Embryo midterm review part 1

Which cranial nerve corresponds to the Trigeminal nerve

CN V

Is the hypoblast the source of embryonic mesoderm?

no

The _____ is the site of gastrulation in the early embryo

primitive streak

What are the three defining features of the Pierre Robin sequence?

Micrognathia, glossoptosis, and cleft palate.

In cardiac development, what does the foramen secundum represent?

A normal communication between the two atria

What is a common clinical feature of DiGeorge syndrome related to electrolyte balance?

hypocalcemia

What does the notochord eventually become in the adult spine?

The nucleus pulposus

What is the developmental cause of Primum and Secundum Atrial Septal Defects (ASDs)?

Abnormal separation between the two atria.

Where does the septum secundum form in relation to the septum primum?

On the right side of the septum primum

Which pharyngeal arch artery (PAA) gives rise to the pulmonary artery?

6th PAA

What is the developmental fate of the 3rd pharyngeal cleft?

It becomes part of the cervical sinus, which disappears later.

What is the developmental fate of the 1st pharyngeal cleft?

external auditory meatus

In normal fetal circulation, into which heart chamber does most blood from the superior vena cava flow?

into the right atrium and then the right ventricle

Which cranial nerve ganglion is associated with the 1st pharyngeal arch?

trigeminal ganglion

Which cranial nerve ganglion is associated with the 2nd pharyngeal arch?

geniculate ganglion

Which cranial nerve ganglion is associated with the 3rd pharyngeal arch?

petrosal ganglion

Which cranial nerve ganglion is associated with the 4th and 6th pharyngeal arches?

nodose ganglion

In fetal circulation, why does the ascending aorta have a higher oxygen content than the descending aorta?

Due to the presence and location of the ductus arteriosus.

How does a patent ductus arteriosus affect blood flow between the aorta and pulmonary arteries

Blood in the aorta is partially diverted into the pulmonary arteries.

List the three kidney systems in their sequential order of formation.

Pronephros, Mesonephros, and Metanephros.

Which germ layer gives rise to the pronephros, mesonephros, and metanephros?

Intermediate mesoderm

What specific cellular transition is associated with neural crest development?

Epithelial to mesenchymal transition (EMT).

What adult lymphoid structure is derived from the 2nd pharyngeal pouch

palatine tonsil

Are the thyroid cartilages derived from the 1st pharyngeal arch?

No, they are derived from the 4th and 6th pharyngeal arches.

Describe the oxygenation level of blood in the fetal pulmonary trunk.

deoxygenated/oxygen poor

From which structure does the respiratory diverticulum arise?

wall of the foregut

Which hindbrain rhombomere (R) gives rise to the neural crest cells of the 2nd pharyngeal arch?

R4

Rhombomere 2 (R2) provides neural crest cells for which pharyngeal arch?

1st pharyngeal arch (PA1)

From which specific mesoderm region do the pleura (thoracic membranes) originate?

lateral plate mesoderm

Physiological gut herniation primarily involves which section of the gut

midgut

Where do the pancreatic buds originate in relation to the stomach?

From the endoderm cranial to the stomach.

The hepatic diverticulum extends from the _____ endoderm

midgut

From which embryonic structure are the outflow semilunar valves derived?

bulbis cordis (endocardial cushions)

What embryonic structure gives rise to the smooth portion of the heart ventricles?

The bulbus cordis.

The heart tube is formed by the fusion of two _____.

endocardial tubes

Which mesoderm region does NOT contribute to the pharyngeal arches?

intermediate mesoderm

A defect in which pharyngeal arch artery (PAA) is often linked to 22q11 deletion syndrome?

4th PAA

Which pharyngeal pouch is typically defective in 22q11 deletion syndrome, leading to low calcium?

The 3rd pharyngeal pouch.

Limb muscle precursors originate from the _____ mesoderm.

somatic parietal

An opening anterior to the sternocleidomastoid muscle may result from the failure of which pharyngeal arch to grow caudally?

2nd pharyngeal arch

four main subdivisions of a somite.

Dermatome, Sclerotome, Myotome, and Syndetome

pneumonic: Dirty Scale My Sin

The ectomesenchyme of the 1st pharyngeal arch is formed by neural crest cells from which brain regions?

midbrain and hindbrain

List the five stages of pulmonary development in chronological order.

Embryonic, pseudoglandular, canalicular, saccular, and alveolar

memory: Every Person Can Sing Along

The flutter valve over the foramen ovale is formed by the _____.

septum primum

Is the annulus fibrosus derived from the notochord?

