Chapter 6

Question 1

Five primary functions of the Skeletal System

Answer 1

1. Support
2. Storage of Minerals (calcium) and Lipids (yellow
   marrow)
3. Blood Cell Production (red marrow)
4. Protection
5. Leverage (force of motion)

Question 2

Small, irregular bones that are found between the flat bones of the skull

Answer 2

Sutural Bones

Question 3

Bones that have complex shapes

• Examples: spinal vertebrae, pelvic bones

Answer 3

Irregular Bones

Question 4

Bones that are small and thick

• Examples: ankle and wrist bones

Answer 4

Short Bones

Question 5

Bones that are thin with parallel surfaces and are found in the skull, sternum, ribs, and scapulae

Answer 5

Flat Bones

Question 6

Bones that are Long and thin and are found in arms, legs, hands, feet, fingers, and toes

Answer 6

Long Bones

Question 7

Bones that are Small and flat and develop inside tendons near joints of knees, hands,
and feet

Answer 7

Sesamoid Bones

Question 8

Term for bone markings that are found along bone surface

Answer 8

Depressions or grooves

Question 9

Term for bone markings that are found where tendons and ligaments attach and at articulations with other bones

Answer 9

Elevations or projections

Question 10

Term for bone markings that are found where blood and nerves enter bone

Answer 10

Tunnels

Question 11

The shaft of the long bone that is made of a heavy wall of compact bone, or dense bone

Answer 11

Diaphysis

Question 12

What is the central space in the diaphysis called?

Answer 12

medullary (marrow) cavity

Question 13

Wide part at each end of the long bone that articulates with other bones; It is mostly spongy (cancellous) bone and covered with compact bone (cortex)

Answer 13

Epiphysis

Question 14

Structure where diaphysis and epiphysis meet

Answer 14

Metaphysis

Question 15

What is the layer of spongy bone between

the compact bone found within the cranium?

Answer 15

diploë

Question 16

Structure that has dense, supportive connective tissue and contains specialized cells that produce solid matrix of calcium salt deposits

Answer 16

Bone (Osseous) Tissue

Question 17

This structure forms pathways for blood vessels and exchanges nutrients and wastes

Answer 17

Canaliculi

Question 18

This structure covers outer surfaces of bones and consists of outer fibrous and inner cellular layers

Answer 18

Periosteum

Question 19

The bone matrix is composed of two thirds of what compound?

Answer 19

calcium phosphate,

Ca3(PO4)2

Question 20

The bone matrix is composed of one third of what compound?

Answer 20

protein fibers (collagen)

Question 21

Calcium phosphate reacts with calcium hydroxide in the bone matrix to form crystals of?

Answer 21

hydroxyapatite

Question 22

four types of cells of bones

Answer 22

1. Osteocytes
2. Osteoblasts
3. Osteoprogenitor cells
4. Osteoclasts

Question 23

Mature bone cells that maintain the bone matrix and live in lacunae and are between layers (lamellae) of matrix

Answer 23

Osteocytes

Question 24

Two major functions of osteocytes

Answer 24

1. To maintain protein and mineral content of matrix

2. To help repair damaged bone

Question 25

Immature bone cells that secrete matrix compounds | osteogenesis

Answer 25

Osteoblasts

Question 26

matrix produced by osteoblasts, but not | yet calcified to form bone

Answer 26

Osteoid

Question 27

Osteoblasts surrounded by bone become what type of cells?

Answer 27

osteocytes

Question 28

Mesenchymal stem cells that divide to produce | osteoblasts and are located in endosteum. They assist in fracture repair

Answer 28

Osteoprogenitor Cells

Question 29

Giant, multinucleate cells that secrete acids and protein-digesting enzyme which dissolves bone matrix and release stored minerals (osteolysis)

Answer 29

Osteoclasts

Question 30

basic unit of a compact bone

Answer 30

Osteon

Question 31

These structures are perpendicular to the central canal and carry blood vessels into bone and marrow

Answer 31

Perforating canals

Question 32

Describe the characteristics of a spongy bone.

