Chapters 7-9 Flashcards
(203 cards)
1
Q
What are the 4 functions of bones?
A
-Support & protect softer tissue
-Provide point of attachment for muscles and to facilitate movement
-House blood-producing cells
-Store inorganic salts
2
Q
What are the five types of bone shapes?
A
-Long bones
-Short bones
-sesamoid bone
-Flat bones
-Irregular bones
3
Q
Description and examples of long bones?
A
Long and narrow such as the femur and humerus
4
Q
Description and examples of short bones?
A
Length approximates widths such as the carpals and tarsals
5
Q
Description and example of semoid bones?
A
Any round bones that form within tendons adjacent to joint such as the patella
6
Q
Description and example of flat bones?
A
Plate-like bones such as the plates of the skull
7
Q
Description and example of irregular bones?
A
Variety of shapes such as the vertebral bones
8
Q
What is the epiphysis?
A
Expanded end
9
Q
What is the diaphysis?
A
Bone shaft
10
Q
What is the metaphysis?
A
Intervening portion between epiphysis and diaphysis
11
Q
What is the articular cartilage?
A
Covers the ends of bones (epiphysis)
12
Q
Periosteum?
A
Dense connective tissue layer that encloses the bone
13
Q
Compact bone?
A
The weight-bearing wall of the diaphysis
14
Q
Where is spongy/cancellous bone located?
A
Make up the epiphysis
15
Q
Trabeculae?
A
Branching bony plates that make up spongy bone
16
Q
Medullary cavity?
A
Hollow chamber of shaft (diaphysis) that contains bone marrow
17
Q
Endosteum?
A
Lines the interior spaces/cavity of the bone
18
Q
Bone marrow?
A
Fills the medullary cavity-includes red and yellow
19
Q
Bone is made of ____ & ____?
A
Collagen (connective tissue fiber) & inorganic salts (Calcium)
20
Q
Mature bones cells are called ____ and occupy chambers called ____?
A
Osteocytes… Lacunae
21
Q
Passageways that interconnect lacunae are called ____?
A
Canaliculi
22
Q
The structural unit of compact bone is the ____ and is a ____ ____ structure that helps bear ____ and ____ ____?
A
Osteon… cylindrical structure… weight and resist compression
23
Q
The matrix of bone is layered in concentric rings called ____ and are centered around a ____ ____ in which blood vessels and nerves pass through?
A
Lamellae…central canal
24
Q
Adjacent central canals are joined together vie ____ ____?
A
Perforating canals
25
Spongy bone features ____ which is more flexible?
Trabeculae
26
What are the two ways bone develops?
Intramembranous ossification & Endochondral ossification
27
Which bones are formed from intramembranous ossification?
Skull bones
28
What type of bones form from endochondral ossification?
Long bones
29
What is the 4 step process of intramembranous ossification?
-Mesenchymal cell (embryonic cells) become osteoblasts
-Osteoblasts deposit bone matrix
-Osteoblasts become completely surrounded and transform into osteocytes
-Mesenchyme on outside becomes periosteum
30
What is the 7 step process of endochondral ossification?
-Hyaline cartilage model
-Chondrocytes enlarge
-Matrix breaks down as chondrocytes die
-Osteoblasts invade the area
-Osteoblasts deposit bone matrix
-Osteoblasts form spongy and then compact bone
-Once encased in lacunae, osteoblasts become osteocytes
31
What are epiphyseal (growth) plates?
The cartilaginous region where long bones grow in length
32
What happens when the two ossification centers of a bone meet?
The epiphyseal plate ossifies and the bone can no longer grow in length
33
Bone can continue to lengthen as ____ ____ of the ____ ___ remain ____?
Cartilage cells... epiphyseal plate... active
34
What are the four zones of cartilage?
-Resting cartilage
-Proliferating cartilage
-Hypertrophic cartilage
-Calcified cartilage
35
What is the zone of resting cartilage?
They layer closest to end of epiphysis; resting cells that anchor epiphyseal plate to epiphysis
36
What is the zone of proliferating cartliage?
Rows of young cells that are actively dividing (mitotically active)
37
What is the zone of hypertrophic cartilage?
Rows of older cells that help thicken the epiphyseal plate and lengthen the bone; calcifies matrix
38
What is the zone of calcified cartilage?
Thin layer of dead cartilage cells and calcified matrix
39
What is the role of osteoblasts?