No, only the nucleus pulposus is derived from the notochord.

How is the endoderm formed during gastrulation?

The FIRST epiblast cells migrate through the primitive streak.

Which pharyngeal arch contains a mesoderm core derived from the cranial paraxial mesoderm?

1st pharyngeal arch

What is the term for the fetal shunt that allows blood to bypass the lungs by flowing from the pulmonary artery to the aorta?

Ductus arteriosus

The vertebrae are formed through a process that involves _____ of the sclerotome.

resegmentation

Where is the zone of polarizing activity (ZPA) located in the limb bud?

posterior mesoderm

In the limb bud, cells leaving the progress zone first form _____ skeletal elements.

proximal

From which specific part of the somites are the vertebrae derived?

sclerotomes

What is the site of origin for cardiac neural crest cells?

hindbrain

A branchial fistula occurs when the 2nd pharyngeal arch fails to grow in which direction?

caudally

To which pharyngeal arch must the 2nd arch fuse to prevent a branchial fistula?

6th pharyngeal arch

True or False: The anterior pituitary is derived from the adenohypophyseal placode

True

The epibranchial placodes contribute neurons to the ganglion of which three cranial nerves?

CN VII, IX, X (7, 9, 10)

Which pharyngeal arch artery (PAA) gives rise to the pulmonary arteries?

6th PAA

Neural crest cells contribute to the development of the great arteries by providing _____.

vascular smooth muscle

what brings fetal blood to the placenta?

umbillical vein (most oxygenated part of fetal circulation)

_____ is a neural crest derivative.

adrenal medulla

Which cranial nerve innervates the derivatives of the 3rd pharyngeal arch?

Glossopharyngeal nerve (CN IX)

The skeletal muscles of the jaw are derived from _____, rather than neural crest cells.

mesoderm

Which gene is directly linked to holoprosencephaly when its development is perturbed?

Shh

Holoprosencephaly is characterized by the incomplete development of _____ structures.

midline

What structure is formed by the fusion of the septum primum and septum secundum?

Floor of the fossa ovalis

The masseter muscle of the jaw is innervated by which cranial nerve?

CN V (Trigeminal nerve)

The masseter muscle originates from which pharyngeal arch?

1st pharyngeal arch

The auricular hillocks develop from the fusion of which arches?

1st and 2nd

Which type of mesoderm is responsible for the formation of somites?

paraxial mesoderm

Which type of mesoderm gives rise to the heart?

Splanchic mesoderm

Somatic mesoderm contributes to the development of the _____.

body wall

Which embryonic cell population gives rise to the spinal ganglia?

neural crest cells

Does the 2nd pharyngeal arch grow cranially or caudally to fuse with the 6th arch?

caudally

The pulmonary arteries are derived from the right side of which pharyngeal arch artery?

6th PAA

Name the two septa that fuse to form the floor of the fossa ovalis.

Septum primum and septum secundum

Which cranial nerve innervates the 1st pharyngeal arch derivatives?

CN V (Trigeminal nerve)

Which embryonic layer forms the somites?

paraxial mesoderm

The splitting and reforming of sclerotomes to form vertebrae is called _____.

resegmentation

Which placode is responsible for the formation of the anterior pituitary?

Adenohypophyseal placode

Which cranial nerve corresponds to the 3rd pharyngeal arch?

Glossopharyngeal nerve (CN IX)

What midline defect is associated with the Shh gene?

Holoprosencephaly

The body wall originates from _____ mesoderm

somatic

Failure of the 2nd arch to fuse with the 6th arch results in a _____.

branchial fistula

Which cranial nerves receive neurons from epibranchial placodes?

CN VII, IX, and X

The first cells leaving the limb bud progress zone form _____ elements.

proximal

What structure is the precursor to somites?

Paraxial mesoderm

Which cranial nerve provides sensory and motor innervation to the 1st pharyngeal arch?

CN V

Which pharyngeal arches contribute to auricular hillocks?

1st and 2nd arches

The primordium of the vertebral column is the _____.

sclerotomes

True or False: Keratinocytes are derivatives of the neural crest

False (they are ectoderm derived)

Which gene is essential for midline structural development?

Shh

Where in the mesoderm is the heart located during early development?

splachnic mesoderm

What pharyngeal arch failure leads to a branchial fistula?

2nd pharyngeal arch

Which cranial nerve is associated with the 3rd pharyngeal arch?

Glossopharyngeal (CN IX)