Comparative Vertebrate Anatomy Exam 1: Skull And Visceral Skeleton

Front 1

3 basic components of the head skeleton?

Back 1

Neurocranium, splanchnocranium, dermocranium

Front 2

Neurocranium

Back 2

primary braincase – chondrocranium of squalus. Some bones will ossify within neurocranium (it starts out cartilaginous). Does not fully close at the top. Protects the brain and some sense organs. Similar development in all craniates.

Front 3

Cartilagenous development of the neurocranium

Back 3

parachordal (sclerotome mesoderm) and prechordal (trabeculae = neural crest) cartilages form Expand to form floor of brain case (brain pan) = ethmoidal plate and basal plate. Hypophyseal fenestra form. Walls and tectum forms. Brain is there so neurocranium forms around nerves, vessels, leaving formina. 2 sensory capsules form

Front 4

2 sensory capsules forming in the neurocranium during cartilaginous development?

Back 4

Olfactory and otic

Front 5

Basal plate

Back 5

parachordals and notochord floor of the brain pan

Front 6

Ethmoidal plate

Back 6

prechordal floor of brain case.

Front 7

Neurocranial ossifications

Back 7

bones preformed in cartilage

Front 8

What are the Neurocranial ossifications?

Back 8

Occipital, otic, sphenoid, ethmoid

Front 9

Why do the occipital bones on the outside of skull without being covered in dermal bones?

Back 9

They are too deep. They aren’t by the skin so they don’t get covered in bone

Front 10

What are the occipital bones?

Back 10

Basioccipital, supraoccipital, exoccipitals.

Front 11

What are the otic bones?

Back 11

Prootic and opisthotic (together making the petrous bone). Housing the inner ear (with squamosal bone… or the temporal bone of mammals)

Front 12

What are the bones of the Sphenoid?

Back 12

Basisphenoid. Presphenoid. Orbitosphenoid. Lateral sphenoid. Several other wall bones. In the human all are fused.

Front 13

What is the mammal occiptital bone?

Back 13

All 3 occipital bones plus the otic bones

Front 14

Ethmoid

Back 14

remains cartilaginous. Includes nasal septum/turbinal bones = walls of nasal passages of amniotes.

Front 15

Splanchnocranium

Back 15

from the visceral skeleton. From the visceral arches = mandibular and top half of hyoid arches. The hyobranchium do not contribute to the splanchnocranium proper. In mammals it’s disconnected

Front 16

What are Jaws?

Back 16

Visceral (mandibular arch), dermal (invested bones, roots of teeth) epidermal (enamel of teeth) and NC (dentin)

Front 17

Parts of the mandibular arch?

Back 17

Upper jaw, lower jaw

Front 18

Upper Jaw

Back 18

contains the platoquardate.

Front 19

Palatoquardate

Back 19

forms the bony upper jaw or cartilaginous free upper jaw in sharks and rays. PQ is fused to skull in holocephalians, actinopterygians, and osteichthyan fishes.

Front 20

What are the palatoquardate ossifications

Back 20

posterior quadrate, palatal bones, dermal bones form on the Pq

Front 21

What is the quadrate in the human?

Back 21

Incus

Front 22

What is the articular in the human?

Back 22

Malleus

Front 23

Lower Jaw

Back 23

meckel’s cartilage

Front 24

Meckel’s cartilalge

Back 24

jaw in the early placoderms and sharks. It lays the form for dermal bones to be on.

Front 25

What bone forms In Meckels cartilage?

Back 25

Articular bone

Front 26

Hyoid Arch

Back 26

has an upper and lower half. Set behind the meckles cartilage and under the chondrocranium.

Front 27

Upper half of hyoid arch

Back 27

hyomandibula. Jaw articulation hinge of sharks and fishes. In non-mammilian tetrapods it’s the columella. In mammals it’s the stapes.

Front 28

Lower half of hyoid arch

Back 28

“the hyoid” hanging below cranium and jaws.

Front 29

Dermocranium

Back 29

from the dermis. Invested dermal armor on both cranium and jaws.

