Skeletal System 3 - Skull and Visceral Skeleton Flashcards
1
Q
What does the vertebrate skull consist of
A
- neurocranium
- dermatocranium
- splanchnocranium
2
Q
also called endocranium or primary braincase
A
neurocranium
3
Q
lies superficial to neurocranium, has a large number of bones
A
dermatocranium
4
Q
part of the skull that supports the jaws and is made up of bones and cartilage
A
splanchnocranium
5
Q
- protects the brain
- begins as cartilage that is partly or entirely replaced by bone (except in cartilaginous fishes)
A
neurocranium or chondrocranium
6
Q
how does the neurocranium begin
A
pair of parachordal and prechordal cartilages below the brain
7
Q
exapnd and join along with notochord from basal plate
A
parachordal cartilage
8
Q
expands and join to form an ethmoid plate
A
prechordal cartilages
9
Q
where does the cartilage also appear
A
- olfactory capsule
- otic capsule
10
Q
partially surrounding the olfactory epithelium
A
oflactory capsule
11
Q
surrounds inner ear and also develops into sclera of the eyeball
A
otic capsule
12
Q
fuses with olfactory capsules
A
ethmoid plate
13
Q
fuses with otic capsules
A
basal plate
14
Q
further development of cartilaginous neurocranium
A
- development of cartilaginous walls and
- cartilaginous roof over brain (in cartilaginous fishes)
15
Q
retain a cartilaginous neurocranium (or chondrocranium) throughout life
A
Cartilaginous fishes
16
Q
retain highly cartilaginous neurocranium that is covered by membrane bone
A
- Bony fishes
- lungfishes
- most ganoids
17
Q
embryonic cartilaginous neurocranium is largely replaced by replacement bone
A
Other bony vertebrates
18
Q
neurocranial ossification centers
A
- ethmoid center
- sphenoid center
- otic center
- occipital center
19
Q
- most mammals
- nasal chamber is large & filled with ridges from the ethmoid bones -turbinals or ethmoturbinals
- these bones are covered with olfactory epithelium in life - increase the surface area for olfaction (i.e., a more acute sense of smell)
- tend to remain cartilaginous & formanterior to sphenoid
A
ethmoid center
20
Q
ethmoid bones
A
- turbinals or
- ethmoturbinals
21
Q
separates the nasal chamber from the brain cavity within the skull
A
cribiform plate
22
Q
form:
- basisphenoid bone (anterior to basioccipital)
- alisphenoid
- presphenoid bone side walls above basisphenoid
A
sphenoid centers
23
Q
anterior to basioccipital
A
basisphenoid bone
24
Q
- bony process of the sphenoid bone in the skull, located behind each eye
- can also refer to the greater wing of the sphenoid bone.
A
alisphenoid
25
side walls above basisphenoid
presphenoid
26
the cartilaginous otic capsule is replaced in lower vertebrates by several bones:
- prootic
- opisthotic
- epiotic
otic centers
27
several bones that replaces the cartilaginous otic capsule
- prootic
- opisthotic
- epiotic
28
opisthotics fuse with exoccipitals
Frogs & most reptiles
29
- prootic, opisthotic, & epiotic unite to form a single petrosal bone;
- the petrosal, in turn, sometimes fuses with the squamosal to form the temporal bone
Birds & mammals
30
form a single petrosal bone
1. prootic
2. opisthotic
3. epiotic
31
sometimes fuses to form the temporal bone
1. petrosal
2. squamosal
32
cartilage surrounding the foramen magnum may be replaced by as many as four bones
occipital centers
33
four bones that replaces the cartilage surrounding the foramen magnum
1. basioccipital
2. exoccipital (2)
3. supraoccipital
34
refers to a part of the occipital bone that forms the floor and walls of the posterior fossa and surrounds the foramen magnum.
