Embryology Unit 15

Front 1

During the flexion stage, the embryo consists of what three layers?

Back 1

ectoderm
mesoderm
endoderm

Front 2

Which embryonic layer will for them epidermis of the skin, most of the teeth, nervous system, hair, nails, and epithelial tissue?

Back 2

Ectoderm

Front 3

Which embryonic layer gives rise to most of the connective tissue in the body which is the bones, muscles, blood vessels, and cartilages in the body?

Back 3

Mesoderm

Front 4

Which embryonic layer forms the epithelial lining of the entire digestive tract and the epithelial lining of the respiratory tract?

Back 4

Endoderm

Front 5

In the primitive mouth, the _________ is the smooth, undifferentiated bulge.

Back 5

Prosencephalon

Front 6

What part of the primitive mouth is the forebrain of the embryo?

Back 6

Prosencephalon

Front 7

Immediately caudal to the prosencephalon is the ______ ______, or the _________.

Back 7

oral groove, stomodeum

Front 8

What separates the stomodeum and the foregut?

Back 8

Buccopharyngeal membrane

Front 9

Walls on the front of the foregut in the branchial region differentiate into ______ ______ with ________ between them.

Back 9

transverse elevations, depressions

Front 10

The paired elevations grow _______ and meet at the ________ to form ________ ________.

Back 10

together, midline, branchial arches

Front 11

There are ___ branchial arches but only the first __ are visible externally.

Back 11

6, 4

Front 12

Which branchial arch is made up of the lower lip, muscles of mastication, mandible, anterior portion of the tongue, and some structures of the middle ear?

Back 12

Mandibular Arch

Front 13

Which branchial arch is made up of most of the hyoid bone, stapes, and muscles of facial expression?

Back 13

Hyoid Arch

Front 14

Which branchial arch gives rise to the lower body of the hyoid and the posterior portion of the tongue?

Back 14

Arch #3

Front 15

Which branchial arches form the cricoid and arytenoid cartilages and the cartilage of the trachea?

Back 15

Arches #4 and $5

Front 16

The caudal portions of the arches give rise to the _______ _______ and _______ _______.

Back 16

palatine muscles, pharyngeal constrictors

Front 17

Ventral portion of the forebrain is important for the _________ __ ___ _____.

Back 17

development of the face

Front 18

In development of the facial region, what three things happen during the third week?

Back 18

1. The forebrain develops into the frontonasal process.
2. Mandibular arch appears
3. Maxillary processes

Front 19

In the development of the facial region, what three things appear during the fourth week?

Back 19

1. Nasal placodes
2. Nasal pits (medial and lateral nasal processes)
3. Hyoid arches

Front 20

What are the 4 primordial areas of the face during week 5 of development?

Back 20

1. Frontal process
2. Maxillary processes
3. Mandibular arch
4. Hyoid arch

Front 21

In the frontonasal process, the ______ process grows faster than the ______ processes and the lateral processes are now known as _________ processes.

Back 21

medial, lateral, globular

Front 22

The _______ ________ are located between the lateral nasal processes and the mandibular arch.

Back 22

maxillary processes

Front 23

Fusion of what two processes will constrict the nasal pit openings?

Back 23

frontonasal and maxillary

Front 24

What forms the entire caudal border of the oral pit?

Back 24

mandibular arch

Front 25

Growth of what is interrupted by the growth of the heart?

Back 25

hyoid arch

Front 26

During the 6th week, the medial nasal process forms what?

Back 26

The entire cephalic border of the mouth opening

Front 27

During what week of development are the maxillary processes identified as wedge shaped prominences just caudal to the eye?

Back 27

6th week

Front 28

During the 6th week of development, the medial tips of the _______ processes are _______ toward the ______ processes but are not yet ______ with them.

Back 28

maxillary, directed, nasal, fused

Front 29

When does fusion of the medial and lateral nasal processes occur?

Back 29

The 6th week

Front 30

The top of the mandibular arch is the ________ portion of the mouth.

Back 30

caudal

Front 31

During the 6th week, the 3rd and 4th branchial arches are no longer _______ due to a _______ ______.

