Histology Bone

Question 1

Process of Osteocyte Formation

Answer 1

Mesenchyme -> Osteoprogenitor Cells -> Osteoblast -> Osteocyte

Question 2

What is the Function of Osteoclasts?

Answer 2

Absorb Bone Cells

Question 3

What are Osteoclasts Regulated By?

Answer 3

Calcium Levels

Question 4

If Osteoblasts are Stimulated, Then _______

Answer 4

Calcium Levels Are Low

Question 5

If Osteoclasts are Stimulated, Then _____

Answer 5

Calcium Levels are High

Question 6

Characteristics of Trabeculae

Answer 6

No Central Canal, Red Bone Marrow Formation, Surrounded by Blood

Question 7

What is the Purpose of Canaliculi?

Answer 7

To Allow Communication Between Osteocytes

Question 8

The Skeletal System is Composed of:

Answer 8

Bones, Cartilage, and Joints

Question 9

How do nutrients actually get into bone?

Answer 9

From the Periosteum (blood vessels, nerves, etc…, penetrating the compact bone tissue through Perforating (Volkmann’s) Canals

Question 10

What do the Volkmann’s Canals connect?

Answer 10

The Medullary Cavity, Periosteum, and the Central (Haversian) Canals

Question 11

True or False: Bones in infants are rigid and hard.

Answer 11

False

Question 12

True or False: You can NOT tell the difference between Intramembranous Ossification and Endochondral Ossification after the bone is formed.

Answer 12

True

Question 13

Fontanels in an infant skull (soft spots) are composed of ______ and are eventually replaced by bone through _________.

Answer 13

Loose Fibrous Connective Tissue, Intramembranous Ossification

Question 14

Step 1 of Intramembranous Bone Formation:
At the site where bone will develop, _________ cluster together and differentiate into __________ and then into ___________.

Answer 14

Mesenchyme Cells, Osteoprogenitor Cells, Osteoblasts

Question 15

Step 2 of Intramembranous Bone Formation:
Matrix secretion stops and those cells become ____ and lie within ______

Answer 15

Osteocytes, Lacunae

Question 16

When matrix secretion stops, calcium and other minerals start to be deposited leading to ______

Answer 16

The matrix to be calcified

Question 17

Step 3 of Intramembranous Bone Formation:
As bone matrix starts to form, it develops into _______ that fuse with one another to form ______ bone with the appearance of __________.

Answer 17

Trabeculae, Precursor, Spongy Bone

Question 18

When mesenchyme cells start to condense on the outer surface of the developing bone forming ______.

Answer 18

The Periosteum (Dense Irregular Connective Tissue)

Question 19

Step 4 of Intramembranous Bone Formation:
The condensed mesenchyme develops into ______.

Answer 19

Periosteum

Question 20

What is Remodeling?

Answer 20

When surface layers of spongy bones are replaced by compact bone, leaving spongy bone in the center.

Question 21

What is Endochondral Bone Formation?

Answer 21

Replacement of Cartilage by Bone

Question 22

Step 1 of Endochondral Bone Formation:
Development of a _______. Where bone will form, ________ gather in the rough shape of future bone. Those cells differentiate into ______ that produce ______. A _______ develops around the cartilage structure.

Answer 22

Cartilage Precursor, Mesenchyme Cells, Chondroblasts, Hyaline Cartilage, Perichondrium

Question 23

Step 2 of Endochondral Bone Formation:
Cartilage grows by _____ cell division. A nutrient artery penetrates the ______, which is the start of bone formation. ________ in the perichondrium are stimulated to form _______

Answer 23

Continual, Perichondrium, Osteoprogenitor Cells, Ostepblasts

Question 24

Once the perichondrium starts to form bone, it is now called:

Answer 24

Periosteum

Question 25

Step 3 of Endochondral Bone Formation: Development of Primary Ossification - _______ grow into disintegrating cartilage and form the ______ center where _____ will replace most of the cartilage.

Answer 25

Capillaries, Primary Ossification, Bone Tissue

Question 26

Deposit bone matrix over the remnants of calcified cartilage.

Answer 26

Osteoblasts

Question 27

Step 3 of Endochondral Bone Formation (Continued): The ossification center _____ towards the ends of the bone.

Answer 27

Enlarges

Question 28

Break down former spongy bone areas leaving a new medullary cavity.

Answer 28

Osteoclasts

Question 29

Step 4 of Endochondral Bone Formation: The shaft (diaphysis), which was spongy bone, is replaced by ______ with a core of red bone marrow-filled ________.

Answer 29

Compact Bone, Medullary Cavity

Question 30

When do Secondary Ossification Centers develop?

Answer 30

When blood vessels enter the epiphyses (ends), Typically around the time of birth

Question 31

Step 5 of Endochondral Bone Formation: Within Secondary Ossification Centers, ______ remains in the interior of the ______ (no medullary cavity). ______ remains covering the epiphyses.

Answer 31

Spongy Bone, Epiphyses, Hyaline Cartilage

Question 32

What are the five zones of a plate of epiphyseal cartilage (starting from the epiphyseal side)?

Answer 32

Resting Zone, Proliferative Zone, Hypertrophic Zone, Calcified Zone, Ossification Zone

Question 33

True or False: Bone remodeling is a constant process even into adulthood.

Answer 33

True

Question 34

The rate of bone growth in children may be up to ____ times that of an adults.

Answer 34

200

Question 35

What is the process of healing bone after a fracture?

Answer 35

1. Blood vessels crossing the bone are broken. 2. Capillaries begin to grow into hematoma and organized tissue (Procallus) forms. 3. Osteoprogenitor cells begin to develop into osteoblasts which begin to produce new spongy bone that bridges the ends of the broken bone. 4. Remodeling of the Callus

Question 36

What is involved in the process of blood vessels being broken when a bone is fractured? - This process takes place 6-8 Hours after the Fracture occurs

Answer 36

Blood leaks into area and forms a clot (Fracture Hematoma), Hematoma serves as a focus of cellular invasion to help heal the fracture, White blood cells start to flow into the area to clean debris

Question 37

What processes take place during the phase that Procallus is formed? *Lasts about 3 Weeks

Answer 37

Fibroblasts begin to secrete collagen (helps joins fracture ends), Chondroblasts (Cartilage cells) lay down cartilage tissue and procallus, which is now Fibrocartilaginous (Soft) Callus

Question 38

When Osteoprogenitor cells begin to develop into osteoblasts, what else occurs? *Takes Roughly 3-4 Months

Answer 38

The callus is then referred to as a Bony (Hard) Callus

Question 39

What else is included in the remodeling of the callus?

Answer 39

Dead portions of the original fracture are gradually reabsorbed by osteoclasts, Compact bone replaces Spongy bone.

Question 40

What is Osteoporosis?

Answer 40

Condition where the basic problem is that bone reabsorption outpaces bone formation and the bones weaken.