Ch. 6 Bones and Skeletal Tissue Flashcards
(451 cards)
1
Q
What are the three types of cartilage that help form the skeleton?
A
Hyaline, elastic, and fibrocartilage
2
Q
What are the major functions of bones?
A
Support, protection, movement, storage, and blood cell formation
3
Q
How are bones classified?
A
By their location and shape
4
Q
What does the gross structure of all bones consist of?
A
Compact bone sandwiching spongy bone
5
Q
What are the two methods by which bones develop?
A
Intramembranous and endochondral ossification
6
Q
What are the key cells involved in bone remodeling?
A
Osteoblasts, osteocytes, and osteoclasts
7
Q
What are the steps involved in bone fracture repair?
A
Hematoma formation, callus formation, and remodeling
8
Q
What are the disorders of bone remodeling?
A
Osteoporosis, osteomalacia, and Paget’s disease
9
Q
Osteoblasts
A
Cells responsible for bone formation
10
Q
What are the two main types of bone tissue?
A
Compact bone and spongy bone
11
Q
Epiphyseal plate
A
A growth plate that allows long bones to grow
12
Q
What are the major regions of the skeleton?
A
Axial skeleton and appendicular skeleton
13
Q
Osteoclasts
A
Cells that break down bone tissue
14
Q
What is the functional importance of bone markings?
A
They serve as sites for muscle attachment, joint formation, and passage of nerves and blood vessels
15
Q
What are the four bone classes?
A
Long bones, short bones, flat bones, and irregular bones
16
Q
Osteocytes
A
Mature bone cells that maintain the bone matrix
17
Q
How do hormones and physical stress regulate bone remodeling?
A
Hormones and physical stress influence the activity of osteoblasts and osteoclasts, thereby regulating bone deposition and resorption
18
Q
What is the most plentiful type of cartilage in the adult body?
A
Hyaline cartilage
19
Q
Which type of cartilage is found in the external ear and the epiglottis?
A
Elastic cartilage
20
Q
What is a key difference between cartilage and bone tissue?
A
Cartilage grows in an interstitial manner; bone does not.
21
Q
Which type of cartilage is highly compressible with great tensile strength?
A
Fibrocartilage
22
Q
What is the primary function of the perichondrium?
A
To resist outward expansion when the cartilage is compressed and to nourish cartilage cells
23
Q
Where is hyaline cartilage found in the human body?
A
Ends of long bones, rib cage, respiratory passageways, and external nose
24
Q
What are the two ways cartilage grows?
A
Appositional growth and interstitial growth
25
What cells are found within the lacunae of cartilage?
Chondrocytes
26
Perichondrium
A layer of dense irregular connective tissue that surrounds cartilage and contains blood vessels to nourish cartilage cells
27
What is the primary function of hyaline cartilage?
To provide support with flexibility and resilience
28
Chondrocytes
Cells found in cartilage that are enclosed in small cavities called lacunae
29
Where can elastic cartilage be found in the body?
In the external ear and the epiglottis
30
What is the main characteristic of fibrocartilage?
It is highly compressible with great tensile strength
31
Appositional growth
Growth where cartilage-forming cells in the perichondrium secrete new matrix against the external face of existing cartilage
32
What is the difference between appositional and interstitial growth in cartilage?
Appositional growth adds new layers on the surface, while interstitial growth expands the cartilage from within
33
Interstitial growth
Growth where chondrocytes divide and secrete new matrix, expanding the cartilage from within
34
What is one of the primary functions of bones in the human body?
Support
35
Which bones protect the brain?
Fused bones of the skull
36
What is the role of bones in mineral storage?
Reservoir for minerals like calcium and phosphate
37
Where does most blood cell formation occur?
Red marrow of certain bones
38
What type of marrow stores fat?
Yellow marrow
39
What hormone is produced by bones to help regulate insulin secretion?
Osteocalcin
40
How do bones assist in movement?
They act as levers for skeletal muscles
41
What is the primary function of red marrow in bones?
Hematopoiesis (blood cell formation)
42
Which type of marrow is responsible for fat storage?
Yellow marrow
43
What hormone do bones produce that helps regulate insulin secretion?
Osteocalcin
44
How do bones contribute to mineral storage in the body?
Bones act as a reservoir for minerals like calcium and phosphate, releasing them into the bloodstream as needed.
45
What function do bones serve in relation to skeletal muscles?
Bones serve as levers for skeletal muscles, allowing movement of the body and its parts.
46
Hematopoiesis
The formation of blood cells, which occurs in the red marrow of certain bones.
47
Osteocalcin
A hormone produced by bones that helps regulate insulin secretion, glucose homeostasis, and energy expenditure.
48
Mineral storage
The process by which bones store minerals like calcium and phosphate and release them into the bloodstream as needed.
49
Anchorage
The function of bones serving as levers for skeletal muscles, allowing movement of the body and its parts.
50
Support
The function of bones providing a framework that supports the body and cradles its soft organs.
51
What are the two major regions of the human skeleton?
Axial and appendicular
52
Which bones are part of the axial skeleton?
Skull, vertebral column, and rib cage
53
What is the primary function of the appendicular skeleton?
Locomotion and manipulation of the environment
54
Which of the following is an example of a long bone?
Femur
55
What shape classification does the sternum fall under?
Flat bones
56
Which bones are classified as short bones?
Wrist and ankle bones
57
What is a unique feature of sesamoid bones?
They form in a tendon
58
Which of the following is an example of an irregular bone?
Vertebra
59
What is the function of the femur's hollow-cylinder shape?
Provides maximum strength with minimum weight
60
What is the primary function of the axial skeleton?
To protect, support, or carry other body parts
61
Which bones are included in the axial skeleton?
The bones of the skull, vertebral column, and rib cage
62
What is the primary function of the appendicular skeleton?
To help us move from place to place and manipulate our environment
63
Which bones are included in the appendicular skeleton?
The bones of the upper and lower limbs and the girdles (shoulder bones and hip bones)
64
How are bones classified by shape?
As long, short, flat, or irregular
65
What are examples of long bones?
All limb bones except the patella, wrist, and ankle bones
66
What are examples of short bones?
The bones of the wrist and ankle
67
What is a special type of short bone that forms in a tendon?
Sesamoid bones
68
What are examples of flat bones?
The sternum, scapulae, ribs, and most cranial bones of the skull
69
What are examples of irregular bones?
The vertebrae and hip bones
70
Axial skeleton
The part of the skeleton that forms the long axis of the body, including the skull, vertebral column, and rib cage
71
Appendicular skeleton
The part of the skeleton that includes the bones of the upper and lower limbs and the girdles that attach the limbs to the axial skeleton
72
Long bones
Bones that are considerably longer than they are wide, with a shaft and two ends
73
Short bones
Bones that are roughly cube shaped, such as the bones of the wrist and ankle
74
Sesamoid bones
A special type of short bone that forms in a tendon, such as the patella
75
Flat bones
Bones that are thin, flattened, and usually a bit curved, such as the sternum and scapulae
76
Irregular bones
Bones with complicated shapes that do not fit into the other categories, such as the vertebrae and hip bones
77
What is the dense outer layer of bone called?
Compact bone
78
What fills the open spaces between trabeculae in living bones?
Red or yellow bone marrow
79
What is the main function of the periosteum?
Covers the external surface of the bone
80
Which part of a long bone contains yellow marrow in adults?
Medullary cavity
81
What type of bone cell is responsible for bone resorption?
Osteoclasts
82
What is the structural unit of compact bone?
Osteon
83
Which type of bone contains osteons?
Compact bone
84
What are the small needle-like or flat pieces in spongy bone called?
Trabeculae
85
What is the role of osteocytes in bone tissue?
Monitor and maintain the bone matrix
86
Which bone marking is a large rounded projection that may be roughened?
Tuberosity
87
What are the two types of bone tissue found in all bones?
Compact bone and spongy bone
88
What is the primary function of red bone marrow?
Hematopoiesis (blood cell formation)
89
Where is yellow bone marrow primarily found in adults?
In the medullary cavity of long bones
90
What type of bone tissue forms the outer layer of bones?
Compact bone
91
What is the name of the membrane that covers the external surface of bones?
Periosteum
92
What is the structural unit of compact bone?
Osteon or Haversian system
93
What is the role of osteocytes in bone tissue?
To monitor and maintain the bone matrix
94
What type of cells are responsible for bone resorption?
Osteoclasts
95
What is the function of articular cartilage?
To cushion the bone ends during movement and absorb stress
96
What are trabeculae?
Small needle-like or flat pieces of spongy bone
97
Diaphysis
The tubular shaft that forms the long axis of a long bone
98
Epiphysis
The ends of a long bone, consisting of an outer shell of compact bone and an interior of spongy bone
99
Periosteum
A double-layered membrane covering the external surface of bones, except at the joints
100
Endosteum
A delicate connective tissue membrane covering internal bone surfaces
101
Osteoblasts
Bone-forming cells that secrete the bone matrix
102
Osteoclasts
Giant multinucleate cells responsible for bone resorption
103
Osteon
The structural unit of compact bone, also known as the Haversian system
104
Lamellae
Layers of bone matrix in compact bone
105
Canaliculi
Hairlike canals that connect lacunae to each other and to the central canal
106
Trabeculae
The small, needle-like or flat pieces of spongy bone
107
What are the two types of ossification processes in bone development?
Intramembranous and endochondral ossification
108
What type of bone development involves replacing hyaline cartilage?
Endochondral ossification
109
Which bones are primarily formed through intramembranous ossification?
Cranial bones and clavicles
110
At what stage of development does bone tissue begin to replace fibrous or cartilage structures?
Around week 8 of embryonic development
111
What is the primary function of the epiphyseal plate in long bones?
To allow for the lengthening of the bone
112
Which of the following structures consists of hyaline cartilage?
Epiphyseal plate
113
What happens to the chondrocytes in the hypertrophic zone of the epiphyseal plate?
They enlarge and their lacunae break down
114
What is the role of osteoclasts during the lengthening of a long bone?
To break down calcified spicules of cartilage
115
What type of bone growth occurs during infancy and youth?
Interstitial growth of the epiphyseal plate
116
Which hormone is the most important stimulus for epiphyseal plate activity during infancy and childhood?
Growth hormone
117
Ossification
The process of bone tissue formation
118
What type of tissue does intramembranous ossification begin with?
Fibrous connective tissue membranes
119
Endochondral ossification
A process where bone develops by replacing hyaline cartilage
120
What is the primary ossification center?
The region in the diaphysis where bone tissue begins to form during endochondral ossification
121
Epiphyseal plate
A disc of hyaline cartilage that grows during childhood to lengthen the bone
122
What happens in the hypertrophic zone during the growth of long bones?
Older chondrocytes enlarge and their lacunae erode, leaving large interconnecting spaces
123
What is the role of osteoblasts in bone growth?
Osteoblasts secrete osteoid, which calcifies to form bone tissue
124
Periosteal bud
A collection of elements including a nutrient artery and vein, nerve fibers, red marrow elements, osteoprogenitor cells, and osteoclasts that invades the internal cavities during endochondral ossification
125
What remains in long bones after secondary ossification is complete?
Hyaline cartilage remains at the epiphyseal plates and articular cartilages
126
What is the significance of the bone collar in endochondral ossification?
It stabilizes the hyaline cartilage model during the early stages of bone formation
127
Osteogenesis
Another term for the process of bone tissue formation
128
What is the primary function of osteoclasts in bone remodeling?
Bone resorption
129
Which cells are responsible for depositing new bone matrix?
Osteoblasts
130
What triggers the release of parathyroid hormone (PTH)?
Low blood calcium levels
131
What is the role of osteocytes in bone remodeling?
Sensing mechanical stress and signaling for bone remodeling
132
What is the effect of calcitonin on blood calcium levels?
Lowers blood calcium levels temporarily at high doses
133
What is Wolff's law in the context of bone remodeling?
Bone grows or remodels in response to the demands placed on it
134
What happens to osteoclasts after they complete bone resorption?
They undergo apoptosis (cell death)
135
What is the main function of parathyroid hormone (PTH) in bone remodeling?
Stimulating osteoclast activity to release calcium into the blood
136
Which hormone is primarily responsible for maintaining calcium homeostasis in the blood?
Parathyroid hormone (PTH)
137
What is the result of sustained high blood levels of calcium?
Formation of kidney stones and undesirable deposits of calcium salts in other organs
138
What is the primary function of osteoclasts in bone remodeling?
Osteoclasts break down bone matrix during bone resorption.
139
What is the role of osteoblasts in bone remodeling?
Osteoblasts deposit new bone matrix during bone deposition.
140
How often is spongy bone replaced in the human skeleton?
Every three to four years.
141
Which hormone is primarily responsible for regulating blood calcium levels?
Parathyroid hormone (PTH).
142
What triggers the release of parathyroid hormone (PTH)?
A decline in blood calcium levels.
143
What is the effect of mechanical stress on bone remodeling?
Mechanical stress triggers bone remodeling to strengthen the bone where stress is applied.
144
What is the result of hypocalcemia on neuromuscular function?
Hypocalcemia causes hyperexcitability of nerves and muscles.
145
What happens to osteoclasts after they complete bone resorption?
Osteoclasts undergo apoptosis (cell death).
146
Osteoid seam
An unmineralized band of gauzy-looking bone matrix where new bone formation begins.
147
Calcification front
The abrupt transition zone between the osteoid seam and the older mineralized bone.
148
Wolff's law
The principle that a bone grows or remodels in response to the demands placed on it.
149
Hypercalcemia
A condition characterized by high levels of calcium in the blood, leading to nonresponsiveness and potential organ dysfunction.
150
What is the first step in the bone fracture repair process?
A hematoma forms
151
In fracture classification, what term describes a fracture where the bone ends retain their normal position?
Nondisplaced fracture
152
What type of fracture is common in children and involves the bone breaking incompletely?
Greenstick fracture
153
Which cells produce collagen fibers that span the break and connect the broken bone ends during fracture repair?
Fibroblasts
154
What is the final stage of bone fracture repair?
Bone remodeling occurs
155
What type of fracture involves the bone being crushed and is common in porous bones?
Compression fracture
156
What material initially connects the broken ends of bones together?
Collagen fibers
157
What is the term for a fracture where the bone ends penetrate the skin?
Open (compound) fracture
158
Which type of fracture is particularly common in the aged due to brittle bones?
Comminuted fracture
159
What type of fracture occurs when excessive twisting forces are applied to a bone?
Spiral fracture
160
What are the four major stages of bone fracture repair?
Hematoma formation, fibrocartilaginous callus formation, bony callus formation, and bone remodeling.
161
Hematoma
A localized collection of blood outside the blood vessels, usually in liquid form within the tissue.
162
What type of fracture involves the bone ends retaining their normal position?
Nondisplaced fracture.
163
What is the term for a fracture where the bone ends penetrate the skin?
Open (compound) fracture.
164
Fibrocartilaginous callus
A temporary formation of fibroblasts and chondroblasts that forms at the site of a bone fracture as part of the healing process.
165
What type of fracture is common in children and involves the bone breaking incompletely?
Greenstick fracture.
166
What is the main difference between a complete and an incomplete fracture?
A complete fracture means the bone is broken through, while an incomplete fracture means the bone is not broken all the way through.
167
Bony callus
A hard callus formed by osteoblasts that replaces the fibrocartilaginous callus during bone healing.
168
What is the purpose of reduction in fracture treatment?
Reduction is the realignment of the broken bone ends.
169
What type of fracture is characterized by bone fragments into three or more pieces?
Comminuted fracture.
170
What is the childhood condition analogous to osteomalacia?
Rickets
171
What causes osteomalacia and rickets?
Insufficient calcium in the diet or a vitamin D deficiency
172
Which demographic is most commonly affected by osteoporosis?
Postmenopausal women
173
What characterizes osteoporosis?
Bone resorption outpaces bone deposit
174
Which of the following is a common risk factor for osteoporosis?
Decreased sex hormones
175
What is a characteristic feature of Paget’s disease?
Excessive and haphazard bone deposit and resorption
176
Which bones are most commonly affected by Paget’s disease?
Spine, pelvis, femur, and skull
177
What is a common treatment for osteoporosis?
Weight-bearing exercise and adequate calcium and vitamin D intake
178
What is a potential trigger for Paget’s disease?
A viral infection
179
What is the primary cause of osteomalacia and rickets?
Insufficient calcium in the diet or a vitamin D deficiency.
180
Osteomalacia
A disorder where bones are poorly mineralized, making them soft and weak, often due to insufficient calcium or vitamin D.
181
What is a common symptom of osteomalacia?
Pain when weight is put on the affected bones.
182
Rickets
A childhood disease analogous to osteomalacia, characterized by bowed legs and deformities of the pelvis, skull, and rib cage.
183
What is the main difference between osteomalacia and rickets?
Osteomalacia occurs in adults, while rickets occurs in children and is more severe.
184
What is osteoporosis?
A group of diseases where bone resorption outpaces bone deposit, leading to porous and fragile bones.
185
Osteoporosis
A condition characterized by decreased bone mass and increased fragility, often affecting postmenopausal women.
186
What are common fracture sites in individuals with osteoporosis?
Compression fractures of the vertebrae and fractures of the neck of the femur.
187
What factors can contribute to osteoporosis?
Decreased sex hormones, insufficient bone stress, poor diet, smoking, genetics, hormone-related conditions, alcohol, and certain medications.
188
Paget’s Disease
A disorder characterized by excessive and haphazard bone deposit and resorption, leading to weakened and deformed bones.
189
What is a characteristic feature of Paget’s disease?
The formation of pagetic bone, which is hastily made and has an abnormally high ratio of spongy bone to compact bone.
190
What are common sites affected by Paget’s disease?
The spine, pelvis, femur, and skull.
191
Which germ layer gives rise to embryonic mesenchymal cells?
Mesoderm
192
By what age are nearly all bones completely ossified?
25
193
At what stage of life does bone formation exceed bone resorption?
Childhood and adolescence
194
Which bones are exceptions to age-related bone mass decrease?
Skull bones
195
What factor plays the major role in determining bone density changes over a lifetime?
Genetics
196
Which hormone is primarily responsible for the growth spurt during adolescence?
Sex hormones
197
Which bones begin ossifying by 8 weeks after conception?
Most long bones
198
What is a common consequence of diminished blood supply to bones in old age?
Fractures heal more slowly
199
What germ layer gives rise to embryonic mesenchymal cells?
Mesoderm
200
By what week after conception do most long bones begin ossifying?
8 weeks
201
At what age are nearly all bones completely ossified?
By age 25
202
What process predominates in old age: bone formation or bone resorption?
Bone resorption
203
Which gene helps determine the tendency to accumulate bone mass and risk of osteoporosis?
The gene that codes for vitamin D’s cellular docking site
204
Primary ossification centers
Areas in the fetus where bone formation begins, typically well-developed by 12 weeks
205
Epiphyseal plates
Growth plates in long bones that allow for bone growth during childhood and adolescence
206
What happens to bone mass beginning in the fourth decade of life?
Bone mass decreases with age
207
Which bones are an exception to age-related bone mass decrease?
Bones of the skull
208
Secondary ossification centers
Areas where bone formation continues after birth, allowing for the growth of long bones
209
What vitamin does the skin provide that is necessary for proper calcium absorption?
Vitamin D
210
How does muscle activity affect bones?
Increases bone strength and viability
211
What does the skeletal system protect in the nervous system?
Brain and spinal cord
212
Which system's hormones regulate the uptake and release of calcium from bones?
Endocrine system
213
Where does blood cell formation occur in the skeletal system?
Bone marrow cavities
214
What is the role of the skeletal system in the lymphatic system?
Provides protection to lymphatic organs
215
How does the respiratory system support the skeletal system?
Provides oxygen and disposes of carbon dioxide
216
What do gonads produce that influence the form of the skeleton?
Hormones
217
How does the skeletal system support the integumentary system?
It provides support for body organs including the skin.
218
What role does the skin play in relation to the skeletal system?
The skin provides vitamin D needed for proper calcium absorption and use.
219
How does the skeletal system contribute to muscle activity?
It provides levers and ionic calcium for muscle activity.
220
What effect does muscle activity have on bones?
Muscle pull on bones increases bone strength and viability; helps determine bone shape.
221
How does the skeletal system protect the nervous system?
It protects the brain and spinal cord and provides a depot for calcium ions needed for neural function.
222
What is the role of nerves in the skeletal system?
Nerves innervate bone and joint capsules, providing for pain and joint sense.
223
How does the endocrine system interact with the skeletal system?
Hormones regulate uptake and release of calcium from bone; promote long bone growth and maturation.
224
What is the function of bone marrow cavities in relation to the cardiovascular system?
They provide a site for blood cell formation.
225
How does the skeletal system support the lymphatic system?
It provides some protection to lymphatic organs and is the site of origin for lymphocytes involved in immune response.
226
What role does the respiratory system play in relation to the skeletal system?
It provides oxygen and disposes of carbon dioxide.
227
How does the skeletal system protect the digestive system?
It provides some bony protection to intestines, pelvic organs, and liver.
228
What is the role of the kidneys in relation to the skeletal system?
They activate vitamin D and dispose of nitrogenous wastes.
229
How do gonads influence the skeletal system?
They produce hormones that influence the form of the skeleton and epiphyseal closure.
230
Homeostasis
The maintenance of a stable internal environment within an organism.
231
Vitamin D
A nutrient that is essential for calcium absorption and bone health.
232
Bone Marrow
The soft tissue inside bones where blood cells are produced.
