Osseous Tissue and Skeletal Structure

Question 1

What are the 5 functions of the skeletal system

Answer 1

1. Support
2. Storage of minerals
3. Blood cell production
4. Protection
5. Movement

Question 2

Explain what a long bone is give examples

Answer 2

Relatively long and slender greater in length and width

Arm, forearm, thigh, legs, fingers, toes

Question 3

Explain what a short bone is give examples

Answer 3

Cube like greater in width then length

Wrist and ankle bones

Question 4

Explain what a flat bone is and give examples

Answer 4

Thin and flat sternum, skull bones, ribs

Question 5

Explain what an irregular bone is and give examples

Answer 5

Complex shapes

Sphenoid bone, ethmoid bone, temporal bone, vertebrae, os coxae(pelvis)

Question 6

Explain what a sesamoid bone is give example

Answer 6

“Sesame seed” shaped

Patella

Question 7

Explain what a sutural bone is give examples

Answer 7

Small flat & irregularly shaped

Located between flat bones of skull

Question 8

In the structure of a long bone what are the epiphysis?

Answer 8

The ends of the bone

Question 9

In the structure of a long bone what is the diaphysis?

Answer 9

Long middle part of the bone

Question 10

What kind of cartilage is found at the epiphysis of a long bone where the joint would be found?

Answer 10

Articular cartilage

Question 11

What is the periosteum of a long bone what are its three main functions?

Answer 11

Surrounds bone made of fibrous and cellular layer

1. Protection
2. Growth and repair
3. Provides route for blood vessel entry

Question 12

What is the endosteum of a long bone where is it found?

Answer 12

Lines marrow cavity connective tissue and cells growth repair

Question 13

Explain what the marrow cavity of a long bone is what does it contain?

Answer 13

“Medullary” contains yellow marrow= fat

Question 14

Explain what spongy bone is where do you find it in a long bone?

Answer 14

Cancellous and trabecular porous contains red marrow found in ends of long bone

Question 15

Explain what compact bone is where do you find it in a long bone?

Answer 15

Dense smooth bone surrounds bone deep to periosteum

Question 16

What is the structure of flat, short, and irregular bones?

Answer 16

Spongy bone sandwich
Compact bone
Spongy bone
Compact bone

Question 17

What does bone histology mean?

Answer 17

The microscopic structure of bone

Question 18

What is the basic functional unit of mature compact bone

Answer 18

The osteon

Question 19

An arrangement of osteocytes in lacunae in concentric circles is a ___

Answer 19

Osteon or haversian system

Question 20

The central canal of an osteon contains what?

Answer 20

Contains blood vessels and nerves

Question 21

The osteocyte in an osteon is located in the ___

Answer 21

In lacunae

Question 22

In an osteon what is the canaliculi?

Answer 22

Small passageways that link lacunae to the Haversian canal

Question 23

In an osteon what are the lamellae?

Answer 23

Matrix rings

Question 24

Spongy bone forms struts and plates called ___

Answer 24

Trabeculae

Question 25

What are volkmans canals?

Answer 25

Perforating canal runs horizontally

Question 26

If a Haversian canal becomes blocked with age, how would this affect the osteocyte?

Answer 26

Osteocytes would die b/c lack of nutrients

Question 27

What is an osteoclast?

Answer 27

Multinucleate cell that secretes acids and enzymes to dissolve bone matrix *cells that chew bone (break it down )

Question 28

What is an osteoprogenitor cell?

Answer 28

Stem cell whose divisions produce osteoblasts bone stem cells

Question 29

What is an osteoblast?

Answer 29

Immature bone cell that secretes organic components of matrix (bone builders)

Question 30

What is an osteocyte? Where is it located? What does it maintain?

Answer 30

Mature bone cell that maintains the bone matrix Housed in lacunae Maintains protein and mineral content of bone

Question 31

How much of the bone composition is made of cells?

Answer 31

About 2%

Question 32

Is the matrix of cells abundant or non-abundant?

Answer 32

Matrix

Question 33

What are the inorganic components of bone? What does it provide to the bone flexibility or strength?

Answer 33

Calcium & phosphorus salts Hydroxyapatites ~65% Provides strength to bone matrix

Question 34

What are the organic components of bone? What does it provide to the bone flexibility or strength?

Answer 34

Carbon and hydrogen Collagen fibers ~35% Tough yet flexible provides tolerance to distortion

Question 35

When does bone formation= ossification occur?

Answer 35

~6 weeks after fertilization

Question 36

What are the two types of bone formation?

Answer 36

Intra-membranous ossification | Endochondral ossification

Question 37

How many steps are there to intra-membranous ossification?