Replace cartilage with bone tissue
40
What is the role of osteoclasts?
Break down calcified matrix
41
Which bone is the last to ossify?
Clavicle
42
When are all bone ossified?
By the age of 25
43
What two process maintain bone tissue homeostasis?
Resorption and deposition
44
What is bone resorption?
Removal of bone; action of osteoclasts
45
What is bone deposition?
Formation of bone; action of osteoblasts
46
What are the 3 vitamins critical for bone health?
D, C, & A
47
What are the three hormones that play a role in bone health?
Growth hormone, Thyroid hormone, & Parathyroid hormone
48
What is the role of vitamin D in bone health?
Calcium obsorption
49
What does deficiency of vitamin D cause in children?
Rickets
50
What does deficiency of vitamin D cause in adults?
Osteomalacia (softening of bones)
51
What role does vitamin A play in bones?
Affects osteoblast and osteoclast activity
52
What does deficiency in vitamin A cause in bone?
Retards bone development
53
What role does vitamin C play in bone formation?
Helps with collagen synthesis
54
What does deficiency in vitamin C cause in bones?
Slender and fragile bones
55
What disease can result from vitamin C deficiency?
Scurvy
56
What does growth hormone (GH) do for bone development?
Stimulates cartilage cell division
57
Insufficiency in growth hormone causes ____?
Pituitary dwarfism
58
Excess of growth hormone in children causes ____?
Gigantism
59
Excess of growth hormone in adults causes ____?
Acromegaly
60
What two functions does the thyroid hormone have in bone development?
Causes replacement of cartilage with bone in epiphyseal plate and affects osteoblast activity
61
What does the parathyroid hormone do for bone formation?
Stimulates the breakdown of bone by stimulating osteoclast activity
62
What are the two general categories of fractures?
Simple/closed fractures and compound/open fractures
63
What are simple/closed fractures?
Fracture is protected by uninjured skin
64
What are compound/open fractures?
Fractures in which bone is exposed to the outside through the opening in the skin
65
What are the six classifications of fractures?
-Greenstick
-Transverse
-Oblique
-Spiral
-fissured
-Comminuted
66
What is a greenstick fracture?
An incomplete break often seen in children
67
What is a fissured fracture?
Incomplete longitudinal break
68
What is comminuted fracture?
Complete; fragments the bone
69
Transverse fracture?
Complete; occurs at a right angle to the bone shaft
70
Oblique fracture?
Oblique, occurs at an angle other than a right angle
71
Spiral fracture?
Caused by excessive twisting; associated with child abuse
72
What are the 4 phases of fracture repair?
-Hematoma
-Cartilaginous (soft) callus
-Bony callus
-Remodeling
73
Fracture repair process hematoma?
Large blood clot forms
74
Fracture repair process cartilaginous (soft) callus?
Phagocytes remove debris and fibrocartilage invades
75
Fracture repair process bony callus?
Osteoblasts invade and a hard callus fill the space
76
Fracture repair process remodeling?
Bone restored to close to original shape
77
What are the 5 major functions of bones?
-Provide shape
-Support body structures
-Protect body structures
-Aids in body movement (bones act as levers which muscles can use to produce motion)
-Contains tissue that produce blood cells
-Stores inorganic salts
78
Hematopoiesis?
Process by which blood cells are formed
79
Where does blood cell production occur?
Red bone marrow
80
What does yellow bone marrow do?
Stores fat
81
What is the most abundant crystal in bone?
Hydroxyapatite
82
What is hydroxyapatite?
Calcium (Ca++) and Phospahte (PO4----)
83
What does calcitonin do?
Stimulates osteoblasts to deposit Ca++ in the cones which effectively lower blood Ca++ levels
84
Where is calcitonin released from?
Thyroid gland
85
What does the parathyroid hormone do?
Causes osteoclasts to breakdown bone to release calcium which effectively raises blood Ca++ levels
86
What is a fragility fracture a sign of?
Low bone density?
87
What is a fragility fracture?
A fracture that occurs from less than standing height
88
What is osteopenia?
Bone loss
89
What is osteoporosis?
Severe bone loss that leaves canals in bones and weakens them
90
Who is osteopenia and osteoporosis common in?
Common in post-menopausal women due to hormone changes
91
What are three ways to prevent osteopenia and osteoporosis?