Back 31

visible, cervical sinus

Front 32

During the latter part of the 6th week, the _______ and the _______ _____ processes begin to fuse.

Back 32

maxillary, medial nasal

Front 33

Upon completion of the 6th week, there will be a shelf of ______ which separates the _____ and ______ cavities. The shelf is the ________ ______.

Back 33

tissue, oral, nasal, primary palate

Front 34

What are formed by the posterior projection of the globular processes?

Back 34

Nasal laminae

Front 35

Nasal laminae fuse to form the ______ _______.

Back 35

nasal septum

Front 36

What indicates that the fusion has taken place between the maxillary and globular processes?

Back 36

The philtrum

Front 37

During which week of development is there a more pronounced change in the face of the embryo?

Back 37

the 7th week

Front 38

During the 7th week of development, the _____ area becomes more prominent and the eyes have moved _______.

Back 38

nasal, anteriorly

Front 39

During the 7th week of development, there is very little change in the _______.

Back 39

mandible

Front 40

Which week of development is very important in the development of the palate?

Back 40

7th week

Front 41

When does the primary palate form?

Back 41

the 6th week

Front 42

What accounts for much of the further development of the palate?

Back 42

Differential facial growth

Front 43

(Secondary Palate) - The ______ is so large that it completely fills the _____ ______.

Back 43

tongue, oral cavity

Front 44

(Secondary Palate) - Tissue grows ________ and will become the ________ _________ of the maxillae.

Back 44

downward, palatine processes

Front 45

(Secondary Palate) - The palatine processes can fuse only when the _______ has moved ______, made possible by the ______ of the __________ arch.

Back 45

tongue, down, growth, mandibular

Front 46

(Secondary Palate) - The tongue ______ and the processes begin a rapid growth in the ________ plane. The __________ _________ then fuse together with the ________ _________.

Back 46

drops, horizontal, palatine processes, nasal septum

Front 47

Cleft palate can occur when fusion of the _______ _______ and ________ _______ is interrupted.

Back 47

primitive palate, palatine processes

Front 48

What are the 4 severities of cleft palate?

Back 48

Complete (all the way back)
Incomplete (lips are fine - cleft seen in interior)
Unilateral (on one side)
Bilateral (both sides)

Front 49

Areas that give rise to the tongue first appear during the ___ or ___ week.

Back 49

7th or 8th

Front 50

(Development of the Tongue) Two swellings are evident on the inside of the mandibular arch, called ________ ________ swellings.

Back 50

lateral lingula

Front 51

(Development of the Tongue) Two more swellings, the ________ _____ and _________ ________ will form on the midline between the two lateral lingula swellings.

Back 51

tuberculum impar, hypobranchial eminence

Front 52

The anterior and posterior parts of the tongue are marked by the _______ _______, the _____ which is the site of the ________ ______.

Back 52

sulcus terminalis, apex, foramen cecum

Front 53

When first developed, the tongue is composed only of ________ _______.

Back 53

mucous membrane

Front 54

Later in tongue development, ________ _________ _________migrate into it, causing a rapid __________ in its dimensions.

Back 54

striated muscle fibers, expansion

Front 55

The musculature of the tongue does not come from the ________ _______ but rather from the three ________ _______.

Back 55

branchial arches, occipital somites

Front 56

(Respiratory Development) Caudal to the primitive mouth, the ________ becomes widened and flattened to form the _________.

Back 56

foregut, pharynx

Front 57

What is the name of the groove that appears during the 4th week on the floor of the pharynx?

Back 57

the laryngeotracheal groove

Front 58

The laryngeotracheal groove deepens and fuses to form the ____________ _____.

Back 58

laryngeotracheal tube

Front 59

The cranial end of the laryngeotracheal tube develops into the ________, while the remainder forms the ________.

Back 59

larynx, trachea

Front 60

At the caudal extent of the laryngeotracheal tube, two lateral outgrowths arise to form the ______ _______ and the right and left _____ _____.

Back 60

main bronchi, lung buds

Front 61

The structures of the larynx that appear first are located at what end of the laryngeotracheal tube?

