Chapter 5 - Skeletal System

Question 1

How many bones are there?

Answer 1

206.

Question 2

2 divisions of skeleton?

Answer 2

Axial and appendicular.

Question 3

2 types of bone tissue?

Answer 3

Compact and spongy.

Question 4

How much of the body mass is bone?

Answer 4

20%.

Question 5

What are the components of the skeletal system?

Answer 5

Cartilage, bone, tendons, and ligaments.

Question 6

Functions of the skeletal system?

Answer 6

Protection, support, movement, storage, and blood cell production.

Question 7

Cartilage consists of?

Answer 7

Cells and extracellular matrix.

Question 8

Does cartilage have arteries, veins, or lymphocytes?

Answer 8

No.

Question 9

What are the types of cartilage?

Answer 9

Hyaline, elastic, and fibrocartilage.

Question 10

Hyaline cartilage structure and location?

Answer 10

Most common but weakest. Chondrocytes, chonrotin sulfate, and some collagen. Embryonic skeleton, articular surfaces, respiratory passages, nasal septum, between ribs & sternum.

Question 11

Elastic cartilage structure and location?

Answer 11

Chondrocytes, chondrotin sulfate, densely packed elastic fibers. Auricle, tip & lateral walls of nose, and epiglottis.

Question 12

Fibrocartilage structure and location?

Answer 12

Chondrocytes, chondrotin sulfates, densely packed collagen fibers. Intervertebral disc, pubic symphysis, articular catrilage in knee.

Question 13

Perichondrium structure and function?

Answer 13

Fibrous connective tissue. Support and protection surrounds cartilage.

Question 14

Locations of perichondrium?

Answer 14

Hyaline cartilage and elastic cartilage.

Question 15

Layers of perichondrium?

Answer 15

Outer: binds cartilage to adjacent tissues, provides support and protection. Inner: for growth & maintenance.

Question 16

What is appositional growth?

Answer 16

Starts in perichondrium, mesenchymal cells become chondrogenic cells then chondroblasts which force cells apart and become chondrocytes.

Question 17

What is interstitial growth?

Answer 17

Chondrocytes are enclosed in matrix and divide they start to move apart. Growth of cartilage from within.

Question 18

Characteristics of osseous tissue?

Answer 18

Supportive CT, contains specialized cells, and solid extracellular matrix.

Question 19

What is the osseous extracellular matrix composed of?

Answer 19

Osteoid (organic portion), ground substance (Ca salt), and water.

Question 20

Types of bone cells?

Answer 20

Osteoprogenitor, osteoblasts, osteocytes, and osteoclasts.

Question 21

What are osteoprogenitors?

Answer 21

Play role in initial bone growth and fracture repair.

Question 22

What are osteoblasts?

Answer 22

Secrete osteoid causing bone growth.

Question 23

What are osteocytes.

Answer 23

Mature cells, maintain homeostasis of Ca & PO4, found in Lacunae.

Question 24

What are osteoclasts?

Answer 24

Breakdown bone.

Question 25

Bone matrix is composed of?

Answer 25

Inorganic materials (65%) and osteoid (35%).

Question 26

Compact bone is arranged into?

Answer 26

Osteons, which contain blood vessels and nerves and concentric lamellae.

Question 27

Spongy bone is arranged into?

Answer 27

Trabeculae, latticework of thin plates of bone filled with red marrow, found in ends of long bones, and lightens bone.

Question 28

Osteocytes communicate through?

Answer 28

Canaliculi that radiate outward and connect one cell to the next.

Question 29

The different types of lamellae?

Answer 29

Concentric, interstitial, and circumferential.

Question 30

Concentric lamellae is?

Answer 30

Layers of bone surrounding the central canal (makes up osteons).

Question 31

Interstitial lamellae is?

Answer 31

Found between the osteons and represents older osteons partially removed during tissue remodeling.

Question 32

Circumferential lamellae is?

Answer 32

Surrounds compact bone and directly produced from periosteum.

Question 33

Spongy bone consists of?

Answer 33

Trabeculae, osteocytes in lacunae, canaliculi, and matrix.

Question 34

What does periosteum do and absent from where?

Answer 34

Encloses bone. Site of attachemetn of muscles, tendons, and ligaments or surfaces covered by articular cartilage.

Question 35

What are the layers of periosteum?

Answer 35

Outer: gives rose to collagen. Inner: for growth of new cells & maintenance.

Question 36

What is the endosteum?

Answer 36

1 cell layer, covers surfaces of spongy bone & medullary cavity.

Question 37

Cell types of the endosteum?

Answer 37

Osteogenic, osteoblasts, and osteoclasts.

Question 38

Anatomy of a long bone?

