(Lesson 4) Chapter 6-Skeletal System

Question 1

Cartilage in the body

Answer 1

Ear, Nose, ribs, joints, larynx, air tubes, between vertebrae, pubic symphisis

Question 2

Perichondrium

Answer 2

A layer of dense irregular connective tissue that surrounds cartilage.

Question 3

Three types of cartilage

Answer 3

Hyaline, Elastic, and Fibrocartilage

Question 4

Hyaline Cartilage

Answer 4

looks like frosted glass. Provides support, flexibility and resilience. Makes up the articular cartilage that covers the end of adjoining bones in movable joints. Also forms attachment from ribs to sternum, most cartilage in respiratory structures, and forms embryonic skeleton.

Question 5

Elastic Cartilage

Answer 5

More elastic than hyaline cartilage. Can tolerate repeated bending. Epiglottis and outer ear are made of this cartilage.

Question 6

Fibrocartilage

Answer 6

resists both strong compression and strong tension (pulling) forces. Portion of discs between vertebrae, articular discs of some joints like the menisci of the knee.

Question 7

Composition of bone

Answer 7

Bone is 65% inorganic and 35% organic.

Compact bone: the external and especially hard part of bones

Question 8

Compact Bone

Answer 8

External and especially hard part of bones

Question 9

Spongy bone

Answer 9

less dense than compact bone. Usually found deep to compact bone. AKA Trabecular bone (trabeculae=little beams. Space between beams are filled with marrow.)

Question 10

Bone marrow

Answer 10

2 types: yellow and red.

Question 11

Support (bone function)

Answer 11

Hard framework supports the weight of the body. ie leg bones support trunk of the body.

Question 12

Movement (bone function)

Answer 12

muscles attach to bones by tendons and use bones as levers to move body parts. Humans can walk, lift, etc

Question 13

Protection

Answer 13

Some bones provide protective casing. ie skull, vertebrae, ribs

Question 14

Mineral storage

Answer 14

Reservoir for minerals-most importantly calcium and phosphate. minerals are distributed through the blood stream as needed.

Question 15

Blood cell formation and energy storage

Answer 15

Bones contain red and yellow bone marrow.

Question 16

Red Bone marrow

Answer 16

makes blood cells

Question 17

yellow bone marrow

Answer 17

stores fat-no role in blood-cell formation.

Question 18

Long bones

Answer 18

longer than they are wide. Has shaft and two distinct ends. Limbs, fingers, toes. Size is unimportant

Question 19

Short bones

Answer 19

roughly cube shaped. occur in write and ankle

Question 20

Sesamoid bones

Answer 20

special type of short bone that forms within a tendon. Patella. Vary in size and number in different people. Reduce friction/alter direction of pull of tendon.

Question 21

Flat bones

Answer 21

Thin, flattened, and usually somewhat curved. Most cranial bones, ribs, sternum, scapula.

Question 22

Irregular bones

Answer 22

various shapes that dont fit in any categories. ie vertebrae and hip bones.

Question 23

Diaphysis

Answer 23

Shaft of long bone.

Question 24

Epiphses

Answer 24

bone ends.

Question 25

Epiphyseal line

Answer 25

Remnant of the epiphyseal plate-a disc of hyaline cartilage that grows during childhood to lengthen the bone.

Question 26

Osteon/Haversian System

Answer 26

A structural component of compact bone. Long cylindrical structures, parallel to the long axis of the bone. Weight bearing pillars.Contains a group of concentric tubes resembling the rings of a tree trunk.

Question 27

Lamella

Answer 27

Tubes inside of tubes inside of osteon. Fibers of adjacent lamellae run in opposite directions-optimal for withstanding torsion, twisting, or stresses. Inhibit crack propagation-dispersing forces around lamellar boundaries to prevent crack progression and bone fracture.

Question 28

Central/Haversian Canal

Answer 28

At the core of each osteon, lined with endosteum. Contains its own blood vessels which supply nutrients to bone cells.

Question 29

Perforating/Volkmann's Canal

Answer 29

Lie at right angles to central canals and connect blood/nerve supply to periosteum and marrow cavity.

Question 30

Osteocytes

Answer 30

Mature bone cells. Spider-shaped. Bodies occupy lacunae and legs occupy canaliculi inside of osteon. Maintains the bone matrix

Question 31

Lacunae

Answer 31

cavities in the solid bone matrix of osteon, lamellae.