Back 61

cranial

Front 62

(The Larynx) Two _______ _______ appear on lateral sides of the larygeotracheal groove.

Back 62

arytenoid swellings

Front 63

(The Larynx) The arytenoid swellings grow and meet the _________ __________ to form the __ - _______ _____.

Back 63

hypobranchial eminence, T-shaped cleft

Front 64

(The Larynx) After the T-shaped cleft appears, the tissue ________ ____ the opening of the larynx until the ____ month.

Back 64

closes off, 3rd

Front 65

After the entrance to the larynx is reestablished, the ________ _______ can be seen, as well as tissue that will become the ________ and _______ folds.

Back 65

laryngeal ventricles, ventricle, vocal

Front 66

The arytenoid swellings become the _______ cartilages and _________ cartilages.

Back 66

arytenoid, corniculate

Front 67

The folds that join the arytenoid and corniculate cartilages to the epiglottis are the ___________ folds. The _______ _________ are a derivative of the epiglottis.

Back 67

aryepiglottic, cuneiform cartilages

Front 68

The __________ ___________ is formed by the 4th and 5th branchial arches.

Back 68

thyroid cartilage

Front 69

The ________ ________is formed by the 5th branchial arch.

Back 69

cricoid cartilage

Front 70

_____ _____ appear before the laryngeotracheal groove converts into a tube.

Back 70

Lung buds

Front 71

Lung buds divide into _______, __ on the right, __ on the left.

Back 71

lobules, 3, 2

Front 72

The lungs develop in ____ stages and continues until after birth.

Back 72

3

Front 73

When is the first sign of teeth development?

Back 73

5th or 6th week

Front 74

When do the tooth buds begin to develop?

Back 74

During the 7th week.

Front 75

The swellings and positions of tooth buds correspond to what?

Back 75

location of the primary teeth

Front 76

The nervous system makes it's first appearance as what?

Back 76

neural folds

Front 77

The ______ _______ which forms between the neural folds gradually deepens and the folds become _______.

Back 77

neural groove, elevated

Front 78

Ultimately, the neural folds meet and fuse in the midline to form what?

Back 78

the neural tube

Front 79

Prior to fusion of the neural folds, ________ ______ form lateral to each fold.

Back 79

ectodermal cells

Front 80

What gives rise to spinal and cranial nerve ganglia as well as ganglia of the sympathetic trunk of the ANS?

Back 80

the neural crest

Front 81

The rostral part of the neural tube is ______ and _____ and ultimately forms the ______, while the _________ caudal portion forms the ______ ______.

Back 81

broad, flat, brain, narrow, spinal cord

Front 82

What forms the ventricles of the brain and the central canal of the spinal cord?

Back 82

the lumen (inside walls) of the neural tube

Front 83

Where does fusion of the neural folds begin?

Back 83

in the region of the future hindbrain

Front 84

Embryonic growth is in the _______ direction; the _____ _____ will follow.

Back 84

caudal, neural groove (tube)

Front 85

The neural crest gives rise to the _______ ______ ______ and _______ _______ _______ of the spinal nerves.

Back 85

dorsal root ganglia, dorsal sensory roots

Front 86

The _______ ______ on the fibers peripheral to the neural tube arises from _______ _____ in the neural crest.

Back 86

myelin sheath, supportive cells

Front 87

What says that the dorsal half of the spinal cord is sensory in function and the ventral half is motor?

Back 87

Bell's Law

Front 88

The basic division of the spinal cord and part of the brain stem does not apply to the ________ ________ of the neural tube which later develops into the brain.

Back 88

cephalic portion

Front 89

(Primary Brain Vesicles) The rostral portion of the neural tube begins to _______ and ________.

Back 89

enlarge, differentiate

Front 90

What are the initial dilations or primary brain vesicles to appear?

Back 90

1. Prosencephalon (which develops into the telencephalon and the diencephalon)
2. Mesencephalon
3. Rhombencephalon

Front 91

The primary brain vesicles undergo complicated _______ and further ________ and ultimately give rise to all the structures of the ______ _____.

Back 91

flexion, differentiation, adult brain