-30 min exercise/day
-Get enough Ca2+ and Vit. D
-Stop smoking
92
What are the 5 signs of bones and aging?
a. Height decreases starting at age 30 as bones thin and weaken
b. Osteoclasts outnumber osteoblasts with age
c. Spongy bone weakens before compact bone
d. Bone loss is rapid in menopausal women
e. Hip fractures and vertebral compression fractures become more common
93
What in another name for joints?
Articulations
94
What are the three classifications of joints based on structure?
-Fibrous
-Cartilaginous
-Synovial
95
What is a syndesmosis?
An amphiarthrotic joint either formed by an interosseous membrane or an interosseous ligament such as the tibia-fibular joint
96
What is a suture?
A connection between flat bones of the skull. Consists of a thin layer of connective tissue (sutural ligament). Synarthrotic
97
What is a gomphosis?
Cone-shaped process fitting into a socket of jawbone and held with a periodontal ligament. Synarthrotic
98
What is a synchondrosis?
Composed of bands of hyaline cartilage such as the epiphyseal plate and between manubrium and 1st rib. Synarthrotic
99
What is a symphysis?
Pad of fibrocartilage between bones with the articular surface being covered with hyaline cartilage such as pubic symphysis and intervertebral discs. Amphiarthrotic
100
What structure make up a synovial joint?
1. articular cartilage
2. capsule
a. synovial membrane
b. synovium (fluid)
ii. bursa
iii. meniscus
101
What are the 6 types of synovial joints?
1. ball-and-socket (egs., hips & shoulders)
2. condylar (egs., metacarpals & phalanges)
3. plane (eg., carpals)
4. hinge (eg., elbow)
5. pivot (eg., atlantoaxial – C1/C2)
6. saddle (eg., carpals/metacarpals of thumb)
102
Ball-and-socket joint?
-aka spheroidal joint
-features a round head fitting in a cupped cavity
-exhibits widest range of motion
-multiaxial, plus rotation
-egs., hips, shoulders
103
Condylar joint?
-aka ellipsoidal joint
-oval condyle fits into elliptical cavity
-Back-and-forth; side-to-side motions
-Biaxial movement, but with no rotation
-egs., joints between metacarpals & phalanges
104
Plane joint?
-aka gliding joint
-almost flat; or, slightly curved
-Back-and-forth; twisting
-nonaxial movement
-eg. wrist & ankle joints
105
Hinge joint?
-convex surface of one bone sits in concave surface of another bone
-uniaxial movement (in one plane)
-egs., elbows; joints b/w phalanges
106
Pivot joint?
-aka trochoid joint
cylindrical surface rotates within ring of another bone
-uniaxial movement
-rotation only
-egs., atlas (C1) & dens of axis (C2)
107
Saddle joint?
-aka sellar joint
-both bones have concave and convex surfaces
-biaxial movement (in two planes)
-egs., carpal & metacarpals of thumb
108
What is a suture?
-occurs between flat bones of the skull
-consists of thin layer of connective tissue (sutural ligament)
-synarthrotic
109
What is a gomphosis?
-cone-shaped bony process in a socket in jawbone
-periodontal ligament
-synarthrotic
110
What are the two types of cartilaginous joints?
i. synchondrosis (eg., costal cartilage)
ii. symphysis (egs., pubic symphysis, intervertebral discs)
111
What is a synchondrosis?
-composed of bands of hyaline cartilage form joint
-eg, epiphyseal plate (temporary)
-eg., between manubrium & 1st rib
costal cartilage
112
What is a symphysis?
-pad of fibrocartilage between bones
-articular surfaces covered by hyaline cartilage
amphiarthrotic
-eg., pubic symphysis
-eg., intervertebral discs
113
What are the three types of joints based on function?
a. Synarthrotic
b. Amphiarthrotic
c. Diarthotic
114
What are the 4 basic features of skeletal muscle?
a. voluntary
b. promotes movement: attached to bones
c. striated
d. multiple nuclei near periphery of cell
115
A skeletal muscle is an ____ of the skeletal system?
Organ
116
What 4 tissues does skeletal muscle consist of?
muscle tissue, nervous tissue, blood & connective tissue
117
What are the three types of connective tissue in muscle?
i. fascia – dense connective tissue that surrounds the muscle and tapers to form tendons
ii. aponeuroses – broad, fibrous sheet of connective tissue
118
What are the 3 coverings in a muscle?
