Embryology + Genetics

Question 1

Function of somites in embryo

Answer 1

Give rise to bones and muscles

Question 2

What is a totipotent zygote

Answer 2

initial cell has the capacity to develop into any kind of cell in the body

Question 3

What is cleavage

Answer 3

Growth of the zygote via cell division

Question 4

What is gastrulation

Answer 4

When the embryo which begins as a bilaminar disc becomes a trilaminer disc

Question 5

What does Arch 1 give rise to

Answer 5

Arch 1 gives rise to the maxillary and
mandibular process

Question 6

What are the 5 embryonic prominence

Answer 6

1 x Frontonasal
2 x Maxillary
2 x Mandibular

Question 7

What is the stomodaeum

Answer 7

Primitive mouth

Question 8

Three layers that make up each arch

Answer 8

Ectoderm, endoderm, mesoderm

Question 9

What is ossophocation

Answer 9

Cartilage becoming bone

Question 10

Cranial nerve derived from PA1

Answer 10

V Trigeminal

Question 11

Muscles derived from PA1

Answer 11

Muscles of mastication, including the mylohyoid & ant. belly of digastric, Tensor tympani
Tensor veli palatini

Question 12

Muscles derived from PA2

Answer 12

Muscles of facial expression: Stapedius, stylohyoid, post. belly of diagastric

Question 13

Cranial nerve derived from PA2

Answer 13

VII Facial nerve

Question 14

Cranial nerve derived from PA3

Answer 14

IX Glosssopharyngeal

Question 15

Muscles derived from PA3

Answer 15

Stylopharyngeus

Question 16

Cranial nerve derived from PA4-6

Answer 16

X Vagus

Question 17

Muscle derived from PA4-6

Answer 17

Cricothyroid, Levator veli palatine, Constrictors of pharynx, Intrinsic muscles of the larynx
larynx, palate and esophagus

Question 18

Proliferation meaning

Answer 18

Cell division

Question 19

What is the structure that will become the future eye of the baby

Answer 19

The optic vesicle

Question 20

What does the maxillary prominence develop from

Answer 20

Pharyngeal arch I

Question 21

What does the mandibular prominence develop from

Answer 21

PA1

Question 22

Development of the middle nose, upper lip and primary palate

Answer 22

Localised ectodermal thickenings become nasal placodes, ectomesenchyme proliferates and produces a ridge converting to nasal pits and medial and lateral nasal prominences, gives rise to middle of nose, upper lip and primary palate

Question 23

How do the lateral side of the nose and lips develop

Answer 23

At weeks 7-8 the lateral nasal processes fuses with the maxillary processes

Question 24

What formation makes the middle portion of the nose, the philtrum, upper portion of the upper lip and primary palate

Answer 24

Medial nasal process + frontonasal process

Question 25

How is the lower lip formed

Answer 25

Formation of the two mandibular processes

Question 26

Four steps of the formation of the tongue

Answer 26

1. formation of lateral (distal) & medial swellings 2. distal swellings enlarge to become anterior 2/3 (facial nerve, chorda tympani branch) 3. arch 3 & 4 overgrow arch 2 to form posterior 1/3 (glossopharyngeal nerve) 4. arch 4 gives rise to epiglottis & CN X

Question 27

The developing tongue receives a contribution from branchial arches I to IV. Which arch contributes to the anterior 2/3 of the tongue?

Answer 27

I

Question 28

The posterior 1/3 of the tongue is largely derived from which pharyngeal/ branchial arch?

Answer 28

III

Question 29

which developmental week post-fertilisation can branchial arches be seen?

Answer 29

Week 4

Question 30

Most of the mesenchyme is derived from which embryonic structure?

Answer 30

Neural crest cells

Question 31

What is mesenchyme

Answer 31

Type of embryological tissue derived from neural crest cells

Question 32

The epiglottis is derived from which branchial arch?

Answer 32

PA

Question 33

Which of the branchial arches gives rise to the cartilages of the larynx?

Answer 33

PA4-6

Question 34

which arch do CARTILAGES Thyroid Cricoid Artenoid Corniculate Cuneform

Answer 34

PA4-6

Question 35

Which arch does the inferior hyoid bone develop from

Answer 35

PA3

Question 36

Where is the styloid process and what arch does it develop from

Answer 36

Pokey bit behind TMJ joint, develops from PA2

Question 37

Where are the malleus and incus located and what arch do they develop from

Answer 37

Ossicles of the middle ear, develop from PA1

Question 38

Where is the stapes located and what pharyngeal arch does it develop from

Answer 38

Middle ear, develops from PA2

Question 39

Which arch does the superior part of the hyoid bone develop from

Answer 39

PA2

Question 40

Where is the palatine bone and which arch does it develop from

Answer 40

Posterior section of the palate in the skull, develops from PA1

Question 41

Where is the vomer bone located and which arch does it derive from

Answer 41

Bone above palate that is visible on skeleton as a thin line in the nose, derived from PA1

Question 42

Development of the face (6 steps)

Answer 42

1. Facial prominences appear 2. Frontonasal prom. form upper margin of stomodeum 3. Nasal placodes form nasal pits and prominence 4. Maxillary prominence grows medially and nasal prominence merges to midline to form upper lip 5. Mandible prom. merge to midline to form midline 6. Face develops to adult form

Question 43

What makes up the primary palate

Answer 43

Premaxillary segment of the maxilla, which contains the four incisor teeth and incisive canal

Question 44

How does the primary palate form

Answer 44

Two medial nasal prominence in the midline fuse, driven through the growth of the maxillary prom which pushes nasal prominences towards the midline

Question 45

What does the secondary palate form from

Answer 45

Via outgrowths of the maxillary prominence called the palatine shelves

Question 46

How does the secondary palate from

Answer 46

Palatine shelves project on either side of the tongue, as the mandible expands and grows the tongue moves down allowing the palatine shelves to grow towards the midline and fuse to form the secondary palate (palatine bone and palatine segment)