Ch. 6 Bones and Skeletal Tissue Flashcards
What are the three types of cartilage that help form the skeleton?
Hyaline, elastic, and fibrocartilage
What are the major functions of bones?
Support, protection, movement, storage, and blood cell formation
How are bones classified?
By their location and shape
What does the gross structure of all bones consist of?
Compact bone sandwiching spongy bone
What are the two methods by which bones develop?
Intramembranous and endochondral ossification
What are the key cells involved in bone remodeling?
Osteoblasts, osteocytes, and osteoclasts
What are the steps involved in bone fracture repair?
Hematoma formation, callus formation, and remodeling
What are the disorders of bone remodeling?
Osteoporosis, osteomalacia, and Paget’s disease
Osteoblasts
Cells responsible for bone formation
What are the two main types of bone tissue?
Compact bone and spongy bone
Epiphyseal plate
A growth plate that allows long bones to grow
What are the major regions of the skeleton?
Axial skeleton and appendicular skeleton
Osteoclasts
Cells that break down bone tissue
What is the functional importance of bone markings?
They serve as sites for muscle attachment, joint formation, and passage of nerves and blood vessels
What are the four bone classes?
Long bones, short bones, flat bones, and irregular bones
Osteocytes
Mature bone cells that maintain the bone matrix
How do hormones and physical stress regulate bone remodeling?
Hormones and physical stress influence the activity of osteoblasts and osteoclasts, thereby regulating bone deposition and resorption
What is the most plentiful type of cartilage in the adult body?
Hyaline cartilage
Which type of cartilage is found in the external ear and the epiglottis?
Elastic cartilage
What is a key difference between cartilage and bone tissue?
Cartilage grows in an interstitial manner; bone does not.
Which type of cartilage is highly compressible with great tensile strength?
Fibrocartilage
What is the primary function of the perichondrium?
To resist outward expansion when the cartilage is compressed and to nourish cartilage cells
Where is hyaline cartilage found in the human body?
Ends of long bones, rib cage, respiratory passageways, and external nose
What are the two ways cartilage grows?
Appositional growth and interstitial growth
What cells are found within the lacunae of cartilage?
Chondrocytes
Perichondrium
A layer of dense irregular connective tissue that surrounds cartilage and contains blood vessels to nourish cartilage cells
What is the primary function of hyaline cartilage?
To provide support with flexibility and resilience
Chondrocytes
Cells found in cartilage that are enclosed in small cavities called lacunae
Where can elastic cartilage be found in the body?
In the external ear and the epiglottis
What is the main characteristic of fibrocartilage?
It is highly compressible with great tensile strength
Appositional growth
Growth where cartilage-forming cells in the perichondrium secrete new matrix against the external face of existing cartilage
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
Interstitial growth
Growth where chondrocytes divide and secrete new matrix, expanding the cartilage from within
What is one of the primary functions of bones in the human body?
Support
Which bones protect the brain?
Fused bones of the skull
What is the role of bones in mineral storage?
Reservoir for minerals like calcium and phosphate
Where does most blood cell formation occur?
Red marrow of certain bones
What type of marrow stores fat?
Yellow marrow
What hormone is produced by bones to help regulate insulin secretion?
Osteocalcin
How do bones assist in movement?
They act as levers for skeletal muscles
What is the primary function of red marrow in bones?
Hematopoiesis (blood cell formation)
Which type of marrow is responsible for fat storage?
Yellow marrow
What hormone do bones produce that helps regulate insulin secretion?
Osteocalcin
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.
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.
Hematopoiesis
The formation of blood cells, which occurs in the red marrow of certain bones.
Osteocalcin
A hormone produced by bones that helps regulate insulin secretion, glucose homeostasis, and energy expenditure.
Mineral storage
The process by which bones store minerals like calcium and phosphate and release them into the bloodstream as needed.
Anchorage
The function of bones serving as levers for skeletal muscles, allowing movement of the body and its parts.
Support
The function of bones providing a framework that supports the body and cradles its soft organs.
What are the two major regions of the human skeleton?
Axial and appendicular
Which bones are part of the axial skeleton?
Skull, vertebral column, and rib cage
What is the primary function of the appendicular skeleton?
Locomotion and manipulation of the environment
Which of the following is an example of a long bone?
Femur
What shape classification does the sternum fall under?
Flat bones
Which bones are classified as short bones?
Wrist and ankle bones
What is a unique feature of sesamoid bones?
They form in a tendon
Which of the following is an example of an irregular bone?
Vertebra
What is the function of the femur’s hollow-cylinder shape?
Provides maximum strength with minimum weight
What is the primary function of the axial skeleton?
To protect, support, or carry other body parts
Which bones are included in the axial skeleton?
The bones of the skull, vertebral column, and rib cage
What is the primary function of the appendicular skeleton?
