A&p 1 Exam #2

Front 1

what makes up most of the skeleton

Back 1

bones

Front 2

where does cartilage occur at

Back 2

isolated areas such as the nose

Front 3

what do ligaments do

Back 3

reinforce joints and connect bones

Front 4

what are articulations

Back 4

aka: joints

-the junctions between bones and provide mobility

Front 5

how much body mass do the bones make up

Back 5

20% of the body mass

Front 6

what is the human skeleton initially made up of

Back 6

cartilages and fibrous membranes

Front 7

what are the early supports of the skeleton system usually replaced by

Back 7

bone

Front 8

where are the few cartilages that remain in adults found

Back 8

regions where flexible skeletal tissue is needed

Front 9

what fibers mostly make up skeletal cartilages

Back 9

collagen

Front 10

what supplies skeletal cartilages nutrients

Back 10

perichondrium

Front 11

what is perichondrium

Back 11

dense irregular CT

Front 12

what do skeletal cartilages not have

Back 12

nerves or blood vessels

Front 13

what are the 2 basic components of CT that all skeletal cartilages have

Back 13

1. chondrocytes (lacuna)

2.extracellular matrix

Front 14

what are the 3 types of cartilages that make up skeletal cartilage

Back 14

1. hyaline cartilage

2. elastic cartilage

3. fibrocartilage

Front 15

what does hyaline cartilage do

Back 15

provides support, flexibility, and resilience

Front 16

what cartilage is the most abundant skeletal cartilage

Back 16

hyaline

Front 17

what fibers are present in hyaline cartilage

Back 17

only collagen fibers

Front 18

what specific areas are hyaline cartilage present in skeletal cartilage and what does the hyaline cartilage do in those areas

Back 18

articular cartilage- covers the ends of long bones at movable joints

costal cartilage- connects the ribs to the sternum

respiratory cartilage- makes up larynx, reinforces air passages

nasal cartilage- supports the nose

Front 19

describe the elastic cartilage in skeletal cartilage

Back 19

similar to hyaline cartilage but contains more stretchy elastic fibers

-found only in epiglottis and ear

Front 20

what is fibrocartilage in skeletal cartilage

Back 20

-flexible

-highly compressible with great tensile strength

-contains rows of chondrocytes alternating with thick collagen fibers

Front 21

where is fibrocartilage found in skeletal cartilage

Back 21

places subjected to both heavy pressure and stretch. such as the padlike cartilage (menisci) of the knee and intervertebral discs

Front 22

what does fibrocartilage lack

Back 22

perichondrium since vessels penetrate up to 40% of the cartilage

Front 23

what does cartilage have that accommodates mitosis

Back 23

a flexible matrix

Front 24

besides flexible matrix what does cartilage have for cartilage growth

Back 24

ideal tissue to lay down the embryonic skeleton

Front 25

when does cartilage growth end

Back 25

during adolescence when skeleton stops growing

Front 26

what is appositional growth

Back 26

"growth from outside"

-cells in perichondrium secrete matrix against the external face of existing cartilage

Front 27

what is intersitial growth

Back 27

"growth from inside"

-lacunae-bound chondrocytes inside the cartilage divide and secrete new matrix, expanding the cartilage from within

Front 28

what are the 6 functions of bones

Back 28

1. support

2. protection

3. assistant in movement

4. mineral homeostasis

5. blood cell formation

6. triglyceride

Front 29

what is the role of support of bones

Back 29

-structural framework for the body by supporting soft tissues

-provide attachment points for the tendons

Front 30

what is the role of protection of bones

Back 30

provide a protective case for the brain, spinal cord, and vital organs

Front 31

what is the role of assistant in movement in the bones

Back 31

when skeletal muscles contract they pull on bones to produce movement

Front 32

what is mineral homeostasis

Back 32

(storage and release)

-reservoir for minerals, especially calcium and phosphorus

-release and store minerals when needed

Front 33

what is blood cell formation

Back 33

(hematopoiesis)

-occurs within the red marrow cavities of bones

Front 34

what is triglyceride

Back 34

(energy)

