Lab activity/homework #1

1. Define and give the function of the ff: A. Zygapophysis articulations between successive vertebrae. It is further subdivided into

prezygapophysis (anterior projections) and postzygapophysis (posterior projections). It functions as a facet joint for the lumbar spine area.

B. Basapophysis Basapophysis or hemapophysis (basal stumps) is a pair of ventral projections of the centrum. It may serve as rib attachments.

C. Diapophysis Lateral projections of the vertebra used for the attachment of the upper head of two-headed ribs.

D. Parapophysis Lateral projections of the vertebra used for the attachment of the lower head of two-headed ribs.

E. Pleurapophysis Lateral projections for the rib attachments of the vertebra as well as the fused rib.

F. Hypapophysis Mid-ventral projections from the centrum.

G. Neural arch Part of the vertebra, located dorsally, that encloses the spinal cord.

H. Haemal arch Part of the vertebra, located ventrally, that encloses the blood vessels.

2. Differentiate cartilage bone from a dermal bone.

Cartilage bones emerge from chondroblasts whereas dermal bones emerge from osteoblasts. Dermal bones are tissues which consist of collagen, hydroxyapatite crystals, cementing substance, and osteocytes in lacunae that are connected by canaliculi. Dermal bones are either compact or spongy. They also contain Haversian canals and are surrounded by a membranous periosteum.

Cartilage bones, on the other hand, consist of a collagenous matrix, mucopolysaccharide in the interstices of the matrix and chondrocytes in lacunae. Cartilage Bones are hyaline, fibrocartilage, or elastic cartilage. They are also sometimes calcified. They are surrounded by a membranous perichondrium.

3. Give the type of vertebra of the ff based on the shape of the centra: A. Turtle Amphicoelous (both ends of the centra are concave) B. Dogfish Amphicoelous (both ends of the centra are concave) C. Chicken Heterocoelous (both ends of the centra are shaped like the seak of a saddle

placed transversely at one end and vertically at the other) D. Cat Amphiplatyan (both ends of the centra are flat)

4. What are chevron bones?

Chevron bones are bones on the ventral side of the tail in reptiles and in some

mammals. It is located below the centrum of the tail bone. Its main function is to protect nerves and blood vessels from being damaged whenever weight is put on the tail.

5. What is an odontoid process? Give the function. (CAT)

The odontoid process or the dens is a small tooth-like projection from the second

vertebra of the neck, acting as a pivot allowing the first vertebra to rotate. In cats, it enables the cat to turn its head.

6. What is a synsacrum?

A synsacrum is a sacrum united with other vertebrae. In modern birds, it is the fusion of the last thoracic vertebra, all lumbars, the sacrals, the first few caudals, and their ribs.

7. What is the function of the uncinate process in birds?

The uncinate process is a projection from the ribs in birds for muscle attachment. The length of the uncinate process is different depending on the birds specialization. Short uncinate processes are for walking birds, long uncinate prcesses are for diving birds and uncinate processes of intermediate length are for non-specialist birds.

8. Differentiate monospondyly from diplospondyly.

A monospondyly is a vertebra having only one centrum whereas a diplospondyly is a

vertebra with two centras per segment.

9. Differentiate the trunk vertebra from the tail region of the dogfish.

10. Describe how the vertebra is formed. (5 points)