233
Lymphocytes
A type of white blood cell that is part of the immune system.
234
Epiphyseal Closure
The process by which the growth plate in long bones hardens and stops producing new bone.
235
What is achondroplasia?
A congenital condition involving defective cartilage and endochondral bone growth, resulting in short limbs but normal-sized membrane bones.
236
What is a bony spur?
An abnormal projection from a bone due to bony overgrowth.
237
What does ostealgia refer to?
Pain in a bone.
238
What is osteogenesis imperfecta also known as?
Brittle bone disease.
239
What causes osteomyelitis?
Pus-forming bacteria that enter the body via a wound or spread from an infection near the bone.
240
What is the primary treatment for osteomyelitis?
Antibiotics, draining abscesses, and removing dead bone fragments.
241
What age group is most commonly affected by osteosarcoma?
10–25 years of age.
242
What is a pathologic fracture?
A fracture in a diseased bone involving slight or no physical trauma.
243
What is the purpose of traction in treating fractures?
To keep the parts of a fractured bone in proper alignment and prevent muscle spasms.
244
Achondroplasia
A congenital condition involving defective cartilage and endochondral bone growth, resulting in short limbs but normal-sized membrane bones; a type of dwarfism.
245
What is a bony spur?
An abnormal projection from a bone due to bony overgrowth, common in aging bones.
246
Ostealgia
Pain in a bone.
247
Osteitis
Inflammation of bony tissue.
248
Osteogenesis imperfecta
Also called brittle bone disease, a disorder where the bone matrix contains inadequate collagen, making bones prone to shattering.
249
Osteosarcoma
A form of bone cancer typically arising in a long bone of a limb, most often in individuals aged 10–25, which grows aggressively and tends to metastasize to the lungs.
250
What is a pathologic fracture?
A fracture in a diseased bone that occurs with slight or no physical trauma, such as a hip bone weakened by osteoporosis breaking and causing a fall.
251
Traction
Placing sustained tension on a body region to keep fractured bone parts in proper alignment and prevent muscle spasms.
252
What type of cartilage is the most abundant in the skeletal system?
Hyaline cartilage
253
Which type of cartilage contains abundant elastic fibers and supports the outer ear?
Elastic cartilage
254
What is the primary function of fibrocartilage?
Resisting compression and stretching
255
What are the two types of cartilage growth?
Interstitial and appositional growth
256
How are bones classified based on their shape?
Long, short, flat, irregular
257
What type of bone tissue is found in the diaphysis of a long bone?
Compact bone
258
Which cells are responsible for bone resorption?
Osteoclasts
259
What is the main inorganic component of bone matrix?
Hydroxyapatites (calcium salts)
260
Which process forms most of the bones in the body?
Endochondral ossification
261
What hormone is released when blood calcium levels decline?
Parathyroid hormone (PTH)
262
What is the sequence of bone repair after a fracture?
Hematoma, fibrocartilaginous callus, bony callus, remodeling
263
What condition is characterized by excessive and abnormal bone remodeling?
Paget’s disease
264
Hyaline cartilage
A type of cartilage that appears glassy and contains collagen fibers, providing support with flexibility and resilience. It is the most abundant skeletal cartilage.
265
What type of cartilage supports the outer ear and epiglottis?
Elastic cartilage
266
Fibrocartilage
A type of cartilage that contains thick collagen fibers, is highly compressible, and resists stretching. It forms intervertebral discs and knee joint cartilages.
267
What are the two methods of cartilage growth?
Interstitial growth and appositional growth
268
Osteoblasts
Cells that synthesize bone matrix and are responsible for bone formation.
269
What is the main function of osteoclasts?
Bone resorption (breaking down bone tissue)
270
Osteon
The structural unit of compact bone, consisting of a central canal surrounded by concentric lamellae of bone matrix.
271
What is the role of the periosteum in bone structure?
It covers the diaphysis (shaft) of long bones and contains cells that contribute to bone growth and repair.
272
Intramembranous ossification
The process by which bone forms directly from mesenchymal tissue, primarily forming the clavicles and most skull bones.
273
Osteoporosis
A condition where bone resorption outpaces bone formation, leading to weak and porous bones.
274
What is the primary cause of osteomalacia and rickets?
Inadequate mineralization of bones, often due to insufficient vitamin D.
275
Bone remodeling
The continuous process of bone deposition and resorption in response to hormonal and mechanical stimuli.
276
What is the function of red marrow in adults?
It is the site of hematopoiesis (blood cell production) and is found within the spongy bone of flat bones and occasionally within the epiphyses of long bones.
277
What type of fracture does Liliana have?
Open fracture
278
When assessing Liliana’s condition relative to her tibia fracture after the open reduction, the nurse will be especially alert for signs of which of these problems?
Infection
279
Which of the following statements about Liliana’s condition are correct?
Her leg will not heal to its normal length if the epiphyses have been damaged.
280
Which of Liliana's statements indicates the need for further patient education?
The only supplement I should need would be calcium, so I will take a calcium supplement every morning.
281
How likely is it that Liliana’s knee cartilage will regenerate?
Unlikely, because cartilage has limited ability to regenerate.
282
What type of fracture does Liliana have?
A fracture of the superior right tibia with a 3.5-cm laceration where the bone protrudes.
283
After the open reduction of Liliana's tibia fracture, what problem should the nurse be especially alert for?
Infection
284
What might prevent Liliana's leg from healing to its normal length?
Damage to the epiphyses.
285
Which cells are involved in Liliana's leg healing?
Osteoclasts and osteoblasts.
286
What is the role of the periosteum in bone healing?
The periosteum is crucial for bone healing; damage to it can affect the healing process.
287
Approximately how long should it take for bone to heal given an uncomplicated recovery?
It typically takes about 6-8 weeks for a bone to heal.
288
What complications might arise from the damage to the nutrient artery in tibia?
Potential complications include delayed healing or nonunion of the fracture.
289
How likely is it that knee cartilage will regenerate?
Cartilage has limited regenerative capacity, so it is unlikely to fully regenerate.
290
Open Reduction
A surgical procedure to realign broken bones.
291
Nutrient Artery
An artery that supplies blood to the bones.
292
Medial Meniscus
A fibrocartilage disc in the knee joint that acts as a cushion.
293
Osteoid
Unmineralized bone matrix.
294
Medullary cavity
Central cavity of a long bone. Contains yellow or red (bone) marrow.
295
Osteocytes
Mature bone cell.
296
Perichondrium
Fibrous, connective-tissue membrane covering the external surface of cartilaginous structures.
297
Spongy bone
Internal layer of skeletal bone. Also called trabecular bone.
298
Hypertrophy
Growth of an organ or tissue due to an increase in the size of its cells; differs from hyperplasia (an increase in size due to increased cell numbers).
299
Osteon
System of interconnecting canals in the microscopic structure of adult compact bone; unit of bone; also called Haversian system.
300
Osteoblasts
Bone-forming cells.
301
Trabeculae
(1) Any of the fibrous bands extending from the capsule into the interior of an organ; (2) strut or thin plate of bone in spongy bone.
302
Diploë
The internal layer of spongy bone in flat bones.
303
Appositional growth
Growth accomplished by the addition of new layers onto those previously formed.
304
Perforating canals
Canals that run at right angles to the long axis of the bone, connecting the vascular and nerve supplies of the periosteum to those of the central canals and medullary cavity; also called Volkmann’s canals.
305
Ossification
The process of bone formation; also called Osteogenesis.
306
Endosteum
Connective tissue membrane covering internal bone surfaces.
307
Fractures
A break in a bone.
308
Paget’s disease
Disorder characterized by excessive bone breakdown and abnormal bone formation.
309
Periosteum
Double-layered connective tissue that covers and nourishes the bone.
310
Hematoma
Mass of clotted blood that forms at an injured site.
311
Lamella
A layer, such as of bone matrix in an osteon of compact bone.
312
Osteoporosis
Decreased density and strength of bone resulting from a gradual decrease in rate of bone formation.
313
Interstitial lamellae
Incomplete lamellae that lie between intact osteons, filling the gaps between forming osteons, or representing the remnants of an osteon that has been cut through by bone remodeling.
314
Parathyroid hormone (PTH)
Hormone released by the parathyroid glands that regulates blood calcium level.
315
Hematopoiesis
Blood cell formation; hemopoiesis.
316
Fiber
A slender threadlike structure or filament. May refer to a cell, part of a cell, or a protein. See also A muscle cell, Axon of a neuron, The most abundant of the three types of protein fibers found in the extracellular matrix of connective tissue.
317
Foramen
Hole or opening in a bone or between body cavities.
318
Endochondral ossification
Embryonic formation of bone by the replacement of calcified cartilage; most skeletal bones are formed by this process.
319
Calcitonin
Hormone released by the thyroid. Lowers blood calcium levels only when present at high (therapeutic) levels.
320
Bone resorption
The removal of osseous tissue; part of the continuous bone remodeling process.
321
Reduction
Chemical reaction in which electrons and energy are gained by a molecule (often accompanied by gain of hydrogen ions) or oxygen is lost.
322
Bone remodeling
Process involving bone formation and destruction in response to hormonal and mechanical factors.
323
Sesamoid bones
Short bones embedded in tendons, variable in size and number, many of which influence the action of muscles; largest is the patella (kneecap).
324
Epiphyses
The end of a long bone, attached to the shaft.
325
Central canal (Haversian)
The canal in the center of each osteon that contains minute blood vessels and nerve fibers that serve the needs of the osteocytes
326
Diaphysis
Elongated shaft of a long bone.
327
Haversian system
System of interconnecting canals in the microscopic structure of adult compact bone; unit of bone; also called Haversian system.
328
Epiphyseal plate
Plate of hyaline cartilage at the junction of the diaphysis and epiphysis that provides for growth in length of a long bone.
329
Osteomalacia
Disorder in which bones are inadequately mineralized; soft bones.
330
Osteogenesis
The process of bone formation; also called ossification.
331
Osteoclasts
Large cells that resorb or break down bone matrix.
332
Lacunae
A small space, cavity, or depression; lacunae in bone or cartilage are occupied by cells.
333
Endochondral bone
Bone formed by using hyaline cartilage structures as models for ossification.
334
What is a key functional property of cartilage tissue?
It is very resilient and can return to its original shape after being compressed.
335
Why does cartilage not contain blood vessels?
To maintain a high water content and resilience without the need for direct blood supply.
336
How do cartilage cells receive nutrients?
Through diffusion from blood vessels in the surrounding perichondrium.
337
Which type of cartilage is most abundant in the skeletal system?
Hyaline cartilage
338
Where would you typically find fibrocartilage?
In the knee menisci and between vertebrae.
339
What distinguishes elastic cartilage from hyaline cartilage?
Elastic cartilage contains more stretchy elastic fibers.
340
How does appositional growth occur in cartilage?
Cartilage-forming cells in the perichondrium secrete new matrix against the existing cartilage.
341
What is a characteristic of interstitial growth in cartilage?
It involves the division of chondrocytes within the cartilage, expanding it from within.
342
When does cartilage typically stop growing?
During adolescence, when the skeleton stops growing.
343
What is a key difference between cartilage and bone?
Cartilage is surrounded by the perichondrium, while bone is surrounded by the periosteum.
344
Which cells are found in the lacunae of cartilage?
Chondrocytes
345
How does the extracellular matrix of bone compare to that of cartilage?
The matrix of bone is rigid due to inorganic calcium salts.
346
Which of the following best describes the support function of bones?
Bones provide a framework that supports the body and cradles its soft organs.
347
How do bones protect vital organs in the human body?
The fused bones of the skull protect the brain.
348
What role do bones play in movement?
Bones serve as points of attachment for muscles, allowing for the movement of the body.
349
Which minerals are primarily stored in the bones?
Calcium and phosphate.
350
Where does most blood cell formation occur in the human body?
In the red marrow of certain bones.
351
What is the primary function of yellow marrow found in the cavities of long bones?
To store fat as a source of energy for the body.
352
Which hormone is produced by bones and helps to regulate insulin secretion, glucose homeostasis, and energy expenditure?
Osteocalcin.
353
Which part of the human skeleton is primarily responsible for protection, support, and carrying other body parts?
Axial skeleton
354
The appendicular skeleton is essential for:
Locomotion and manipulation of the environment
355
What does the axial skeleton include?
Skull, vertebral column, and rib cage
356
Which of the following is a characteristic of long bones?
They have a shaft and two expanded ends
357
Sesamoid bones, like the patella, are classified as:
A special type of short bone
358
Which type of bone is typically involved in protecting internal organs?
Flat bones
359
The bones that make up the wrist and ankle are classified as:
Short bones
360
An example of an irregular bone is:
The vertebrae
361
Why are long bones such as the femur designed to be hollow?
To provide maximum strength with minimum weight
362
Flat bones like the scapulae are important for:
Protection of internal organs and providing large areas for muscle attachment
363
What is the primary structural difference between compact and spongy bone?
Compact bone forms the dense outer layer of bones, while spongy bone is found internally and has a honeycomb structure.
364
Which of the following best describes the location of red and yellow marrow in adult bones?
Yellow marrow is found in the medullary cavity of long bones, while red marrow is located in the trabeculae of spongy bones in certain bones like the sternum and hip bones.
365
What is the function of articular cartilage in long bones?
To cushion the opposing bone ends during movement and absorb stress.
366
What is the significance of bone markings on the external surface of bones?
They provide information about the attachment of muscles and ligaments, and the formation of joints.
367
Which category of bone markings includes surfaces that form joints?
Surfaces that form joints.
368
What is the role of osteocytes in bone tissue?
To monitor and maintain the bone matrix and act as stress or strain sensors.
369
Which cells are responsible for forming new bone tissue?
Osteoblasts.
370
How do nutrients reach the osteocytes in compact bone?
Through the central canal in each osteon.
371
What is the primary organic component of the bone matrix that contributes to bone's flexibility and tensile strength?
Osteoid, including collagen fibers.
372
Which of the following best describes the role of the inorganic components in bone?
They contribute to bone's hardness and its ability to resist compression.
373
How does the structure of bone contribute to its strength?
The organic components allow it to resist tension, while the inorganic components allow it to resist compression.
374
Which of the following best describes intramembranous ossification?
A bone develops from a fibrous membrane.
375
Endochondral ossification is primarily responsible for the formation of which type of bones?
Long bones below the base of the skull, excluding the clavicles.
376
What initiates the process of ossification in intramembranous ossification?
Mesenchymal cells specializing into osteoblasts.
377
During endochondral ossification, what is the significance of the bone collar forming around the diaphysis of the hyaline cartilage model?
It marks the beginning of the primary ossification center.
378
In the process of endochondral ossification, what happens after the cartilage calcifies and develops cavities?
The periosteal bud invades, bringing in elements to form spongy bone.
379
What role do osteoclasts play in the formation of the medullary cavity during endochondral ossification?
They break down newly formed spongy bone to open up the cavity.
380
How do long bones grow in length?
By interstitial growth of the epiphyseal plate cartilage.
381
What is the role of the epiphyseal plate in the longitudinal growth of long bones?
It maintains a constant thickness while allowing the bone to lengthen.
382
Which hormone is most important for stimulating epiphyseal plate activity during infancy and childhood?
Growth hormone.
383
What effect do sex hormones have on bone growth during puberty?
They induce epiphyseal closure, ending longitudinal bone growth.
384
How do bones grow in width (thickness)?
By appositional growth, with osteoblasts adding bone matrix externally.
385
What is the outcome of hormonal imbalances on bone growth, such as an excess of growth hormone in children?
It results in excessive height, known as gigantism.
386
What is the primary location where bone is deposited and removed in the adult skeleton?
At the endosteal surface
387
Which cells are responsible for bone resorption by breaking down the bone matrix?
Osteoclasts
388
What initiates the calcification of the newly deposited osteoid during bone deposition?
The release of matrix vesicles containing alkaline phosphatase by osteoblasts
389
How does parathyroid hormone (PTH) primarily affect bone remodeling?
By indirectly stimulating osteoclasts to resorb bone
390
Which hormone is thought to have a negligible effect on calcium homeostasis in humans under normal conditions?
Calcitonin
391
What is the primary role of mechanical stress in bone remodeling?
