BS: The Gross Structure

Question 1

Bone structure has three levels:

Answer 1

1. gross
2. microscopic
3. chemical

Question 2

Dense outside layer […] surrounds the inside […].

Answer 2

compact; spongy

Question 3

Internal to the spongy bone (also known as trabecular bone) lies…

Answer 3

trabeculae– honeycomb of small flat pieces

Question 4

What is in between trabeculae?

Answer 4

red or yellow marrow

Question 5

For flat bones […] bone sandwiches […].

Answer 5

spongy; compact

Question 6

Which bones share a simple pattern?

Answer 6

1. short
2. irregular
3. flat

Question 7

What are the 4 parts of the simple pattern short/irregular/flat bones?

• sif bones

Answer 7

compact bone covers spongy

spongy contains bone marrow between trabeculae but no defined cavity

bone is covered in and out by connective tissue membranes

joints covered by hyaline cartilage

Question 8

Thin plates of spongy bone also known as…

Answer 8

diploe

Question 9

The connective tissue membranes of sif bones?

Answer 9

periosteum (outside) and endosteum (inside)

Question 10

LB: What is the general structure of long bones?

Answer 10

a shaft, bone ends, and membranes

Question 11

LB: A tubular […], also known as the shaft, forms the long […] of the bone.

Answer 11

diaphysis; axis

Question 12

LB: The thick collar of […] bone surrounds a central […] cavity or […] cavity.

Answer 12

compact; medullary; marrow

Question 13

LB: What are the bone ends?

Answer 13

epiphyses

Question 14

LB: What forms the epiphyses?

Answer 14

compact bone extension (exterior)

spongy bone (interior)

Question 15

LB: What covers the surface of the epiphyses?

Answer 15

thin layer of articular/hyaline cartilage

Question 16

LB: What is the purpose of the articular/hyaline covering?

Answer 16

cushioning during movement and absorbing stress

Question 17

LB: Between the diaphysis and each epiphysis is an […] line.

Answer 17

epiphyseal

Question 18

LB: The epiphyseal plate is located…

Answer 18

at the junction of the epiphyseal and diaphysis

Question 19

LB: The epiphyseal plate ([…] plate), is a disc of […] cartilage that grows during childhood.

Answer 19

growth; hyaline

Question 20

LB: The flared middle portion of the bone where the diaphysis and epiphysis meet

Answer 20

metaphysis

Question 21

LB: Periosteum covers the […] surface EXCEPT the […] surfaces.

Answer 21

external; joint

Question 22

LB: The periosteum/endosteum has two layers:

Answer 22

fibrous (outer)

osteogenic (inner)

Question 23

LB: The fibrous outer layer of the periosteum is […] connective tissue.

Answer 23

dense

Question 24

LB: The inner periosteum layer contains what type of cells?

Answer 24

osteoprogenitor cells (osteogenic)
osteoclasts
osteoblasts

Question 25

LB: What are the osteoprogenitor cells?

Answer 25

primitive stem cells give rise to most bone cells

Question 26

LB: Why are broken bones so painful?

Answer 26

The periosteum is richly supplied with nerve fibers and blood vessels

Question 27

LB: The periosteum also provides [...] points for tendons/ligaments.

Answer 27

anchoring

Question 28

LB: What are perforating fibers? Where can you find them?

Answer 28

bundles of collagen fibers that secure the layer to the bone by extending to the matrix in the periosteum layer perforating: pierce/make holes

Question 29

LB: The endosteum covers [...] bone surface both spongy and compact.

Answer 29

internal

Question 30

LB: What cells are within the endosteum?

Answer 30

the same as the periosteum

Question 31

What are the main vessels serving the diaphysis?

Answer 31

nutrient artery and nutrient vein

Question 32

Where do the blood vessels and nerves run through?

Answer 32

nutrient foramen-- an opening in the diaphysis wall

Question 33

Pathway of blood and nerve vessels:

Answer 33

diaphysis---nutrient foramen---bone marrow/spongy bone---branches to compact

Question 34

Red marrow also known as...

Answer 34

hematopoietic (blood forming tissue)

Question 35

Where do children house red marrow?

Answer 35

the medullary cavity of the diaphysis and all areas of spongy bone

Question 36

Where do adults house red marrow?

Answer 36

small amount in between trabeculae

Question 37

Why is there little red marrow within the long bones of an adult?

Answer 37

most of it has been replaced by yellow marrow

Question 38

In which bones can you find red marrow?

