Skeletal Systems I: Bone Histology

Question 1

function of bone

Answer 1

• support
• protection
• movement
• blood cell production
• storage

Question 2

bone support

Answer 2

• structural framework

- supports/supported by soft tissues (muscles, organs)

Question 3

bone protection

Answer 3

-protects internal organs

Question 4

bone movement

Answer 4

• muscle to bone via tendons

- contraction muscle causes bone to move

Question 5

bone blood cell production

Answer 5

• medullary cavity

- “red marrow”

Question 6

bone blood cell production medullary cavity

Answer 6

-hollow space inside bones

Question 7

bone blood cell production red marrow

Answer 7

-produces new blood cells

Question 8

bone storage

Answer 8

-consists of fats and minerals

Question 9

bone storage fat

Answer 9

• “yellow marrow” of long bones

- in medullary cavity

Question 10

bone storage minerals

Answer 10

• in matrix of bone tissue
• mostly calcium and phosphate
• other minerals in smaller amounts

Question 11

bone matrix composition

Answer 11

• inorganic matrix (nonliving portion)

- organic matrix (living portion)

Question 12

bone matrix composition inorganic matrix

Answer 12

• 2//3 of total bone mass
• calcium and phosphate salts –> hydroxyapatite crystals
• crystals deposit around collagen fibers
• principle source of rigidity and strength against compression

Question 13

bone matrix composition organic matrix

Answer 13

• 1/3 of total mass
• cells, collagen, and intercellular matrix
• provides resistance to twisting and stretching
• provides degree of elasticity

Question 14

types of bone arrangement

Answer 14

• compact (cortical) bone

- spongy bone (cancellous)

Question 15

compact bone

Answer 15

• dense and solid
• comprises outer surface of bones
• primary component of long bone shafts
• bone shafts are very close together

Question 16

spongy bone

Answer 16

• contains wide spaces in bone that resemble “holes” in a sponge
• holes are filled with red marrow

Question 17

bone membrane types

Answer 17

• periosteum

- endosteum

Question 18

periosteum bone membrane

Answer 18

• protective outer CT covering

- entry point: nerves/vessels

Question 19

endosteum bone membrane

Answer 19

-inner lining of bone found within medullary cavity (hollow space within)

Question 20

bone cell types

Answer 20

• osteocyte
• osteoblast
• osteoclast
• chondroblasts and chondrocytes

Question 21

osteocyte

Answer 21

-mature bone cell, resides in a space called lacunae

Question 22

lacunae

Answer 22

-cell sized empty spaces

Question 23

osteoblast

Answer 23

• cell which helps form bone by producing osteoid (the organic component of bone matrix
• produces osteocytes (found in lacunae)

Question 24

osteoclast

Answer 24

• resorption

- freed minerals enter blood stream

Question 25

resorption

Answer 25

-break down bone with enzymes

Question 26

chondroblasts and chondrocytes

Answer 26

- lay down cartilage model which ossifies (connected to bone) - active during phases of growth and repair (constantly repairing)

Question 27

another name for osteon

Answer 27

-haversian system

Question 28

osteon definition

Answer 28

-the basic functional and structural unit of mature bone

Question 29

osteon characteristics

Answer 29

- long cylindrical structures - oriented parallel to the long axis of a bone - arranged in a pattern that allows bone to withstand compression and torsion ("miniature weight bearing pillars")

Question 30

torsion

Answer 30

another name for twisting

Question 31

structural components of an osteon

Answer 31

- concentric lamellae - haversian (central) canal - canaliculi (small channels) - perforating (volkmann's) canals * *all have a rich blood supply

Question 32

osteogenesis

Answer 32

-bone formation and development

Question 33

processes of bone formation

Answer 33

- ossification | - calcification

Question 34

ossification

Answer 34

-osteoblasts secrete osteoid (inorganic part of matrix)

Question 35

calcification

Answer 35

- deposition of insoluble calcium salts (inorganic component of bone) - results in hardening of bone

Question 36

types of bone formation

Answer 36

- intramembranous bone | - endochondral bone

Question 37

intramembranous bone formation

Answer 37

- osteoblasts form bone in a connective tissue membrane - early in fetal development - in bones, required for protection

Question 38

intramembranous bone formation example

Answer 38

-flat bones of the skull

Question 39

endochondral bone formation

Answer 39

- begins with hyaline cartilage model - osteoblasts gradually replace model with bone - process may occur up to age 25 - most of the skeleton is formed this way

Question 40

endochondral bone formation example

Answer 40

- rib - femur - phalanges

Question 41

factors regulating bone growth

Answer 41

- nutritional requirements | - hormonal regulation

Question 42

nutritional requirements regulating bone growth

Answer 42

- calcium and phosphate salts - vitamins A and C - vitamin D

Question 43

nutritional requirements: vitamin A and C

Answer 43

-healthy osteoblast production

Question 44

nutritional requirements: vitamin D

Answer 44

-affects calcium absorption and transport

Question 45

types of hormones that regulate bone growth

Answer 45

- parathyroid hormone - calcitonin - growth hormone - sex hormones

Question 46

parathyroid hormone

Answer 46

-stimulates osteoclasts and increases Ca absorption in GI system

Question 47

calcitonin

Answer 47

- inhibits osteoclasts | - produced in thyroid gland

Question 48

growth hormone

Answer 48

-promotes growth

Question 49

sex hormones

Answer 49

- estrogen and testosterone | - ->stimulate osteoblasts

Question 50

types of bones

Answer 50

- flat bones - long bones - short bones - irregular bones - sesamoid bone

Question 51

flat bone

Answer 51

-composed of layer of spongy bone surrounded by two plates of compact bone

Question 52

flat bone examples

Answer 52

- parietal - sternum - rib

Question 53

long bone

Answer 53

- longer, narrower - shaft=compact one (diaphysis) - ends (epiphysis) primarily spongy

Question 54

long bone examples

Answer 54

- femur - humerus - phalanges

Question 55

short bone

Answer 55

-spongy bone surrounded by compact bone (like spongy candy)

Question 56

short bone examples

Answer 56

- cuboid bone | - carpal and tarsal bones

Question 57

irregular bone

Answer 57

-shape and structure do not fit into other categories (not long, short, or flat)

Question 58

irregular bone examples

Answer 58

-vertebrae

Question 59

sesamoid bone

Answer 59

-forms with tendons

Question 60

sesamoid bone examples

Answer 60

-patella

Question 61

what is the most functionally important structure in the skeleton?

Answer 61

-long bones

Question 62

structure of a typical long bone

Answer 62

- diaphysis - epiphysis - epiphyseal plate - medullary cavity - periosteum - endosteum - articular cartilage - nutrient vessels

Question 63

diaphysis

Answer 63

- shaft of long bone | - primarily compact bone

Question 64

epiphysis

Answer 64

- ends of long bone | - primarily spongy bone

Question 65

epiphyseal plate

Answer 65

- plate of cartilage in growing bones | - lengthwise bones grow here

Question 66

medullary cavity

Answer 66

- cavity with diaphysis | - mostly yellow bone marrow

Question 67

periosteum

Answer 67

- fibrous, protective outer membrane of bone - isolates the bound surrounding the tissue - provides a route for the circulatory and nervous supply - actively participates in bone growth and repair - dense connective tissue

Question 68

endosteum

Answer 68

-inner membrane of bone containing cells involved of bone formation

Question 69

articular cartilage

Answer 69

-hyaline cartilage located on the ends of long bones for protection

Question 70

nutrient vessels

Answer 70

-blood vessels that penetrate bone to supply it with nutrients