A&P Chapter 6: Flashcards
(131 cards)
1
Q
contains no blood vessels or nerves, composed primarily of water, surrounded by the perichondrium that resists outward expansion and contains the blood vessels
A
skeletal cartilage
2
Q
layer of dense connective tissue surrounding cartilage like a girdle
A
perichondrium
3
Q
made up of chondrocytes, cells encased in small cavities (lacunae) within jelly-like extracellular matrix
A
cartilage
4
Q
three types of cartilage
A
hyaline cartilage, elastic cartilage, and fibrocartilage
5
Q
provides support, flexibility, and resilience, most abundant skeletal cartilage
A
hyaline cartilage
6
Q
covers the ends of long bones
A
articular (hyaline)
7
Q
connects the ribs to the sternum
A
costal (hyaline)
8
Q
makes up larynx, reinforces air passages
A
respiratory (hyaline)
9
Q
supports the nose
A
nasal (hyaline)
10
Q
similar to hyaline cartilage, found in the external ear and the epiglottis
A
elastic cartilage
11
Q
highly compressible yet with great tensile strength, contains thick collagen fibers (many fibers nearly in parallel to form fibrils), found in menisci of the knee, pubic symphysis, and intervertebral discs
A
fibrocartilage
12
Q
cartilage grows in two ways
A
1.) appositional growth
2.) interstitial growth
13
Q
cartilage-forming cells in perichondrium secrete matrix against external face of existing cartilage; new matrix laid down on surface of cartilage
A
appostitional growth
14
Q
chondrocytes within lacunae divide and secrete new matrix, expandingcartilage from within; new matrix made with cartilage
A
interstitial growth
15
Q
occurs during normal bone growth in youth, but can also occur in old age; hardened cartilage os not the same as bone
A
calcification of cartilage
16
Q
there are seven important functions of bones
A
1.) support
2.) protection
3.) movement
4.) mineral and growth factor storage
5.) blood cell formation
6.) triglyceride (fat) storage
7.) hormone prodection
17
Q
for body and soft organs
A
support
18
Q
protect brain, spinal cord, and vital organs
A
protection
19
Q
levers for muscle action
A
movement
20
Q
calcium and phosphorus, and growth factors reservoir
A
mineral and growth factor storage
21
Q
hematopoiesis occurs in red marrow cavities of certain bones
A
blood cell formation
22
Q
used for an energy source, is stored in bone cavities
A
triglyceride (fat) storage
23
Q
osteocalcin secreted by bones helps to regulate insulin secretion, glucose levels, and metabolism
A
hormone production
24
Q
classification of bones
A
206 named bones in the human skeleton
25
two groups that divide based on the location
1.) axial skeleton
2.) appendicular skeleton
26
bones of the skull, vertebral column, and rib cage
axial skeleton
27
bones of the upper and lower limbs, shoulder, and hip
appendicular skeleton
28
four shapes of bones
1.) long bone
2.) short bone
3.) flat bone
4.) irregular bone
29
longer than they are wide (humerus)
long bones
30
cube-shaped bones of the wrist and ankle
short bones
31
thin, flattened, and a bit curved (sternum, ribs, scapulae, and most skull bones)
flat bones
32
more complex shapes (vertebrae, facial and pelvic bones)
irregular bone
33
small round bones formed in tendons (Patella) also considered short bones
sesamoid bones
34
three levels of structure
1.) gross
2.) microscopic
3.) chemical
35
dense outer layer on every bone that appears smooth and solid
compact bone (gross anatomy)
36
honeycomb of trabeculae; fills the epiphyses and is filled with red bone marrow
spongy bone (gross anatomy)
37
covers outside of compact bone
periosteum (gross anatomy)
38
covers inside portion of compact bone; for one growth, repair and remodeling, contains osteoblasts and osteoclast
endosteum (gross anatomy)
39
a shaft (diaphysis), bone ends (epiphyses), and membranes
structure of a long bone
40
ubular shaft between proximal and distal ends of long bones
diaphysis
41
wider section at each end of the bone
epiphysis
42
Between diaphysis and epiphysis is where bone growth occurs
epiphyseal plate
43
two types (periosteum and endosteum)
membranes
44
covers the outer surface of the bone; white, double-layered membrane that covers external surfaces except joints
periosteum
45
outer layer consisting of dense irregular connective tissue consisting of Sharpey’s fibers that secure to bone matrix
fibrous layer
46
inner layer abutting bone and contains primitive osteogenic stem cells that gives rise to most all bone cells
osteogenic laye
47
membrane lining the medullary cavity and spongy bone; for one growth, repair and remodeling, contains osteoblasts and osteoclast
endosteum
48
found within trabecular cavities of spongy bone and diploë of flat bones, such as sternum
red marrow
49
sites of attachment for muscles, ligaments, and tendons, Joint surfaces, Foramen (hole) conduits for blood vessels and nerves