-storage as the yellow bone marrow

Front 35

what does every bone have

Back 35

compact bone and spongy bone

Front 36

where is compact bone found and what does it do

Back 36

found beneath the periosteum of all bones

-makes up the bulk of the diaphyses of long bones

-provides protection and support

-strongest form of bone tissue

Front 37

what is compact bone composed of

Back 37

osteons

Front 38

what does the compact bone resist

Back 38

the stresses produced by weight and movement

Front 39

where is spongy bone located and what does it do

Back 39

located inside the bones

-allows the bone to move more rapidly when pulled by a skeletal muscle

Front 40

where is spongy bone oriented

Back 40

along the lines of stress

Front 41

what is spongy bone filled with

Back 41

yellow or red bone marrow

Front 42

what does spongy bone lack compared to compact bone

Back 42

osteons

Front 43

which one is lighter.... compact bone or spongy bone

Back 43

spongy bone

Front 44

what does a long bone consist of

Back 44

A. diaphysis

B. 2 epiphyses

C. 2 metaphyses

D. Articular cartilage covering both ends

E. Periosteum

F. Medullary cavity

G. Endosteum

Front 45

what is the diaphysis

Back 45

the bone shaft

Front 46

what is the 2 epithyses

Back 46

both ends of the bone at the joints

Front 47

what is the 2 metaphyses

Back 47

region between diaphysis and epiphysis

Front 48

what is the periosteum

Back 48

connective tissue surrounding the diaphysis

Front 49

what is the medullary cavity

Back 49

hollow space within diaphysis

Front 50

what is the endosteum

Back 50

thin membrane lining the medullary cavity

Front 51

what is the structure of short, irregular and flat bones

Back 51

-has no diaphysis or epiphysis

-contain red bone marrow between the trabeculae

-no significant marrow cavity is present

-thin plates of periosteum-covered compact bone on the outside with endosteum-covered spongy bone (dipole) on the inside

Front 52

what does every bone have

Back 52

-compact bone

-spongy bone

-blood and nerve supply

-long, short, flat or irregular bones

Front 53

what are the 4 major cell types of bone tissue

Back 53

1. osteoprogenitor cells

2. osteoblasts

3. osteocyte

4. osteoclasts

Front 54

what are osteoprogenitor cells

Back 54

-stem cells derived from mesenchyme

-only bone cell to undergo cell division

-periosteum, endosteum and canals

-give rise to osteoblasts

Front 55

what are osteoblasts

Back 55

bone-forming cells

Front 56

what do osetoblasts produce

Back 56

organic matrix called osteoid

Front 57

what are osteocytes

Back 57

mature bone cells

most abundant

in contact with each other (gap junctions)

Front 58

what cells do osteocytes cells contain and what do they do

Back 58

-mechanosensory cells

-they play a role in regulating and maintaining normal skeletal and mineral homeostasis

Front 59

what are osteoclasts

Back 59

cell that break down (resorb) bone matrix

-breaks bone into its components (does everything)

-they're multinucleated

-largest of the bone cells

Front 60

what are the 2 chemical compostitions of bone

Back 60

1. osteoid

2. inorganic components

Front 61

describe the osteoid

Back 61

45% of bone

-organic (unmineralized) bone matrix

-15% water

30% collagen fibers

-provide tensile strength and flexibility

Front 62

which cells produce the osteoid

Back 62

osteoblasts

Front 63

describe the inorganic components

Back 63

-crystallized mineral salts

-hydroxyapatites (55%)

Front 64

what other ions are in the inorganic components

Back 64

magnesium, fluoride, potassium, and sulfate

Front 65

what are the inorganic components responsible for

Back 65

bone hardness and its resistance to compression

Front 66

how are inorganic components present

Back 66

in the form of tiny packed crystals in and around the collagen fibers

Front 67

why do bones last after death

Back 67

because of the inorganic components

Front 68

how do nutrients reach the ostecytes

Back 68

because of the canaliculi- little canals connecting to osteocytes and to the central canal

