Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

BIOL 307 lab > Cranial skeleton > Flashcards

Cranial skeleton Flashcards

1
Q

What are the three main components of the cranial skeleton?

A

chondrocranium: base of the braincase

splanchnocranium: visceral arches

dermatocranium: outer part of the braincase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the 3 skull modifications: temporal fenestrae/fossae?

A

anapsid: no fenestrae

synapsid: pair of 1 fenestra

diapsid: pairs of 2 fenestrae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Which vertebrates are anapsids?

A

fish and turtles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Which vertebrates are synapsids?

A

mammals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Which vertebrates are diapsids?

A

some reptiles and birds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the proposed purpose for temporal fenestrae/fossae?

A

location for jaw muscle attachment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

T or F: the chondrocranium is a single piece

A

true, but it’s made of numerous fused bones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

WHat are the major bone groups in the chondrocranium?

A

occipitals, sphenoids, ethmoids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the chondrocranium derived from?

A

mesodermal sclerotome and neural crest cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

In the embryo, paired cartilages underneath the brain develop into what two things?

A

parts of the cranium to support the brain

the roof of the mouth or primary/hard palate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the sense organs housed in during embryonic stage?

A

cartilage capsules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What forms around the brain during development beginning at the notochord?

A

cartilage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

When sense organs are surrounded by cartilage during development what 3 things do they form?

A

the optic capsule (eyes)
the otic capsule (ears) - if present
the nasal capsule (olfactory)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Which two cartilage capsules encasing sensory organs fuse to the chondrocranium?

A

the nasal and otic capsules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the sclera? What is its purpose?

A

the optic cartilage forms the sclera instead of fusing to the chondrocranium

it contains cartilage or bone

allows movement of the eyes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How many pairs of cartilages make up the human chondrocranium?

A

6

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the 6 paired cartilages in the human chondrocranium?

A

parachordal cartilages - forms around notochord

prechordal cartilages- forms in front of notochord

occiptal cartilages- forms where the brain meets the spinal cord

otic capsule - forms inner ear

orbital cartilages - forms eye

nasal capsules - forms olfactory organ

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What does the splanchnocranium contribute to?

A

jaws

forms the gill arches, hyoid, and cartilages at anterior end of trachea, glottis, epiglottis, larynx

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What does the splanchnocranium develop from?

A

visceral arches that provide gill support in fishes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what is the visceral skeleton derived from?

A

splanchnic (gut) mesoderm, neural crest cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the purpose of the pharynx?

A

involved in feeding
in lesser derived: in respiration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

T or F: more derived vertebrates have less gill slits - why/why not?

A

true

they have evolved away from filter feeding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is another name for visceral arches?

A

gill bars

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the mandibular arch derived from?