-Epimysium
-Perimysium
-Endomysium
119
What is the epimysium?
surrounds whole muscle
120
Perimysium?
surrounds fascicles within a muscle
121
Fascicle?
is a bundle of muscle fibers (cells)
122
Endomysium?
surrounds muscle fibers within the facsicle
123
Why is a muscle cell multinucleated?
result of multiple cells fusing together
124
Sarcolemma?
muscle fiber membrane
125
Sarcoplasm?
the cytoplasm of the muscle fiber
126
Myofibrils?
the actin (thin) & myosin (filament) fibers within the muscle cell
127
Sarcoplasmic reticulum?
specialized endoplasmic reticulum where Ca++ ions are stored
128
Transverse tubules?
– invaginations of the sarcolemma that extend into the sarcoplasm
129
Triad?
1. triad: 2 cisternae (of SR) + transverse tubule
130
Sarcomere?
the functional unit of the muscle cell
131
Z-line?
i. boundaries of the sarcomere
132
A-band?
represents the thin & thick filaments
133
H-zone?
thick filaments only – myosin protein
134
I-band?
thin filaments only (flank the edges of the sarcomere) – actin protein
135
Thick filaments?
Myosin
136
Thin filaments?
Actin
137
What proteins regulate cross-bridging?
1. troponin
2. tropomyosin
138
Sliding filament model?
i. contraction occurs as a result of actin (thin) and myosin (thick) filaments sliding past one another
139
Does the length of filaments change?
No
140
What is the final result in the sarcomere after contraction?
the H- and I-bands narrow; and, the Z-lines move closer together
141
Skeletal muscle connects to nervous system via ____ ____?
Neuromuscular junction (NMJ)
142
Motor neuron?
nervous tissue that relays signal from the central nervous system to the skeletal muscle
143
Motor end plate?
portion of the skeletal muscle that responds to the motor neuron
144
Synaptic cleft?
space between the motor neuron & the motor end plate
145
Synaptic vessicles?
membranous “sacs” found within the terminus of the motor neuron each of which contains neurotransmitter that stimulates a muscle contraction
146
What is the neurotransmitter for skeletal muscle?
acetylcholine (ACh)
147
How does a neurotransmitter work?
a. the motor end plate features ACh receptors that bind to the neurotransmitter
b. ACh stimulates a change in membrane potential across the motor end plate
c. Results in the release of Ca++ ions from the SR
148
What are the 6 steps of the contraction cycle?
-Resting
-ACh stimulates the release of Ca++ ions
-Cross-bridge formation
-Power-stroke
-Cross-bridge release
-Cocking of myosin heads
149
Contraction cycle: what happens during the resting phase?
Ca++ ions are sequestered in the SR; troponin/tropomyosin is blocking cross-bridge formation
150
Contraction cycle: what happens during the ACh stimulates the release of Ca++ ions phase?
Ca++ ions from the SR which binds to troponin and facilitates a shift in tropomyosin that reveals myosin-binding sites on actin
151
Contraction cycle: what happens during the cross-bridge formation phase?
the myosin heads bind to actin
152
Contraction cycle: what happens during the power-stroke phase?
the release of ADP from myosin causes the filaments to slide
153
Contraction cycle: what happens during the cross-bridge release?
the myosin-actin association is disrupted when high-energy ATP binds to the myosin head
154
Contraction cycle: what happens during the cocking of myosin head phase?
the ATP is hydrolyzed to ADP releasing energy which “resets” the myosin heads
155
3 step process of muscle relaxation?
i. acetylcholinesterase is an enzyme that decomposes the ACh that remains in the synapse
ii. ATP is needed to sequester (pump) Ca++ ions back into the SR
1. Removal of Ca++ results in troponin/tropomyosin to conceal myosin-binding sites on actin again
iii. ATP is also needed to reset (“cock”) myosin heads
156
What decomposes ACh?
i. acetylcholinesterase
157
What is ATP?
Adenosine triphosphate
158
What are the 4 phases of energy used for contraction?
-ATP in the cytoplasm is quickly exhausted during contraction
-Creatine phosphate
-Anaerobic
-Aerobic
159
Creatine phosphate?
enables muscle cells to regenerate ATP from ADP via phosphate transfer when cellular ATP is low
160
Where does the anaerobic phase occur?
1. occurs in the cytoplasm
161
Oxygen debt?
the amount of oxygen needed by liver cells to convert lactic acid back to sugars, and to restore muscle ATP & creatine phosphate to original levels
162
When is the anaerobic phase used?
– limited oxygen availability due to strenuous exertion
163
What does the anaerobic phase produce?
2 ATP and pyruvic acid which turns into lactic acid
164
____ ____ ____ + ____ ____ ____ = Aerobic Phase
Citric acid cycle + electron transport chain
165
Where does the aerobic phase occur?
mitochondria
166
What does the aerobic phase produce?
34 ATP
167
What is myoglobin?
an oxygen-binding molecule that helps supply additional oxygen when vascular supplies dwindle
168
What causes muscle fatigue?
– the inability to contract muscle
1. due to: decreased blood flow; ion imbalance (across sarcolemma); loss of desire to continue to exercise; accumulation of lactic acid
169
What is a muscle cramp?
sustained, involuntary contraction
170
What causes a muscle cramp?
changes in electrolyte levels in fluid surrounding muscle cell
171
Muscle contraction can be measured by ____ ____ ____ ____ ____ of a dissected muscle?
examining changes in muscle length
172
What is a threshold stimulus?
the minimum strength of stimulus required for contraction
1. produces an action potential resulting in the release of Ca++ ions from the SR of the muscle sample
173
What is a twitch?
the contractile response to a single impulse
174
3 periods of a twitch?
a. latent period
b. period of contraction
c. period of relaxation
175
Optimum starting length is the same as ____ length of a muscle fiber?
Resting
176
Summation?
the process of combining the force generated by individual muscle fiber twitches
177
Extremely prolonged contraction called ____ ____ don't normally occur in humans?
tetanic contractions
178
What is a motor unit?
(1) the motor neuron + (2) all of the muscle fibers under its control
179
Coarse movements are produced by?
large # of fibers recruited within a motor unit
180
Precise movements are produced by?
smaller # of fibers within a motor unit
181
Recruitment?
the increase in the # of motor units becoming activated which produces additional force
182
What motor units are recruited 1st during muscle contraction?
1. smaller motor units are recruited 1st during sustained contraction
183
What motor units are recruited 2nd during muscle contraction?
2. larger motor units are recruited next during sustained contraction
184
___ motor units will become activated if a stimulus is significantly long?
All
185
____ + ____ produce contractions of increasing strength?
Summation + Recruitment
186
Isotonic?
muscle contracts & changes length
187
Concentric?
shortening contraction
188
Eccentric?
lengthening contraction
189
Isometric?
muscle contracts but does not change length (holding a heavy object stationary)
190
Slow-twitch muscle fibers?
-aka Type 1
-resistant to fatigue
-slower to contract
-stimulated by aerobic exercise
-high myoglobin
-red coloration
191
Fast-twitch, fatigue resistant muscle fibers?
-aka Type IIa
-quicker to contract than Type 1
-resistant to fatigue
-stimulated by forceful exercise
-high myoglobin
-red coloration
192
Fast-twitch, glycolytic fibers?
-aka Type IIb
-contract rapidly
-susceptible to fatigue
-low myoglobin
-white coloration
193
Two types of smooth muscle?
Multi-unit & Visceral
194
Multi-unit smooth muscle?
1. associated with eye (iris) & walls of blood vessels
2. cells are less organized
3. each fiber functions independently
195
Visceral smooth muscle?
1. found in walls of hollow organs
2. cells function collectively as a unit
3. exists as sheets of spindle-shaped muscle fibers
4. exhibits rhythmicity
196
How do smooth muscle fibers appear?
b. fibers are shorter than skeletal muscle, have tapered ends
c. each fiber has a central nucleus
d. not striated
197
What structures do smooth muscles miss?
d. not striated
e. no transverse tubules; SR not fully developed
198
What do smooth muscles use in place of troponin?
calmodulin
199
What do smooth muscles use a a neurotransmitter?
norepinephrine as a neurotransmitter, in addition to ACh
200
What are cardiac muscles joined by?
intercalated discs
201
How are cardiac muscles stumulated?
Rhythmic: self-exciting
202
How do cardiac muscles appear?
Striated and branching
203
Cardiac muscles features ____ ____ ____ than skeletal muscle?
longer refractory period