To help us move from place to place and manipulate our environment
Which bones are included in the appendicular skeleton?
The bones of the upper and lower limbs and the girdles (shoulder bones and hip bones)
How are bones classified by shape?
As long, short, flat, or irregular
What are examples of long bones?
All limb bones except the patella, wrist, and ankle bones
What are examples of short bones?
The bones of the wrist and ankle
What is a special type of short bone that forms in a tendon?
Sesamoid bones
What are examples of flat bones?
The sternum, scapulae, ribs, and most cranial bones of the skull
What are examples of irregular bones?
The vertebrae and hip bones
Axial skeleton
The part of the skeleton that forms the long axis of the body, including the skull, vertebral column, and rib cage
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
Long bones
Bones that are considerably longer than they are wide, with a shaft and two ends
Short bones
Bones that are roughly cube shaped, such as the bones of the wrist and ankle
Sesamoid bones
A special type of short bone that forms in a tendon, such as the patella
Flat bones
Bones that are thin, flattened, and usually a bit curved, such as the sternum and scapulae
Irregular bones
Bones with complicated shapes that do not fit into the other categories, such as the vertebrae and hip bones
What is the dense outer layer of bone called?
Compact bone
What fills the open spaces between trabeculae in living bones?
Red or yellow bone marrow
What is the main function of the periosteum?
Covers the external surface of the bone
Which part of a long bone contains yellow marrow in adults?
Medullary cavity
What type of bone cell is responsible for bone resorption?
Osteoclasts
What is the structural unit of compact bone?
Osteon
Which type of bone contains osteons?
Compact bone
What are the small needle-like or flat pieces in spongy bone called?
Trabeculae
What is the role of osteocytes in bone tissue?
Monitor and maintain the bone matrix
Which bone marking is a large rounded projection that may be roughened?
Tuberosity
What are the two types of bone tissue found in all bones?
Compact bone and spongy bone
What is the primary function of red bone marrow?
Hematopoiesis (blood cell formation)
Where is yellow bone marrow primarily found in adults?
In the medullary cavity of long bones
What type of bone tissue forms the outer layer of bones?
Compact bone
What is the name of the membrane that covers the external surface of bones?
Periosteum
What is the structural unit of compact bone?
Osteon or Haversian system
What is the role of osteocytes in bone tissue?
To monitor and maintain the bone matrix
What type of cells are responsible for bone resorption?
Osteoclasts
What is the function of articular cartilage?
To cushion the bone ends during movement and absorb stress
What are trabeculae?
Small needle-like or flat pieces of spongy bone
Diaphysis
The tubular shaft that forms the long axis of a long bone
Epiphysis
The ends of a long bone, consisting of an outer shell of compact bone and an interior of spongy bone
Periosteum
A double-layered membrane covering the external surface of bones, except at the joints
Endosteum
A delicate connective tissue membrane covering internal bone surfaces
Osteoblasts
Bone-forming cells that secrete the bone matrix
Osteoclasts
Giant multinucleate cells responsible for bone resorption
Osteon
The structural unit of compact bone, also known as the Haversian system
Lamellae
Layers of bone matrix in compact bone
Canaliculi
Hairlike canals that connect lacunae to each other and to the central canal
Trabeculae
The small, needle-like or flat pieces of spongy bone
What are the two types of ossification processes in bone development?
Intramembranous and endochondral ossification
What type of bone development involves replacing hyaline cartilage?
Endochondral ossification
Which bones are primarily formed through intramembranous ossification?
Cranial bones and clavicles
At what stage of development does bone tissue begin to replace fibrous or cartilage structures?
Around week 8 of embryonic development
What is the primary function of the epiphyseal plate in long bones?
To allow for the lengthening of the bone
Which of the following structures consists of hyaline cartilage?
Epiphyseal plate
What happens to the chondrocytes in the hypertrophic zone of the epiphyseal plate?
They enlarge and their lacunae break down
What is the role of osteoclasts during the lengthening of a long bone?
To break down calcified spicules of cartilage
What type of bone growth occurs during infancy and youth?
Interstitial growth of the epiphyseal plate
Which hormone is the most important stimulus for epiphyseal plate activity during infancy and childhood?
Growth hormone
Ossification
The process of bone tissue formation
What type of tissue does intramembranous ossification begin with?
Fibrous connective tissue membranes
Endochondral ossification
A process where bone develops by replacing hyaline cartilage
What is the primary ossification center?
The region in the diaphysis where bone tissue begins to form during endochondral ossification
Epiphyseal plate
A disc of hyaline cartilage that grows during childhood to lengthen the bone
What happens in the hypertrophic zone during the growth of long bones?
Older chondrocytes enlarge and their lacunae erode, leaving large interconnecting spaces
What is the role of osteoblasts in bone growth?
Osteoblasts secrete osteoid, which calcifies to form bone tissue
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
What remains in long bones after secondary ossification is complete?
