Exam 1 Part Three Flashcards Preview

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Flashcards in Exam 1 Part Three Deck (134):
1

The flat bone of skull is formed by

Intramembranous ossification

2

Contains concentric lamallae

Osteon

3

Spongy bone is formed by

Trabeculae

4

End of a long bone

Epiphysis

5

Organic components of bone matrix

Osteoid

6

The parathyroid hormone stimulates

Osteoclasts to become active

7

The endosteum lines

The medullary cavity

8

Osteoclasts are responsible for

Bone resorption

9

Vitamin D increases

Calcium absorption in intestine

10

Hydroxyapatite is

Calcium phosphate/ hydroxide crystals

11

The immature cells that produce osteoid are called

Osteoblasts

12

Hyaline cartilage is found in these places

Trachea, layrnx, fetal skeleton

13

A small space within compact bone housing an osteocyte is termed a

Lacuna

14

Endochondral ossification begins with a _____ model of bone

Hyaline cartilage

15

Production of new bone _______as a result of increased sex hormone production at puberty.

Increases rapidly

16

An epiphyseal line appears when

Epiphyseal plate growth as ended

17

The condition of inadequate ossification that may accompany aging and is a result of reduced calcification is called

Osteopenia

18

The femur is an example of a?

Long bone

19

A large, rough projection of a bone is termed a

Tuberosity

20

Identify the three types of cartilage, describing the extracellular matrix of each type

1) Hyaline
2) Elastic
3) Fibrocartilage
A matrix of protein fibers embedded within a gel-like ground substance. Chondroblasts are the cells that produce the matrix of cartilage. Once they become encased w/in the matrix they have produced and secreted, the cells are called chondrocytes & occupy small spaces called lacunae. These mature cartilage cells maintain the matrix & ensure that it remains healthy & viable

21

Describe the structure of the periosteum, & list its functions

It is a tough sheath that covers the outer surface of bone, except for the areas covered by articular cartilage. Made of dense irregular connective tissue & consists of an outer fibrous layer & an inner cellular layer.
Its functions are:
*Protects the bone from surrounding structures
*Anchors blood vessels & nerves to the surface of bone
*Provides stem cells (osteoprogenitor cells & osteoblasts) for bone width growth & fracture repair

22

What are the types of bones?

Long bones, short bones, flat bones, irregular bones

23

What are the functions of the skeletal system?

1) Support: Provides structural support & serve as the framework for the entire body
2) Protection: surrounds soft tissue- ex. ribs and sternum protect the heart and lungs, - skull protects the brain
3) Movement: skeletal muscle is attached to bone so it pulls on the bone when it contracts
4) Hemopoiesis: The process of blood cell production. Red bone marrow produces red blood cells, white blood cells and other blood elements
5) Storage of mineral & energy reserves: storage of minerals and lipids(fats)---yellow marrow stores fat --(found in long bones) stores calcium and phosphate--minerals are released into the blood when needed

24

Endochondral ossification basic steps

1) A hyaline cartilage model of bone forms
2) Bone first replaces hyaline cartilage in the diaphysis
3) Later, bone replaces hyaline cartilage in the epiphyses
4) Eventually, bone replaces hyaline cartilage everywhere, except the epiphyseal plates & articular cartilage
5) By a persons late 20s, the epiphyseal plates have ossified, & lengthwise bone growth is complete

25

Osteoporosis is

In which bone mass becomes reduced enough to compromise normal function. A large number of older women & a smaller number of older men suffer from this.

26

Name the steps of appositional growth

1) Stem cells at the internal edge of the perichondrium begin to divide, forming new stem cells & committed cells
2) The committed cells differentiate into chondroblasts
3) These chondroblasts begin to produce & secrete new cartilage matrix. As a result, they push apart & become chondrocytes, each occupying its own lacuna
4) The new matrix has been produced peripherally, & thus appositional growth as occurred

27

Describe the microscopic anatomy of compact bone

Organized structure when viewed under the microscope. A cylindrical osteon is the basic functional & structural unit of mature compact bone. Osteons run parallel to the diaphysis of the long bone.

