Lab 4 - Comparison of Cranial Skeleton

Question 1

What is the function of the skeleton?

Answer 1

For locomotion and support for the animal

Question 2

What are the two basic parts of the skeleton?

Answer 2

The dermal skeleton and endoskeleton

Question 3

What kinds of structures are the dermal skeleton?

Answer 3

Outer skull bones, teeth, and structures like a turtle shell

Question 4

What does the endoskeleton consist of?

Answer 4

It can be divided into visceral and somatic components

Question 5

What structures make up the visceral skeleton?

Answer 5

The gill arches, jaw components, and support of the pharynx.

Question 6

What makes up the somatic skeleton?

Answer 6

Axial and Appendicular skeleton subdivisions.

Question 7

What structures make up the axial skeleton?

Answer 7

The vertebrae, ribs, and sternum

Question 8

What structures make up the appendicular skeleton?

Answer 8

The paired appendages and the girdles that support them.

Question 9

What is the cranial skeleton composed of?

Answer 9

It consists of both the dermal skeleton and endoskeleton.

Question 10

What is special about the Chondrichthyes skull?

Answer 10

It is entirely cartilaginous and has a movable upper jaw.

Question 11

What is the palatoquadrate cartilage?

Answer 11

It forms the upper jaw in sharks

Question 12

What is the rostrum?

Answer 12

It houses the nares and ampullae of lorenzini

Question 13

What is Meckel’s (or mandibular) cartilage?

Answer 13

It forms the lower jaw in sharks

Question 14

How does an Osteichthyes skull differ from a dogfish skull?

Answer 14

The skull isn’t cartilaginous, its upper jaw is fused to the rest of the skull, and there are opercular bones.

Question 15

What is the maxilla?

Answer 15

The upper jaw

Question 16

What is the mandible?

Answer 16

The lower jaw

Question 17

What are the quadrate and articular bones important for in non-mammals?

Answer 17

They function as the hinge point for the jaw (quadrate=above, articular=lower)

Question 18

What is the dentary bone?

Answer 18

Makes up the majority of the lower jaw in most vertebrates

Question 19

What is the palatine?

Answer 19

It is the bone at the roof of the mouth. It is important for creating a barrier between the nasal passage and mouth

Question 20

What is the choana?

Answer 20

There are two (one for each of the nares) that open into the nasopharynx

Question 21

What is the temporal fenestrae?

Answer 21

“Holes” near the top of the skull where muscles attach on one side for the jaw.

Question 22

What is special about the rattlesnake skull?

Answer 22

It has a highly modified quadrate bone, where it is attached to an extra hinge, allowed for a greater range of motion. Also, it is elongated and they can move their upper jaw to an extent

Question 23

What is the difference between aves skulls and reptile?

Answer 23

Aves skulls have more spongy bone and fusion of bones and have more holes, so they are lighter. Also, The orbit is massive in the aves, which is important because they have good sight. Also, no teeth.

Question 24

When did the palatine bone evolve?

Answer 24

The amphibians have a greatly reduced one, but it is quite prominent in reptilia first.