Embryology 1

Question 1

What does the face look like in week 4?

Answer 1

No face- no distinguishing external features

Question 2

What is the Head and neck like in the 4th week?

Answer 2

1/2 of the length of the embryo

Question 3

What do the pharyngeal arches become?

Answer 3

Brain, CVS and special sensory organs

Question 4

What do the arches mean by segmental development?

Answer 4

Each arch has its own neurovascular plan and develops its own muscles and skeletal elements

Question 5

Where is the gut tube made?

Answer 5

Pharynx

Question 6

What is te gut tube made of?

Answer 6

Endoderm

Question 7

What are pharyngeal arches?

Answer 7

System of mesenchmyal proliferations in the neck region of the embryo

Question 8

How many pharyngeal arches are there?

Answer 8

5 in total

numbered 1-6

5 is not in humans

Question 9

What cranial nerve is associated with the 1st arch?

Answer 9

Trigeminal nerve

Question 10

What does arch 1 become?

pharyngeal

Answer 10

Muscles of mastication, Digastic and mylohyoid

Meckels cartilage- mandible, malleus and incus

Question 11

What is arch 1 sensory become?

pharyngeal

Answer 11

Skin og the face and lining of the mouth and nose

part of tongue

Question 12

What nerve is associated with Arch 2?

pharyngeal

Answer 12

Facial

Question 13

What does Arch 2 become?

pharyngeal

Answer 13

Muscles of facial expression

Reicherts cartilage- stapes, upper body of hyoid and lesser horn, styloid process and stylohoid ligament

Question 14

What is arch 2 sensory?

Pharyngeal

Answer 14

part of the tongue

Question 15

What nerve is associated with arch 3?

Pharyngeal

Answer 15

Glossopharyngeal

Question 16

What does the 3rd arch become?

Pharyngeal

Answer 16

Stylopharyngeus

lower body of hyoid and greater horn

Question 17

What is the sensory of the 3rd arch?

Pharyngeal

Answer 17

part of the Tongue

Question 18

What is the associated nerve with the 4th arch?

Pharyngeal

Answer 18

Vagus- superior laryngeal branch

Question 19

What does the 4th arch become?

Pharyngeal

Answer 19

Pharyngeal muscles, cricothyroid

Thyroid cartilage and cricoid cartilage

Question 20

What is the nerve associated with the 6th arch?

Pharyngeal

Answer 20

Vagus

recurrent laryngeal branch

Question 21

What does the 6th arch become?

Pharyngeal

Answer 21

Intrinsic muscles of the larynx

Arytenoid cartilage

Question 22

What does the 1st and 2nd aortic arch become?

Answer 22

Disappear

Question 23

What does the 3rd artic arch become?

Answer 23

Internal carotid

Question 24

What does the 4th aortic arch become?

Answer 24

Arch of the aorta and Brachiocephalic

Question 25

What does the 6th aortic arch become?

Answer 25

Pulmonary arch

Question 26

What are pharygeal pouches?

Answer 26

Endoderm lined pockets in the pharynx

Question 27

Why is the first pharyngeal pouch important?

Answer 27

Largest and becomes the tympanic cavity

Question 28

What do pharyngeal pouches become?

Answer 28

Palatine tonsils Parathyroid gland thymus

Question 29

What does the 1st pharyngeal cleft become?

Answer 29

external acoustic meatus

Question 30

What does the 2nd pharyngeal cleft do?

Answer 30

Grow down and covers others so obliterates other clefts

Question 31

What happens if there are remnants of the pharyngeal clefts?

Answer 31

Brachial cyst or fistula

Question 32

What drives development of the face?

Answer 32

Expansion of the cranial neural tube Appearance of a comples tissue system associated with- cranial gut tube, outflow of the developing heart Development of sense organs and need to seperate the resp tract from Gi

Question 33

How does the face develop?

Answer 33

Facial primordia- first pharyngeal arch and frontonasal prominence

Question 34

Where is teh FNP?

Answer 34

surrounds the ventral lateral part of the forebrain

Question 35

What are the components of the face?

Answer 35

Stomatodeum- becomes buccopharyngeal membrane Frontonasal prominence 1st pharyngeal arch which had maxillary and mandibular prominence

Question 36

What facial features does the FNP develop into?

Answer 36

forehead Brige of nose Nose Philtrum

Question 37

What does the maxillary prominence become?

Answer 37

Cheeks lateral upper lip and jaw

Question 38

What does the mandibular prominence become?

Answer 38

Lower lip and jaw

Question 39

Where do nasal placodes appear?

Answer 39

Frontonasal prominence

Question 40

What do nasal placodes sink to become?

Answer 40

Nasal pits

Question 41

What from either side of nasal pits?

Answer 41

Nasal promincence

Question 42

Where do maxillary promineces grow?

Answer 42

Medially pushing the nasal prominence together in the midline Fuse with medial nasal prominence and then fuse with the midline

Question 43

How are the nasal and oral cavities separated?

Answer 43

Fusion of medial nasal prominence created the intermaxillary segment

Question 44

What is the secondary palate (Main part) derived from?

Answer 44

Palatal shelves from maxillary prominence

Question 45

How do the maxillary promience grow?

Answer 45

Vertically downwards into the oral cavity on each side of the developing tongue

Question 46

How does the tongue develop?

Answer 46

Question 47

What is a lateral cleft lip?

Answer 47

Failure of fusion of medial nasal prominence and maillary prominence

Question 48

What is cleft lip and cleft palate?

Answer 48

Combined with failure of shelves to meet in midline and lateral cleft lop

Question 49

What does the middle ear cavity and ossicles develop from?

Answer 49

1st pharangeal pouch and cartilage and 1st and 2nd arches respectively

Question 50

How do auricles develop?

Answer 50

proliferation within 1st and 2nd pharngeal arches surrounding the meatus

Question 51

What is the position of the ear?

Answer 51

External ears develop in neck to begin with Mandible grows the ears ascend and lie in line with the eyes

Question 52

What do all common chromosomal abnormalities have?

Answer 52

Abnormalities associated with external ear

Question 53

Why is fetal alcohol syndrome a thing?

Answer 53

Face is derived from neural crest cells in pharyngeal arches which migration is sensitive to alcohol As is brain development