Skull and Sockets (complete)

Question 1

What are the main cranial bones?

Answer 1

1 - occipital bone
2 - parietal bones
2- temporal bones
1- frontal bone

Question 2

What are the main facial bones

Answer 2

2- Nasal bones
2- zygomatic bones
1- Maxilla
1- Mandible

Question 3

What does the Otic Placode eventually become

Answer 3

the Eye

Question 4

What is a placode?

Answer 4

a thickening in the Ectoderm

Question 5

What triggers the formation of a placode?

Answer 5

Signaling from the CNS (notocord as well)

Question 6

What do placodes develop into?

Answer 6

1. The special senses

2. The neural tube (signaled by the notocord)

Question 7

What does the olfactory/nasal placode develop into?

Answer 7

The nose

Question 8

What does the stomodeum develop into

Answer 8

the oral cavity

Question 9

What does the otic placode develop into

Answer 9

the ear

Question 10

Which prominence is the largest and most contributory to facial development

Answer 10

The frontal nasal prominence

Question 11

Which arch is the most important in facial development

Answer 11

the 1st arch

Question 12

What are the steps in development of the ear

Answer 12

1. Auricular hillocks form
2. Auricular hillocks and external auditory meatus migrate to the Otic placode
3. Hillocks and Meatus join and form the ear

Question 13

Where do the hillocks come from? and how many are there?

Answer 13

They come from Arches 1 and 2.

3 from each arch, so 6 in total

Question 14

What are the steps in development of the eye

Answer 14

1. Optic placode forms
2. Optic placode moves anteriorly
3. Optic placode moves to the front of the face

Question 15

What are the steps in development of the nose

Answer 15

1. Nasal placode forms
2. Nasal pit forms in the center, lateral and medial nasal processes form around the pit
3. Frontonasal prominence migrates down between medial nasal processes
4. Lateral nasal processes and maxillary prominence join to form the nasolacrimal groove
5. The medial nasal and fronto nasal processes join to form the philtrum
6. Medial nasal and maxillary processes join to form the upper lip

Question 16

What is the philtrum

Answer 16

The vertical groove between the base of your nose and the top of your upper lip

Question 17

What are the two components of the skull

Answer 17

Neurocranium

Viscerocranium

Question 18

What is the neurocranium

Answer 18

the bones that encase the brain

Question 19

What are the two types of Neurocranium structures

Answer 19

1. membranous neurocranium

2. cartilagenous neurocranium

Question 20

What is the viscerocranium

Answer 20

The bones that make up the face

Question 21

Where do the neural crest cells originate

Answer 21

at the edges of the neural plate. When the neural tube forms, the neural crest cells are released into the body, and are free to move to their destination

Question 22

Which way do neural crest cells usually migrate

Answer 22

from posterior neural tube region to the anterior

Question 23

what do neural crest cells carry with them

Answer 23

the genetic code for development

Question 24

Which bones make up the viscerocranium

Answer 24

Facial bones

1. Mandible
2. Maxilla
3. Zygomatic bones
4. Vomer
5. Nasal bone
6. lacrimal bones
7. palatine
8. conchae

Question 25

Where do the bones of the viscerocranium come from

Answer 25

Neural crest cells

Question 26

Where do the bones of the neurocranium come from

Answer 26

Both the Neural Crest Cells, and the mesoderm

Question 27

Which bones make up the neurocranium?

Answer 27

1. temporal bone 2. Sphenoid bone 3. Ethmoid bone 4. Frontal bone 5. Occipital 6. parietal

Question 28

Which bones of the neurocranium come from neural crest cells

Answer 28

1. Squamosal portion of temporal bone 2. Sphenoid 3. Ethmoid 4. Frontal

Question 29

Which bones of the neurocranium come from the Mesoderm

Answer 29

1. Petrosal part of temporal bone 2. occipital bone 3. parietal bone

Question 30

Which bones of the skull come from the neural crest cells

Answer 30

``` Viscerocranium 1. mandible 2. Maxilla 3. Zygomatic 4. Vomer 5. Palatine 6. Lacrimal 7. Nasal bone 8. Conchae neurocranium 1. squamosal portion of temporal bone 2. sphenoid 3. ethmoid 4. frontal ```

Question 31

Which bones of the skull come from the mesoderm

Answer 31

1. Petrosal part of temporal bone 2. occipital 3. parietal

Question 32

All bones of the body are mesoderm except

Answer 32

1. the bones of the viscerocranium 2. Squamosal portion of the temporal bone 3. Ethmoid 4. Frontal bones 5. Hyoid

Question 33

What are the two classifications of bone formation

Answer 33

1. intermembranous | 2. endochondral

Question 34

What is intermembranous ossification

Answer 34

The development of bone with the absence of cartilage

Question 35

How does intermembranous ossification work

Answer 35

1. mesenchymal cells aggregate and proliferate 2. Mecenchymal cells differentiate into osetoblasts that secrete osteoid at multiple ossification centers 3. the Osteoid is mineralized

Question 36

What bones are formed through intermembranous ossification

Answer 36

the Flat bones of the face and the skull | mandible and clavicle

Question 37

What is endochondral ossification

Answer 37

the development of bone through the means of a cartilagenous precursor

Question 38

how does endochondral ossification work

Answer 38

1. A hyaline cartilage template is in place 2. mesenchymal osteoblasts create ossification centers 3. osteoid is deposited in the place of the cartilage 4. the last place for bone to be deposited is the epiphyseal (growth) plate

Question 39

What is the chondrocranium

Answer 39

The cranial base that embrionically is cartilage

Question 40

What are the sutures of the skull

Answer 40

the joints formed when the parts of the skull come together

Question 41

What are fontanelles

Answer 41

the soft spots found on infants and young childrens skulls. | they are the places where the bones of the skull have not completely fused.

Question 42

What is the benefit of unfused sutures and fontanelles for fetus'

Answer 42

they allow for movement through the birth canal by allowing the skull to change shape on its way through

Question 43

What is cranioschisis

Answer 43

When the cranial vault fails to form. Meaning the bones surrounding the skull don't develop

Question 44

What is craniosynostosis

Answer 44

The premature closure of one or more of the cranial sutures

Question 45

what are the 4 examples of craniosynostosis

Answer 45

1. scaphocephaly 2. brachycephaly 3. Plagiocephaly 4. cloverleaf skull

Question 46

What is scaphocephaly

Answer 46

when the sagittal suture fails (fuses early) making the head long and narrow (anterior posteriorly)

Question 47

What is brachycephaly

Answer 47

when the coronal or frontal suture fails (fuses early) | this causes the skull to be short ( anterior posteriorly)

Question 48

What is plagiocephaly

Answer 48

unilateral coronal and lambdoid sutures failiing, | this causes asymmetric flattening of the skull

Question 49

What is cloverleaf skull

Answer 49

when most cranial sutures fuse early | this causes the brain to push out of the bottom causing the face and neck to swell

Question 50

What are FGFs and FGFRs important for

Answer 50

they are involved in bone formation (especially in the skull)

Question 51

What is an FGFR

Answer 51

a receptor for the FGF proteins

Question 52

What do we need to know about FGFs and FGFRs

Answer 52

that they are involved in bone formation (especially in the skull)