28

An osteon is a three-dimensional structure that has several components

*The central canal
*Concentric lamellae
*Osteocytes
*Canaliculi

29

Simple fracture=

(Closed) Bone does not break through the skin

30

Compound fracture=

(Open) Broken ends of the bone protrude through the skin

31

Complet fracture=

Bone is broken into two or more pieces

32

What are the steps to fracture repair in bones

1) A fracture hematoma forms
2) A fibrocartilage (soft) callus forms
3) A hard (bony) callus forms
4) The bone is remodeled

33

comminuted fracture is

Bone is splintered into several small pieces between the main parts

34

Incomplete fracture=

Fracture extends only partway across the bone

35

Greenstick fracture=

Partial fracture; convex side of bone breaks-the other side is bent

36

Transverse fracture=

Fracture at right angles to the long axis of the bone

37

Spiral fracture=

Fracture spirals around axis of long bone; results from twisting stress

38

What kind of secretion does the sebaceous glands secrete?

Holocrine

39

Sesamoid bones are

small round & flat bones that form within tendons, highly variable from individual to individual except for the patella

40

Flat bones

have two parallel plates of compact bone with a thin layer of spongy bone sandwiched in between them

41

Mesenchyme are

Star shaped cells- They are stem cells that give rise to all connective tissue

42

Osteoprogenitor is

From mesenchyme (usually in the endosteum)
Can divide & differentiate into osteoblasts
Differentiate during bone formation and after bone fracture...

43

Fibroblast

*Produce all connective tissue fibers
*Collagen, reticular & elastic fibers

44

Cartilage forming cells

Chondroblast

45

Encased chondroblasts

Chondrocytes

46

Bone forming cells

Osteoblast

47

Osteocytes are

Encased osteoblasts
*mature bone cells occupying lacuna (maintains bone)

48

Osteoclasts are

Bone destroying cells
*Giant multinucleate (fused bone marrow stem cells)
*contain lysosomes
*secret HCI
*dissolve bone matrix (osteolysis)
*frees Ca++ into the blood

49

What are the 3 types of cell secretion?

Merocrine (eccrine), apocrine, holocrine

50

What is the mature cell of cartilage?

Chondrocyte

51

What kind of bone is the patella?

Sesamoid bone

52

What is one unit of compact bone called?

Osteon

53

What causes skin color?

Melanin, carotene, blood

54

Where are melanocytes located?

Stratum Basale

55

What is the waterproof protein of skin & hair?

Keratin

56

What is the band of cartilage between diaphysis and epiphysis?

Epiphyseal plate..

57

Bone matrix composition

Organic framework: collagen fibers
*Secreted by osteoblasts, roughly 1/3 the weight of bone.
*Due to its toughness & flexibility, provides bone its tensile strength (acting like rebar)
Inorganic salts: Ca3(PO4)2-Calcium Phosphate
• Hardest matrix material
• Tooth enamel!
• Rigid
• Brittle
• Small plates of Ca3(PO4)2 lie alongside the collagen fibers (like cement with rebar)

58

Trabeculae

form a lattice-like network of struts.
* Significantly decrease the weight
*Keeps strength

59

“Direct” ossification

Intramembranous Ossification

60

Describe Intramembranous Ossification

*Eight weeks of development- 8 weeks
*Osteoblasts form within connective tissue (“dermal bones”).
*Only about 10% of your bones form this way: many in the skull, clavicle, scapula, os coxae & all sesamoid bones (including patella)

61

What are the steps to Intramembranous Ossification

Step 1 – Mesenchyme cell clusters become osteoprogenitor cells that become osteoblasts.
Osteoblasts produce osteoid. Osteoid begins to mineralize as the ossification center...
Step 2 – Bony spicules (trabeculae) begin to radiate out from the ossification center. Any trapped osteoblasts become osteocytes; blood vessels branch & grow.
Step 3 – Over time, this bone assumes the structure of spongy bone with blood vessels trapped in trabeculae
Step 4- Bone remodeling results in two layers of
compact bone with spongy bone and small marrow cavities in between. A sandwich!

62

Endochondral Ossification is

* “Indirect” ossification via cartilage
*A hyaline cartilage skeleton model is made first, then that cartilage is converted into bone.
*Most bones form this way...

63

Summary of Endochondral Bone-

• Hyaline cartilage model develops (in fetus via chondroblasts).
• Cartilage calcifies and periosteal collar forms.
• Primary ossification center (osteoblasts in diaphysis.
• Secondary ossification centers (epiphysis).
• Replacement of cartilage w/ bone (except epiphyseal plates.
• Complete ossification (epiphyseal line)

64

Appositional bone growth

*proceeds as periosteal cells differentiate into new osteoblasts which lay down bone on the bone’s exterior.
*New osteons will organize over time.
*Osteoclasts on the endostium will dissolve bone enlarging the marrow cavity...

