Ch 6, 4 Bone structure Flashcards Preview

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Flashcards in Ch 6, 4 Bone structure Deck (25):
1

bone markings

bulges, depressions and holes serve as
-types of attachment for muscles, ligaments, and tendons
-joint surfaces
-conduits for blood vessels and nerves

2

bone textures

compact bone--dense outer layer made up of osteons
spongy (cancellous) bone-- inner core, honeycomb of trabeculae

3

structure of a long bone
diaphysis shaft

-compact bone forms outer layer
-spongy bone forms inner core around medullary cavity
-medullary cavity in adults contains yellow marrow-fat

4

long bone structure
epiphyses

--expanded ends
proximal-end towards main body mass
distal-end away from main body mass
--has spongy bone interior containing red marrow cavities

5

epiphyseal line

remnant growth plate (cartilage line)

6

articular cartilage

hyaline, on joint surfaces
protects bone ends

7

periosteum membrane

connective tissue membranes encloses outside of bone
-has outer fibrous layers
-inner osteogenic layer-bone forming layer
-contains..
osteoblasts-bone forming cells
osteoclasts-bone destroying cells
osteogenic cells- stem cells

8

endosteum membrane

delicate connective tissue membrane on inside surfaces of bone
-also contains osteoblasts and osteoclasts

9

nutrient foramen membrane

(formina) openings in periosteum where blood vessels, lymph vessels and nerves enter bones

10

sharpeys membrane

collagen fibers that attach periosteum to bone

11

structure of short, irregular and flat bone

like a sandwich
-compact bone covered with periosteum on both surfaces
-spongy bone covered with endosteum in the center-spongy bone layer called diploe
-red bone marrow between the trabeculae

12

location of hematopoietic tissue (red marrow)

in adults
-in trabecular cavities of heads of femur and humerous
-in trabecular cavities of the diploe of flat bones
-sternum and pelvis
in newborn infants
-in medullary cavities of long bones
-in all spaces of spongy bone

13

osteogenic cells

stem cells in periosteum and endosteum that gives rise to osteoblasts
-un specialized

14

osteoblasts

-bone forming cells
-divide by mitosis then specialize
-produces matrix

15

osteocytes

-as matrix develops around the osteoblasts they mature into osteocytes
-mature bone cells trapped inside cavities in the bone called lacunae
-maintains the health of the bone

16

osteoclasts

-unrelated to the other 3
-they are macrophages (WBCs) that break down (resorb) bone by secreting enzymes that break down the matrix and release minerals into the blood

17

haversian system or osteon
histology of compact bone

lamellae-
weight bearing, column-like matrix tubes
produced by a ring of osteoblasts(like tree rings)
collagen fibers run in different directions in adjacent lamella--increases strength

Central (haversian) cord-
contains the blood vessels and cords

18

perforating (Volkmann's) canals
histology of compact bone

at right angles to the central canal
connects blood vessels and nerves of the periosteum and central canal

19

lacunae
compact bone

small cavities that contain osteocytes

20

canaliculi
compact bone

hair like canals that connect lacunae to each other and the central canal

21

circumferential lamellae
compact bone

encloses whole bone
resist twisting force

22

trabeculae
spongy bone

align along lines of stress

23

spongy bone

-contain irregularly arranged lamellae, osteocytes and canaliculi
-contain capillaries in endosteum supply nutrients

24

organic components

a. osteogenic cells, osteoblasts, osteocytes, osteoclasts
b. osteoid-organic bone matrix secreted by osteoblasts (35% of bone mass)
contains proteoglycans, glycoproteins and collagen fibers
c. provides tensile strength and flexibility
d. resists stretching and twisting

25

inorganic compounds

a. hydroxyapatites (mineral salts)
b. 65% bone mass
c. Mainly calcium phosphate crystals
d. provides hardness and resistance to compression