Embryology Of The Endocrine System

Front 1

Where do the pharyngeal arches arise from?

Back 1

The site of neural tube closure

Front 2

What pharyngeal arch forms the face?

Back 2

Arch 1

Front 3

What pharyngeal arch forms the neck?

Back 3

Arches 2-4, 6

Front 4

What pharyngeal arch recedes in mammals?

Back 4

Arch 5

Front 5

What is the indent on the inside of a pharyngeal arch called?

Back 5

Pouch

Front 6

What is the indent from the outside of a pharyngeal arch called?

Back 6

Cleft

Front 7

What are the shared structures of the pharyngeal arches; i.e. what embryonic tissues are they composed of?

Back 7

Core mesoderm containing a pharyngeal arch artery

Neural crest surrounding the core messoderm

Ectoderm on the outside

Endoderm on the outside

Front 8

What structure forms from the first cranial cleft?

Back 8

External auditory meatus

Front 9

What structure forms from the first cranial pouch?

Back 9

Middle ear
auditory tube

Front 10

What aortic arch derivative forms from the first pharyngeal arch?

Back 10

Maxillary artery

Front 11

What cranial nerve forms from the first pharyngeal arch?

Back 11

Trigeminal nerve

Front 12

What muscles form from the first pharyngeal arch?

Back 12

Muscles of mastication:

Tensor tympani
Mylohoyid
Tensor veli palatini
Anterior belly of digastric

Front 13

What are the skeletal derivatives of the first pharyngeal arch?

Back 13

Malleus
Incus

Front 14

What are the aortic arch derivatives of the second pharyngeal arch?

Back 14

Stapedial artery
Hyoid artery

Front 15

What cranial nerve originates from the second pharyngeal arch?

Back 15

CNVII

Front 16

What muscles originate from the second pharyngeal arch?

Back 16

Muscles of facial espression

Stapedius
Stylohyoid
Posterior belly of the digastric

Front 17

What are the skeletal derivatives of the second pharyngeal arch?

Back 17

Stapes
Styloid process
Lesser horn of the hyoid
Stylohyoid ligament

Front 18

What are the aortic arch derivatives of the third pharyngeal arch?

Back 18

Internal carotid artery

Front 19

What cranial nerve is derived from the third pharyngeal arch?

Back 19

CNIX

Front 20

What muscle(s) is derived from the third pharyngeal arch?

Back 20

Stylopharyngeus

Front 21

What are the skeletal derivatives of the third pharyngeal arch?

Back 21

Greater horn of the hyoid
Part of the body of the hyoid

Front 22

What are the aortic derivatives of the fourth pharyngeal arch?

Back 22

Right subclavian
Aorta

Front 23

What CN is a derivative of the fourth pharyngeal arch?

Back 23

CNX

Front 24

What muscles are derived from the fourth pharyngeal arch?

Back 24

Pharyngeal
Laryngeal

Front 25

What are the skeletal derivatives of the fourth pharyngeal arch?

Back 25

Laryngeal cartilages

Front 26

What is the adult derivative of the second pharyngeal pouch?

Back 26

Supratonsilar fossa

Front 27

What is the adult derivative of the third pharyngeal pouch?

Back 27

Ventral elongation: Thymus
Solid dorsal epithelial mass: Inferior parathyroid gland

Front 28

What is the endocrine adult derivative of the fourth pharyngeal pouch?

Back 28

Solid epithelial dorsal mass: Superior parathyroid gland
Post-branchial body: parafollicular cells of the thyroid

Front 29

What is the only pharyngeal cleft to yield a normal adult structure? What is formed?

Back 29

The first

External auditory meatus

Front 30

What are consequences of dysgenesis of the pharyngeal clefts?

Back 30

Fistulas (incomplete closure)
Cysts (cleft didn't completely degenerate)

Front 31

What pharyngeal pouches form endocrine glands?

Back 31

3 and 4

Front 32

What is unique about the parathyroid development?

Back 32

The inferior (pouch 3) and superior (pouch 4) reverse orientation in the adult

Front 33

What is a complication that can occur with parathyroid or thymic tissue?

Back 33

They can be ectopid:

PT gland doesn't descend/ascend

Front 34

What is the cause of DiGeorge syndrome? What are the clinical features?

Back 34

A disorder of the pharyngeal arch

Thymic hypoplasia
Hypoparathyroidism
Congenital heart defects (aortic arch, outflow tract)
Velopharyngeal dysfunction

Front 35

What gland is not derived from the pharyngeal pouches?

Back 35

Thyroid

Front 36

What is the embryonic structure that is a precursor to the thyroid gland?

Back 36

Foramen cecum

Front 37

What is the elongation of the thyroid gland called? What direction does it elongate?

Back 37

Thyroid diverticulum

Front 38

How many lobes does the thyroid normally have?

Back 38

2 OR 3. The "normal" is 2, but 3 happens 50% of the time

Front 39

What distinguishes a thyroglossal cyst from a pharyngeal arch cyst?

Back 39

The thyroglossal cyst is midline, while the pharyngeal is lateral to the SCM

Front 40

What is the most common endocrine disorder in infants? What are the labs like? What is the effect? What is the cause?

Back 40

Congenital hypothyroidism

High TSH levels

Cretinism

Thyroid dysgenesis

Front 41

What gene family is responsible for the positional information for the pharyngeal arches?

Back 41

Hox genes from the neural crest

Front 42

What is the nature of the interaction between the ectoderm, mesoderm, and endoderm during pharyngeal arch development?

Back 42

It's like a conversation

You need to have both sides working properly for development to occur correctly

Front 43

What tissues give rise to the pituitary gland?

Back 43

Ectoderm from the early mouth (stomedeum) gives rise to the anterior pituitary

Infundibulum from the ventral side of the diencephalon gives rise to the posterior pituitary

Front 44

What tissue gives rise to the anterior and intermediate pituitary?

Back 44

The ectoderm from the early mouth (Rathke's pouch)

Front 45

What tissue gives rise to the posterior pituitary?

Back 45

Infundibulum from the diencephalon

Front 46

What transcription factor is responsible for the development of thyrotropes? What is a consequence of its loss?

Back 46

Prop1

Hypothyroidism

Front 47

What is the most typical cause of DiGeorge's Syndrome?

Back 47

A gene deletion event:

TBX1
CRKL