65

Hormones influence what in bones?

Ca++ balance, as well as the timing of growth spurts & the end of growth

66

Calcitonin from the thyroid & parathyroid hormone from the parathyroid glands control

homeostasis of Ca++

67

Human Growth Hormone & Thyroxine maintain

epiphyseal cartilages until growth is done

68

Estrogen & testosterone accelerate

bone growth & the “closure” of epiphyseal plates


69

Ligaments join

bone to bone

70

Tendons join

Muscle to bone

71

Bursa

small pockets of synovial membrane, filled with synovial fluid, eases motion & cushions friction

72

Tendon sheaths are

Tubular bursae that surround tendons with bony friction

73

Articular discs are

Articular discs: fibrocartilage pads that limit movement, also called menisci

74

Name the different knee injuries

• Meniscus tear
• ACL tear
• Medial colateral tear
• Patellar ligament tear

75

Rotator cuff injury

• Shoulder- greatest range of movement!
• Muscles (with tendons) hold head of humerus in glenoid fossa

76

Carpal tunnel syndrom

Any compression of either the median nerve or the tendons in the tunnel results in carpal tunnel syndrome.

77

Tennis elbow

Also called lateral epicondylitis is a painful condition resulting from trauma or overuse of the common extensor tendon of the posterior forearm muscles. It arises from the lateral epicondyle of the humerus, the attachment site of the common extensor tendon

78

What are the indications that bone is alive?

It grows, repairs, thickens and undergoes atrophy

79

Osteocytes communicate through?

Canaliculi

80

Describe the characteristics of articular cartilage

A thin layer of hyaline cartilage covering the epiphysis at a joint surface. It helps reduce friction & absorb shock in movable joints

81

What are the characteristics of the medullary cavity

The hollow, cylindrical space within the diaphysis. In adults it contains yellow bone marrow

82

The characteristics of the endosteum are

An incomplete layer of cells that covers all internal surfaces of the bone, such as the medullary cavity. Contains osteoprogenitor cells, osteoblasts, & osteoclasts, & is active during bone growth, repair, & remodeling

83

Why is spongy bone able to withstand stress in an area such as the expanded end of a long bone?

Spongy bone is lighter & able to withstand stresses applied from many directions.

84

What is ossification?

The developmental process of bone formation

85

What are the effects of exercise on bone mass

*Bone has the ability to increase its strenght over a period of time by increasing the amounts of mineral salts deposited & collagen fibers synthesized
*Bones of athletes become thicker
*Weight lifting or walking help build and retain bone mass
*lack of exercise weakens bone

86

What is the difference between intramembranous ossification and endochondral ossification?

Intramembranous ossification [flat bones] & endochondral ossification [long bones].The essential between them is the presence or absence of cartilaginous phase

87

Bones growth in length is called?

Interstitial growth

88

Bones growth in diameter or thickness is called?

Appositional growth

89

Interstitial growth occurs

Within the epiphyseal plate as chondrocytes undergo mitotic cell division in zone 2 & chondrocytes hypertrophy in zone 3
*these activities combine to push the zone of resting cartilage toward the epiphysis, while the new bone is being produced at the same rate in zone 5, resulting in increased bone length.

90

Appositional growth occurs

Within the periosteum. Osteoblasts in the inner cellular layer of the periosteum lay down bone matrix in layers parallel to the surface. As these lamellae increase in number, the structure widens. As new bone is being laid down the osteoclasts along the medullary cavity resorb bone matrix, creating an expanding medullary cavity

91

List the four types of arteries that are found in a long bone and what portion of each bone does the artery supply

1) Nutrient artery-Diaphysis
2) Metaphyseal arteries & metaphyseal veins-Diaphyseal side of the epiphyseal plate
3) Epiphyseal arteries & epiphyseal veins-Epiphyses
4) Periosteal arteries & periosteal veins-External circumferential lamellae & the superficial osteos within the compact bone at the external edge of the bone

92

Supraorbital forearm

Frontal bone

93

Foremen magnum

Occipital bone

94

Sella turcica

Sphenoid bone

95

Cribriform plate

Ethmoid bone

96

Transverse foramina

Cervical vertebrae

97

Costal demifacets

Thoracic vertebrae

98

Xiphoid process

Sternum

99

Upper Jaw

Maxillae

100

Which bones form the hard palate?