Answer 32

* Does not have osteons * The matrix forms an open network of trabeculae * Trabeculae have no blood vessels * The space between trabeculae is filled with red bone marrow * In some bones, spongy bone holds yellow bone marrow

Question 33

Found in the space between trabeculae that forms red blood cells and supplies nutrients to osteocytes

Answer 33

red bone marrow

Question 34

Why is the yellow bone marrow 'yellow'?

Answer 34

because it stores fat

Question 35

collagen fibers of the periosteum

Answer 35

Perforating fibers

Question 36

Functions of Periosteum

Answer 36

1. Isolates bone from surrounding tissues 2. Provides a route for circulatory and nervous supply 3. Participates in bone growth and repair

Question 37

Incomplete cellular layer in the compact bone that lines the medullary (marrow) cavity; It covers trabeculae of spongy bone, lines central canals, contains osteoblasts, osteoprogenitor cells, and osteoclasts and are active in bone growth and repair

Answer 37

Endosteum

Question 38

Bone formation is called?

Answer 38

Osteogenesis

Question 39

The process of replacing other tissues with bone

Answer 39

Ossification

Question 40

The process of depositing calcium salts which occurs during bone ossification and in other tissues

Answer 40

Calcification

Question 41

Two main forms of ossification

Answer 41

1. Endochondral ossification | 2. Intramembranous ossification

Question 42

Form of ossification where it ossifies bones that originate as hyaline cartilage

Answer 42

Endochondral Ossification

Question 43

``` Form of ossification where it occurs in the dermis and produces dermal bones such as mandible (lower jaw) and clavicle (collarbone) ```

Answer 43

Intramembranous Ossification

Question 44

Intramembranous Ossification is also called?

Answer 44

dermal ossification

Question 45

A single pair of large blood vessels that enter the diaphysis through the nutrient foramen

Answer 45

Nutrient Artery and Vein

Question 46

Blood vessels that supply the epiphyseal cartilage

Answer 46

Metaphyseal Vessels

Question 47

Blood vessels that supply blood to superficial osteons

Answer 47

Periosteal Vessels

Question 48

If deposition is greater than removal, bones get ________

Answer 48

stronger

Question 49

If removal is faster than replacement, bones get | _________

Answer 49

weaker

Question 50

Effects of Exercise on Bone

Answer 50

* Mineral recycling allows bones to adapt to stress | * Heavily stressed bones become thicker and stronger

Question 51

Hormone made in the kidneys that helps absorb calcium and phosphorus from digestive tract; it is synthesized from vitamin D3 (cholecalciferol)

Answer 51

hormone calcitriol

Question 52

Vitamin required for collagen synthesis, and | stimulation of osteoblast differentiation

Answer 52

Vitamin C

Question 53

Vitamin that stimulates osteoblast activity

Answer 53

Vitamin A

Question 54

Vitamins that help synthesize bone proteins

Answer 54

Vitamins K and B12

Question 55

Hormones that stimulate bone growth

Answer 55

Growth hormone and thyroxine

Question 56

Hormones that stimulate osteoblasts

Answer 56

Estrogens and androgens

Question 57

Hormones that regulate calcium | and phosphate levels

Answer 57

Calcitonin and parathyroid hormone

Question 58

Hormone produced by parathyroid glands in neck which increases calcium ion levels

Answer 58

Parathyroid Hormone (PTH)

Question 59

How does PTH increase calcium ion levels?

Answer 59

by: 1. Stimulating osteoclasts 2. Increasing intestinal absorption of calcium 3. Decreasing calcium excretion at kidneys

Question 60

Secreted by C cells (parafollicular cells) in thyroid that decreases calcium ion

Answer 60

Calcitonin

Question 61

How does Calcitonin decreases calcium ion levels?

Answer 61

by: 1. Inhibiting osteoclast activity 2. Increasing calcium excretion at kidneys

Question 62

Four steps of fracture repair

Answer 62

1. Bleeding 2. Cells of the endosteum and periosteum 3. Osteoblasts 4. Osteoblasts and osteocytes remodel the fracture for up to a year