Histo - Cartilage/Bone Flashcards

1
Q

What is the general composition of connective tissue?

A

cells + ecm (protein fibers and ground substance)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the 3 types of protein fibers?

A

collagen, reticular, elastic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the 3 examples of ground substance given?

A
  1. glycosaminglycans (GAGs ex: hyaluranic acid, chondroiton sulfate)
  2. proteoglycans
  3. multiadhesive glycoproteins (ex: laminin and fibronectin)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

In epithelium, nervous tissue, muscle tissue, ___ is the major component of connective tissue.

In cartilage, ___ is the major component of connective tissue.

A

first: cells
second: ECM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

ECM is usually secreted by ___

A

cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Describe the ground substance characteristics

A

unstructured, amorphous materials between cells and fibers

provides a medium through which nutrients can diffuse

can be fluid, semi-fluid, gelatinious, or calcified.

hydrophilic.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

All connective tissue is derived from ____

A

mesenchyme

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is mesenchyme?

A

loosely organized embryonic connective tissue

contains elongated, spindle shaped undifferentiated stem cells

multipotent cells with oval and round nucleus, prominent nucleolus, fine chromatin, thin cytoplasmic processes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are chondroblasts derived from?

A

mesenchyme

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What cells are found in cartilage?

A

chondroblasts (secrete ECM)

chondrocytes (secrete and maintain ECM)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What % volume is the ECM in cartilage?

A

95%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

The ECM of cartilage is rich in ___ and ___. This allows it to withstand ____.

A

ECM of cartilage is rich in glycosaminoglycans and proteoglycans

allows it to withstand mechanical forces (it is resilient)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

ECM allows it to withstand _____

A

mechanical forces (making it resilient)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the perichondrium?

A

the dense CT covering MOST of the cartilage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What does the perichondrium contain?

A

perichondrium contains blood vessels, nerves, chondrogenic cells, type I collagen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Perichondrium of cartilage is essential for ____

A

growth and maintenance of cartilage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Is cartilage avascular or vascular?

A

avascular

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How do chondrocytes receive nutrients?

A

chondrocytes in lacunae receive nutriets via diffusion from perichondrial blood cells

(remember: chondrocytes are in lacunae and the cartilage is avascular, so they need a new means to receive nutrients)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What aspect of the cartilage allows for easy diffusion?

A

ECM is high in water content so allows for diffusion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the 2 mechanisms for cartilage growth?

A
  1. appositional growth

2. interstitial growth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is appositional growth?

A

growth by additional to existing surface
generation of new chondroblast

when chondroblasts secrete new matrix so much that they are inside of it (now it’s called a chondrocyte)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is interstitial growth?

A

growth by internal expansion

proliferation of chondrocytes to form isogenic groups

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are the 3 types of cartilage?

A
  1. hyaline cartilage
  2. elastic cartilage
  3. fibrocartilage
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Describe the ECM of hyaline cartilage

A

high in % water
proteoglycans, hyaluronic, chondroiton sulfate, keratin sulfate, type II collagen

H2O bound to negative GAGs, makes it resilient and a shock absorber

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Describe where hyaline cartilage is found

A

articular cartilage, nose, larynx, trachael rings, esophygeal plates, fetal bone models

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Is perichondrium found in hyaline cartilage

A

Yes. in most hyaline cartilage..

there are a few exceptions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is the appearance of hyaline cartilage?

A

It is different in a fresh dissection and a histological dissection.

Fresh dissection - blu-ish white and translucent

Histologically - matrix generally is basophilic (because of negative GAGs.
- in HE stain: collagen fibers indiscernible because same refractie index as surrounding sunstance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What are the 3 cell populations in hyaline cartilage?

A

chondrogenic cells
chondroblasts
chondrocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What are chondrogenic cells and where are they found?

A

inner portion of perichondrium, can develop into chondroblasts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What are chondroblasts and where are they found?