A

the first visceral arch

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What are jaws mainly derived from?
the mandibular arch
26
T or F: jaws are modified gill supports
true, they are derived from the mandibular arch which is derived from the first visceral arch (gill slits)
27
What are the two components of the mandibular arch?
the mandibular cartilage (lower jaw) palatoquadrate cartilage (upper jaw)
28
What is the hyoid arch?
the second visceral arch
29
in tetrapods, what purpose does the hyoid arch/2nd visceral arch serve?
supports the jaw and tongue
30
What is the tongue attached to?
hyoid bone
31
In tetrapods, which part of the tongue/hyoid articulates with the chondrocranium?
the dorsal part = the hyomandibula (remember in the frog dissection, the tongue was attached at the dorsal end of the mouth, not the anterior like ours)
32
What did visceral arches 3-7 become? what do they do?
branchial arches involved in respiration
33
What 2 arches work together to allow jaw movement?
mandibular and hyoid arches
34
What are the 3 the mandibular and hyoid arches can be articulated with the chondrocranium? what vertebrate groups have these styles?
amphistylic - early cartilaginous and early bony fishes hyostylic - elasmobranchs and most bony fish autostylic - lungfishes and tetrapod ancestors
35
Describe amphistylistic articulation. what are the vertebrate groups that have this?
jaw is directly connected to chondrocranium and is supported by hyomandibula early cartilaginous fish early bony fish
36
Describe hyostylistic articulation. what are the vertebrate groups that have this?
upper and lower jaw supported only by hyomandibula upper law has no connection to chondrocranium elasmobranchs and bony fishes
37
Describe autostylistic articulation. what are the vertebrate groups that have this?
upper jaw is either articulated or fused with the chondrocranium lower jaw forms mandibular cartilage jaw not supported by hyomandibular lungfish tetrapod ancestors
38
what is the dermatocranium?
bones that: compose the roof of the cranium (outer braincase) cover the major sense organs and brain form plates and armour for some vertebrates
39
Where does the dermatocranium develop?
within the dermal layer of the skin
40
T or F: dermatocranium, like the chondrocranium and splanchnocranium is made up of bones that are preceded in development by cartilages?
false they are not preceded by cartilages
41
What are the dermal bones in ostracoderms?
the original dermal scales (armour) which sink into and attach to the neurocranium and become ossified
42
What does ossified mean?
turned into bone
43
What are dermal bones derived from?
neural crest cells
44
What are formina? singular: foramen
collective name for the various small openings in the skull aka fenestrae
45
What is the purpose of foramina?
they are openings for the series of 10 paired cranial nerves to connect to the brain and major sense organs, facial muscles, tongue, teeth, etc
46
What are cranial sutures?
an immovable, fibrous joint in the skull bone surfaces are closely connected by connective tissue
47
What are the 4 types of cranial sutures?
coronal - between frontal bone and 2 parietal bones sagittal - between 2 parietal bones lambdoidal - between right and left parietal bones and occipital bone squamosal - between parietal and temporal bone on each side
48
What are Wormian bones? where are they located?
small bone fragments located in sutures especially found in sagittal and lambdoidal
49
What are 2 skull modifications for more powerful jaws?
otic notch temporal fossae
50
How does the otic notch increase jaw power?
the otic notch is an adaptation for muscle attachment to compensate for increased jaw muscles and counter dermal bone
51
Are turtles anapsids or diapsids?
they were thought to be anapsid, but new evidence suggests that like their reptilian relatives, they're diapsids
52
How do temporal fossae/fenestrae increase jaw power?
paired openings on the skull create an attachment location for larger jaw muscles
53
What are the two possible temporal fenestrae?
infratemporal and supratemporal
54
In what two ways can the eye orbital be related to the temporal fenestrae/fossae?
the eye orbit can be separate from fossae - ex. cats, horses, humans or can be merged - ex. wolves, rats
55
What was a major skull modification for breathing air?
evolution of the secondary palate
56
What are the 3 stages of secondary palate evolution?
primary unmodified palate = complete roof to the mouth - fishes and amphibians partial secondary palate = a trend toward the evolution of the secondary palate - some bones developed (ex. maxilla, premaxilla, palatine) - some reptiles (not birds) complete secondary palate = alligator has complete bony mammals have complete not bony birds have complete fleshy
57
How can amphibians live on land if their palate is primary and unmodified for breathing air (ie., complete roof)?
they use cutaneous respiration and perform gas exchange across their skin for respiration
58
What type of secondary palate do alligators have?
complete bony
59
What type of secondary palate do birds have?
complete fleshy
60
What type of secondary palate do mammals have?
complete function - both bony and fleshy components q
61
Why do birds have complete fleshy secondary palates instead of bony like their reptilian relatives?
to save weight
62
What are fontanels? what is their function?
membrane-filled soft spots in mammalian skulls present only while developing which later are filled in with bone function: connect the incomplete cranial bones during development allow the head to change shape during birth to fit through narrow birth canal allow rapid growth during first 2 years of development
63
how many middle ear bones do mammals have? reptiles, amphibians?
mammals = 3 reptiles, amphibians = 1
64
What are turbinal bones?
pairs of rolled up bones covered in olfactory epithelium usually located in the nose of animals to increase surface area for smelling
65
Why is the evolution of jaws so significant for vertebrates?
allowed them to capture and eat larger food
66
How is the evolution of the jaw related to the size of vertebrates?
being able to eat larger food more quickly allowed vertebrates to grow in size faster than invertebrates
67
which vertebrates have upper jaws that are not fused to the chondrocranium? what does this allow?
some fish, like sharks can move their jaws independently of their skull
68
Why does it appear like sharks can dislocate their upper jaw from the skull when they open their mouth to catch prey?
the upper jaw is not united to the chondrocranium and can therefore move independently of the skull
69
What is the function of the hyoid bone?
it supports the tongue also attaches to muscles of the phayrnx and neck
70
How is a swinging jaw an advantageous adaptation?
a swinging jaw is not fused to the cranium so it allows the mouth to open wider and for the animal (fish) to catch larger prey and provides a stronger bite
71
What bones comprise the upper and lower jaws in mammals?
upper: palatoquadrate cartilage of the mandibular arch lower: the dentary bone (just one bone)
72
What does the hyomandibular do in fishes?
73
What does the hyomandibular become in reptiles and amphibians?
the only middle ear bone
74
What does the hyomandibular become in mammals?
becomes a bone in the middle ear
75
What do the articular and quadrate bones become in mammals?
each becomes a bone in the middle ear
76
How many middle ear bones do mammals have? reptiles and amphibians?
mammals = 3, from the hyomandibular, articular, and quadrate reptiles and amphibians = 1 from the hyomandibular

BIOL 307 lab (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions