also present are cardiovascular and minor facial defects. All of these defects involve neural crest cells that populate the 1st and 2nd pharyngeal clefts neural crest cells that populate the 2nd and 3rd pharyngeal arches neural crest cells that populate the 3rd and 4th pharyngeal pouches neural crest cells that populate the trunk regions of the embryo regions of the embryo not populated by neural crest cells

neural crest cells that populate the 3rd and 4th pharyngeal pouches

In CNS development the cells that give rise to neurons, oligodendrocytes, astrocytes and ependymal cells are called glial lineage progenitor cells neuroectodermal cells bipotential progenitor cells type 1 astrocyte progenitor cells radial progenitor cells

neuroectodermal cells

The hypophysis develops from two separate ectodermal primordia. One of these primordia is a ventral down growth of the diencephalon which is termed the hypophysial diverticulum epiphysis epithalamus pars superior neurohypophysial diverticulum

neurohypophysial diverticulum

Thalidomide is well known to cause the defect seen on the adjacent diagram referred to as A. amelia B. phocomelia C. syndactyly D. brachydactyly

phocomelia

The hyaloid artery supplies blood to the upper eyelid the developing choroid the choriocapillaris the developing vitreous and lens and then regresses the developing cornea and then regresses

the developing vitreous and lens and then regresses

An examination of a normal healthy looking newborn immediately after delivery revealed the presence of an isolated midline palatal cleft. In your talk with the new parents you explain that this results from non-fusion structures during development. What is the name of these structures? a) mandibular processes b) medial nasal process and the mandibular process c) mandibular and maxillary processes d) the lateral palatine shelves e) a lateral palatine shelf with the premaxillary segment

the lateral palatine shelves

Refer to the adjacent diagram. The structure in the red rectangle represents A: the remnant of the thyroglossal duct B: a lymphnode C: the remnant of the lateral cervical sinus D: the parathyroid gland E: the isthmus of the thyroid gland

the remnant of the thyroglossal duct

The endodermal lining of the pharyngeal pouches gives rise to important organs and structures. Using the adjacent diagram, identify the structure that forms from the pouch labelled "C". A: external auditory meatus B: thymus C: lateral cervical sinus D: auditory tube

thymus