Week 2 // Chapter 6 // Bone Tissue

Question 1

List functions of the skeletal system

PAGE 23 of 46

Answer 1

• Provides Support
• Protects internal organs
• Assists body movements (with muscles)
• Mineral homeostasis (calcium + phosphorus)
• Participates in blood cell production (hemopoiesis)
• Stores triglycerides in adipose cells of yellow marrow

Question 2

Bone is an organ made up of several different tissues working together.
Name the tissues

Answer 2

bone, cartilage, dense connective tissue, adipose, and nervous tissue

Question 3

Name the parts of a long bone

Answer 3

Long bones contain

Diaphysis (bone shaft), 2 epiphyses (both ends of the bone at the joints), 2 metaphyses (region between diaphysis and epiphysis), Articular cartilage covering both epiphyses, Periosteum (connective tissue surrounding the diaphysis), Medullary cavity (hollow space within diaphysis), Endosteum (thin membrane lining the medullary cavity)

Question 4

The long bone shaft is called a

Answer 4

Diaphysis

Question 5

The ends of the long bone are called the

Answer 5

epiphysis

Question 6

The region between the diaphysis (shaft) and epiphysis (end) is called the ______

Answer 6

metaphyses

(this is where bone growth occurs!)

Question 7

What covers both epiphysis in a long bone?

Answer 7

Articular cartilage

Question 8

The connective tissue surrounding the diaphysis is called the _______

Answer 8

Periosteum

Question 9

What is the hollow space within diaphysis and what does it contain?

Answer 9

The Medullary cavity contains the yellow bone marrow

Question 10

This lines the medullary cavity

Answer 10

The Endostium

Question 11

Spongy bone vs. Compact Bone

Answer 11

• Compact bone is good at providing protection and support; strongest
• Spongy bone is lightweight and provides tissue support; also called trabecular or cancellous bone

Question 12

What are the 4 types of bone cells?

Answer 12

• Osteoprogenitor cells (bone stem cells able to differentiate into the other types of cells)
• Osteoblasts (bone-building cells that secrete matrix; initiate calcification)
• Osteocytes (mature bone cells)
• Osteoclasts (remodel bones and cause them to release calcium; bone resorption)

Question 13

Bones are supplied with blood and nerves via

Answer 13

Periosteal arteries and nutrient arteries

Question 14

How do Periosteal arteries enter the bone?

Answer 14

Periosteal arteries (accompanied by nerves) enter the diaphysis through Volkmann’s canals. They are accompanied by periosteal veins.

Question 15

How do nutrient arteries enter the bone?

Answer 15

A nutrient artery enters the center of the diaphysis through a nutrient foramen.
Nutrient veins exit via the same canal.

Metaphysis and epiphysis also have their own arteries and veins that enter the ends of the bones

Question 16

The process of bone formation is called

Answer 16

Ossification/ Osteogenesis

Question 17

Bones form in these 4 situations

Answer 17

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

Question 18

What are the 2 types of ossification?

Answer 18

1) Intramembranous
2) Endochondral

Question 19

What is Intramembranous ossification?

Answer 19

Intramembranous ossification occurs in flat bones when a connective tissue membrane is replaced by bone.

(It is the process of bone development from fibrous membranes. It is involved in the formation of the flat bones of the skull, the mandible, and the clavicles.)

Question 20

When does Endochondral ossification happen?

Answer 20

Endochondral ossification replaces cartilage with bone in the developing embryo and fetus.

Endochondral ossification also occurs in epiphyseal plates of long bones as they grow in length

Question 21

The cooperative action of osteoblasts and osteoclasts results in this

Answer 21

Bones thicken thanks to the cooperative action of osteoblasts and osteoclasts.

(Osteoblasts create bone and osteoclasts dissolve bones and initiate normal bone remodeling)

Question 22

Bone fractures heal in these three stages

Answer 22

• The reactive phase is an early inflammatory phase.
• The reparative phase includes formation of a fibrocartilaginous callus first and a bony callus second.
• The bone remodeling phase is the last step as the bony callus is remodeled.

Question 23

Factors affecting bone growth and remodelling

(Minerals, Vitamins, Hormones)

Answer 23

Minerals
calcium, phosphorus, magnesium, fluoride, manganese

Vitamins
Vitamins A, C, D, K and B12

Hormones
IGFs (stimulated by GH), T3 and T4,
sex hormones (estrogen in females, testosterone in males)

Question 24

Types of fractures

Open, Communited, Potts, Greenstick, Colles, Vertebral Compression Fracture

Answer 24

Open / Compound (outside of skin),

Communited (splinters/crushed and small pieces between two main parts of bone)

Greenstick (only small children), Impacted (one end forcefully driven into other),

Pott (ankle rolled out, fibula borken with damage to the tibia joint),

Colles (distal end of tibia pushed posteriorly),

VCF (vertebra cracked adn compressed into a wedge shape)

Question 25

Bones store \_\_\_\_% of the body’s calcium.

Answer 25

99%

Question 26

What is the bone's role in calcium homeostasis?

Answer 26

The parathyroid gland secretes parathyroid hormone (PTH) when calcium levels drop. Osteoclasts are stimulated to increase bone resorption and calcium is released. PTH also stimulates the production of calcitriol by the kidneys to increase calcium absorption in the intestines.

Question 27

Bone remodelling and age

Answer 27

From birth through adolescence, more bone is produced than is lost during remodeling. In adults, the rates are the same. Older individuals, especially post-menopausal women, experience a decrease in bone mass when resorption outpaces deposition.