A

elliptical shape, long axis parallel to cartilage surface

these begin to synthesize and secrete ECM

once completely surrounded by matrix (in lacuna) called chondrocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Where are chondrocytes and where are they found?

A

They are in lacuna

they are more rounded than chondroblasts

found in isogenous groups (isogenic clusters)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What are isogenous groups? AKA ___

A

aka isogenic clusters

chondrocytes that recently went through mitosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What are the 2 matrix types in hyaline cartilage?

A

territorial matrix and interterritorial matrix

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

what is territorial matrix?

A

rich in GAG poor in collagen

surrounds each chondrocyte and isogenic group

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What is interterritorial matrix?

A

collagen more abundant, farther from chondrocytes/isogenous groups

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What is the ECM composition of elastic cartilage?

A

it is essentially the same as hyaline cartilage with type II collagen fibers

and ADDITION OF ELASTIC FIBERS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Where is elastic cartilage found?

A

auricle (aka pinna), auditory canal, auditory (pharyngotympanic) tube, epiglottis

found in these locations because elastic cartilage is pliable and resilient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Is there perichondrium in elastic cartilage?

A

present (perichondrium is acidophilic)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What is the appearance of elastic cartilage?

A

different in a fresh dissection vs histologically

fresh dissection - yellowish (because elastic fibers)

histologically- with SPECIAL STAINING, elastic fibers are prominent. they are a dense network of branching/anastomosing fibers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

How do elastic cartilage and hyaline cartilage compare?

A

elastic cartilage has:

  • elastic fibers
  • higher ratio of chondrocytes to ECM
  • fewer cells per isogenous group
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

As people age, the _____ cartilage in their epiglottis shrinks and is replaced by _____

A

elastic cartilage shrinks and is replaced with unilocular adipose tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What is the composition of the ECM if fibrocartilage?

A

type I and II collagen fibers, less proteoglycans than other cartilages

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Where is fibrocartilage found? Why?

A

found in intervertebral discs, pubic symphysis, major tendon-bond anchorages

because of components of the ECM, fibrocartilage is found in areas that undergo lots of pulling forces/compression forces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Is there a perichondrium present in fibrocartilage?

A

perichondrium is absent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What is fibrocartilage appearance histologically?

A

tissue is an intermediate between dense regular connective tissue and hyaline cartilage

chondrocytes are arranged in long rows, separated by coarse collagen fibers

matrix is more acidophilic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Think of fibrocartilage as an intermediate between ___ and ____

A

fibrocartilage is the intermediate between hyaline cartilage and dense connective tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

How is fibrocartilage similar to hyaline cartilage?

A

fibrocartilage contains chondrocytes in lacunae and type II collagen which gives fibrocartilage the ability to withstand compression forces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

How is fibrocartilage similar to dense connective tissue?

A

fibrocartilage contains type I collagen which gives fibrocartilage high tensile strength

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

Fibrocartilage can withstand both ___ and ___ forces

A

compression and shearing forces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

Describe chondrocytes in fibrocartilage

A

there are fewer chondrocytes in fibrocartilage than there are in hyaline or elastic cartilage

chondrocytes are alligned along collagen bundles either singularly or in isogenous groups

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

Often fibrocartilage is seen adjacent to ___, and the transition between the two is ____.

A

dense connective tissue

transition between the two is gradual

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

what is the general composition of connective tissue?

A

cells + ecm (protein fibers + ground substance)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

What are examples protein fibers in bone?

A

collagen, reticular, elastic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

What are examples of ground substance in bone?

A
  1. GAGs aka glycosaminoglycans (ex: hyaluronic acid, chondroiton sulfate)
  2. Proteoglycans
  3. Multiadhesive glycoproteins (ex: laminin and fibronectin)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

What are the 5 functions of bones?