Hyaline cartilage remains at the epiphyseal plates and articular cartilages
What is the significance of the bone collar in endochondral ossification?
It stabilizes the hyaline cartilage model during the early stages of bone formation
Osteogenesis
Another term for the process of bone tissue formation
What is the primary function of osteoclasts in bone remodeling?
Bone resorption
Which cells are responsible for depositing new bone matrix?
Osteoblasts
What triggers the release of parathyroid hormone (PTH)?
Low blood calcium levels
What is the role of osteocytes in bone remodeling?
Sensing mechanical stress and signaling for bone remodeling
What is the effect of calcitonin on blood calcium levels?
Lowers blood calcium levels temporarily at high doses
What is Wolff’s law in the context of bone remodeling?
Bone grows or remodels in response to the demands placed on it
What happens to osteoclasts after they complete bone resorption?
They undergo apoptosis (cell death)
What is the main function of parathyroid hormone (PTH) in bone remodeling?
Stimulating osteoclast activity to release calcium into the blood
Which hormone is primarily responsible for maintaining calcium homeostasis in the blood?
Parathyroid hormone (PTH)
What is the result of sustained high blood levels of calcium?
Formation of kidney stones and undesirable deposits of calcium salts in other organs
What is the primary function of osteoclasts in bone remodeling?
Osteoclasts break down bone matrix during bone resorption.
What is the role of osteoblasts in bone remodeling?
Osteoblasts deposit new bone matrix during bone deposition.
How often is spongy bone replaced in the human skeleton?
Every three to four years.
Which hormone is primarily responsible for regulating blood calcium levels?
Parathyroid hormone (PTH).
What triggers the release of parathyroid hormone (PTH)?
A decline in blood calcium levels.
What is the effect of mechanical stress on bone remodeling?
Mechanical stress triggers bone remodeling to strengthen the bone where stress is applied.
What is the result of hypocalcemia on neuromuscular function?
Hypocalcemia causes hyperexcitability of nerves and muscles.
What happens to osteoclasts after they complete bone resorption?
Osteoclasts undergo apoptosis (cell death).
Osteoid seam
An unmineralized band of gauzy-looking bone matrix where new bone formation begins.
Calcification front
The abrupt transition zone between the osteoid seam and the older mineralized bone.
Wolff’s law
The principle that a bone grows or remodels in response to the demands placed on it.
Hypercalcemia
A condition characterized by high levels of calcium in the blood, leading to nonresponsiveness and potential organ dysfunction.
What is the first step in the bone fracture repair process?
A hematoma forms
In fracture classification, what term describes a fracture where the bone ends retain their normal position?
Nondisplaced fracture
What type of fracture is common in children and involves the bone breaking incompletely?
Greenstick fracture
Which cells produce collagen fibers that span the break and connect the broken bone ends during fracture repair?
Fibroblasts
What is the final stage of bone fracture repair?
Bone remodeling occurs
What type of fracture involves the bone being crushed and is common in porous bones?
Compression fracture
What material initially connects the broken ends of bones together?
Collagen fibers
What is the term for a fracture where the bone ends penetrate the skin?
Open (compound) fracture
Which type of fracture is particularly common in the aged due to brittle bones?
Comminuted fracture
What type of fracture occurs when excessive twisting forces are applied to a bone?
Spiral fracture
What are the four major stages of bone fracture repair?
Hematoma formation, fibrocartilaginous callus formation, bony callus formation, and bone remodeling.
Hematoma
A localized collection of blood outside the blood vessels, usually in liquid form within the tissue.
What type of fracture involves the bone ends retaining their normal position?
Nondisplaced fracture.
What is the term for a fracture where the bone ends penetrate the skin?
Open (compound) fracture.
Fibrocartilaginous callus
A temporary formation of fibroblasts and chondroblasts that forms at the site of a bone fracture as part of the healing process.
What type of fracture is common in children and involves the bone breaking incompletely?
Greenstick fracture.
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.
Bony callus
A hard callus formed by osteoblasts that replaces the fibrocartilaginous callus during bone healing.
What is the purpose of reduction in fracture treatment?
Reduction is the realignment of the broken bone ends.
What type of fracture is characterized by bone fragments into three or more pieces?
Comminuted fracture.
What is the childhood condition analogous to osteomalacia?
Rickets
What causes osteomalacia and rickets?
Insufficient calcium in the diet or a vitamin D deficiency
Which demographic is most commonly affected by osteoporosis?
Postmenopausal women
What characterizes osteoporosis?
Bone resorption outpaces bone deposit
Which of the following is a common risk factor for osteoporosis?
Decreased sex hormones
What is a characteristic feature of Paget’s disease?
Excessive and haphazard bone deposit and resorption
Which bones are most commonly affected by Paget’s disease?
