Skeletal System

Question 1

What are the functions of the skeleton?(6)

Answer 1

1. support soft tissues of the body
2. Mineral reserves
   a. calcium and phsophate
   b. 98% of the body’s calcium is in the bones
3. energy storge
   a. yellow bone marrow
4. Blood cell Production
5. Protection of Vital Organs
6. Leverage and movement

Question 2

What are the Connective tissues of the body?

Answer 2

1. Connective tissue proper
2. Supporting connective Tissues
3. Fluid Connective Tissue

Question 3

Describe Connective Tissue Proper

Answer 3

1. Dense Regular- ligaments, bone sheaths, tendons,
2. Adipose- stored in bones

Question 4

Describe Supporting Connective Tissues

Answer 4

1. Cartilage- articular ends of bones, joint discs, intervertebral discs, symphysis pubis
2. Osseous Tissue- Bone

Question 5

Describe Fluid Connective Tissue

Answer 5

Blood and lymph
a. formed in red bone marrow

Question 6

What do All connective tissues differentiate from?

Answer 6

Mesenchyme- embryonic Connective Tissue

Question 7

What are the characteristics of Cartilage?(8)

Answer 7

1. No blood vessels/nerves
2. Consist of mostly water (60-80%)
3. Surrounded by the perichondrium(not fibroblasts)
4. Growth stops at around 18-20 years
5. little healing in adulthood
6. Collagen resist tension
7. poor at resisting shearing
8. contains cartilage cells

Question 8

Where does cartilage get its gas and nutrients from?

Answer 8

Gas and nutrients diffuse from surrounding blood vessels

Question 9

What kind of motion does cartilage resist?

Answer 9

Compression

Question 10

Describe the Perichondrium

Answer 10

1. Acts like a girdle
2. Blood vessels here; helps in growth and repair
3. provides gas and nutrients to cartilage cells

** fibrocartilage does not have perichondrium

Question 11

Describe the cartilage cells

Answer 11

1. Chondroblasts- immature cartilage cells
2. chondrocytes- mature, dividing cells trapped in lacunas

Question 12

what are the cartilage types

Answer 12

1. Hyaline
2. Elastic
3. Fibro

Question 13

Describe hyaline cartilage(3)

Answer 13

1. Most abundant
2. has fibers that are too small to see
3. located on the end of bones, growth plates, and costal cartilage

Question 14

Describe Elastic Cartilage(3)

Answer 14

1. Many elastic fibers
2. tolerates repeated bending/recoil
3. located within the ears and epiglottis

Question 15

Describe Fibrocartilage(4)

Answer 15

1. abundant collagen fibers
2. resist twisting and compression
3. no perichondrium
4. located in the intervertebral discs, and the menisci

Question 16

What are the two types of osseous tissue?

Answer 16

1. Spongy
2. Compact

Question 17

Describe Spongy Bone(5)

Answer 17

1. Honeycomb like network of bone
   a. allows it to transmit weight, form cavities for bone marrow and to be lightweight
2. Form trabeculae tp resist directional stresses
   3.Cavities are filled with red bone marrow
3. found in the epiphysis and center of the bone organ
4. replaced every 4 years

Question 18

Describe Compact bone(4)

Answer 18

1. Beams of bone help to transmit weight within the bone
2. allows for compression down the medial diaphysis, and tension along lateral diaphysis
3. formed into highly organized osteons, nested rings
4. replaced every 10 years

Question 19

Describe the composition of bone (3)

Answer 19

1. Bone is a “supporting connective tissue”
2. Specialized cells within a matrix
3. bone cells within osteoid

Question 20

Describe organic compounds that make up the non cellular matrix

Answer 20

1. provides flexibility
2. primarily collagen fibers
3. resist twisting and tension

Question 21

Describe the inorganic compounds that make up the non-cellular matrix

Answer 21

1. Provides durability and hardness
2. Calcium and phosphate
3. 98% of calcium held in bone

Question 22

What are the 4 different bone cells

Answer 22

1. Osteoclasts
2. Osteoprogenitor
3. Osteoblast
   4 .Osteocyte

Question 23

Describe Osteoclasts

Answer 23

1. Derived form WBC
2. Function: Breaks down old matrix(osteoid)
3. Releases calcium and phosphate

Question 24

Describe Osteoprogenitor Cells

Answer 24

1. Will form all new bone cells
2. Can divide

Question 25

Describe Osteoblasts

Answer 25

1. Immature bone cells
2. Secretes New matrix (osteoid)

Question 26

Describe Osteocytes

Answer 26

1. Mature Bone Cells
2. Trapped in Lacunae

Question 27

Describe Canaliculi transfer

Answer 27

1. Mineralized Matrix- No diffusion though the matrix
2. Protoplasmic Extension(arm) of adjacent cells connect with canaliculi Transfer
3. Transports waste, nutrients, gasses, etc. from cell to cell
   * Canaliculi- small cracks in which transfer takes place

Question 28

What are the two types of bone development(ossification)

Answer 28

1. Intramembranous
2. Endochondral

Question 29

Describe Intramembranous Ossification

Answer 29

1. Occurs in Dermal bone- flat bones of skull
2. bones that develop in muscles or tendons- sesamoid bones
3. Occurs directly from mesenchyme
4. form by appositional growth
   * Embryonic connective tissue cells change into osteoblasts -> form Bone

Question 30

Describe Endochondral Bone ossification

Answer 30

1. Occurs in most bones
2. bon tissue replaces initial hyaline cartilage model
3. after formation, hyaline cartilage remains as articular cartilage
4. Grows by interstitial growth and appositional growth

Question 31

Describe Bone Growth

Answer 31

1. grows in length until age 15-20
2. grows in width until 15-20, but continues to from new bone for life
3. spongy bone replaced every 4 years
4. compact bone replaced every 10 years

Question 32

What are the two methods of bone growth

Answer 32

1. interstitial
2. Appositional

Question 33

Describe Appositional growth

Answer 33

1. growth in width of the bone
2. Bone cells lay down new bone tissue along outside of bone
   a. deep to the periosteum