A
1 support
2 protection
3 movement
4 storage
5 blood cells formation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

Describe how bones support the body

A

because bones are the framework of the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

Describe how bones protect the body

A

skull protects the brain, vertebrae protect spinal cord, ribcage protects the lungs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

Describe how bones help with body movement

A

because skeletal muscles are attached to bones predominately via tendons and use bones as levers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

Describe how bones assist in storage

A

bones are a reservoir for minerals (calcium and phosphate)

yellow bone marrow contains white/unilocular adipose cells which store triglycerides, potential chemical energy source

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

Describe how bones assist in blood cell formation

A

occurs in red bone marrow found in bone marrow cavities and other locations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

What are the 5 classifications of bone according to shape?

A
1 long bone
2 short bone
3 flat bone
4 irregular bone
5 sesamoid bone
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

Describe long bones generally

A

longer than wide
have shaft and 2 end parts
all bones of extremeties except patella, carpal bones, tarsal bones
some long bones (phallanges) not that long but are still longer than they are wide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

Describe short bones generally

A

cubed, equal length and diameter, includes the carpal and tarsal bones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

Describe flat bones generally

A

thin, flattened, plate-like bones

ex: sternum, scapulae, ribs, most of skull

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

Describe irregular bones generally

A

complicated shape

vertebrae and hip bones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

Describe sesamoid bones generaly

A
  • special type of short bone that forms a tendon
  • there is only one named sesamoid bone - = petallar bone
  • number of sesamoid bones varies in individuals
  • act to alter direction of pull of tendon
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

What are the 2 gross-observation classifications of bone?

A

compact (cortical) bone and spongy bone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

What is the difference between compact and spongy bone in gross observation?

A

in GROSS observation, compact (cortical bone) looks solid to naked eye (is not actually solid)

in GROSS observation, spongy bone contains thin bone spicules called trabeculae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

Under histological observation, what is the difference between spongy and compact bone?

A

They are made up of similar composition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

Describe the 4 parts of a long bone

A

1 diaphysis
2 epiphysis
3 metaphysis
4 epiphyseal plate/line

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

Diaphysis of long bone: what is the outside part and inside part?

A

outside part is compact bone

inside part is medullary (marrow) cavity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

What can the medullary (marrow) cavity of the diaphysis of a long bone be filled with?

A
  1. RED bone marrow (hematopoesis)

2. YELLOW bone marrow (triglyceride storage)

73
Q

In adults, what occurs with hematopoeisis?

A

over time, hematopoesis is limited to certain areas of the body because most red bone marrow has begun to convert to yellow

74
Q

Epiphysis: what is the outside part and inside part?

A

compact bone on outside

spongy bone on inside

75
Q

Where is the diaphysis on the long bone?

A

the shaft

76
Q

Where is the epiphysis of the long bone?

A

on the bone ends

77
Q

What is located between the bone spicules of spongy bone in long bones?

A

red or yellow bone marrow

78
Q

Where is the metaphysis on the long bone?

A

flared portion of bone between epiphysis and diaphysis

each metaphysis extends from the diaphysis to the epiphyseal line

79
Q

Where is the epiphyseal plate/line found on a long bone?

A

between the metaphysis and epiphysis

80
Q

What is the epiphyseal plate? What is it made up of?

A

epiphyseal plate is in still growing areas aka the growth plate

composed of hyalie cartilage

81
Q

What takes place in the epiphyseal plate?

A

activities that take place in plate allow for long bone to grow lengthwise

82
Q

What is the hyaline cartilage of the epiphyseal plate replaced with? Once replaced, what is the new term?

A

replaced with bone

then called epiphyseal line

83
Q

What are the two membranes of long bone?

A

periosteum and endosteum

84
Q

Where is the periosteum on a long bone?

A

covers the outer surface of bone with exceptions of articular surfaces and tendon and ligament insertion

85
Q

Is the periosteum vascular or avascular?

A

vascularized

86
Q

Periosteum is double layered. What are the 2 layers?