Front 30

Roofing bones of dermocranium

Back 30

nasals, frontals, parietals, postparietals (fused interparietals in mammals)

Front 31

Orbital bones of dermocranium

Back 31

lacrimal, prefrontal, post frontal, post orbital, jugal

Front 32

Bones of posterior angle in dermocranium

Back 32

intertemporal, supratemporal, squamosal, tabular, quadratojugal

Front 33

Upper Jaw bones of the derocranium

Back 33

premaxillae, maxille, jugal*, quadratojugal* (*they are endochondral bones)

Front 34

Lower jaw bones

Back 34

dentary, splenial, coronoid, angular (tumpanic bone of mammals)

Front 35

Opercular bones and gular series in dermocranium

Back 35

they are only in osteichthyans. They are dermal tissue flanges from hyoid arch and extends out over gill slits.

Front 36

Palatal dermocranium bones

Back 36

parasphenoid, vomers, pterygoids, palatine, ectopterygoids.

Front 37

Evolutionary Trends in the vertebrate skull (there are nine.) ?

Back 37

Assimilation of cranial components. General trend for a reduction in the numbers of elements. Reduction of “visceral” jaws and parallel shift to “dermal” Jaws = Evolution of sound conduction routes. Devoleopment of temporal fossae. Development of secondary palate Specialization of the visceral skeleton. Evolutionary trends in teeth.

Front 38

Assimilation of cranial components

Back 38

chondrification of neurocranium and sensory capsules. Fusion of splanchnocranium to the skull. Endochondral bones form in components. Dermocranium forms around neuro and splanchnocranium

Front 39

General trend for a reduction in the number of elements

Back 39

the dermal bone numbers become reduced (placoderms to mammals). There is a fusion of bones (occipital complex to the occipital bone)

Front 40

Reduction of “visceral” jaws and parallel shift to “dermal” Jaws: Upper Jaw

Back 40

palatoquardate cartilage to endochondral quadrate and platform for dermal bones in non-mammals. Quardate to middle ear bone in mammals with articular in tow. Epipterygoid to aslisphenoid of mammals

Front 41

Reduction of “visceral” jaws and parallel shift to “dermal” Jaws: Lower Jaw

Back 41

meckel’s cartilage to articular and form for dermal bones. Articular to inner ear. Jaw in mammals is all dermal with remnant of meckel’s inside it.

Front 42

Development of temporal fossae

Back 42

dermocranium covered muscles operating the jaws like fishes with solid outer dermal cranium. Needfor room for belly of the muscles during contraction

Front 43

Anapsids

Back 43

No hole in dermal cranium but muscle squeezed out the back. Turtles are the only extant form of this because they completely blew out the back of their head.

Front 44

Diapsid

Back 44

most non-mammilian tetrapods are these. 2 temporal fossae for the muscle contraction. One above (superior temporal fossa), the post orb and squamosal will come, and then one below them (inferior temporal fossa). Muscles shift to the edge of the fossa.

Front 45

Synapsids

Back 45

1 temporal fossa (inferior one of the diapsids. Lateral temporal fossa (same spot as inferior). Muscles moved out onto outside of the dermocranium. Mammals.

Front 46

Euryapsids

Back 46

single dorsal temporal fossa. All of these are extinct.

Front 47

Development of a secondary plate

Back 47

allowed for animals to chew their food and breathe.

Front 48

Animals with a secondary palate

Back 48

in some amphibians, it is existent but crappy in reptiles, and it is complete in mammals (and alligators, those weird freaks).

Front 49

Specializtion of the visceral skeleton

Back 49

1st arch of the branchial arches is the jaws. 2nd visceral arch is the hyomandibula, ceratohyal, and basihyal. 3rd visceral arch is the part of body of hyoid and thyrohyal. 4th visceral archis the thyroid (mammal). 5th visceral arch is the larynx. 6+ visceral arches are not present in mammals.

Front 50

continuous teeth replacement

Back 50

teeth shed one at a time

Front 51

polyphyodont

Back 51

poly modal replacement in staggered waves down jaw

Front 52

di, monophydont

Back 52

1-2 waves of apearance (the molars don't shed)

Front 53

homodont teeth

Back 53

the animal has only 1 tooth homology (non mammals with teeth)

Front 54

heterodont teeth

Back 54

the animal has more than 1 single tooth homology