Anatomy- Bone Histology and Physiology

Question 1

What is bone made out of?

Answer 1

Connective Tissue

Question 2

What three types of Cells do bones have?

Answer 2

Osteoblasts, Osteoclasts, and Osteocytes

Question 3

What is the main function of Osteoblasts?

Answer 3

Osteoblasts build bone and they’re immature bone cells

Question 4

What are 2 traits of Osteocytes?

Answer 4

-Mature bone surrounded by bone matrix
-House in the Lacuna

Question 5

What are 3 traits of Osteoclasts?

Answer 5

-They’re very large cells
-They’re cells that break down bone
-“blasts build, Clasts Kill”

Question 6

Why do we need Osteoclasts?

Answer 6

-balance Ph
-Balance blood calcium
-to get rid of old bone

Question 7

What is the bone matrix made out of?

Answer 7

-Collagen (protein) 30%
-Salts

Question 8

What strength does collagen provide to a bone?

Answer 8

-provides tensile strength like a rope

Question 9

What are most of the salts that make up the bone matrix?

Answer 9

Most salts are Calcium salts in the form of Hydroxyapatite
-salts in the bone provide compressive strength to bear body weight
-if you didn’t have salts in the bone it would be flexible

Question 10

Why would someones bone break?

Answer 10

-insufficient amount of vita D., Leading to rickets
-Calcium Consumption
-Age
-Use it or lose it

Question 11

What is the difference between cancellous and compact bone?

Answer 11

-Cancellous more spongy, has red bone marrow in it, and has osteoclasts, Osteoblasts, and Osteocytes
Compact more is more organized.
-Osteons
-Central canal (red dot through the middle/blood vessel)
-Interestital lamallae (line outside the Osteon)
-Concentric Lamellae (big circles within the Osteon)
-Canaliculi (Spider leg projections)

Question 12

What does the Canaliculi do?

Answer 12

-Connects to Osteocytes
-Microscopic
-Contains Fluid
-Communication between osteocytes

Question 13

What happens during appositional bone growth?

Answer 13

-The bone gets wider
-Occurs in the Diaphysis
-Growth Hormones
-The medullary cavity grows, but compact material does not get thicker

Question 14

What are some causes of Bone remodeling?

Answer 14

-Injury (fracturing a bone
-Growth (maturing)
-Stress (more bone needed when there’s stress
-Reshaped (spine)

Question 15

What happens in Osteoclastic activity?

Answer 15

2 ways to break down a bone
-Secretes acid (Dissolves Hydroxyapatite)
-Secretes Proteolytic (kills enzymes and proteins)
Takes 1 year and dissolves collagen

Question 16

Bone repair/how does a bone heal itself?

Answer 16

4 steps:
-Hematoma formation (blood floods to the injury site)
-Calloused formation(a mass of connective tissue connects to the ends of a broken bone
-Callus densities with cancellous bone?
-Connective to compact (some of the external cells remain)

Question 17

what are the Ossification process steps?

Answer 17

1. Chondrocytes = mitosis
   2.Old Chondrocytes will move to the diaphysis side of the growth plate
   3.Lacuna grows
   4.Calcium salts fill Lacuna
2. Chondrocytes die
   6.Blood vessels grow into the Lacuna
   7.Osteoblasts and Clasts work to ossify the bone
   8.The growth plate ossifies with hormonal changes