A

outer portion = fibrous dense irregular CT

inner portion = osteogenic layer (osteogenic cells, osteoblasts, osteoclasts)

87
Q

What is the periosteum connected to? How?

A

Periosteum is connected to underlying bone via perforating/sharpey’s fibers (which are collagen fibers)

88
Q

What are perforating/sharpey’s fibers? Where are they? What do they do?

A

Collagen fibers

attach periosteum to underlying bone

89
Q

Describe the endosteum

A

Consists of cells that belong to the stroma of the marrow or are derived from resting osteoblasts

main source of lining cells of cortical haversion canals

90
Q

What is articular cartilage?

A

articular joint surfaces covered with cartilage

composed of hyaline cartilage

cushions opposing ends of bones during movement and absorbs different stresses

91
Q

Do the short/flat/irregular/sesamoid bones have the same parts as the long bones?

A

no.

short/flat/irregular/sesamoid bones do not have a diaphysis, epiphysis, metaphysis or marrow cavity

92
Q

What are the components of short / flat / irregular / sesamoid bones?

A

look like chocolate dipped oreo cookies

chocolate covering - periosteum of compact bone

cookie - compact bone

cream filling - spongy bone in middle (called diploe)

93
Q

What is a diploe?

A

The spongy bone in the middle of the compact bone

94
Q

What is the covering for the trabeculae of diploe (spongy bone) and the covering for the passageways of the compact bone?

A

endosteum

95
Q

What is between the endosteum lined trabeculae?

A

either red or yellow bone marrow

96
Q

How are the trabeculae of diploe lined up?

A

lined up along stress lines

although they look like they are lined up randomly

97
Q

What is the composition of bone tissue?

A

cells + ECM

98
Q

What are the 4 cells types of bone tissue?

A

osteogenic cells, osteoblasts, osteocytes, osteoclasts

99
Q

What are the 2 components of ECM in bone tissue?

A
  1. organic part (osteoid part)

2. inorganic part

100
Q

What is the organic (osteoid) part of the ECM of bone tissue secreted by?

A

osteoblasts

101
Q

What does the organic (osteoid) part of the ECM of bone tissue contain?

A

type I collagen, bone matrix proteins (GAGs, hyaluronic acid, chondroitin sulfate, glycoproteins, osteocalcin, osteonectin)

102
Q

What is osteocalcin and where is it found?

A

found in the organic (osteoid) part of the ECM of bone tissue

osteocalcin is a bone-specific multiadhesive glycoprotein

103
Q

What is osteonectin and where is it found?

A

found in the organic (osteoid) part of the ECM of bone tissue

osteonectin is a vitamin-k-dependent polypeptide, important for the calcification of bone

104
Q

What is the in-organic part of ECM of bone tsisue composed primarily of?

A

hydroxyapitite crystals (most abundant component of inorganic part of ECM in bone tissue)

105
Q

What makes up 50% of the dry weight of bone matrix in bone tissue?

A

inorganic part of ECM

106
Q

In the inorganic part of ECM of bone tissue, the association between collagen fibers and inorganic portion (HA crystals) is responsible for _____

A

hardness/resistance of bone

107
Q

What are the 4 types of bone cells?

A

1 osteoprogenitor cells/osteogenic cells
2 osteoblasts
3 osteocyte
4 osteoclasts

108
Q

What do osteoprogenitor cells develop into?

A

osteoblasts

109
Q

What are osteoprogenitor cells?

A

basically mesenchymal stem cells

110
Q

Osteoprogenitor cells have the potential to divide via ____ to differentiate into ___

A

potential to divide via mitosis to differentiate into osteoblasts

111
Q

Where are osteoprogenitor cells found?

A

inner layer of periosteum and endosteum

112
Q

What develops into the osteoblasts?

A

osteoprogenitor cells

113
Q

Osteoblasts are responsible for synthesis/secretion of _____

A

organic component of ECM (osteoid)

114
Q

What bone cell is responsible for the synthesis/secretion of organic component (osteoid) of ECM?

