Ch. 6 Bone Tissue

Question 1

Long Bones

Answer 1

• longer than wide; contain more compact bone than spongy bone
• slightly curved to absorb stress of body weight to evenly distribute
• ex. humerus (arm), ulna and radius (forearm bones), femur (thigh), tibia and fibula (leg bones), metacarpals (hand bones), metatarsals (foot bones), phalanges (finger and toe bones)

Question 2

Short Bones

Answer 2

cube-shaped, similar in length, width and depth; consists mostly of spongy bone
ex. carpal and tarsal

Question 3

Flat Bones

Answer 3

• thin, contain a layer of spongy bone sandwiched between 2 parallel layers of compact bone
• protection and provide extensive areas for muscle attachment
• ex. cranial bones, sternum and ribs, and scapulae, pelvic girdle

Question 4

Irregular Bones

Answer 4

• contain varied shapes and many surface features for muscle attachment or articulation
• ex. bones of vertebral column and certain facial bones, and calcaneus

Question 5

Sesamoid Bones

Answer 5

• protect tendons from excessive wear and tear, and alter direction of pull
• generally small smooth bones that develop within tendons
• ex. patellae, base of big toe

Question 6

Anatomy of a Long Bone

Answer 6

1. Diaphysis: long, cylindrical shaft of the bone
2. Epiphysis: proximal and distal end of bone; contain spongy bone (red bone marrow- hemopoiesis)
3. Metaphysis: between epiphysis and diaphysis that contains epiphyseal line (chrondocytes cartilagenous is a site of mitotic activity of bone cells)
4. Articular cartilage: hyaline cartilage covering the epiphysis; reduce friction and absorbs shock
5. Periosteum: dense irregular connective tissue; has blood supply and attaches periosteum to underlying bone by perforating (Sharpey’s) fibers
6. Endosteum: thin membrane (dense irregular tissue) that line the medullary cavity and contains bone marrow
7. Medullary cavity: within diaphysis that contains yellow bone marrow and numerous blood vessels; inner softer part of spongy bone

Question 7

Functions of Bones

Answer 7

1. support
2. protect: eg. cranial bone and vertebral column, rib cage, pectoral & pelvic girdle
3. movement
4. mineral storage: 90% stored and released by bone; calcium- muscle contraction, blood clotting, and nerve impulse transmission
5. blood cell formation (hemopoiesis): stem cell in red bone marrow and adipose tissue in yellow bone marrow
6. fat storage: triglyceride storage in adipose cells

Question 8

Nutrient Foramina

Answer 8

allows passage for blood vessels

Question 9

Depressions and Openings

Answer 9

form joints or allow the passage of soft tissues

- Fissure, fossa, foramen, sulcus, meatus

Question 10

Fissure

Answer 10

Narrow slit between adjacent parts of bones through which blood vessels or nerves passes

Question 11

Foramen

Answer 11

Opening through which blood vessels, nerves, or ligaments pass

Question 12

Fossa

Answer 12

shallow depression

ex. coronoid fossa of the humerus

Question 13

Suclus

Answer 13

furrow along a bone surface that accommodates a blood vessel, nerve, or tendon
ex. intertubercular sulcus of the humerus

Question 14

Meatus

Answer 14

tubelike opening

ex. external and internal auditory meati of the temporal bone

Question 15

Processes that Form Joints

Answer 15

projections or outgrowths that help form joints

1. Condyle: large round protuberance with a smooth articular surface at the end of a bone
2. Facet: smooth, flat, slightly concave or convex articular surface
3. Head: usually rounded articular projection supported on the neck of a bone

Question 16

Processes that Form Attachment Points for Connective Tissues

Answer 16

1. Crest
2. Epicondyle
3. Line
4. Spinous Processes
5. Trochanter
6. Tubercle
7. Tuberosity

Question 17

Bone Tissue Cell Types

Answer 17

1. Osteogenic cell: develops into an osteoblast
2. Osteoblast: forms bone matrix
3. Osteocyte: maintains bone tissue
4. Osteoclast: functions in reabsorption, the breakdown of bone matrix (limit growth)

Question 18

Compact Bone

Answer 18

bone surface, high density; contains small spaces, concentric layers near surface, concentric circles or rings (osteons) deeper

Question 19

Spongy Bone

Answer 19

bone interior, low density; large spaces visible to the naked eye, lamellae arranged into thin columns (trabeculae)
- red bone marrow and yellow bone marrow stored

Question 20

Periosteal Arteries

Answer 20

small arteries accompanied by nerves, enter the diaphysis and supply the periosteum and outer part of compact bone with blood

Question 21

Nutrient Artery

Answer 21

enters the diaphysis through the nutrient foramen, and carries blood into proximal and distal regions of the medullary cavity

Question 22

Metaphyseal and Epiphyseal Arteries

Answer 22

• enter the metaphyses of a long bone and together with the nutrient artery, supply red bone marrow and bone tissue of the matephyses
• enter the epiphyses of a long bone and supply red bone marrow and bone tissue of the epiphyses

Question 23

Periosteal Veins

Answer 23

drain blood from the periosteum and outer layers of compact bone

Question 24

Nutrient Veins

Answer 24

accompany respective arteries and drain blood from the proximal and distal regions of the medullary cavity

Question 25

Metaphyseal and Epiphyseal Veins

Answer 25

drain blood from the ends of long bones and the red bone marrow