Skeletal System

Question 1

What is osteology?

Answer 1

The study of bones (ossa) that combine to form the skeletons of diverse animal species.

Question 1

What is “bone” in Latin?

Answer 1

Ossa

Question 2

What are the main components of bones? What is a bone when it has all these components?

Answer 2

1) BONE TISSUE
2) ENDOSTEUM (sheaths the inside of the bone tissue)
3) PERIOSTEUM (sheaths the outside of the bone tissue)
4) BONE MARROW (medulla ossium)
5) BLOOD VESSELS
6) NERVES

All these components classify a bone as an organ.

Question 3

What is “bone marrow” in Latin?

Answer 3

medulla ossium

Question 4

What is meant by the “maceration of bone”?

Answer 4

process of removing organic components through the use of weak lye.

Question 5

What does acid treatment do to bones?

Answer 5

removes the inorganic or mineralized components.

Question 6

Where do all components of the skeletal system develop?

Answer 6

skeletal system components develop from the middle embryonic germ layer (mesoderm).

Question 7

What is the Latin name for the “middle embryonic germ layer”?

Answer 7

mesoderm

Question 8

What does the mesoderm differentiate into?

Answer 8

1) CELLS
2) FLUID FILLED INTERCELLULAR SPACES
3) FIBROUS COMPONENTS (eg. collagen and elastin)

Question 9

What are the two elements of tissue support? What do they develop from?

Answer 9

1) cartilage
2) bone

develop from primordial loose connective tissue (textus connecticus collagenous laxus)

Question 10

What do bone and cartilage originate from?

Answer 10

mesenchymal precursor cells.

Question 11

What develops into the cartilage?

Answer 11

chondroblasts –> chondrocytes

Question 12

What develops into the bone?

Answer 12

osteoblasts –> osteocytes

Question 13

What are the five different types of bones? Latin names?

Answer 13

1) long bones (ossa longa)
2) short bones (ossa brevia)
3) flat bones (ossa plana)
4) pneumatic bones (ossa pneumatica)
5) irregular bones (ossa irregularia)

Question 14

Explain the principal features of long bones.

Answer 14

characterised by a SHAFT, or DIAPHYSIS, formed from:
- a thick outer layer of COMPACT BONE (substantia compacta),
- an INNER MEDULARRY CAVITY (cavum medullare).

long bones have two ends:
- PROXIMAL EPIPHYSIS
- DISTAL EPIPHYSIS

both EPIPHYSIS:
- covered by a thin layer of CORTICAL SUBSTANCE (substantia corticalis).
- contain SPONGY BONE (ossified sponge with delicate pores)

Question 15

What do long bones form?

Answer 15

the basis of limbs.
eg. upper arm (humerus), shin bone (tibia), metacarpal bones (ossa metacarpalia).

Question 16

Explain the principal features of short bones.

Answer 16

contain an extensive latticework of SPONGIOSA (in which HEAMORETICULAR tissue is present)

Question 17

State examples of short bones.

Answer 17

vertebral column
hock joint (ankle joint)

Question 18

What are the different forms of short joints?

Answer 18

• cylindrical
• cubic
• round

Question 19

Explain the principal features of flat and wide bones.

Answer 19

consist of 2 layers of COMPACT BONE (tubulae) surrounding either:
1) SPONGY BONE (diploe)
2) AIR (sinus)

Question 20

State examples of flat and wide bones.

Answer 20

scapula,
ribs,
iliac bone (in the medulla)

Question 21

What is the Latin name for cavities of air?

Answer 21

Ossa pneumatica

Question 22

State examples of irregular bones.

Answer 22

SESAMOID BONES (ossa sesamoidea): found close to the joints
APOPHYSIS: developed from an independent ossification center, provide attachment sites for muscles and ligaments.

Question 23

Which bones are not related to the locomotor system?

Answer 23

bones of the organs, such as:
- the penis of a male cats and dogs
- bovine heart

Question 24

What does the stability of the bone depend on?

Answer 24

• structure of the compact bone
• arrangement of the spongy bone
• form of the central medullar cavity
• principles of the tensile and compressive stress
• stress trajectories
• flexure demands on bones

Question 25

What is the basis substance of compact bones?

Answer 25

compact lamallae.