bone markings
50
three types of bone markings
projection, depression, and opening
51
outward bulge of bone; may be due to increased stress from muscle pull or is a modification for joints
projection
52
bowl- or groove-like cut-out that can serve as passageways for vessels and nerves, or plays a role in joints
depression
53
hole or canal in bone that serves as passageways for blood vessels and nerves
openings
54
five major cells types
1.) osteogenic cells
2.) osteoblast
3.) osteocytes
4.) bone-lining cells
5.) osteoclasts
55
mitotically active stem cells in periosteum and endosteum; also called osteoprogenitor cells
osteogenic cells
56
bone-forming cells that secrete unmineralized bone matrix called osteoid; are actively mitotic
osteoblast
57
mature bone cells in lacunae that no longer divide; maintain bone matrix and act as stress or strain sensors
osteocytes
58
flat cells on bone surfaces believed to also help maintain matrix (along with osteocytes)
bone-lining cells
59
on external bone surface, lining cells
periosteal cells (bone-lining cells)
60
on internal surfaces
endosteal cells (bone-lining cells)
61
derived from same hematopoietic stem cells that become macrophages; giant, multinucleate cells function in bone resorption (breakdown of bone)
osteoclasts
62
also called lamellar bone
compact bone
63
compact bone consists of
* Osteon (Haversian system)
▪ Canals and canaliculi
▪ Interstitial and circumferential lamellae
64
the structural unit of compact bone
osteon (haversian system)
65
an osteon cylinder consists of several rings of bone matrix
lamellae
66
central channel containing blood vessels and nerves
Haversian canal (central canal)
67
channels lying at right angles to the central canal, bringing blood and nerve supply from the periosteum in to said central canal
Perforating (Volkmann’s) canals
68
small cavities that contain osteocytes
lacunae
69
hairlike canals that connect lacunae to each other and to central canal
canaliculi
70
some fill gaps between forming osteons; others are remnants of osteons cut by bone remodeling; not part of osteon
Interstitial lamellae
71
just deep to periosteum, but superficial to endosteum, these layers of lamellae extend around entire surface of diaphysis; help long bone to resist twisting
Circumferential lamellae
72
appears poorly organized but is actually organized along lines of stress to help bone resist any stress
spongy bone
73
Organic components
osteogenic cells, osteoblasts, osteocytes, bone-lining cells,
osteoclasts, and osteoid
74
makes up one-third of organic bone matrix, is secreted by
osteoblasts
osteoid
75
Inorganic components
Hydroxyapatites (mineral salts)
76
makeup 65% of bone by mass, consist mainly of tiny calcium phosphate crystals in and around collagen fibers, responsible for hardness and resistance to compression
Hydroxyapatites (mineral salts)
77
the process of bone tissue formation; bone remodeling and repair are lifelong
Ossification (osteogenesis)
78
up to about week 8, fibrous membranes and hyaline cartilage of fetal skeleton are
replaced with bone tissue
formation of the body skeleton
79
bone forms by replacing hyaline cartilage, bones are called cartilage (endochondral) bones, form most of skeleton
endochondral ossification
80
bone develops from fibrous membrane, bones are called membrane bones
intramembranous ossification
81
5 Stages of Endochondral Ossification
1. Formation of bone collar
2. Cavitation of the hyaline cartilage
3. Invasion of internal cavities by the periosteal bud, and spongy bone formation
4. Formation of the medullary cavity; appearance of secondary ossification centers in the epiphyses
5. Ossification of the epiphyses, with hyaline cartilage remaining only in the epiphyseal plates
82
Four major steps are involved
1. Ossification centers are formed when mesenchymal cells cluster and become osteoblasts
2. Osteoid is secreted, then calcified
3. Woven bone is formed when osteoid is laid down around blood vessels, resulting in trabeculae
4. Lamellar bone replaces woven bone, and red marrow appears
83
increase in length, cartilage continually grows and is replaced by bone
Interstitial Growth
84
increased thickness and remodeling of all bones by osteoblasts and osteoclasts on bone surfaces, specifically the periosteum and endosteum
Appositional Growth
85
Epiphyseal plate consists of five zones
1. Resting (quiescent) zone
2. Proliferation (growth) zone
3. Hypertrophic zone
4. Calcification zone
5. Ossification (osteogenic) zone
86
area of cartilage on epiphyseal side of epiphyseal plate that is relatively inactive
resting (quiescent) zone
87
area of cartilage on diaphysis side of epiphyseal plate that is rapidly dividing; new cells formed move upward, pushing epiphysis away from diaphysis, causing lengthening
proliferation (growth) zone
88