Answer 38

LB: femur and humerus FB: skull, sternum, ribs, clavicles, scapulae IB: hip bones and vertebrae

Question 39

How can an adult revert to red marrow?

Answer 39

if they become anemic

Question 40

Bone marking can fit into 3 categories:

Answer 40

1. projections 2. surfaces 3. depressions/opening

Question 41

Projections:

Answer 41

site of muscle and ligament attachment

Question 42

Surfaces:

Answer 42

form joints

Question 43

Depressions/openings:

Answer 43

for blood/nerve vessels

Question 44

What are the 5 major cell types:

Answer 44

1. osteoprogenitor 2. osteoblasts 3. osteoclasts 4. bone lining cells 5. osteocytes

Question 45

All of these except for the [...] originate from embryonic connective tissue cells.

Answer 45

osteoclasts

Question 46

What is the process remodeling?

Answer 46

cells continuously resorb and deposit

Question 47

In growing bones, [...] cells are flattened or squamous.

Answer 47

osteogenic

Question 48

When osteogenic cells are stimulated, some of these cells turn to [...].

Answer 48

osteoblasts

Question 49

Osteoblasts secretions includes:

Answer 49

1. collagen (90%) | 2. calcium-binding proteins

Question 50

What do calcium-binding proteins create?

Answer 50

the initial, un-mineralized bone (osteoid)

Question 51

Matrix calcification is done by [...] cells.

Answer 51

osteoblasts

Question 52

Osteocytes occupy what spaces?

Answer 52

lacunae

Question 53

What are the 3 function of osteocytes?

Answer 53

maintain and monitor bone matrix respond to mechanical stimuli trigger bone remodeling

Question 54

Osteocyte trigger bone remodeling due to mechanical [...] or to maintain [...] homeostasis.

Answer 54

stress; calcium

Question 55

Where can you find bone lining cells?

Answer 55

on surfaces where bone remodeling is not going on

Question 56

What is the purpose of bone lining cells?

Answer 56

maintain the matrix

Question 57

Osteoclasts are giant [...] cells located at sites of bone [...].

Answer 57

multinucleate; resorption

Question 58

Where are osteoclasts derived from?

Answer 58

WBC lineage that creates macrophages

Question 59

Osteoclasts lie in a shallow [...].

Answer 59

depression

Question 60

Osteoclasts have a distinct [...] border that [...] contacts the bone.

Answer 60

ruffled; directly

Question 61

What is the purpose of the osteoclasts ruffled border?

Answer 61

plasma membrane infoldings increase surface area for enzymatically degrading bones

Question 62

The structural unit of compact bone is [...] which is parallel to the long [...] of the bone.

Answer 62

osteon; axis

Question 63

What is the function of osteons?

Answer 63

tiny weight-bearing pillars

Question 64

What is the matrix tube of osteons called?

Answer 64

lamella

Question 65

Osteon's design as a "twister resister" is due to what?

Answer 65

collagen fibers running in different directions to withstand torsional stresses

Question 66

How can collagen fibers within lamella alternate their direction?

Answer 66

tiny crystals of bone lamellae

Question 67

What is in the core of each osteon?

Answer 67

central canal (Haversian canal)

Question 68

What does the core of each osteon contain?

Answer 68

small blood vessels and nerve fibers (serve the cells)

Question 69

Osteon canals of a second type called [...] canals or Volkmann's canals.

Answer 69

perforating

Question 70

Perforating canals lie at [...] angles to the long axis of the bone. They connect [...] and [...] supply of the [...] cavity to central canals.

Answer 70

right; blood vessels; nerve fibers; medullary

Question 71

Perforating canals are not surrounded by [...].

Answer 71

lamellae

Question 72

Osteocytes occupy [...] at the junctions of lamellae.

Answer 72

lacunae

Question 73

Hairlike canals called [...] radiate from the [...] connecting them to each other and to the central canal/

Answer 73

canaliculi; lucanae

Question 74

Osteon = [...]

Answer 74

Haversian System

Question 75

What is the structural unit of compact bone?

Answer 75

osteon

Question 76

Lamellae:

Answer 76

compact bone matrix consisting of a cylinder with many rings

Question 77

What contributes to the hardness of bone?

Answer 77

hydroxyapatite-- makes 65% of the mass

Question 78

What are the inorganic components of the bone matrix?

Answer 78

hydroxyapatite