Chapter 6 Bone Tissue

Question 0

Structure of a long bone

Define diaphysis

Answer 0

Shaft of the bone

Question 1

What are the 6 important functions of the skeletal system?

Answer 1

1. Support. 2. Protection. 3. Assists in body movement
2. Stores and releases salts of calcium and phosphorous
3. Participates in blood cell production (hemopoiesis)
4. Stored triglycerides in adipose cells of yellow marrow

Question 2

Structure of a long bone

Define epiphyses

Answer 2

Both ends of the bones at the joints.

Question 3

Structure of a long bone

Define metaphyses

Answer 3

Region between diaphysis and epiphyses

Question 4

Structure of a long bone

Define periosteum

Answer 4

Connective tissue surrounding the diaphysis

Question 5

Structure of a long bone

Define medullary cavity

Answer 5

Hollow space within diaphysis

Question 6

Structure of a long bone

Define endosteum

Answer 6

Thin membrane lining the medullary cavity

Question 7

Bones contain 4 types of cells
Define osteoprogenitor cells
Osteoblasts
Osteocytes
Osteoclasts

Answer 7

Osteoprogenitor - bone stem cells, differentiate
Osteoblasts - bone-building cells that secrete matrix
Osteocytes - mature bone cells
Osteoclasts - remodel bones and cause them to release calcium

Question 8

Define compact bone

Answer 8

Provides protection and support

Question 9

Define spongy bones

Answer 9

Lightweight and provides tissue support

Question 10

Periosteal arteries and veins enter the _______ through _________ ___________.

Answer 10

The diaphysis through Volkmann’s canals

Question 11

Nutrient artery enters the center of the _________ through a ________ __________. Nutrient veins exit the same canal.

Answer 11

Diaphysis through a nutrient Foramen.

Question 12

What is ossification/osteogenesis?

Answer 12

The process of bone formation.

Question 13

What 4 situations do bones form?

Answer 13

1. During embryological and fetal development
2. When bones grow before adulthood
3. When bones remodel
4. When fractures heal

Question 14

Ossification takes place in 2 forms.

Answer 14

Intramembranous and endochondral

Question 15

When does intramembranous ossification occur?

Answer 15

In flat bones when a connective tissue membrane is replace by bone.

Question 16

When does endochondral ossification occur?

Answer 16

It replaces cartilage with bone in a developing embryo and fetus.
Also occurs epiphyseal plates of long bones as they grow in length.

Question 17

What cells cause bones to thicken?

Answer 17

Osteoblasts and osteoclasts

Question 18

What are the 3 different phases and 4 steps involved in the healing process of a fracture?

Answer 18

Reactive phase - the early inflammatory phase
Reparative phase - formation of a fibrocartilaginous callus first, bony callus second
Bone remodeling phase - last step as the bony callus is remodeled

Question 19

Some common fractures include…

Answer 19

Open (compound) - bone presses against or through skin
Comminuted - little pieces of bone between fracture
Green stick - happens in children, one side breaks, the other bends
Impacted - top portion impacts into bottom portion
Potts - break of the distal end of the fibula
Coles - break in the distal radius with posterior displacement

Question 20

Bones store ____% of the body’s calcium. The parathyroid gland secretes ____________ when calcium levels drop. This causes ________ to stimulate and increase bone resorption and ________ is released. Also stimulates the production of _________ by the kidneys to increase calcium absorption in the intestines.

Answer 20

99% 
Parathyroid hormone (PTH) 
Osteoclasts 
Calcium 
Calcitriol

Question 21

Older individuals, especially post-menopausal women, experience a ___________ in bone mass when _______ outpaces _______.

Answer 21

Decrease in bone mass when resorption outpaces deposition