Module 7: Skeletal System

Question 1

Name the functions of the Skeletal System (P.B.E.A.M.S)

Answer 1

• Protection
• Blood Formation
• Electrolyte Balance
• Acid-Base Balance
• Movement
• Support

Question 2

To balance electrolytes, bone store and release ___ & ____ ions

Answer 2

Calcium & Potassium Ions

Question 3

To balance Acid-Bases bone buffers blood or maintains neutral pH by what means?

Answer 3

absorbing or releasing phosphate or carbonate salts

Question 4

Bone matrix is composed of

Answer 4

1/3 organic & 2/3 inorganic

Question 5

organic matrix is made of

Answer 5

collagen

Question 6

inorganic matrix is made of

Answer 6

hydroxyapatite

Question 7

hydroxyapatite - Structure & Fxn

Answer 7

crystallized salt made up of calcium & phosphate; provides strength to tissue

Question 8

If bone did not have organic matrix this would cause bone to be

Answer 8

very brittle & fragile; Hydroxyapatite crystals would fracture

Question 9

If bone did not have Hydroxyapatite this would cause bone to be

Answer 9

rubbery & have no strength

Question 10

Name 4 types of Bone cells

Answer 10

Osteogenic Cells
Osteoblasts
Osteocytes
Osteoclasts

Question 11

Osteogenic Cells: fxn & location

Answer 11

stem cells found in endosteum & inner layer of periosteum

Question 12

Osteoblasts

Answer 12

• derived from osteogenic cells
• nonmitotic (cannot reproduce themselves)
• bone forming
• produce organic bone tissue

Question 13

______ remove calcium from bloodstream to build bone matrix, which lowers blood calcium levels

Answer 13

Osteoblasts

Question 14

Osteocytes

Answer 14

• mature osteoblasts

- maintains homeostasis of bone material

Question 15

Osteoclasts

Answer 15

• arise from fusion of 4 stem cells
• found on bone surface, has ruffled borders which increase surface area
• release hydrochloric acid returning calcium & phosphate into blood
• increasing calcium levels

Question 16

Bone is formed by two types of tissue

Answer 16

Spongy & Compact Bone

Question 17

Compact Bone

Answer 17

for weight bearing; formed by combining osteon

Question 18

Osteon’s central & perforating canals contain

Answer 18

blood vessels & nerves

Question 19

Lacunae

Answer 19

on edges of lamellae; tiny cavities contain osteocytes

Question 20

Canaliculi

Answer 20

slender channels & allow osteocytes to communicate with one another

Question 21

Spongy Bone

Answer 21

lattice of rods, spines & projections of bone

Question 22

Osteons include … Name structures

Answer 22

Central Canal, Perforating Canal, Lamellae, Lacunae

Question 23

Spicules

Answer 23

Spike & projections that stick out into cavity of spongy bone

Question 24

Trabeculae: Structure & Features

Answer 24

form thin, plate-like structure; contain lamellae, no central canal

Question 25

Spaces between Trabeculae are filled with____

Answer 25

Bone Marrow

Question 26

____ ____ develops along lines of stress, disperses stress & pressure which allows for strength without weight

Answer 26

Spongy Bone

Question 27

Long Bones

Answer 27

- longer than wide, work as levers - used for movement, blood production & storage - Ex(s) arms, legs, bones in hands & feet

Question 28

Short Bones

Answer 28

- equal in length & width - limited motion - Ex(s) wrists & ankles

Question 29

Flat Bones

Answer 29

- enclose, protects, and provides broad surface for muscle attachments - Ex(s) cranial bones, ribs, sternum, scapula

Question 30

Irregular Bones

Answer 30

vertebra of spinal column & sphenoid in cranium

Question 31

Long Bone Anatomy: Epiphysis

Answer 31

ends of bone where they articulate, form joints with other bones

Question 32

Long Bone Anatomy: Diaphysis

Answer 32

Shaft / middle of bone; forms walls of medullary cavity

Question 33

Long Bone Anatomy: Medullary Cavity

Answer 33

aka Marrow cavity; contains bone marrow (red & yellow)

Question 34

Long Bone Anatomy: Periosteum

Answer 34

- fibrous tissue covering/attaching to bone surface - provides strength / anchors attaching muscles & tendons - contains 2 layers: outer layer made of thin collagen fibers inner layer bone tissue forming cells

Question 35

Long Bone Anatomy: Endosteum

Answer 35

thin layer of reticular connective tissue; lines medullary cavity

Question 36

Long Bone Anatomy: Metaphysis Plate

Answer 36

aka Epiphyseal plate; connection between epiphysis & diaphysis - made of hyaline cartilage in juveniles

Question 37

Long Bone Anatomy: Articular Cartilage

Answer 37

- made of hyaline cartilage - covers surface of epiphysis - reduces friction to allow for smooth movement

Question 38

Process of Ossification

Answer 38

bone growth; two types - Intramembranous & Endochondral

Question 39

Intramembranous Ossification

Answer 39

produces flat bones; within membrane of mesenchyme

Question 40

Endochondral Ossification

Answer 40

- produces long bones, ribs, vertebra, etc.. | - develops from cartilage converted to osseous tissue