Answer 37

4

Question 38

Explain the first step of intra membranous ossification

Answer 38

1. Ossification center formed in fibrous membrane

Question 39

Break down the first step of intra membranous ossification into 3 steps what's the first step

Answer 39

A. Embryonic cells cluster in the fibrous membrane and form matrix by secreting collagen fibers

Question 40

Break down the first step of intra membranous ossification into 3 steps what is the 2nd step

Answer 40

B. the embryonic cells develop into osteoblasts

Question 41

Break down the first step of intramembranous ossification into 3 steps what is the 3rd step

Answer 41

C. This group of osteoblasts forms an ossification center

Question 42

Explain the 2nd step of intramembranous ossification

Answer 42

Osteocytes deposit mineral salts

Question 43

Break down the second step of intramembranous ossification into 2 steps what is the first step?

Answer 43

A. Osteoblasts develop into osteocytes osteocytes deposit calcium salts in matrix (calcification)

Question 44

Break down the second step of intramembranous ossification into 2 steps what is the second step

Answer 44

Blood vessels penetrate to provide nutrients

Question 45

Explain the 3rd step of intramembranous ossification

Answer 45

Formulation of trabeculae

Question 46

Break down the 3rd step of intramembranous ossification into 2 steps what is the first step

Answer 46

Bony plates called trabeculae grow from the ossification center into the matrix

Question 47

Break down the 3rd step of intramembranous ossification into 2 steps what is the second step?

Answer 47

Blood vessels may become trapped

Question 48

Explain the 4th step of intramembranous ossification

Answer 48

Periosteum surrounds the entire bone

Question 49

Break down the 4th step of intramembranous ossification into 2 steps what is the first step

Answer 49

Spongy bone is formed initially and is remodeled to produce compact bone

Question 50

Break down the 4th step of intramembranous ossification into 2 steps what is the second step?

Answer 50

Periosteum develops around the bone

Question 51

What is the key point of intramembranous ossification

Answer 51

Bones are built from a fibrous connective tissue membrane

Question 52

What is endochondral ossification

Answer 52

How long bones are formed

Question 53

What is the key point of endochondral ossification?

Answer 53

Bones are built from a hyaline cartilage model

Question 54

How many steps are there to endochondral ossification?

Answer 54

5

Question 55

What is the first step of endochondral ossification

Answer 55

1. Cartilage model enlarges

Question 56

What is the second step of endochondral ossification?

Answer 56

Blood vessels grow around edges

Question 57

What is the third step of endochondral ossification?

Answer 57

Invasion of vessels and formation of marrow cavity. Primary ossification center formed in diaphysis.

Question 58

Explain the 4th step of endochondral ossification

Answer 58

Secondary ossification centers formed in epiphysis ~time of birth for some bones Marrow cavity created as osteoclasts become active

Question 59

Explain the 5th step of endochondral ossification

Answer 59

Remaining cartilage

Question 60

How do bones grow in width what is this called?

Answer 60

Appositional growth | Cells of the periosteum- osteoblasts add layers of bone

Question 61

How do bones grow in length what is it called?

Answer 61

Epiphyseal growth on epiphyseal plate

Question 62

What is the difference between the epiphyseal line and the epiphyseal line?

Answer 62

The epiphyseal line is when the growth in length has completely stopped

Question 63

What is the age at which bone growth in length ends?

Answer 63

18-25 years

Question 64

Why does bone growth in length end? How?

Answer 64

Epiphyseal cartilage has closed and formed the epiphyseal line b/c bone production became greater than cartilage growth

Question 65

Dealing with the dynamic nature of bone when components are recycled and renewed during life it allows for changes in what?

Answer 65

In shape and adjustment to stress

Question 66

Dealing with the dynamic nature of bone, bone is deposited by ____ and reabsorbed by _____

Answer 66

Osteoblasts | Osteoclasts

Question 67

How does nutrition affect bone growth? What are some of the vitamins?

Answer 67

Calcium and phosphorus Vitamin D: necessary for absorption of Ca2+ in gut Vitamin A, C, K, B12: stimulates osteoblasts of protein synthesis

Question 68

How does growth hormone effect bone growth?

Answer 68

Promotes growth of bone by stimulating osteoblasts

Question 69

How does the thyroid hormone affect bone growth?

Answer 69

Promotes bone growth by stimulating osteoblasts

Question 70

How does the sex hormone affect bone growth?

Answer 70

Testosterone & estrogen stimulate bone growth

Question 71

How does the hormone calcitonin affect bone growth?

Answer 71

Works to decrease blood Ca2+ levels by stimulating osteoblasts

Question 72

How does the parathyroid hormone affect bone growth?

Answer 72

Works to increase blood Ca2+ levels by stimulating osteoclasts

Question 73

How does exercise bone growth?

Answer 73

Stimulates bone growth