Front 69

what is ossification or osteogenesis

Back 69

bone tissue formation

Front 70

what are the 4 situations where bones form

Back 70

1. during embryological and fetal development

2. when bones grow before adulthood

3. when bones remodel

4. when fractures heal

Front 71

when does the formation of the boney skeleton develop

Back 71

begins at 8 weeks of embryo development

Front 72

what are the two types of ossification

Back 72

1. intramembranous ossification

2. endochondral ossification

Front 73

what does intramembranous ossification form

Back 73

flat bones like the clavicle and cranial bones

Front 74

what tissue does the membrane bone develop from in intramembranous ossification and what cells is it formed by

Back 74

fibrous CT

-mesenchymal cells

Front 75

what are the stages of intramembranous ossification

Back 75

-an ossification center appears in the fibrous CT membrane

-bone matrix is secreted within the fibrous membrane

-woven bone and periosteum form

-bone collar of compact bone forms, and red marrow appears

Front 76

what does the endochondral ossification use

Back 76

hyaline cartilage models

Front 77

what does the endochondral ossification require

Back 77

the breakdown of hyaline cartilage prior to ossification

Front 78

what are the first 4 stages of endochondral ossification

Back 78

-hyaline cartilage is infiltrated by blood vessels, converting it to a vascular periosteum

-formation of bone collar is produced by osteoblasts by encasing the cartilage with bone

-cartilage in the bone collar calcifies, dies, and forms cavities

-the peristeal bud invades the internal cavities allowing osteoblast and osteoclast to enter the area. osteoclasts remove the calcified cartilage and osteoblasts replace it with bone (earliest version of spongy bone)

Front 79

what are the last 3 steps of endochondral ossification

Back 79

-the diaphysis elongates and a medullary cavity forms

-the epiphysis ossify (secondary ossification)

-when secondary ossification is complete, hyaline cartilage remains at only two places

1. at the epiphyseal surfaces as articular cartilage

2. at the junction of diaphysis and epiphysis forming the epiphyseal plate

Front 80

how many ossification centers do short bones have

Back 80

1

Front 81

how many ossification centers does irregular bones have

Back 81

develop from several distinct ossification centers

Front 82

what is intersitial growth

Back 82

bones growing in length

-endochondral ossification also occurs in epipyseal plates of long bones as the grow in length

Front 83

what is longitudinal bone growth

Back 83

"resting zone"

-cartilage on the side of the epiphyseal plate facing the epiphysis is relatively inactive

Front 84

what happens with the cartilage next to diaphysis

Back 84

organizes into a pattern that allows fast, efficient growth

Front 85

what happens in the growth zone

Back 85

cartilage undergoes mitosis

Front 86

what happens in the hyperthropic zone

Back 86

older cartilage cells enlarge

Front 87

what happens in the calcification zone

Back 87

matrix becomes calcified; cartilage cells die; matrix begins deteriorating

Front 88

what happens in the ossification zone

Back 88

new bone formation is occuring

aka: osteogenic zone

Front 89

what is growth in width

Back 89

"appositional growth"

-real bones cells doing the work

-bones thicken thanks to the cooperative action of osteoblasts and osteoclasts

-osteoblast beneath periosteum secrete bone matrix on eternal surface while osteoclast in endosteum (in the diaphysis) remove bone

Front 90

what two processes does bone remodeling have

Back 90

1. bone deposit

2. bone resorption

Front 91

what are remodeling units

Back 91

adjacent osteoblasts and osteoclasts deposit and resorb bone at periosteal and endosteal surfaces

Front 92

when bone deposition and resorption rates are equal the bone mass remains constant. why?