A

osteoblast

115
Q

Osteoblast activity signals for ____ of bone.

A

calcification of bone.

This is the depositing of the inorganic part of ECM

116
Q

Which bone cell type activity is responsible for calcification of bone (aka deposits the inorganic part of the ECM)?

A

Osteoblasts

117
Q

Where are osteoblasts located?

A

osteoblasts are located on the surface of bone matrix, side by side like simple epithelium

118
Q

Which type of bone cell looks like simple epithelium, aligned along the surface of bone matrix?

A

osteoblasts

119
Q

What happens to osteoblasts histologically when they are actively producing matrix?

A

they are cuboidal/columnar in shape with a basophilic cytoplasm

120
Q

Which type of cell becomes cuboidal/columnar in shape with a basophilic cytoplasm when they are actively producing matrix?

A

osteoblasts

121
Q

What happens with the osteoblast secretes so much matrix that they encapsulate themselves?

A

they are now called osteocytes

122
Q

Where do osteocytes sit?

A

in lacunae in the matrix

which they themselves maintain

123
Q

As osteocytes transition from osteoblasts, they extend ____ that are found in ____.

A

long cytoplasmic extensions of osteocytes are found in tunnels called canaliculi

124
Q

Which bone cell type has cytoplasmic extensions? when they do they develop?

A

osteocytes have long cytoplasmic extensions

they develop when the osteocytes are formed from osteoblasts

125
Q

Where are the long cytoplasmic extensions of osteocytes found?

A

the tunnels called canaliculi

126
Q

What are caniliculi? What is found within them?

A

Caniliculi are tunnels

found within them are the long cytoplasmic extensions of osteocytes (which develop when osteocytes are being formed from osteoblasts)

127
Q

Which bone cell type is associated with caniliculi?

A

osteocyte

128
Q

Describe the organelles of osteocytes

A

more reduced rER, reduced golgi complex, more condensed chromatin than osteoblasts

129
Q

What do osteoclasts do?

A

remove/resorb bone

130
Q

Are osteoclasts large or small?

A

large

131
Q

How long can osteoclasts live?

A

many years

132
Q

What are osteoclasts derived from?

A

derived from same stem cells that produce macropahges (aka are derived from monocytes)

formed by the fusion of many monocytes that is why osteoclasts are multinucleated

133
Q

How do osteoclasts dissolve bone matrix?

A

by secreting enzymes and hydrogen ions, creating an acidic environment

134
Q

Osteoclasts sit in ____

A

pits called resorption bays or howship’s lacunae

135
Q

What are resorption bays? AKA ____

What sits in resorption bays?

A

resorption bays aka howship’s lacunae

osteoclasts sit there

136
Q

Osteoclasts have a ___ border. What does that do?

A

osteoclasts have a ruffled border

That is where the cell is actively working to break down the bone matrix

137
Q

What are the two classifications of bone tissue histologically?

A

1 primary bone (aka woven bone/immature bone)

2 secondary bone (lamellar bone/mature bone)

138
Q

What is the first type of bone to develop? When does this begin?

A

primary bone

develops in embryonic development and fracture repair

139
Q

How are collagen fibers arranged in primary bone?

A

laid down in a random order

140
Q

Describe primary bone’s mineral content and osteocyte amount?

A

low mineral content

more osteocytes

141
Q

Is primary bone permanent or temporary?

A

temporary.

eventually replaced with secondary bone in most locations

142
Q

How are collagen fibers arranged in secondary bone?

A

very organized, collagen fibers arranged in layers with ALL fibers in parallel direction of concentrically vascular canal

143
Q

What is the structural unit of a compact bone called?