To direct remodeling where it strengthens the bone
392
What is the main purpose of maintaining calcium homeostasis in the blood through bone remodeling?
To ensure proper muscle contraction and nerve function
393
According to Wolff’s law, how does the anatomy of a bone reflect its function?
Bones grow or remodel in response to the stresses placed on them
394
What is the outcome when the balance between bone deposit and resorption is lost?
It can lead to bone diseases due to imbalance
395
Which of the following best describes a nondisplaced fracture?
The bone ends retain their normal position.
396
What characterizes a complete fracture?
The bone is broken through.
397
An open (compound) fracture is distinguished by which of the following?
The bone ends penetrate the skin.
398
What is the first step in treating a fracture?
Reduction, the realignment of the broken bone ends.
399
Which method involves the surgical securing of bone ends with screws and plates?
Open (internal) reduction.
400
How long does it typically take for a simple fracture of small or medium-sized bones in young adults to heal?
Six to eight weeks.
401
What occurs immediately after a bone breaks?
A hematoma forms.
402
During the second step of bone repair, what type of callus forms?
Fibrocartilaginous callus.
403
What role do osteoblasts play in bone repair?
They begin forming spongy bone within the repair tissue.
404
In the final stage of bone repair, what process occurs?
Bone remodeling.
405
Which treatment has been suggested to potentially hasten the repair and healing of fractures?
Daily ultrasound treatments or electrical stimulation of fracture sites.
406
What is a common symptom of osteomalacia?
Pain when weight is put on the affected bones
407
Rickets is most analogous to which condition in adults?
Osteomalacia
408
What are common causes of osteomalacia and rickets?
Insufficient calcium in the diet or vitamin D deficiency
409
Which group is most often affected by osteoporosis?
Postmenopausal women
410
What are common risk factors for developing osteoporosis?
Decreased sex hormones and insufficient bone stress
411
Which parts of the skeleton are most often involved in Paget’s disease?
Spine, pelvis, femur, and skull
412
What is a common treatment for Paget’s disease?
Bisphosphonates and calcitonin
413
How can osteoporosis be prevented or delayed?
Minimizing controllable risk factors like diet and exercise
414
Which category of drugs is used to treat osteoporosis by inhibiting osteoclasts?
Bisphosphonates
415
What is a recommended lifestyle change for preventing bone disorders like osteomalacia?
Increasing vitamin D intake and sunlight exposure
416
At what stage of development do most long bones begin ossifying?
8 weeks after conception
417
What is the primary role of the epiphyseal plates in bone development?
To provide for long bone growth during childhood and adolescence
418
By what age are nearly all bones in the human body completely ossified, marking the cessation of skeletal growth?
25 years
419
In which age group does bone formation exceed bone resorption?
Children and adolescents
420
Which factor plays the major role in determining a person's bone density changes over a lifetime?
Genetics
421
What is the trend in bone mass as individuals enter their fourth decade of life?
Bone mass decreases
422
Which demographic is generally known to experience faster age-related bone loss?
White females
423
What qualitative change occurs in bones as people age?
More osteons remain incompletely formed, and mineralization is less complete
424
Why do fractures heal more slowly in older adults?
Because of a diminished blood supply to the bones
425
What is a characteristic feature of achondroplasia?
Short limbs with normal-sized membrane bones
426
Achondroplasia results from which of the following?
Defective cartilage and endochondral bone growth
427
What is a bony spur?
An abnormal projection from a bone due to overgrowth
428
Bony spurs are most commonly associated with which of the following conditions?
Aging bones
429
What does ostealgia refer to?
Pain in a bone
430
Osteitis is characterized by:
Inflammation of bony tissue
431
Osteogenesis imperfecta puts bones at risk for:
Shattering due to inadequate collagen
432
Osteomyelitis is primarily caused by:
Pus-forming bacteria entering through a wound
433
A common treatment for osteomyelitis includes:
Antibiotics and draining abscesses
434
Osteosarcoma is a form of:
Bone cancer
435
The survival rate for osteosarcoma, if detected early, is approximately:
50%
436
A pathologic fracture occurs due to:
Disease weakening the bone, leading to fracture with minimal trauma
437
The purpose of traction in medical treatment is to:
Keep parts of a fractured bone in proper alignment
438
What is the primary function of the large amounts of water found in the extracellular matrix of skeletal cartilage?
To provide resilience
439
Which type of skeletal cartilage is characterized by its glassy appearance and collagenous fibers?
Hyaline cartilage
440
Fibrocartilages are best suited for which of the following functions?
Resisting stretching and being highly compressible
441
How does interstitial growth contribute to the growth of cartilage?
By growing from within the cartilage
442
Appositional growth of cartilage involves which of the following processes?
The addition of new cartilage tissue at the periphery
443
Which of the following is NOT a function of bones?
To conduct nerve impulses
444
Bones that are classified as "flat" are primarily characterized by:
Two thin plates of compact bone enclosing a layer of spongy bone
445
The axial and appendicular classifications of bones are based on:
Their location in the body
446
What triggers the release of parathyroid hormone (PTH) during bone remodeling?
A decline in blood calcium levels
447
The initial step in the bone healing process after a fracture is:
Formation of a hematoma
448
Which condition is characterized by excessive and abnormal bone remodeling?
Paget’s disease
449
Intramembranous ossification is responsible for forming:
Most of the skull bones and clavicles
450
Osteoporosis is a condition in which:
Bone breakdown outpaces bone formation, leading to weak and porous bones
451
A key factor in the development of osteomalacia and rickets is:
Inadequate vitamin D
