Development of tongue and thyroid gland

Question 1

Early Events in Tongue Development

____, opens into a chamber that comprises the first portion of the gut tube, the pharynx.

Answer 1

Primitive mouth, or stomodeum

Question 2

Early Events in Tongue Development

Posterior to the hypopharyngeal eminence is ____ and ____

Answer 2

the opening of the laryngotracheal groove, and the esophagus.

Question 3

Early Events in Tongue Development

Primitive mouth, or stomodeum, opens into a chamber that comprises____

Answer 3

the first portion of the gut tube, the pharynx.

Question 4

Early Events in Tongue Development

Primitive mouth, or stomodeum, opens into a chamber that comprises the first portion of the gut tube, the pharynx.

→ The endoderm that lines this space covers ____

Answer 4

each pharyngeal arch.

Question 5

Early Events in Tongue Development

Muscles derived from (1)_____ migrate into floor of the pharynx and drag axons of the hypoglossal nerve with them as they migrate.

Answer 5

occipital somites

Question 6

Early Events in Tongue Development

Muscles derived from occipital somites migrate into floor of the pharynx and drag axons of ____ with them as they migrate.

Answer 6

the hypoglossal nerve

Question 7

Early Events in Tongue Development

Muscles derived from occipital somites migrate into floor of the pharynx and drag axons of the hypoglossal nerve with them as they migrate.

→ These muscles create ____ and ____ of under the first pharyngeal arch.

Answer 7

the lateral lingual swellings and median lingual swelling

Question 8

Early Events in Tongue Development

Muscles derived from occipital somites migrate into floor of the pharynx and drag axons of the hypoglossal nerve with them as they migrate.

→ These muscles create the lateral lingual swellings and median lingual swelling of under ____

Answer 8

the first pharyngeal arch.

Question 9

Early Events in Tongue Development

What is the The copula?

Answer 9

a swelling of the second pharyngeal arch.

Question 10

Early Events in Tongue Development

They create _____ under the third and fourth pharyngeal arches.

Answer 10

the hypopharyngeal eminence

Question 11

Growth Up the Tongue

In the floor of the pharynx, ___ and _____ enlarge, begin to protrude anteriorly.

Answer 11

the lateral and median lingual swellings

Question 12

Growth Up the Tongue

The third arch grows over ____, obliterating the copula.

Answer 12

the second arch

Question 13

Growth Up the Tongue

The third arch grows over the second arch, obliterating __

Answer 13

the copula.

Question 14

Growth Up the Tongue

In the floor of the pharynx, the lateral and median lingual swellings enlarge, begin to protrude anteriorly.

The third arch grows over the second arch, obliterating the copula.

This drags ____ toward the front of the oral opening.

Answer 14

the hypopharyngeal eminence

Question 15

Growth Up the Tongue

In the floor of the pharynx, the lateral and median lingual swellings enlarge, begin to protrude anteriorly.

The third arch grows over the second arch, obliterating the copula.

This drags the hypopharyngeal eminence toward the front of ____

Answer 15

the oral opening.

Question 16

Mature Appearance of the Tongue

The anterior 2/3 of the tongue

• is derived form ____
• is innervated by ____

Answer 16

• the first arch
• the mandibular division of the trigeminal nerve.

(Recall that muscles of the tongue are innervated by the hypoglossal nerve.)

Question 17

Mature Appearance of the Tongue

Taste buds on the anterior 2/3rd of the tongue are separately innervated by ____

Answer 17

a branch of the facial nerve (chorda tympani)

(Recall that muscles of the tongue are innervated by the hypoglossal nerve.)

Question 18

Mature Appearance of the Tongue

The posterior 1/3rd of the tongue

• is derived form ____
• is innervated by ____

Answer 18

• the third arch
• the glossopharyngeal nerve.

(Recall that muscles of the tongue are innervated by the hypoglossal nerve.)

Question 19

Early Events in Tongue Development

→ Identify

Answer 19

Question 20

Early Events in Tongue Development

→ Identify the arches with their corresponding nerves

Answer 20

Question 21

Growth Up the Tongue

→ IDENTIFY

Answer 21

Question 22

Mature Appearance of the Tongue

→ IDENTIFY

Answer 22

Question 23

Identify 2

Answer 23

2. Tuberculum impar

Question 24

The lingual divisions & nerves

Pharyngeal arch: 1st

Tongue Primordia: ??

Cranial nerve: ??

Derivatives: ???

Answer 24

• Tongue Primordia:
  
  • Tuberculum impar
  • lateral lingual swellings
• Cranial nerve: CN V/3
• Derivatives:
  
  • Connective tissue of tongue carrying CN 5/3 (lingual nerve, general sensation)
  • Mucosa of anterior 2/3 of tongue lies above this part (ECTODERM!)

