Ch 6, 4 Bone structure Flashcards Preview

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

bone markings

A

bulges, depressions and holes serve as

  • types of attachment for muscles, ligaments, and tendons
  • joint surfaces
  • conduits for blood vessels and nerves
2
Q

bone textures

A

compact bone–dense outer layer made up of osteons

spongy (cancellous) bone– inner core, honeycomb of trabeculae

3
Q

structure of a long bone

diaphysis shaft

A
  • compact bone forms outer layer
  • spongy bone forms inner core around medullary cavity
  • medullary cavity in adults contains yellow marrow-fat
4
Q

long bone structure

epiphyses

A

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

5
Q

epiphyseal line

A

remnant growth plate (cartilage line)

6
Q

articular cartilage

A

hyaline, on joint surfaces

protects bone ends

7
Q

periosteum membrane

A

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
Q

endosteum membrane

A

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

9
Q

nutrient foramen membrane

A

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

10
Q

sharpeys membrane

A

collagen fibers that attach periosteum to bone

11
Q

structure of short, irregular and flat bone

A

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
Q

location of hematopoietic tissue (red marrow)

A

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
Q

osteogenic cells

A

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

14
Q

osteoblasts

A
  • bone forming cells
  • divide by mitosis then specialize
  • produces matrix
15
Q

osteocytes

A
  • 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
Q

osteoclasts

A
  • 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
Q

haversian system or osteon

histology of compact bone

A

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
Q

perforating (Volkmann’s) canals

histology of compact bone

A

at right angles to the central canal

connects blood vessels and nerves of the periosteum and central canal

19
Q

lacunae

compact bone

A

small cavities that contain osteocytes

20
Q

canaliculi

compact bone

A

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

21
Q

circumferential lamellae

compact bone

A

encloses whole bone

resist twisting force

22
Q

trabeculae

spongy bone

A

align along lines of stress

23
Q

spongy bone

A
  • contain irregularly arranged lamellae, osteocytes and canaliculi
  • contain capillaries in endosteum supply nutrients
24
Q

organic components

A

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
Q

inorganic compounds

A

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