COMPARATIVE VERTEBRATE ANATOMY (SKULL)

Question 1

The vertebrate skull consist of:

Answer 1

neurocranium
dermatocranium
splanchnocranium

Question 2

also called endocranium or primary braincase

Answer 2

neurocranium

Question 3

membrane bones

Answer 3

dermatocranium

Question 4

visceral skeleton

Answer 4

splanchnocranium

Question 5

protects the brain

Answer 5

neurocranium

Question 6

begins as cartilage that is partly or entirely replaced by bone

Answer 6

neurocranium

Question 7

neurocranium begins as pair of parachordal & prechordal cartilages below the brain

Answer 7

cartilaginous stage

Question 8

parachordal cartilages expand and join; along with the notochord from the basal plate

Answer 8

cartilaginous stage

Question 9

prechordal cartilages expand & join to form an ethmoid plate

Answer 9

cartilaginous stage

Question 10

where does cartilage appear?

Answer 10

olfactory capsule
otic capsule

Question 11

partially surrounding the olfactory epithelium

Answer 11

olfactory capsule

Question 12

surrounds inner ear & also develops into sclera of the eyeball

Answer 12

otic capsule

Question 13

In the completion of floor, walls, and roof, it fuses with olfactory capsules

Answer 13

ethmoid plate

Question 14

In the completion of floor, walls, and roof, it fuses with otic capsules

Answer 14

basal plate

Question 15

further development of neurocranium means

Answer 15

development of cartilaginous walls (sides of braincase);
in cartilaginous fishes, cartilaginous roof over the brain

Question 16

retain a cartilaginous neurocranium (or chondrocranium) throughout life

Answer 16

cartilaginous fishes

Question 17

bony fishes, lungfishes, & most ganoids

Answer 17

retain highly cartilaginous neurocranium that is covered by membrane bone

Question 18

Cyclostomes

Answer 18

the several cartilaginous components of the embryonic neurocranium remain in adults as
more or less independent cartilages

Question 19

Other bony vertebrates

Answer 19

embryonic cartilaginous neurocranium is largely replaced by replacement bone
(the process of endochondral ossification occurs almost simultaneously at several ossification centers)

Question 20

what are the neurocranial ossification centers?

Answer 20

occipital centers
sphenoid centers
ethmoid centers
otic centers

Question 21

cartilage surrounding the foramen magnum may
be replaced by as many as four bones:

Answer 21

basioccipital
exoccipital (2)
supraoccipital

Question 22

all 4 occipital elements typically fuse
to form a single occipital bone

Answer 22

mammals

Question 23

neurocranium articulates with the 1st vertebra via 1 (reptiles and birds) or 2
(amphibians and mammals) occipital condyles

Answer 23

tetrapods

Question 24

what does the sphenoid center form?

Answer 24

basisphenoid
presphenoid
side walls of basisphenoid and presphenoid

Question 25

side walls of basisphenoid and presphenoid

Answer 25

orbitosphenoid pleurosphenoid alisphenoid

Question 26

what center tends to remain cartilaginous

Answer 26

ethmoid center

Question 27

what does the ethmoid center form?

Answer 27

anterior to sphenoid cribiform plate of ethmoid & several conchae (or ethmoturbinal bones)

Question 28

nasal chamber is large & filled with ridges from the ethmoid bones called the turbinals or ethmoturbinals.

Answer 28

mammals

Question 29

ridges from the ethmoid bones

Answer 29

turbinals or ethmoturbinals

Question 30

are covered with olfactory epithelium in life and serve to increase the surface area for olfaction (i.e., a more acute sense of smell).

Answer 30

ethmoid bones

Question 31

separates the nasal chamber from the brain cavity within the skull.

Answer 31

cribriform plate

Question 32

the center wherein cartilaginous otic capsule is replaced in lower vertebrates by several bones

Answer 32

otic centers

Question 33

What are the bones that replace cartilaginous capsule in lower vertebrates?

Answer 33

prootic opisthotic epiotic (one or more of these bones may unite with adjacent replacement or membrane bones)

Question 34

opisthotics fuse with exoccipitals

Answer 34

frogs and most reptiles

Question 35

prootic, opisthotic, & epiotic unite to form a single petrosal bone; the petrosal, in turn, sometimes fuses with the squamosal to form the temporal bone

Answer 35

birds and mammals

Question 36

What is formed when prootic, opisthotic, and epiotic unite?

Answer 36

single petrosal bone

Question 37

What is formed when petrosal bone is fused with squamosal bone?

Answer 37

temporal bone

Question 38

What lies superficial to neurocranium

Answer 38

dermatocranium

Question 39

What forms: 1 - bones that form the roof of the brain & contribute to the lateral walls of the skull 2 - bones of the upper jaw 3 - bones of the palate(s) 4 - opercular bones

Answer 39

dermatocranium

Question 40

What does the dermatocranium forms?

Answer 40

1 - bones that form the roof of the brain & contribute to the lateral walls of the skull 2 - bones of the upper jaw 3 - bones of the palate(s) 4 - opercular bones

Question 41

What are the basic pattern of roofing bones?

Answer 41

crossopterygians labyrinthodonts Fontanels

Question 42

a series of paired & unpaired bones along mid-dorsal line of skull (below left)

Answer 42

crossopterygians

Question 43

unpaired bones lost & a series of paired bones resulted (nasals, frontals, parietals, & dermoccipitals) (below right)

Answer 43

labyrinthodonts

Question 44

'soft spots'

Answer 44

fontanels

Question 45

occur when neurocranium is incomplete dorsally (e.g., teleosts & tetrapods)

Answer 45

fontanels

Question 46

can be felt in head until the membranes under the skin have ossified

Answer 46

fontanels

Question 47

What are the bones of the upper jaw?

Answer 47

Pterygoquadrate (palatoquadrate) cartilage Palatal bones

Question 48

1st upper jaw that vertebrate embryos develop

Answer 48

Pterygoquadrate (palatoquadrate) cartilage

Question 49

What only has palatoquadrate as the only upper jaw that develops?

Answer 49

Cartilaginous fishes

Question 50

what has their palatoquadrate becomes covered with dermal bones (premaxillae & maxillae) that make up the adult upper jaw?

Answer 50

bony vertebrates

Question 51

what are the dermal bones?

Answer 51

premaxillae and maxillae

Question 52

the floor on which the brain rests is at the same time the roof of the oral cavity in fishes & amphibians (primary palate)

Answer 52

palatal bones

Question 53

What type of palatal bones is present in sharks?

Answer 53

cartilaginous

Question 54

What type of palatal bones is present in bony vertebrate?

Answer 54

membrane bones

Question 55

a secondary ('false') palate develops creating a horizontal partition that separates the oral cavity into nasal & oral passages.

Answer 55

Birds, mammals, & some reptiles

Question 56

formed from processes of the premaxillae, maxillae, and palatines

Answer 56

secondary palate

Question 57

consist of operculum

Answer 57

Opercular bones

Question 58

fold of the hyoid arch that extends back over the gill slits in holocephalans & bony fishes

Answer 58

operculum

Question 59

no vestiges of opercular bones remain

Answer 59

tetrapods