Embryology

Question 1

Head region comes from which stem cells?

Answer 1

Mesenchyme

Question 2

The head region is derived from …

Answer 2

Paraxial and lateral plate mesoderm, neural crest, thickened regions of ectoderm known as ectodermal placodes

Question 3

The frontal bone, temporal bone and face bones derive cells from?

Answer 3

Neural crest

Question 4

Parietal bone, occipital bones derive cells from?

Answer 4

Paraxial mesoderm

Question 5

Laryngeal cartilage and connective tissue in this region derives cells from?

Answer 5

Lateral plate mesoderm

Question 6

Sensory ganglia derives from?

Answer 6

Ectodermal placode and neural crest

Question 7

When do the branchial/pharyngeal arches appar?

Answer 7

In the fourth and fifth week of development

Question 8

Arches are separated by?

Answer 8

Pharyngeal clefts

Question 9

At the end of fourth week the center of the face is formed by ….

Answer 9

Stomodeum

Question 10

What are the five mesenchymal prominences? And which develops later?

Answer 10

Two mandibular, Two maxillary, one frontonasal

Later the nasal prominence

Question 11

What does the pharyngeal arch consist of?

Answer 11

Core of mesenchymal tissue, coveres by ectoderm surface and on the inside epithelium of endodermal origin

Question 12

Neural crest cells migrate to the arches to contribute to what?

Answer 12

Skeletal components

Question 13

First pharyngeal arch consists of two processes, which and with what?

Answer 13

The mandibular (with Meckel’s cartilage) and maxillary process.

Question 14

Muscularture of the first pharyngeal arch includes .. and are supplyed by which nerve?

Answer 14

Muscle of mastication, anterior belly of digastic, mylohyoid, tensor tympani, tensor palatini. Mandibular nerve of trigeminal nerve

Question 15

What happens to the frontalnasal prom. and the maxillary proc. in the 6th week? What is the week called?

Answer 15

Gestational week. Fronalnasal prom gets nasalpits and lateral + medial nasal prominance. Maxillary proc proliferates towards the midline.

Question 16

What becomes the upper lip?

Answer 16

2 medial nasal processes and 2 maxillary processes

Question 17

What becomes the lower lip?

Answer 17

2 mandibular processes

Question 18

What nerve supplies the second pharyngeal arch?

What cartilage does it contain?

Answer 18

Facial nerve, Reichert’s cartilage

Question 19

Third pharyngeal arch gives what and supplies?

Answer 19

Hyoid bone, stylopharyngeal muscle and glossopharyngeal nerve

Question 20

4-6 pharyngeal arch supplied by?

Answer 20

Vagus nerve (gives laryngeal nerve)

Question 21

First pharyngeal pouch gives rise to?

Answer 21

Middle ear, auditory tube

Question 22

Secound pharyngeal pouch gives rise to?

Answer 22

Primordium for palatine fossa

Question 23

Third pharyngeal pouch gives rise to?

Answer 23

Inferior parathyroid gland and thymus

Question 24

Fourth pharyngeal pouch gives rise to?

Answer 24

Superior parathyroid gland, thyroid gland (first ultimobranchial body)

Question 25

First cleft gives rise to?

Answer 25

External auditory tube, airdrum

Question 26

Keeping the 2-4 clefts together

Answer 26

Cervical sinus

Question 27

Fusing the 2-4 clefts together forming …

Answer 27

Epicardial ridge

Question 28

What are rhombomeres?

Answer 28

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