CHAPTER 6- BONES AND SKELETAL TISSUE

Question 1

hyaline cartilages

Answer 1

provide support, flexibility, and resilience. most abundant type.

in: cargilage in nose and ribs

Question 2

elastic cartilages

Answer 2

similar to hyaline cartilages, but contain elastic fibers.

Question 3

fibrocartilages

Answer 3

collagen fibers- have great tensile strength.

in: between vertebral disks, meniscus, and pubic bones

Question 4

skeletal cargilage

Answer 4

heals cery sloww

Question 5

growth of cartilage

Answer 5

1. appositional
2. interstitial

Question 6

calcification of cartilage occurs during…

Answer 6

• normal bone growth
• old age

Question 7

apposition growth of cartilage

Answer 7

chondroblasts secrete matrix against the EXTERNAL force of existing cartilage

Question 8

interstitial growth of cartilage

Answer 8

chondrocytes divide and secrete new matrix, expanding cartilage from WITHIN

Question 9

bones of the skeleton

Answer 9

two main groups, by location:
- axial skeleton (ribs, vertebrae, skull- right down axis)
- appendicular skeleton (all limbs + pelvis & os coxa)

Question 10

classification of bones by shape

Answer 10

• long bones (longer than wide)
• short bones (cube shaped- in wrist and ankle; sesamoid bones (in tendons- like patella)
• flat bones (slightly curved- sternum)
• irregular bones (complicated shapes- vertabrae)

Question 11

function of bones

Answer 11

support
- for body and soft organs
protection
- for brain, spinal cord, and organs
movement
- levers for muscle action

Question 12

functions of bones cont…

Answer 12

storage
- minerals (calcium and phosphorous) and growth factors
blood cell formation
- (hematopoiesis) storage in bone cavities
*triglyceride (energy) storage in bone cavities

Question 13

bone markings: bulges, depressions, and holes serve as…

Answer 13

• sites of attachment for muscles, ligaments, and tendons
• joint surfaces
  -conduits for blood vessels and nerves

Question 14

bone markings: projections

Answer 14

projections that help to form joints:
head
- bony expansion carried on narrow neck
facet
- smooth, nearly flat articular surface
condyle
- rounded articular projection
ramus
- armlike bar

Question 15

bone markings: depressions and openings

Answer 15

meatus
- canal-like passageway
sinus
- cavity within a bone
fossa
- shallow, basinlike depression
groove
- furrow
fissure
- narrow, slitlike opening
foramen
- round or oval opening through a bone

Question 16

bone textures

Answer 16

compact bone
- dense outer layer
spongy bone
- honeycomb of trabeculae

Question 17

structure of a long bone- diaphysis

Answer 17

diaphysis (shaft)
- compact bone collar surrounds medullary (marrow) cavity
- medullary cavity in adults contains fat (yellow marrow)

Question 18

structure of a lone bone- epiphyses

Answer 18

epiphyses
- expanded ends
- spongy bone interior
- epiphyseal line (or growth plate, if cartilage)
- hyaline cartilage on joint surfaces

Question 19

membranes of bone- periosteum

Answer 19

periosteum:
1. outer fibrous layer
2. inner osteogenic layer
- osteoblasts (bone-forming cells)
- osteoclasts (bone-destroying cells)
- osteogenic cells (stem cells)

2. nerve fibers, blood vessels, and lymphatic vessels enter the bone via nutrient foramina
3. periosteum secured to underlying bone by perforating fibers

Question 20

membranes of bone- endosteum

Answer 20

endeosteum:
- delicate membrane on internal surfaces of bone
- also contains osteoblasts and osteoclasts

Question 21

structure of short, irregular, and flat bones

Answer 21

1. periosteum- covered compact bone on the outside
2. endosteum-covered spongy bone within
3. spongy bone called diploe in flat bones
4. bone marrow between trabeculae

Question 22

location of hematopoietic tissue (red marrow)

Answer 22

red marrow cavities of adults:
- trabecular cavities of the heads of the femur and humerus
- trabecular cavities of the diploe of flat bones
red marrow of newborn infants:
- medullary cavities and all spaces in spongy bone

Question 23

microscopic anatomy of bone

Answer 23

cells of bones:
osteogenic cells
- stem cells in periosteum and
endosteum that give rise to osteoblasts
osteoblasts
- bone-forming cells
osteocytes
- mature bone cells
osteoclasts
- cells that break down (resorb) bone
matrix
- involved in bone repair

Question 24

microscopic anatomy of bone: compact bone

Answer 24

perforating canals
- perpendicular to central canal
- connects blood vessels and nerves of periosteum and central canal

lacunae- small cavities that contain osteocytes

canaliculi- hairlike canals that connect lacunae to each other and the central canal

Question 24

microscopic anatomy of bone: compact bone

Answer 24

perforating canals
- perpendicular to central canal
- connects blood vessels and nerves of periosteum and central canal

lacunae- small cavities that contain osteocytes

canaliculi- hairlike canals that connect lacunae to each other and the central canal

Question 25

microscopic anatomy of bone: spongy bone

Answer 25

trabeculae
- align along lines of stress
- no osteons
- contain irregularly arranged lamellae, osteoctytes, and canaliculi
- capillaries in endosteum supply nutrients

Question 26

chemical composition of bone: organic

Answer 26

cells
- osteogenic (stem) cells, osteoblasts, osteocytes, osteoclasts
*once a bone cell is in a lacuna, it’s an osteocyte

osteoid: organic bone matrix secreted by osteoblasts
- ground substance (proteoglycans, glycoproteins)
- collagen fibers (provide tensile strength and flexibility)

Question 27

chemical composition of bone: inorganic

Answer 27

hydroxyapatites (mineral salts that make up bone)
- 65% of bone by mass
- mainly calcium phosphate crystals
-responsible for hardness and resistance to compression

Question 28

cartilage most abundant in the fetus

Answer 28

hyaline cartilage

Question 29

cartilage most abundant in adults

Answer 29

hyaline cartilage