Lecture 11 Flashcards
- List the dermal components of the pectoral girdle.
- Cleithrum (-a)
- Clavicle
- Interclavicle
- List the endochondral components of the pectoral girdle.
- Procoracoid
- Coracoid
- Scapula
The Cleithrum is what part of the pectoral girdle?
dermal
The scapula is what component of the pectoral girdle?
endochondral
The Coracoid and Procoracoid are what type of components of the pectoral girdle?
endochondral
What components provide muscle attachment surfaces???
Dermal components provide surfaces for muscle attachment.
Endochondral components serve as major base of
attachment for limb muscles.
Why do chondricthyians only have endochondral components?
In the shark and other chondrichthians, the pectoral girdle only consists of endochondral components.
Describe the coracoid bar:
The main component is the coracoid bar:
o Carries the fin attachment
o Is typically “U”-shaped
o Scapular processes sit on top of lateral ends of coracoid
Describe the comparative anatomy of both dermal and endochondral components from fishes through the mammals.
There is a chart in the notes comparing fish, tetrapods, etc.
Does the pelvic girdle have dermal components in vertebrates?
No. The pelvic girdle lacks dermal components in all vertebrates.
The pelvic girdle consists of three paired endochondral bones: What are they?
Pubis, Ischium, Illum
Where is the pubis located?
ventral and anterior to the other two components
Where is the Ischium located relative to the other pelvic girdle bones?
posterior and ventral to the other two
The illum is found:
located dorsal to the other two components
What is the acetabular fossa?
Where all three bones carry limb articulation in most vertebrates
What does the Ilium articulate with?
Ilium articulates with sacral vertebra(e) either directly or via sacral ribs.
Which two bones of the pelvic girdle are used for muscle attachment?
Pubis and Ischium
Describe the pelvic girdle of bony fishes.
In bony fishes, the pelvic girdle consists of a pair of ventral triangular plates fused along their midline. They are never articulated with the axial skeleton.
T/F A shark pelvic girdle is entirely cartilaginous?
True. I’m seeing a trend here
What is the obturator foramen?
The obturator foramen is an opening between the pubis and ischium which provides a passageway for a nerve (obturator nerve) supplying the limb muscles.
The acetabulum develops
above the puboisciadic plate and forms from all three elements except in crocodilians.