Basioccipital
35
relating to a bone or region on each side of the foramen magnum of the skull
exoccipital
36
bone in the cranium that is located in the upper rear portion and forms part of the rear of the skull
supraoccipital
37
all 4 occipital elements typically fuse to form a single occipital bone
Mammals
38
neurocranium articulates with the 1st vertebra via 1 (reptiles and birds) or 2 (amphibians and mammals) occipital condyles
Tetrapods
39
neurocranium articulates with the 1st vertebra via 1 occipital condyles
- reptiles
- birds
40
neurocranium articulates with the 1st vertebra via 2 occipital condyles
- amphibians
- mammals
41
- membrane bones of the skull and mandible
- lies superficial to neurocranium & forms:
- bones that form the roof of the brain & contribute to the lateral walls of the skull
- bones of the upper jaw
- bones of the palate(s)
- opercular bones
dermatocranium
42
basic pattern of roofing bones
1. crossopterygians
2. labyrinthodonts
43
a series of paired & unpaired bones along mid-dorsal line of skull
Crossopterygians
44
unpaired bones lost & a series of paired bones resulted (nasals, frontals, parietals, & dermoccipitals)
Labyrinthodonts
45
- soft spots
- occur when neurocranium is incomplete dorsally
fontanels
46
palatoquadrate is the only upper jaw that develops
Cartilaginous fishes
47
palatoquadrate becomes covered with dermal bones (premaxillae & maxillae) that make up the adult upper jaw
Bony vertebrates
48
floor on which the brain rests is at the same time the roof of the oral cavity in fishes & amphibians (primary palate)
palatal bones
49
a secondary ('false') palate develops creating a horizontal partition that separates the oral cavity into nasal & oral passages.
Birds, mammals, & some reptiles
50
formed from processes of the premaxillae, maxillae, and palatines.
secondary palate
51
fold of the hyoid arch that extends back over the gill slits in holocephalans & bony fishes
Operculum
52
no vestiges of opercular bones remain
Tetrapods
53
neurocranial-dermatocranial complex in tetrapods
1. temporal fossae
2. secondary palate
54
Different tempral fossae
1. anapsid
2. synapsid
3. euryapsid
4. diapsid
55
- Has no openings in the skull near the temples.
- include turtles, which can be fully terrestrial, amphibious, freshwater, or marine
anapsid
56
- Has one opening low in the skull roof behind each eye
- Includes all living and extinct mammals and therapsids.
Synapsid
57
- One high opening (above the postorbital and squamosal bones)
- Has openings in the skull bordered by the parietal, postfrontal, postorbital, and squamosal bones.
Euryapsid
58
- Has two openings in the skull behind each eye, one on top of the other
- include many reptiles and birds
Diapsid
59
consists of 7 sets of paired cartilages in the 7 visceral arches & a series of mid-ventral cartilages (basihyal & basibranchials) in the pharyngeal floor
Fish visceral skeleton
60
- resembles that of sharks except that bone is added
- Pterygoquadrate become the quadrate bones
- remainder becomes the palatine & pterygoid bones
- posterior tip of Meckel's cartilage becomes an articular bone
Bony fishes
61
movement between the upper jaw and braincase
cranial kinesis
62
advantage of cranial kinesis
- provides a way to change the size and configuration of the mouth rapidly
- optimize biting and rapid feeding.
63
disadvantage of cranial kinesis
- lose force
- difficult to optimize apposition of occlusive surfaces
64
jaw-hyoid complex of fishes requires bracing against some support to function effectively, and the nearest one is the neurocranium (endocranium)
jaw suspension
65
Types of jaw suspension
1. autostyly
2. amphistyly
3. hyostyly
66
hyomandibula play no role in bracing the jaws (lungfish & tetrapods)
autostyly
67
jaws & hyomandibula both braced directly against the braincase (extinct sharks)
amphistyly
68
- mandibular cartilage is braced against the otic capsule;
- jaws braced against hyomandibula (sharks & present-day bony fishes)
hyostyly
69
what happened to the visceral skeleton of tetrapods
underwent substantial modification
70
? = embryonic upper jaw cartilage
pterygoquadrate (palatoquadrate) cartilage
71
posterior end undergoes endochondral ossification & becomes the quadrate (which articulates with the articular bone of the lower jaw)
amphibians, reptiles, & birds
72
dentary (lower jaw) articulates with the squamosal of skull (quadrate separates from the rest of the palatoquadrate & becomes the incus of the middle ear)
Mammals
73
rod-shaped structure that forms in the mandibular process of vertebrate embryos and plays a role in the development of the jaw and middle ear
Meckel's cartilage
74
Meckel's cartilage largely ensheathed by dermal bones (as in the above turtle)
Reptiles
75
Meckel's cartilage have few or no remnants in adult lower jaw
Birds & mammals
76
hyomandibular cartilage
arch II
77
become part of hyoid apparatus
arches III -> V
78
not present in tetrapods
arches VI & VII
79
- consists of a body & 2 or 3 horns (cornua)
- anchors tongue, provides attachment for some extrinsic muscles of larynx,
- site of attachment of muscles that aid in swallowing
hyoid apparatus of tetrapods
80
- may have originated as part of a visceral arch, as in sharks (mandibular cartilage)
- in bony vertebrates, mandibular cartilage is reinforced & largely replaced by a series of dermal bones
lower jaw in mammals