area with older chondrocytes closer to diaphysis; cartilage lacunae enlarge and erode, forming interconnecting spaces
hypertrophic zone
89
surrounding cartilage matrix calcifies; chondrocytes die and deteriorate
calcification zone
90
chondrocyte deterioration leaves long spicules of calcified cartilage at
epiphysis-diaphysis junction; Ultimately replaced with spongy bone
ossification zone
91
closure occurs when epiphysis and diaphysis fuse
epiphyseal plate
92
growing bones widen as they lengthen through
appositional growth
93
beneath periosteum secrete bone matrix on external bone
osteoblasts
94
remove bone on endosteal surface
osteoclasts
95
most important hormone in stimulating epiphyseal plate activity
in infancy and childhood
growth hormone
96
modulates activity of growth hormone, ensuring proper
proportions
thyroid hormone
97
consists of both bone deposit and bone resorption
bone remodeling
98
packets of adjacent osteoblasts and osteoclasts coordinate
remodeling process
remodeling units
99
function of osteoclasts
resorption
100
accomplished by osteoclasts
bone resorption
101
accomplished by osteoclast
bone deposition
102
Negative feedback loop that controls blood 𝐶𝑎2+ levels
hormonal controls (control of remodeling)
103
produced by parathyroid glands in response to low blood calcium levels
parathyroid hormone (PTH)
104
produced by parafollicular cells of thyroid gland in response to high
levels of blood calcium levels
calcitonin
105
low levels of calcium cause hyperexcitablility
hypocalcemia
106
high levels of calcium cause nonresponsiveness
hypercalcemia
107
a bone grows or remodels in response to forces or demands placed upon it
Wolff's law (Response to mechanical stress)
108
Observations supporting Wolff's law
- Handedness (right or left handed) results in bone of one upper limb being thicker and stronged
- Curved bones are thickest where they are most likely to buckle
- Trabeculae form along lines of stress
- Large, bony projections occur where heavy, active muscles attac
109
causes remodeling by producing electrical signals when bone
is deformed
mechanical stress
110
are breaks
fractures
111
Position of bone ends after fracture
* Nondisplaced: ends retain normal position
▪ Displaced: ends are out of normal alignment
112
Completeness of break
* Complete: broken all the way through
▪ Incomplete: not broken all the way through
113
Whether skin is penetrated
* Open (compound): skin is penetrated
▪ Closed (simple): skin is not penetrated
114
cast or traction is needed for healing
Immobilization
115
Repair involves four major stages
1. Hematoma formation
2. Fibrocartilaginous callus formation
3. Bony callus formation
4. Bone remodeling
116
torn blood vessels hemorrhage, forming mass of clotted blood; site is swollen, painful, and inflamed
hematoma formation
117
capillaries grow into hematoma, phagocytic cells clear debris
fibrocartilaginous callus formation
118
within one week, new trabeculae appear in fibrocartilaginous callus
bony callus formation
119
begins during bony callus formation and continues for several months; excess material on diaphysis exterior and within medullary cavity is removed
bone remodeling
120
Three major bone diseases
- Osteomalacia and rickets
– Osteoporosis
– Paget’s disease
121
bones are poorly mineralized, results in soft, weak bones, pain upon bearing weight
osteomalacia
122
results in bowed legs and other bone deformities because bones ends are enlarged and abnormally long
rickets
123
a group of diseases in which bone resorption exceeds deposit
osteoporosis
124
Risk factors for osteoporosis
- most often aged, postmenopausal women (affects 30% of women aged 60–70 years and 70% by age 80)
- men are less prone due to protection by the effects of testosterone
125
Treating osteoporosis
* Calcium
▪ Vitamin D supplements
▪ Weight-bearing exercise
▪ Hormone replacement therapy
126
decrease osteoclast activity and number, partially reverse osteoporosis in spine
bisphosphonates
127
monoclonal antibody shown to reduce fractures in men with prostate cancer; improves bone density in elderly
denosumab
128
Preventing osteoporosis
- Plenty of calcium in diet in early adulthood
– Reduce consumption of carbonated beverages and alcohol
– Plenty of weight-bearing exercise
129
excessive and haphazard bone deposit and resorption cause bone to grow fast and develop poorly
Paget’s Disease
130
* Embryonic skeleton ossifies predictably, so fetal age is easily determined from X rays or sonograms
* Most long bones begin ossifying by 8 weeks, with primary ossification centers developed by week 12
Developmental Aspects of Bone
131
Birth to Young Adulthood
* At birth, most long bones ossified, except at epiphyses
* Epiphyseal plates persist through childhood and adolescence
* At ~ age 25, all bones are completely ossified, and skeletal growth ceases