A

osteon

144
Q

Osteon aka ____

A

haversian system

145
Q

Around vascular canals are ____

A

lamellae

146
Q

Lamellae (around vascular canals of haversian systems) are composed of _____

A

bone ECM

these central canals and repeating concentric layer of lamellae are what compose an osteon

147
Q

What composes the osteon?

A

the central canal and the repeating concentric layer of lamellae

148
Q

What about the collagen fibers in lamellae increase the strength of the osteon?

A

they are parallel to each other and follow a helical course

then they are at a right angle (90deg) in the next lamellae, this increases the strength of the osteon

149
Q

Between each lamellae are ____

A

osteocytes in their respective lacunae

150
Q

Where are osteocytes located within the osteon?

A

osteocytes are located in their respective lacunae between each lamellae in the osteon

151
Q

What is the cement line of the osteon? What is it composed of?

A

the outermost boundary of the osteon

VERY rich in collagen fibers

152
Q

What is the outermost boundary of the osteon? What is it composed of?

A

cement line of osteon

VERY rich in collagen fibers

153
Q

In long bone of compact bone, how are osteons arranged?

A

osteons in long compact bone are arranged parallel to the long axis of the diaphysis

154
Q

Each osteon is composed of ____

A

4-10 concentric lamellae around a central/haversian canal

155
Q

What are central canals of osteons lined with?

A

endosteum

156
Q

What is within the central canal of osteons?

A

blood vessels, nerves, loose CT

157
Q

How do central canals communicate with marrow cavity and periosteum?

A

via transverse/oblique perforating canals

AKA Volkmann’s

158
Q

Transverse/Oblique perforating canals aka ____

A

Volkmann’s canals

159
Q

Do transverse/oblique perforating canals have concentric lamellae around?

A

No.

160
Q

What do the transverse/oblique perforating canals do?

A

transverse/oblique perforating canals AKA Volkmann’s canals

communicate with periosteum and marrow cavity

161
Q

Why do the osteons need to communicate with the periosteum?

A

Because periosteum has the blood vessels in it.

Osteons need the nutrients.

162
Q

In compact bone, are lamellae associated with central/haversian canals?

A

no

example: we see external and internal circumferential lamellae just beneath periosteum

163
Q

Which type of bone has external and internal circumferential lamellae?

A

compact bone

these are located just beneath periosteum

164
Q

Between osteons in compact bone are ____

A

interstitial lamellae

165
Q

What are interstitial lamellae created by? Where are they located?

A

interstitial lamellae are created by numerous parallel lamellae between osteons

166
Q

What are interstitial lamellae?

A

interstitial lamellae are actually remnants of former osteons

because bone is constantly being remodeled

167
Q

Do spongy bone contain osteons?

A

NO

168
Q

In Spongy bone, what surround red marrow space?

A

trabeculae

169
Q

Bone is considered a ____ and is derived from ___

A

bone is considered a connective tissue

bone is derived from mesenchyme

170
Q

Bone is composed of ____

A

cells and an ECM

171
Q

What are the parts of the long bone?

A

diaphysis, epiphysis, metaphysis, epiphyseal plate/line, medullary (marrow) cavity, periosteum, endosteum

172
Q

Osteoprogenitor cells produce ____

A

osteoblasts

173
Q

Osteoblasts produce ____

- Signals for it’s _____

A

Osteoblasts produce osteoid

Ostoblasts signal for osteoid mineralization

174
Q

Osteocytes reside in ____ and maintain the surrounding ____

A

reside in lacunae and maintain the surrounding bone matrix

175
Q

Osteoclasts ___ bone matrix

A

resorb

176
Q

Histologically, bone tissue is categorized as either ___ or ___

A

primary or secondary bone

177
Q

Compact bone and Spongy bone are both ___

A

secondary bone

178
Q

Which bone type has osteons/haversian system, composed of a concentric lamellae and a central/haversian canal?

A

compact bone

179
Q

Which bone type does NOT have osteons/haversian systems, but still consists of lamellae?

A

spongy bone