Back 92

because if not the bone will become too heavy or brittle

Front 93

what does bone deposit require

Back 93

-requires a diet rich in protein; vitamins C, D, and A; calcium, phosphorus, magnesium and manganese

Front 94

where does bone deposit occur

Back 94

-occurs where bone is injured or added strength is needed

Front 95

what is essential for mineralization of bone in bone deposit

Back 95

alkaline phosphatase

Front 96

how does bone resorption work

Back 96

accomplished by osteoclasts (giant, multinucleated cells)

Front 97

what does the ruffled border of the bone resorption secrete

Back 97

-lysosomal enzymes that digest organic matrix

-hydrochloric acids that converts the calcium salts into soluble forms

-dissolved matrix is then secreted into the interstitial fluid and then into the blood

Front 98

where is most of the calcium in your body

Back 98

99% of your body's calcium is stored in your bones and teeth

Front 99

what is the average persons calcium loss per day

Back 99

400-500mg

Front 100

what is the homeostatic level of calcium

Back 100

9-11 mg of calcium/ 100ml of blood

Front 101

what is involved in maintaining homeostasis in your calcium

Back 101

-transmission of nerve impulses

-muscle contraction

-blood coagulation

-secretion by glands and nerve cells

-cell division

Front 102

what controls continue to remodel our bones

Back 102

hormonal mechanisms like...

-growth hormones

-thyroid hormone

-insulin

-during puberty, testosterone and estrogen

Front 103

what does the growth hormone do

Back 103

-stimulates the production and release of insulin-like growth factor (IGF's) by the liver and bone tissue

-stimulates osteoblasts

-promote cell division at the epiphyseal plate and in periosteum

Front 104

what does the thyroid hormone do

Back 104

*keeps rate and proportion of bones*

-stimulate osteoblasts

-modulate growth hormone activity ensuring that the skeleton has proper proportions as it grows

Front 105

what is the role of insulin

Back 105

enhances the synthesis of the proteins needed to build new bone

Front 106

during puberty, what is the role of testosterone and estrogen

Back 106

-increase obsteoblast activity

-initially promote adolescent growth spurts

-cause masculinization and feminization of specific parts of the skeleton

-later induce epiphyseal plate closure, ending intersitial growth on the epiphyseal plate

Front 107

where do testosterone and estrogen work at

Back 107

epiphyseal plate

Front 108

what is the difference between boys and girls when it comes to estrogen

Back 108

girls have 8 times more estrogen compared to boys

Front 109

what are the 3 hormones that regulate bone remodeling

Back 109

1. parathyroid hormone (PTH)

2. calcitonin

3. calcitriol

Front 110

how does the parathyroid work

Back 110

-falling blood calcium levels signal the parathyroid glands to release this hormone

-it increases number and activity of osteoclasts, which degrades bone matrix and release calcium into the blood

Front 111

how does calcitonin work

Back 111

-rising blood calcium levels trigger the thyroid to release this hormone

-inhibits osteoclast activity

-speeds up blood calcium uptake by bone

-accelerates calcium deposits

Front 112

how does calcitriol work

Back 112

aka: Vitamin D

-PTH stimulates the production by the kidneys

-increase calcium absorption in the intestines

Front 113

what does the bones anatomy reflect

Back 113

the stresses it encounters

ex: muscle's pull and gravity

-serves the need of the skeleton by keeping the bones strong where stressors are acting

Front 114

what is the skeleton continuously under

Back 114

hormonal and mechanical influences

Front 115

what do mechanical forces determine in a bone that must be broken down

Back 115

PTH is released but mechanical forces determine which osteoclasts are most sensitive to PTH

-it ensures that the least stressed areas are broken down

Front 116

what is a fracture

Back 116

a break of a bone

Front 117

what is bone repair

Back 117

the healing process of a bone that involves 3 different phases in 4 steps

Front 118

what are the 3 phases in bone repair and what are the 4 steps

Back 118

1. reactive phase (hematoma formation)

2. reparative phase (fibrocartilagaginous callus formation and bony callus formation)

3. Bone remodeling

Front 119

what is hematoma formation and what phase is it in

Back 119

Reactive phase

"early inflammatory phase"

-torn blood vessels hemorrhage

-a mass of clotted blood (hemotoma) forms at the fracture site

-site becomes swollen, painful and inflamed

-bathes area with nutrients and macrophages

Front 120

what is fibrocartilaginous callus formation and what phase is it in

Back 120

*Reparative phase*

-capillaries grow into the tissue and phagocytic cells begin cleaning debris

-fibroblasts produce collagen fibers that connect the broken cells

Front 121

what tissues make up fibrocartilaginous callus formation

Back 121

hyaline cartilage and fibroblasts

Front 122

what is bony callus formation and what phase is it in

Back 122

*reparative phase*

-areas with well-vascularized healthy bone tissue, osteoprogenitor cells develop into soteoblasts which then produce spongy bone

