Exercise 9

Question 1

Skeleton

Answer 1

The body’s framework; Constructed of cartilage and bone

Question 2

Functions of the skeleton

Answer 2

• support and protect
• system of levers with the skeletal muscles
• store lipids and minerals
• hematopoiesis (blood cell formation)

Question 3

What are the two divisions of the skeleton?

Answer 3

Axial: bones that lie around the body’s center of gravity
Appendicular: bones of the limbs or appendages

Question 4

Name the 7 most important skeleton cartilages

Answer 4

1. ) Articular: cover the bone ends at movable joints
2. ) Costal: found connecting the ribs to the sternum (breastbone)
3. ) Laryngeal: largely constructs the larynx (voice box)
4. ) Tracheal and bronchial: reinforce other passageways of the respiratory system
5. ) Nasal: support the external nose
6. ) Intervertebral discs: separate and cushion bones of the spine (vertebrae)
7. ) Cartilage of the ear

Question 5

What is the dense connective tissue covering in cartilage called?

Answer 5

Perichondrium

Question 6

What are the three cartilage tissue types?

Answer 6

Hyaline: sturdy support with some resilience
Elastic: more flexible, tolerates bending better
Fibrocartilage: great tensile strength, can withstand heavy compression

Question 7

Compact bone

Answer 7

Smooth and homogeneous

Question 8

Spongy bone

Answer 8

Composed of small trabeculae (bars) of bone and lots of open space

Question 9

Long bones

Answer 9

Longer than they are wide, shaft with heads at either end

Question 10

Short bones

Answer 10

Typically cube shaped, contain more spongy bone than compact bone

Question 11

Flat bones

Answer 11

Generally thin, with two waferlike layers of compact bone sandwiching a layer of spongy bone

Question 12

Irregular bones

Answer 12

Bones that do not fall into one of the other bone categories

Question 13

Sesamoid bones

Answer 13

Special types of short bones formed in tendons

Question 14

Wormian (sutural) bones

Answer 14

Tiny bones between cranial bones

Question 15

How many bones are in an adult?

Answer 15

206

Question 16

Bone markings

Answer 16

Where bones from joints with other bones, where muscles, tendons, and ligaments were attached, and where blood vessels and nerves passed

Question 17

What are the categories of bone markings?

Answer 17

Projections: processes that grow out form the bone and serve as sites of muscle attachment or help form joints
Depressions (cavities): indentations or openings in the bone that serve as conduits for nerves and blood vessels

Question 18

Tuberosity

Answer 18

(Site of muscle and ligament attachment) Large rounded projection; may be roughened

Question 19

Crest

Answer 19

(Site of muscle and ligament attachment) Narrow ridge of bone; usually prominent

Question 20

Trochanter

Answer 20

(Site of muscle and ligament attachment) Very large, blunt, irregularly shaped process (only in femur)

Question 21

Line

Answer 21

(Site of muscle and ligament attachment) Narrow ridge of bone; less prominent that a crest

Question 22

Tubercle

Answer 22

(Site of muscle and ligament attachment) Small rounded projection or process

Question 23

Epicondyle

Answer 23

(Site of muscle and ligament attachment) Raised area on or above a condyle

Question 24

Spine

Answer 24

(Site of muscle and ligament attachment) Sharp, slender, often pointed projection

Question 25

Process

Answer 25

(Site of muscle and ligament attachment) Any bony prominence

Question 26

Head

Answer 26

(Help form joints) Bony expansion carried on a narrow neck

Question 27

Facet

Answer 27

(Help form joints) Smooth, nearly flat, articular surface

Question 28

Condyle

Answer 28

(Help form joints) Rounded articular projection

Question 29

Ramus

Answer 29

(Help form joints) Armlike bar of bone

Question 30

Groove

Answer 30

(Passage of blood vessels and nerves) Furrow

Question 31

Fissure

Answer 31

(Passage of blood vessels and nerves) Narrow, slitlike opening

Question 32

Foramen

Answer 32

(Passage of blood vessels and nerves) Round or oval opening through a bone

Question 33

Notch

Answer 33

(Passage of blood vessels and nerves) Indentation at the edge of a structure

Question 34

Meatus

Answer 34

(Others) Canal-like passageway

Question 35

Sinus

Answer 35

(Others) Bone cavity, filled with air and lined with mucous membrane

Question 36

Fossa

Answer 36

(Others) Shallow, basinlike depression in a bone, often serving as an articular surface

Question 37

Endochondral ossification

Answer 37

Except for the collarbones, all bones of the body inferior to the skull form in the embryo by this process

Question 38

Where does endochondral ossification begin?

Answer 38

Primary ossification center of the shaft of a developing bone

Question 39

What is another name for the shaft of a bone?

Answer 39

Diaphysis

Question 40

Periosteum

Answer 40

Fibrous membrane covering the bone surface

Question 41

Perforating (Sharpey's) fibers

Answer 41

Fibers of the periosteum that penetrate into the bone

Question 42

Osteoblasts

Answer 42

Bone-forming cells

Question 43

Osteoclasts

Answer 43

Bone-destroying cells

Question 44

Epiphysis

Answer 44

The end of a long bone

Question 45

Epiphyseal plate

Answer 45

Thin area of hyaline cartilage that provides for longitudinal growth during youth

Question 46

Epiphyseal lines

Answer 46

Replace the epiphyseal plate

Question 47

What is the central cavity of the shaft called and what does it do?

Answer 47

Medullary cavity; Stores adipose tissue (yellow marrow)

Question 48

Where is red marrow found?

Answer 48

In infants, the marrow cavities; In adults, confined to the interior of the epiphyses

Question 49

Endosteum

Answer 49

Lines the trabeculae of spongy bone and the canals of compact bone

Question 50

Central (Haversian) canal

Answer 50

Runs parallel to the long axis of the bone; Carries blood vessels, nerves, and lymph vessels (nerve, vein, artery)

Question 51

Osteocytes

Answer 51

Mature bone cells

Question 52

Lacunae

Answer 52

Chambers with contain osteocytes

Question 53

Concentric lamellae

Answer 53

The arrangement of the osteocytes and lacunae around the central canal

Question 54

Osteon (Haversian system)

Answer 54

Cental canal and all the concentric lamellae

Question 55

Canaliculi

Answer 55

Tiny canal radiating outward from a central canal to the lacunae of the first lamella and then from lamella to lamella

Question 56

Perforating (Volkmann's) canal

Answer 56

Run into the compact bone and marrow cavity from the periosteum at right angles to the shaft; Complete the communication pathway between interior and exterior of bone