Question 32

Canaliculi

Answer 32

Run through bone matrix to connect with neighboring lacunae.

Question 33

Osteoblasts

Answer 33

cells responsible for bone deposition and the precursor to osteocytes

Question 34

Osteoclasts

Answer 34

cells responsible for bone resorption

Question 35

1. Bone collar formation | Stages of Endochondral Ossicfication

Answer 35

Bone begins as a cartilage model. At week 8 perichondrium surrounding diaphysis is invaded by blood vessels and becomes periosteum. Osteoblasts lay down collar of bone tissue around diaphysis.

Question 36

2. Cartilage Calcifies in the center of the diaphysis | Stages of Endochondral Ossicfication

Answer 36

central area of diaphysis calcifies and disintegrates leaving a cavity in the the diaphysis.

Question 37

3. Periostal bud invades the diaphysis and first bone trabeculae form Stages of Endochondral Ossicfication

Answer 37

Bud invades diaphysis cavities and destroys remaining cartilage while secreting bone-forming osteoid. Earliest version of spongy bone is formed.

Question 38

4. Secondary ossification centers form in epiphyses | Stages of Endochondral Ossicfication

Answer 38

Cartilage calcifies, degenerates, and is filled with osteoids to begin forming bone.

Question 39

Elongation of bone

Answer 39

Relies on cell division and growth at the epiphyseal plates of each long bone.

Question 40

Appositional Growth

Answer 40

Causes bones to widen as the osteoblasts in the periosteum add bone tissue to the external face of the diaphysis.

Question 41

Organization of Cartilage within epiphyseal plate from bottom to top

Answer 41

ossification, calcification(dead cartilage cells), hypertrophic(old cells enlarge), proliferation, cells undergo mitosis

Question 42

Intramembranous Ossification

Answer 42

the way flat bones originate in the embryo. - ossification center appears in fibrous connective tissue - fibrous membrane ossifies - periosteum and woven bone formation - compact bone plate formation

Question 43

Comminuted | Types of fractures

Answer 43

Bone fragments into three or more pieces. Common in the aged, whose bones are more brittle.

Question 44

Compression | Types of fractures

Answer 44

Bone is crushed. Common in porous bones-often times after a fall.

Question 45

Spiral | Types of fractures

Answer 45

Ragged break occurs when excessive twisting forces are applied to a bone. Common in sports fractures.

Question 46

Epiphyseal | Types of fractures

Answer 46

Epiphysis separates from diphysis along the epiphyseal plate. Tends to occur where cartilage cells are dying and calcification of matrix is occurring.

Question 47

Depressed | Types of fractures

Answer 47

Broken bone portion is pressed inward. Type of skull fracture.

Question 48

Greenstick | Types of fractures

Answer 48

Bone breaks incompletely, like a twig. one side of shaft breaks and the other bends. Common in children whose bones are more flexible.

Question 49

1. Hematoma Formation | Stages in healing bone fracture

Answer 49

Fracture is accompanied by hemorrhaging. Blood vessels break, releasing a clot to form hematoma around the break.

Question 50

2. Fibrocartilaginous callus formation | Stages in healing bone fracture

Answer 50

Within a few days new blood vessels form in clot. Bone forming cells invade clot and begin forming soft callus.

Question 51

3. Bony callus formation | Stages in healing bone fracture

Answer 51

Within a week trabeculae of new bone begin to form in bone-spanning width of the callus and growing thicker and stronger-becoming firm about two months after injury.

Question 52

4. Bone Remodeling | Stages in healing bone fracture

Answer 52

Over a period of months the bony callus is remodeled. Excess material is removed, compact bone is laid down to strengthen shaft walls.

Question 53

Rickets (osteomalacia in a adults)

Answer 53

Soft and weak bones (that dont calcify) in children. Pain is felt when weight is put on bone. Malformations of child's head and rib cage are common. Leads to bowed legs. Caused by inadequate amount of vitamin D/calcium phosphate. Exposure to sunlight and drinking vitamin D milk can cure it.

Question 54

Osteoporosis

Answer 54

excessive bone reabsorption aged and postmenopausal women (there is a relationship between osteoporosis and low estrogen levels). Treated by calcium, vitamin D, increased exercise, and estrogen replacement.