Strategies For Head And Neck

Question 1

Yellow

Answer 1

Endoderm

Question 2

Blue

Answer 2

Ectoderm

Question 3

Derivatives of pectoral gurdle

Answer 3

Scapula and clavical, traps, omotransversarius, sternocephalicus, brachiocephalicus all attached to pectoral gurdle and all innervated by accessory nerve

Question 4

To build neck

Answer 4

Had to make cervical vertebrea and elongate muscles

Question 5

Septum transversum and the neck

Answer 5

Septum transversum maintains relationship with the caudal part of the neck which is why c5 c6 c7 are origin of phrenic nerve

Question 6

Neural crest cells

Answer 6

Mesencymal cells will move around and form these

Question 7

Pharyngeal arches

Answer 7

Get pharyngeal arches from tissue migrating down and surrounding aortic arches; each one has aortic arch, veins, cranial nerves, paraxial mesoderm and neural crest cells that will form muscles and connective tissue

Question 8

Cranial nerve paths in neck development

Answer 8

These are segmentally oragnized; cranial nerve axon developers when aortic arches in pharyngeal regions cranial nerves will follow aortic arches through hole in pharyngeal arch

Question 9

Consequences of cranial nerve development for reccurent laryngeal nerve

Answer 9

Any aortic arches that persist will take cranial nerve with them (aortic arches on the right degenerate but those on left may stay); left 4th aortic arch becomes aorta 6th left aortic archbecomes ductus arteriosis -> ligamentum arteriosis; L reccurent laryngeal nerve has to go around aortic arch while R reccurent laryngeal nerve has to go round subclavain

Question 10

Left 4th aortic arch

Answer 10

Becomes the aorta

Question 11

Left 6th aortic arch

Answer 11

Becomes ductus arteriosis and eventually ligamentum arteriosis

Question 12

What is the neck

Answer 12

Axial muscles (epaxial and hypaxial), body wall muscles, tubes (gut respritory and vascular), cervical vertebrea and spinal cord, nerves (transverse and longitudinal), no serous membranes, no body cavity, tracheal duct

Question 13

Axial muscles neck

Answer 13

Axial muscles control movements of axial skeletal system (epaxial and hypaxial musculature), this makes up a lot of the neck

Question 14

Tubes in neck

Answer 14

These are important but they don’t take up that much space in neck

Question 15

Duct in neck

Answer 15

Tracheal duct runs in the carotid sheath

Question 16

Nerves in the neck

Answer 16

Transverse nerves and spinal nerves from intervertebral foramen
Longitudinal nerves vagus and accessory nerves, body wall muscles in neck

Question 17

Transverse innervation

Answer 17

Innervates neck body wall

Question 18

Longitudinal nerves

Answer 18

Vagus and accessory nerves also body wall muscles in neck

Question 19

Are there serous membranes or body cavities in the neck

Answer 19

No

Question 20

Development of the head

Answer 20

Tale of two tubes, neural tube and endoderm (gut) tube

Question 21

Oropharyngeal membrane

Answer 21

Where ectoderm meets mesoderm in developing embryo

Question 22

Gastrointestinal tract developed from

Answer 22

Endoderm

Question 23

Creation of the ectoderm lined stomeodeum

Answer 23

Cranial folding brings the rostral pharynx in contact with ectoderm and creates ectoderm lined stomodeum

Question 24

How do you make a face

Answer 24

Tubes give rise to tubes, start with a few tubes they start folding and more come from these

Question 25

Eye development

Answer 25

Eye forms from evagination of developing brain and invagination of overlying ectoderm

Question 26

Invagination

Answer 26

Folding of area of exterior sheet of cells toward inside of blastula

Question 27

Evagination

Answer 27

Turn or be turned inside out

Question 28

Ear formation

Answer 28

Occurs in three parts inner ear, middle ear, outer ear

Question 29

Inner ear formation

Answer 29

Forms when otic placode forms in ectoderm (thickening of ectoderm) (this becomes otic vesicle); cochlea, vestibular apparatus, and petrous temporal bone also from in this stage

Question 30

Middle ear formation

Answer 30

In adult includes ossicles tympanic membrane ect. From pharynx an auditory tube moves toward inner ear and expands forming middle ear

Question 31

Outer ear formation

Answer 31

Neural crest cells programmed to know where to go and when to develope to form outer ear; external ear canal and pinna

Question 32

Some tubes formed by ___ of ___ tubes

Answer 32

Some tubes formed by aggregation of mesenchymal tubes

Question 33

Mandible and maxilla formation

Answer 33

Form from 1st pharyngeal arch which splits into maxillary and mandibular prominences this happens at one time not in an order; maxillary prominence is ventral to developing eye

Question 34

Frontonasal prominence

Answer 34

Frontonasal prominence expands rostral to forebrain these cells come in and wrap around between maxillary prominences forming the incisor? Bone; this prominence is constrained by development of nasal pits; this meets with maxillary prominence Frontonasal prominence forms primary palate where it contacts stomadeum

Question 35

Nasal placode

Answer 35

Frontal prominence expands (envaginates)

Question 36

Stomadeum

Answer 36

Openings into nasal cavity

Question 37

Incisive bone

Answer 37

Hole between nasal cavity and oral cavity; need a hard plate to close this up (ie this is where hard palate will come in)

Question 38

Nasal pits

Answer 38

Nasal placode, med and lat nasal prominence, invaginate from ectoderm, elongate caudally, contract roof of stomadeum to create second passageways into stomadeum

Question 39

Palatial shelf

Answer 39

Maxillary prominence grows under palatial shelf; shelves get firmed and mandible develops and tounge comes down and epithelium comes down so tissue can fuse which leads to the separation of tissues; have caudal openings to allow communication of tissues farther back Growth -> realignment -> fusion

Question 40

Separation of oral and nasal cavities

Answer 40

Invagination of nasal pit contacts stomodeal epithelium followed by breakdown of oronasal membrane and closure of secondary palate to establish separate oral and nasal cavities

Question 41

Cleft palate

Answer 41

Maxillary prominence and frontonasal prominence are supposed to fuse but in cleft palate they don’t; lateral palatal shelf also fails to fuse with hard palate

Question 42

Pharyngeal arch development driven by

Answer 42

Neural crest cells and paraxial mesoderm cells

Question 43

Paraxial mesoderm

Answer 43

Unsegmented in head, segment later on; gives rise to craniofacial muscles

Question 44

Neural crest cells vs paraxial mesoderm

Answer 44

Neural crest cells have less constraints than paraxial mesoderm does; paraxial mesoderm is good at making somites

Question 45

Facial diversity

Answer 45

Neural crest cells permit facial diversity; endo ecto paraxial mesoderm keep doing their same thing and neural crest cells which are independently programmed are where we get facial diversity from

Question 46

Tounge and epiglottis

Answer 46

Form from pharyngeal arches 1-4

Question 47

Development of pharyngeal arches and prominence driven by

Answer 47

Migration of paraxial mesoderm and neural crest cells

Question 48

Neural crest cell migration

Answer 48

Migrate ventrally into pharyngeal arches and frontonasal promience

Question 49

Neural crest cells form __

Answer 49

All skeletal structures and connective tissues of mid face, jaw, mouth, and hyoid apparatus, and most of orbit