9/15 Embriology

Question 1

what is the pharyngeal arches (apparats)

Answer 1

the little buldges that occure at the location of the future jaw.

Question 2

what is antother name for the pharyngeal arches?

Answer 2

branchial arches (or apparatus)

Question 3

describe the topography of the pharyngeal arches

Answer 3

5 paired arches, 3 paired grooves (3 & 4 fuse, 5 not form), 5 paired pouches (5 is bud of 4)

Question 4

another name for the cavity of the fused 3rd and 4th groove

Answer 4

Cervical sinus

Question 5

what structure could contribute the the formation of cysts as the clefts fuse?

Answer 5

the cervical sinus.

Question 6

what gives rise to the lining of the pharynx

Answer 6

the endoderm

Question 7

what cell line gives rise to the surface of the pharyngeal arches

Answer 7

the ectoderm

Question 8

what cell line gives rise to the mesenchyme of the arches of the pharyngeal apparata?

Answer 8

the neural crest cells and the mesoderm

Question 9

The indentations of the pharyngeal arches on the outside of the body

Answer 9

Clefts

Question 10

The indentations on the inside of the pharyngeal arches

Answer 10

Pouches

Question 11

tissue that divides the pouches from the clefts of the pharyngeal arches

Answer 11

Closing plates.

Question 12

the cranial most end of the pharyngeal apparatus

Answer 12

the Oropharyngeal membrane

Question 13

what does the oropharyngeal membrane become?

Answer 13

ruptures to become the mouth.

Question 14

where does the epiglottis form?

Answer 14

at the laryngeal orofice (laryngotracheal groove) located about the 4th ridge.

Question 15

site of formation of the thyroglosssal duct

Answer 15

foraman cecum, an opening at below about the first pouch

Question 16

what does the foramen cecum give rise to?

Answer 16

the thyroid gland

Question 17

extends form the buccopharyngeal membrane to the liver diverticulum

Answer 17

the Foregut

Question 18

where is the pharynx positioned in the foregut?

Answer 18

in the cranial most portion of the foregut, up to and including the respiratory diverticulum

Question 19

what does the 3rd pharangeal arch artery become?

Answer 19

the internal and external carotid arteries

Question 20

what does the 4th pharyngeal arch artery become?

Answer 20

the Arch of the Aorta

Question 21

what does the 6th pharyngeal arch artery become

Answer 21

the pulmonary artery.

Question 22

what does the Pouch 1 of pharyngeal pouches give rise to

Answer 22

auditory tube, tympanic cavity and membrane.

Question 23

what does the Pouch 2 of pharyngeal pouches give rise to

Answer 23

palatine tonsil

Question 24

what does the Pouch 3 of pharyngeal pouches give rise to

Answer 24

inferior parathyroid gland, thymus

Question 25

what does the Pouch 4 of pharyngeal pouches give rise to

Answer 25

superior parathyroid

Question 26

what does the Pouch 5 of pharyngeal pouches give rise to

Answer 26

ultimobranchial body (calcitonin prodicing cells of the thyroid)

Question 27

what happens to the arches 3 and 4?

Answer 27

they fuse and arch 2 grows over and occludes them

Question 28

what is the cervical sinus?

Answer 28

the area where the 2nd arch grows over and occludes the 3rd and 4th.

Question 29

where does the thymus migrate from?

Answer 29

the third pouch! develops as a midline of the lfoor of the pharynx, at about the level of the second phadryngeal pouch.

Question 30

how does the thyroid gland develop?

Answer 30

cells of the foramen cecum migrate from the top of the pharyngeal apparatus, down towards the bottom, 3rd pouch cells migrate to inferior, 4th pouch cells migrate to superior.

Question 31

what is the path that is left behind as the thyroid gland migrates

Answer 31

the thyroglossal duct.

Question 32

what develops if the thyroglossal duct does not degenerate?

Answer 32

the development of a thyroglossal cysts in the midline of the anterior neck.

Question 33

what is the cause of a cyst on the side of the neck?

Answer 33

the overgrowth of the second ridge doesn’t quite finish, and there is a cyst or a fistula to the in or outside.

Question 34

why would the tounge get inervation from differnt parts of the body?

Answer 34

they develop from different arches of the branchial arches

Question 35

what forms the body of the toungue?

Answer 35

the lateral ingual swelling at arch 1 and the tuberculum impar at the bottom of arch 1.

Question 36

what forms the root of the tounge?

Answer 36

the 3rd branchial arch.

Question 37

what forms the epiglottis?

Answer 37

the 4th arch.

Question 38

where does muscle of toungue come from.

Answer 38

occipital somites

Question 39

what is the initial start of the lungs called?

Answer 39

the repiratory diverticulum that starts as a brach of the esophagus.

Question 40

what is a common malformation in the development of the lungs from the esophagus?

Answer 40

the development of a fistula between the esophagus and the brachia, and/or the development of esophageal atresia

Question 41

what is the mesoderm section that folds in to form the gut tube?

Answer 41

the splanchnic mesoderm

Question 42

what is the mesoderm section that folds in to form the outer endoderm layer?

Answer 42

the somatic mesoderm.

Question 43

what is the source of visceral pleura?

Answer 43

the splanchinic mesoderm

Question 44

what is the source of the parietal pleura

Answer 44

the somatic mesoderm

Question 45

what are the number of bronchi branches on the right?

Answer 45

primary - 1; secondary - 3; tertiary - 10

Question 46

what are the number of branches of the branchi on the left?

Answer 46

primary - 1;; secondary — 2;; Tertiary — 8.

Question 47

how can we know that the branching of the bronchi is very specific?

Answer 47

if you remove the esophagus and combine with the spanchnic mesoderm, it will brach in a pietri dish with the right number of branches on each side.

Question 48

what causes the branching of the branchi to develop lungs?

Answer 48

FGF; FGFR; and sprouty (natural antagonist of FGF)

Question 49

how does FGF lead to branches?

Answer 49

trachia express FGFR, the surrounding mesonchime express FGF, and this will cause sprouting.

Question 50

what regulates or limits the amount of brounching activated by FGF?

Answer 50

Sprouty.

Question 51

what other signal molecules could be involved in lung development?

Answer 51

SHH/ Bmp4/ Wnt7b

Question 52

what is the 5-16 week phase fo rlung development

Answer 52

Pseudoglandular: form terminal bronchioles

Question 53

what is the 16-26 week period for the lungs

Answer 53

Canalicular period: terminal bronchioles divide two or more respiratory bronchioles and divide those to 3-6 alveiolar ducts.

Question 54

what is the 26 weeks to birth phase for lungs

Answer 54

Terminal sac period: alveoli are associated with capillaries

Question 55

what is the 36 weeks to early childhood period of lung development.

Answer 55

Alsveolar period: squamos epitheliulm (type I alveiolar cells) lines alveoli, and capillaries form close contacts with alveoli.

Question 56

what are the fraction of avioli at birth

Answer 56

only one sixth the adult number of aveoli are present, the rest come in the next ten years.

Question 57

what is the change that takes place to create the avioli from the terninal sacks

Answer 57

the development of the thin squamous epithelium (type I cells) that then tightly associate with the capilairies.

Question 58

what does surfactant do

Answer 58

it facilitates inflation of the lungs by reducing surface tension at the air-alveolar interface; phosphoipid rich protein.

Question 59

How to differntiate between the Type I and Type II cells in alveioli?

Answer 59

type I is long and thin, and type II is small and cuboidal.

Question 60

what is the importance of type II alveoli cells?

Answer 60

secrete serfactant.