Chapter 6

Question 1

What are functions of the skeletal system?

Answer 1

Support body, facilitate movement, protect internal organs, produce blood cells, store and release minerals and fat

Question 2

What are the two different types of bone marrow and what can you find in them?

Answer 2

Red marrow – blood cells
Yellow marrow – adipose tissue

Question 3

How many bones are in the body?

Answer 3

206

Question 4

List the 5 categories of bones, examples, and functions of each.

Answer 4

Long bones – serve as levers, move when muscles contract – humerus, radius, ulna, femur, tibia, fibula, metacarpals, phalanges, metatarsals
Short bones – stability and support, some limited motion – carpals and tarsals
Flat bones – point of attachment for muscles, protect internal organs – cranial bones, scapulae, sternum, ribs
Irregular bones – protect from compression – vertebrae, facial bones
Sesamoid bones – protects tendons to overcome compression forces - patella

Question 5

Define diaphysis and epiphysis and which marrow is found in these regions.

Answer 5

Diaphysis – tubular shaft between proximal and distal ends – yellow marrow
Epiphysis – wider sections at ends of long bones – red marrow

Question 6

What is the epiphyseal plate and when does it start to fuse? When it fuses, what structure does it become?

Answer 6

The epiphyseal plate is the growth plate that is composed of hyaline cartilage in growing bone. It starts to fuse between 18-21 years and becomes the epiphyseal line.

Question 7

What is a condyle, tuberosity, meatus? (all terms on table 6.2 are fair game – know them all)

Answer 7

Condyle – rounded surface
Tuberosity – rough surface
Meatus – opening into canal

Question 8

What are the three main classes of bone markings?

Answer 8

Articulations, projections, holes

Question 9

What is hydroxyapatite?

Answer 9

Calcium phosphate found in bone tissue that gives bone its hardness and strength

Question 10

Osteoblasts build up/break down bone tissue and osteoclasts build up/break down bone tissue.

Answer 10

1. build up
2. break down

Question 11

Osteoblasts will become ___________ when they are trapped in the matrix.

Answer 11

osteocytes

Question 12

What cell is the only dividing cell in bone tissue?

Answer 12

Osteogenic cells

Question 13

What is lamellae and which type of bone is it found in? What about trabeculae?

Answer 13

Lamellae are concentric rings of calcified matrix found in compact bone. Trabeculae is the lattice-like network found in spongy/cancellous bone.

Question 14

What is the main difference between intramembranous ossification and endochondral ossification?

Answer 14

Intramembranous ossification will lay down calcified matrix while endochondral ossification involves a cartilaginous skeleton in which bone is later formed upon.

Question 15

In endochondral ossification, what type of cartilage is used and eventually replaced with bone?

Answer 15

Hyaline cartilage

Question 16

What is the process in adults where there is resorption of old/damaged bone on the same surface where osteoblasts lay new bone to replace that which is resorbed?

Answer 16

Remodeling

Question 17

Osteogenesis imperfecta is a mutation that affects production of what? What are some common issues found in this disease?

Answer 17

Affects the production of collagen
Issues: fragile skin, weak muscles, loose joints, easy bruising, frequent nosebleeds, brittle teeth, blue sclera, and hearing loss

Question 18

What is the difference between open reduction and closed reduction?

Answer 18

Open reduction - surgery to expose fracture and reset bone
Closed reduction - broken bone manipulated and set into natural position without surgery

Question 19

List the types of fractures. (Table 6.4)

Answer 19

Comminuted, greenstick, impacted, oblique, transverse, spiral, open, closed

Question 20

Why is fluoride important for bone health?

Answer 20

Displaces OH group in hydroxyapatite – fluorapatite – stabilizes and strengthens bone minerals and increases bone density

Question 21

Which hormones influence osteoblasts and how?

Answer 21

Pituitary gland via growth hormone – chondrocyte proliferation/increased mineralization/increased density, thyroid gland via thyroxine – synthesis of bone matrix, testosterone and estrogen – growth spurt, calcitriol – absorb calcium and phosphate from GI tract

Question 22

Which hormones influence osteoclasts and how?

Answer 22

Parathyroid hormone – calcium reabsorption by kidneys and synthesize vitamin D, calcitonin – stimulate calcium uptake by bones and decrease calcium ion in blood

Question 23

How can you differentiate between osteoporosis and Paget’s disease?

Answer 23

Paget’s has an elevated alkaline phosphatase and osteoporosis does not

Question 24

What is the normal level of calcium in the body?

Answer 24

10 mg/dL

Question 25

What hormone is responsible for decreasing calcium levels? What about for increasing calcium levels?

Answer 25

Decreasing levels – calcitonin
Increasing levels – parathyroid hormone