Palatine bones & maxillae

101

The bony portion of the nasal septum is formed by the?

Perpendicular plate of the ethmoid bone and vomer

102

The mandible articulates with the_____bone.

Temporal

103

Some muscles that control the tongue and larynx are attached to the?

Hyoid bone

104

The frontal and parietal bones articulate at the ___ suture

Coronal

105

The compression of an infant's skull bones at birth is facilitated by spaces between unfused cranial bones called

Fontanelles

106

What are the openings in the sphenoid

Foramen rotundum, foramen spinosum, optic canal

107

Each temporal bone articulates with the

Occipital, zygomatic, sphenoid, & parietal bones, and the mandible

108

Most____vertebrae have a long spinous process that is angled inferiorly

Thoracic

109

The clavicles articulate with the _____ of the sternum

Manubrium

110

What are sutures, & how do they affect skull shape & growth?

Immovable joints that form the boundaries between the cranial bones. (coronal, lambdoid, sagittal, & squamous)
They allow the cranium to grow & expand during childhood. In adulthood, when cranial growth as stopped, the sutures fuse and are obliterated.

111

Identify the first two cervical vertebrae

C1-Atlas-supports the head via its articulation with the occipital condyles of the occipital bone
C2-Axis-during development the body of the atlas fuses to the body of the axis
The fusion produces the most distinctive feature of the axis, the prominent dens
The dens acts as a pivot for the rotation of both the atlas & the skull

112

Identify the region of the vertebral column that is most likely to experience a herniated disc, & discuss the causes of this problem

The cervical and lumbar intervertebral discs are the most common discs to be injured, because the vertebral column has a great deal of mobility in these regions, and the lumbar regions bears increased weight.
It occurs when the gelatinous nucleus pulposus protrudes into or through the anulus fibrosus.

113

What are the 5 regions of the vertebral column

1) Cervical vertebrae
2) Thoracic vertebrae
3) Lumbar vertebrae
4) Sacrum
5) Coccyx

114

Describe the similarities and differences among true, false and floating ribs

Ribs 1-7-true ribs which connect individually to the sternum by separate cartilaginous extensions called costal cartilages
Ribs 8-12-false ribs their costal cartilages do not attach directly to sternum, instead they fuse to the costal cartilage of rib 7
Ribs 11-12-floating ribs because they have no connection with the sternum

115

Lateral malleolus

Fibula

116

Supraspinous fossa

Scapula

117

Tarsal bone

Talus

118

Capitulum

Humerus

119

Radial notch

Ulna

120

Acetabulum

Os coxae

121

Lesser trochanter

Femur

122

Medial malleolus

Tibia

123

Sternal end

Clavicle

124

The female pelvis typically has which characteristics?

Wide subpubic angle, greater than 100 degrees

125

The posterior surface depression at the distal end of the humerus is the

Olecranon fossa

126

The spine of the scapula separates which two fossae?

Infraspinous, supraspinous

127

The femur articulates with the tibia at the femur's

Medial & lateral condyles

128

The bony feature palpated on the dorsolateral side of the wrist is the

Styloid process of radius

129

Identify the bone that articulates with the os coxae at the acetebulum

Femur

130

When sitting upright, you are resting on your

Ischial tuberosities

131

The two prominent bumps you can palpate on the sides of your ankle are the

Medial malleolus & lateral malleolus

132

The glenoid cavity articulates with which bone or bone features?

Head of the humerus

133

Compare the anatomic and functional features of the pectoral & pelvic girdles

Pelvic:
-Deep, secure socket for limb attachment
-Lightweight
-Weight-Bearing

Pectoral:
-Shallow socket for limb attachment
-Massive
-Flexibility

134

How do the glenoid cavity & the acetabulum differ?

Compared to the acetabulum (hip-joint) the glenoid cavity is relatively shallow
The glenoid cavity is found in the upper body, where the humerus joins the scapula and is referred to as the shoulder socket. It is not very deep and allows for a great range of motion.
The acetabulum is in the lower body, where the ilium joins the femur. It is a deep socket and is very secure for the support and ability to bear the weight of our bodies