Answer 38

Diaphysis(shaft), epiphysis(one end), metaphysis(growth plate), articular cartilage(over joint surfaces), and medullary cavity(marrow cavity).

Question 39

Types of bone marrow?

Answer 39

Yellow and red marrow.

Question 40

What is yellow marrow?

Answer 40

Areolar and adipose CT, in medullary cavity of long bones, and energy storage

Question 41

What is red marrow?

Answer 41

Areolar and myeloid tissue, produces all types of blood cells, and located in spongy bone in adults.

Question 42

Where are yellow and red marrow found in infants?

Answer 42

Yellow is not and red is in the medullary cavities.

Question 43

The types of arteries of bone?

Answer 43

Periosteal, nutrient, metaphyseal & epiphyseal (all have corresponding veins).

Question 44

What do periosteal arteries do?

Answer 44

Supply periosteum.

Question 45

What do nutrient arteries do?

Answer 45

Enter through nutrient foramen and supplies compact bone of diaphysis & yellow marrow.

Question 46

What do metaphyseal and epiphyseal arteries do?

Answer 46

Supply red marrow and bone tissue of epiphyses and metaphyses.

Question 47

What is ossification?

Answer 47

Replacing CT with bone.

Question 48

What is intramembranous?

Answer 48

Mesenchymal cells to spongy bone.

Question 49

What is endochondral?

Answer 49

Hyaline cartilage to spongy bone

Question 50

Where does bone growth occur?

Answer 50

At the epiphyseal plate.

Question 51

When does growth stop?

Answer 51

When 2 ossification centers meet.

Question 52

Cartilage depletes and epiphyseal plate narrows forming?

Answer 52

Epiphyseal line.

Question 53

What are the 2 types of bone growth?

Answer 53

Appositional and elongation.

Question 54

What is appositional growth?

Answer 54

Compact bone deposited beneath periostium, bone thickens, and bone remodeling occurs throughout life.

Question 55

What causes bone remodeling?

Answer 55

Osteoclasts & osteoblasts.

Question 56

What is bone remodeling?

Answer 56

Continual redistribution of bone matrix along lines of mechanical stress.

Question 57

How much compact bone is remodeled per year?

Answer 57

4%

Question 58

How much spongy bone is remodeled per year?

Answer 58

20%

Question 59

What is remodeled every 4 months?

Answer 59

Distal femur.

Question 60

Two types of fractures?

Answer 60

Closed (simple) and open (compound).

Question 61

What is a closed or simple fracture?

Answer 61

Break that does not penetrate skin.

Question 62

What is an open or compound fracture?

Answer 62

Broken bone penetrates through skin.

Question 63

4 stages of bone repair?

Answer 63

Fracture hematoma, fibrocartilage callus, bony callus, and remodel tissue.

Question 64

How long does a fracture hematoma take to form?

Answer 64

A few hours.

Question 65

What is a fracture hematoma?

Answer 65

A mass of blood with swelling and inflammation.

Question 66

What eliminate dead cells/broken matrix?

Answer 66

Phagocytes and osteoclasts.

Question 67

What is a fibrocartilaginous callus ?

Answer 67

Consists of a mass bridging the broken ends of the bone.

Question 68

What causes the fibrocartilaginous callus?

Answer 68

Fibroblasts in periosteum produce collagen and periosteum cells differentiate into chondrocytes. resulting in fibrocartilage.

Question 69

How long does it take for a fibrocartilaginous callus to form?

Answer 69

About 3 weeks.

Question 70

What causes a bony callus to form?

Answer 70

The fibrocartilaginous callus is converted to spongy bone trabuculae.

Question 71

How long does a bony callus last?

Answer 71

3 to 4 months.

Question 72

What is bone remodeling?

Answer 72

Remaining dead bone fragments are reabsored and compact bone replaces spongy bone.

Question 73

Can you easily see where a bone was fractured when properly healed?

Answer 73

No.

Question 74

How long can bone remodeling take?

Answer 74

weeks to months depending on severity of break.

Question 75

Factors affecting growth, repair, & development.

Answer 75

Nutrition (vitamin D), sunlight, hormones, and physical stress.

Question 76

What are the hormones that affect growth, repair, & development?

Answer 76

Parathyroid (PTH), calcitonin, growth hormone (GH), thyroid, and sex hormones.

Question 77

What is osteoporosis?

Answer 77

Abnormal reduction of bone mass.

Question 78

What causes osteoporosis?

Answer 78

Loss of estrogen at menopause, deficiency of minerals on youth, and imbalance in activity between osteoblasts & osteoclasts.

Question 79

What is fibrodysplasia ossificans progressiva?

Answer 79

Fibrous tissue becomes ossified, genetic disorder, and injury results inappropriate bone formation.