Question 25

**_The lingual divisions & nerves_** **Pharyngeal arch:** 2nd **Tongue Primordia: ??** **Cranial nerve: ??** **Derivatives: ???**

Answer 25

* **Tongue Primordia: NO!** * **Cranial nerve:** CN 7 (chorda tympani) * **Derivatives:** * **Connective tissue** of tongue *carrying CN 7 (chorda tympani)* * taste - anterior 2/3 of tongue

Question 26

**_The lingual divisions & nerves_** **Pharyngeal arch: 3RD & 4TH** **Tongue Primordia: ??** **Cranial nerve:???** **Derivatives: ???**

Answer 26

* **Tongue Primordia:** Copula and hypopharyngeal (hypobranchial) eminence * **Cranial nerve:** CN 9 and CN 10 * **Derivatives:** * **Connective tissue** of the tongue * *General sensation and taste in the posterior 1/3 of tongue (CN9)* * *General sensation and taste at the epiglottis (CN10)* * *Mucosa of posterior 1/3 of tongue lies above this part* (**ENDODERM**!)

Question 27

**_The lingual divisions & nerves_** **Pharyngeal arch: 3RD & 4TH** **Tongue Primordia:** Copula and hypopharyngeal (hypobranchial) eminence **Cranial nerve:** CN 9 and CN 10 **Derivatives: ???**

Answer 27

**Derivatives:** * **Connective tissue** of the tongue * *General sensation and taste in the posterior 1/3 of tongue (CN9)* * *General sensation and taste at the epiglottis (CN10)* * *Mucosa of posterior 1/3 of tongue lies above this part* (**ENDODERM**!)

Question 28

**_The lingual divisions & nerves_** **Tongue Primordia:** Occipital somites **Cranial nerve: ??** **Derivatives: ???**

Answer 28

**Cranial nerve:** CN XII **Derivatives:** * all intrinsic tongue muscles; * all extrinsic tongue muscles (except for palatoglossus)

Question 29

**Tongue and Thyroid Gland** **→** Between the first and second arches is \_\_\_\_

Answer 29

a small invagination of endoderm, the **foramen cecum**.

Question 30

**Tongue and Thyroid Gland** **→** Between the first and second arches is a small invagination of \_\_\_, the **foramen cecum**.

Answer 30

endoderm

Question 31

**Tongue and Thyroid Gland** The **thyroid diverticulum** is located at ____ and remains attached to it by the **thyroglossal duct** late into the 5th week of development.

Answer 31

the terminal end of the foramen cecum

Question 32

**Tongue and Thyroid Gland** **\_\_\_\_** is located at the terminal end of the foramen cecum and remains attached to it by the **thyroglossal duct** late into the 5th week of development.

Answer 32

The **thyroid diverticulum**

Question 33

**Tongue and Thyroid Gland** The **thyroid diverticulum** is located at the terminal end of the foramen cecum and remains attached to it by the \_\_\_\_late into the 5th week of development.

Answer 33

**thyroglossal duct**

Question 34

**Tongue and Thyroid Gland** The **thyroid diverticulum** is located at the terminal end of the foramen cecum and remains attached to it by the **thyroglossal duct** late into ____ (WEEK?)

Answer 34

the 5th week of development.

Question 35

**Decent of the Thyroid Gland** Descends as body elongates Passes \_\_\_\_\_, comes to rest on the anterior surface of the trachea

Answer 35

the hyoid bone, laryngeal cartilages

Question 36

**Decent of the Thyroid Gland** Descends as body elongates Passes the hyoid bone, laryngeal cartilages, comes to rest on \_\_\_\_

Answer 36

the anterior surface of the trachea

Question 37

**Decent of the Thyroid Gland** Descends as body elongates Passes the hyoid bone, laryngeal cartilages, comes to rest on the anterior surface of the trachea → The thyroid bifurcates to produce ___ and ___ as it descends.

Answer 37

**right and left lobes**

Question 38

**Decent of the Thyroid Gland** Descends as body elongates Passes the hyoid bone, laryngeal cartilages, comes to rest on the anterior surface of the trachea → The thyroid bifurcates to produce **right and left lobes** as it descends. → The thyroglossal duct rescinds and the ___ remains as a small pit on the surface of the tongue.

Answer 38

foramen cecum

Question 39

**Tongue and Thyroid Gland** **→ Identify**

Answer 39

Question 40

**Tongue and Thyroid Gland** → identify

Answer 40

Foramen cecum

Question 41

**Tongue and Thyroid Gland** → identify

Answer 41

Question 42

**Decent of the Thyroid Gland**

Answer 42