-fibrocartilaginous callus converts into a bony (hard) callus

Front 123

how long does bone callus lasts

Back 123

about 3-4 months

Front 124

what is bone remodeling

Back 124

the last phase of bone repair

-bony callus is remodeled to resemble that of the original unbroken region to make the bone look how it did before

Front 125

when does spongy bone and compact bone get replaced

Back 125

compact bone gets replaced about every 10 years

-spongy bone gets replaced about every 3-4 years

Front 126

what is an open compound

Back 126

a fracture that breaks the skin

Front 127

what is a closed compound

Back 127

a fracture that doesnt break the skin

Front 128

what is articulation

Back 128

site where two or more bones meet

Front 129

what are the weakest part of the skeleton

Back 129

the joints

Front 130

what are the functions of joints

Back 130

1. give skeleton mobility

2. holds skeleton together

Front 131

what are synovial joints and some examples

Back 131

joints in which the articulating bones are separated by a fluid-containing cavity

-all are freely movable diarthroses

-most common type

ex: all limb joints and most joints of the body

Front 132

all synovial joints have what features?

Back 132

-articular cartilage

-joint (synovial) cavity

-articular capsule

-synovial fluid

-reinforcing ligaments

-innervation and vascularization

Front 133

what is articular cartilage and what does it do

Back 133

-hyaline cartilage

-cushions and absorb compression

-prevent bone ends from being crushed

Front 134

what is the joint cavity and what does it do

Back 134

-feature unique to synovial joints

-space

-filled with synovial fluid

-allows the joints to be freely moveable

Front 135

what is the articular capsule and what does it do

Back 135

joint cavity enclosed by two-layer articular capsule (or joint capsule)

-composed of fibrous capsule and synovial membrane

Front 136

what is the fibrous capsule

Back 136

part of the articular capsule

-composed of irregular dense regular CT

-continuous with periosteum

Front 137

what is synovial mm

Back 137

part of the articular capsule

-composed of synovial mm

-lines all internal parts that aren't hyaline cartilage

Front 138

what is synovial fluid and what does it do

Back 138

-occupies all free spaces within the joint capsule

-produced by synovial mm

-derived from blood filtration

-reduces friction between cartilages

-supply nutrients to cartilage and removes waste

Front 139

what cells does synovial fluid contain

Back 139

phagocytic cells

Front 140

what are reinforcing ligaments responsible for

Back 140

-reinforcement and strengthening

-unite bones and prevent excessive or undesirable motion

-give stability and alignment

Front 141

what is innervation and vascularization

Back 141

-monitor pain but mostly monitor joint position and stretch

-they're richly supplied with sensory nerve fibers

-rich in blood vessels, most of which supply the synovial mm

Front 142

what are synovial joints responsible for

Back 142

friction reducing and

stability

Front 143

what are friction reducing structures

Back 143

Bursae and tendon sheath

Front 144

describe bursae

Back 144

flattened, fibrous sacs lined with synovial membranes and containing synovial fluid

-common where ligaments, muscles, skin, tendons or bones rub together

Front 145

describe tendon sheath

Back 145

elongated bursae that wraps completely around a tendon subjected to friction

Front 146

what is stability determined by

Back 146

-articular surfaces

-ligaments

-muscle tone

Front 147

what do articular surfaces do

Back 147

shape determines what movements are possible

Front 148

what do ligaments do

Back 148

prevent excessive or undesirable motion

THE MORE YOU HAVE AT A JOINT THE STRONGER IT IS

Front 149

what is muscle tone

Back 149

tendons that are kept tight at all times by the tones of their muscle

-very important at reinforcing the shoulder and knee joints

Front 150

what are the two muscle attachments across a joint

Back 150

origin- attachment to the immovable bone

insertion- attachment to the movable bone