Lecture Week 7

Question 1

What are the bone cell types?

Answer 1

Osteoblast, Osteocyte, Osteoclast

Question 2

What do osteoblasts do?

Answer 2

Bone “creating cell”, performs matrix deposition (ossification, osteogenesis)
Take calcium out of blood and put into bone tissue matrix

Question 3

What is an osteocyte?

Answer 3

Mature bone cell in lacuna

Question 4

What does an osteoclast do?

Answer 4

Bone “destroying” cell, performs matrix resorption, functions bone remodeling during growth, maxtrix mineral utilization
Take calcium from matrix to bone

Question 5

Osteoblast process from calcium to blood

Answer 5

Calcium in blood —> calcium in bone matrix
Called matrix deposition

Question 6

Osteoclast process from blood to calcium

Answer 6

Calcium in blood <—- calcium in bone matrix
Called matrix resorption

Question 7

Osteon

Answer 7

Central canal (blood vessels and nerves) + concentric lamellae (matrix layers)

Question 8

Osteocytes live in lacunae

Answer 8

True

Question 9

How do canaliculi connect?

Answer 9

By neighboring lacunae (tunnels)

Question 10

How do central canals connect?

Answer 10

by perforating canals

Question 11

What are lamellae layers around?

Answer 11

Osteon

Question 12

What does circumferential lamellae mean?

Answer 12

Surrounding around

Question 13

What are interstitial lamellae?

Answer 13

Layers between osteon

Question 14

What is the basic structural unit of spongy bone?

Answer 14

Trabeculae

Question 15

What are trabeculae

Answer 15

Small interconnecting bars or plates that contain osteocytes in lacunae and lamellae

Question 16

How are nutrients supplied to the osteocytes?

Answer 16

Canaliculi open onto the surface of each trabeculae so nutrients and gases can move in

Question 17

How many methods of ossification are there?

Answer 17

2

Question 18

Endochondral Ossification (of most bones)

Answer 18

Bone develops from a hyaline cartilage model, perichondrium of the diaphysis is replaced by bone, chondrocytes die, cartilage matrix breakdown, osteoblasts move in, blood vessels follow, osteoblast deposit bone matrix

Question 19

Intramembranous ossification (of flat bones)

Answer 19

Bone develops within connective tissue membrane, cells from membrane become osteoblasts, spongy bone forms first then some is converted to compact bone, osteoblasts surrounded by matrix becomes osteocytes, remaining connective tissue forms periosteum, osteoblasts remain under periosteum to thicken bone

Question 20

How does the bone lengthen in endochondral ossification?

Answer 20

Epiphyseal plates move away from diaphysis

Question 21

During what month of prenatal development does ossification in long bones begin?

Answer 21

3rd month

Question 22

During what month of prenatal development do most primary ossification centers will have appeared in diaphysis of bones?

Answer 22

4th month

Question 23

When do secondary ossification centers appear in epiphysis?

Answer 23

Birth to 5 years

Question 24

When are nearly all bones completely ossified?

Answer 24

23 years for females
25 years for males

Question 25

Joint Capsule

Answer 25

Fibrous layer (dense regular connective) that is continuous with periostium
Synovial membrane (areolar) that secretes synovial fluid for lubrication or cushioning

Question 26

Ligaments

Answer 26

Bind bones together and limit movement
Some are part of fibrous layer, some are separate, some run within joint, some surround

Question 27

Menisci

Answer 27

Fibrocartilage pads between articulating surfaces that provide cushioning

Question 28

Bursae

Answer 28

Synovial fluid filled cavities that provide cushioning

Question 29

Sprains

Answer 29

Damage to dense connective tissue in a join
Takes a long time to heal bc of area being non-vascular
Generally do not heal
Fragments may be removed by arthroscopic surgery

Question 30

Bursitis

Answer 30

Inflammation from trauma or overuse
ex. tennis elbow

Question 31

Arthritis

Answer 31

Large number of disorders with joint swelling and pain
2 big types
Osteoarthritis and Rheumatoid Arthritis

Question 32

Osteoarthritis

Answer 32

Associated with aging, most common form, wearing down of articular cartilage with age

Question 33

Rheumatoid Arthritis (RA)

Answer 33

Autoimmune disorder that damages both cartilage and bone
May be disfiguring as scar tissue forms during healing
Not associated with aging process
Attacking body

Question 34

Arthroscopic Surgery

Answer 34

Surgeon inserts camera and light source into joint cavity and uses forceps to grab damaged cartilage that has broken down into pieces

Question 35

Names of joints (6)

Answer 35

Ball and socket, hinge, gliding, pivot, joint, condyloid

Question 36

Ball and socket joint

Answer 36

Allows for greatest range of movement
ex. shoulder, hip bone

Question 37

Condyloid joint

Answer 37

shapes convex and concave

Question 38

Gliding joint

Answer 38

flat surfaces
ex. found in bones of wrist and tarsals in ankles

Question 39

Hinge joint

Answer 39

provides little movement
ex. knee joints, elbow

Question 40

Pivot joint

Answer 40

rotate
ex. shaking head

Question 41

Saddle joint

Answer 41

look like a saddle, fit together

Question 42

What are fibrous joints held together by?

Answer 42

Dense regular connective tissue

Question 43

Synarthrosis

Answer 43

No movement in bones

Question 44

Amphiarthrosis

Answer 44

Slight movement in bones

Question 45

Diarthrosis

Answer 45

Bones move freely

Question 46

What are the three kinds of fibrous joints?

Answer 46

Syndesmosis (interosseus ligament), Suture (sutural ligament), Gomphosis (periodontal ligament)

Question 47

What are the two kinds of cartilaginous joints?

Answer 47

Synchondrosis (hyaline cartilage), Symphasis (hyaline cartilage/fibrocartilage disc)