Skeletal System 2

Question 1

What is ossification (osteogenesis)?

Answer 1

The process of bone tissue formation

Question 2

What are the two methods of bone formation?

Answer 2

Intramembranous & endochondral ossification

Question 3

What happens in Intramembranous ossification?

Answer 3

Bone forms within the mesenchyme (embryonic connective tissue) which are arranged in sheets of membranes, and form most cranial bones of the skull

Question 4

What happens in endochondral ossification?

Answer 4

Bones from within a hyaline cartilage model derived from the mesenchyme and forms most bones

Question 5

What two factors are necessary for bone growth?

Answer 5

New bone formation & bone remodelling

Question 6

What is appositional growth?

Answer 6

Bone growth in diameter

Question 7

What is interstitial growth?

Answer 7

Bone growth in length

Question 8

What two things happen during interstitial growth?

Answer 8

Growth of epiphyseal plates, and the replacement of cartilage with bone

Question 9

What are the 4 zones of epiphyseal plates

Answer 9

Nearest to epiphysis, zone of resting, proliferating hypertrophic and calcified cartilage

Question 10

What is the function of the resting zone?

Answer 10

Contain resting chondocytes that anchor the growth plates to the bone

Question 11

What is the function of the proliferating zone?

Answer 11

Contain larger chondrocytes that continuously divide to produce new chondrocytes and secrete extra cellular matrix

Question 12

What is the function of the hypertrophic zone?

Answer 12

Contains columns of large maturing chondrocytes

Question 13

What is the function of the calcified zone?

Answer 13

Contain dead chondrocytes replaced by bone matrix, and broken up osteoclasts and becomes part of the new diaphysis

Question 14

What is the epiphyseal line ?

Answer 14

Bony structure of faded cartilage layer which signify the fusing of growth plates.

Question 15

What causes bone thickening?

Answer 15

Increase in weight & muscular activity

Question 16

What happens during appositional growth?

Answer 16

Osteoblasts deposit bone in periosteum, while osteoclasts remove bone matrix from the endosteum to enlarge the medullary cavity & prevent high bone weight

Question 17

What are the two actions involved in bone remodeling?

Answer 17

Bone resorption & bone deposition

Question 18

What two factors control bone remodeling?

Answer 18

Hormones & mechanical stress

Question 19

Describe what happens during low levels of blood calcium?

Answer 19

Low blood calcium levels instigate PT cells to increase the generation of AMP which activates more PTH and stimulates osteoclasts to resorb bone to release Ca+2 & kidneys to retain calcium.

Question 20

What is the function of Calcitonin?

Answer 20

Produced by thyroid gland to decrease Ca+2 in blood

Question 21

What is the function of leptin?

Answer 21

Formed by adipose tissue inhibit osteoblasts

Question 22

What factors affect bone growth?

Answer 22

Hormones such as sex, thyroid and GH, Minerals, Vitamins, Adequate diet, & Exercise

Question 23

What are the four phases of bone fracture?

Answer 23

Reactive, reparative fibrocartilaginous callus phase, reparative bony callus phase & remodeling

Question 24

What happens during the reactive phase of fracture?

Answer 24

Fracture ruptures blood vessels causing blood clot or fracture hematoma formation

Question 25

What happens during the reparative fibrocartilaginous callus phase?

Answer 25

Blood vessels form across fracture & collagen chondroblasts form the fibrocartilaginous callus (soft) across the ends of the bone

Question 26

What happens during the reparative bony callus phase?

Answer 26

Osteoprogenitor cells develop into osteoblasts and form spongy bone trabeculae which connects bone fragments. the the cartilage is calcified into bone

Question 27

What happens during the remodeling phase?

Answer 27

Old bone fracture portions are destroyed by osteoclasts, and replaced by compact bone across the edges of the fracture causing side thickening

Question 28

What is another name for joints?

Answer 28

Articulations

Question 29

Joints are a point of contact between what structures?

Answer 29

Bones, bones & cartilage and bones & teeth

Question 30

How are joints classified?

Answer 30

Their structure & function

Question 31

What are the 3 Structures?

Answer 31

Fibrous, cartilaginous, & synovial

Question 32

What are the three functions?

Answer 32

Immovable synarthroses, slightly moveable amphiarthroses and freely moveable diarthroses

Question 33

What are Fibrous joints?

Answer 33

Synarthroses - little to immovable

Question 34

What are the 3 types of Fibrous joints?

Answer 34

Sutures, Syndesmoses & Interosseous membranes

Question 35

What are Sutures?

Answer 35

Thin layers of connective tissue which join skull bones together & immovable

Question 36

What are Syndesmoses?

Answer 36

Irregular dense connective tissue arranged in bundles or ligaments that connect longer distance joints such as distal tibiofibular ligament - slightly moveable

Question 37

What are interosseous membranes?

Answer 37

Large sheets of connective tissue that span across neighboring long bones

Question 38

What are cartilaginous joints?

Answer 38

Connected by hyaline or fibrocartilage and little - immovable

Question 39

What are the two types of cartilaginous joints

Answer 39

Synchondroses & symphyses

Question 40

What is a Synchondroses joint?

Answer 40

Joints connected by hyaline cartilage such as the epiphyseal growth plates that connect the epiphysis & diaphysis - immovable

Question 41

What is the symphyses joint?

Answer 41

Joints connected by fibrocartilage, such as pubic symphysis which are slightly moveable

Question 42

What are synovial joints?

Answer 42

Joints which are freely moveable & exhibit a joint capsule & synovial cavity

Question 43

What are the 6 types of synovial joints?

Answer 43

Plane, hinge, pivot condyloid, saddle & ball-socket joint

Question 44

What is a plane joint?

Answer 44

Two flat bones that glide past each other such as Intercarpal joints

Question 45

What is a hinge joint?

Answer 45

Angular opening and closing of bones such as elbow

Question 46

What is a pivot joint?

Answer 46

Rotary joints that allow rotary movement in its own longitudinal axis - radioulnar joints

Question 47

What is a condyloid joint?

Answer 47

Two cuplike or oval projections that rest on each other such as metacarpophalangeal joints

Question 48

What is a saddle joint?

Answer 48

Surfaces that are concave and convex such as Carpometacarpal

Question 49

What is a Ball-socket joint?

Answer 49

Ball fits into socket such as shoulder joint

Question 50

What is the basic structure of synovial joints?

Answer 50

Surrounded by joint capsule that contain an outer fibrous and inner synovial membrane

Question 51

Describe the outer fibrous membrane?

Answer 51

Made of dense connective tissue, collagen which enables flexibility & tensile strength and contain ligaments which join synovial joints

Question 52

Describe the inner synovial membrane?

Answer 52

Made areolar connective tissue, elastic fiber, fat pads and secretes synovial fluid in a synovial cavity between the synovial membrane

Question 53

What are the functions of synovial fluid?

Answer 53

Reduce friction, lubricate, absorb shock, nourish with blood and nutrients, and enables exist wastes from chondrocytes

Question 54

What are ligaments?

Answer 54

Connect bones to bones

Question 55

What are Tendons?

Answer 55

Connect bone & muscle

Question 56

What is the menisci?

Answer 56

Crest-shaped discs, between the articular bone and fibrous membrane of synovial joints

Question 57

What are the functions of menisci?

Answer 57

Provide shock absorption, better fit between bone joints, distribute synovial lubricant, and prevent stress, wear and tear.