Spine, pelvis, femur, and skull
What is a common treatment for osteoporosis?
Weight-bearing exercise and adequate calcium and vitamin D intake
What is a potential trigger for Paget’s disease?
A viral infection
What is the primary cause of osteomalacia and rickets?
Insufficient calcium in the diet or a vitamin D deficiency.
Osteomalacia
A disorder where bones are poorly mineralized, making them soft and weak, often due to insufficient calcium or vitamin D.
What is a common symptom of osteomalacia?
Pain when weight is put on the affected bones.
Rickets
A childhood disease analogous to osteomalacia, characterized by bowed legs and deformities of the pelvis, skull, and rib cage.
What is the main difference between osteomalacia and rickets?
Osteomalacia occurs in adults, while rickets occurs in children and is more severe.
What is osteoporosis?
A group of diseases where bone resorption outpaces bone deposit, leading to porous and fragile bones.
Osteoporosis
A condition characterized by decreased bone mass and increased fragility, often affecting postmenopausal women.
What are common fracture sites in individuals with osteoporosis?
Compression fractures of the vertebrae and fractures of the neck of the femur.
What factors can contribute to osteoporosis?
Decreased sex hormones, insufficient bone stress, poor diet, smoking, genetics, hormone-related conditions, alcohol, and certain medications.
Paget’s Disease
A disorder characterized by excessive and haphazard bone deposit and resorption, leading to weakened and deformed bones.
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.
What are common sites affected by Paget’s disease?
The spine, pelvis, femur, and skull.
Which germ layer gives rise to embryonic mesenchymal cells?
Mesoderm
By what age are nearly all bones completely ossified?
25
At what stage of life does bone formation exceed bone resorption?
Childhood and adolescence
Which bones are exceptions to age-related bone mass decrease?
Skull bones
What factor plays the major role in determining bone density changes over a lifetime?
Genetics
Which hormone is primarily responsible for the growth spurt during adolescence?
Sex hormones
Which bones begin ossifying by 8 weeks after conception?
Most long bones
What is a common consequence of diminished blood supply to bones in old age?
Fractures heal more slowly
What germ layer gives rise to embryonic mesenchymal cells?
Mesoderm
By what week after conception do most long bones begin ossifying?
8 weeks
At what age are nearly all bones completely ossified?
By age 25
What process predominates in old age: bone formation or bone resorption?
Bone resorption
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
Primary ossification centers
Areas in the fetus where bone formation begins, typically well-developed by 12 weeks
Epiphyseal plates
Growth plates in long bones that allow for bone growth during childhood and adolescence
What happens to bone mass beginning in the fourth decade of life?
Bone mass decreases with age
Which bones are an exception to age-related bone mass decrease?
Bones of the skull
Secondary ossification centers
Areas where bone formation continues after birth, allowing for the growth of long bones
What vitamin does the skin provide that is necessary for proper calcium absorption?
Vitamin D
How does muscle activity affect bones?
Increases bone strength and viability
What does the skeletal system protect in the nervous system?
Brain and spinal cord
Which system’s hormones regulate the uptake and release of calcium from bones?
Endocrine system
Where does blood cell formation occur in the skeletal system?
Bone marrow cavities
What is the role of the skeletal system in the lymphatic system?
Provides protection to lymphatic organs
How does the respiratory system support the skeletal system?
Provides oxygen and disposes of carbon dioxide
What do gonads produce that influence the form of the skeleton?
Hormones
How does the skeletal system support the integumentary system?
It provides support for body organs including the skin.
What role does the skin play in relation to the skeletal system?
The skin provides vitamin D needed for proper calcium absorption and use.
How does the skeletal system contribute to muscle activity?
It provides levers and ionic calcium for muscle activity.
What effect does muscle activity have on bones?
Muscle pull on bones increases bone strength and viability; helps determine bone shape.
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.
What is the role of nerves in the skeletal system?
Nerves innervate bone and joint capsules, providing for pain and joint sense.
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.
What is the function of bone marrow cavities in relation to the cardiovascular system?
They provide a site for blood cell formation.
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.
What role does the respiratory system play in relation to the skeletal system?
It provides oxygen and disposes of carbon dioxide.
How does the skeletal system protect the digestive system?
It provides some bony protection to intestines, pelvic organs, and liver.
What is the role of the kidneys in relation to the skeletal system?
They activate vitamin D and dispose of nitrogenous wastes.
How do gonads influence the skeletal system?
They produce hormones that influence the form of the skeleton and epiphyseal closure.
Homeostasis
The maintenance of a stable internal environment within an organism.
Vitamin D
A nutrient that is essential for calcium absorption and bone health.
Bone Marrow
The soft tissue inside bones where blood cells are produced.
Lymphocytes
A type of white blood cell that is part of the immune system.
Epiphyseal Closure
The process by which the growth plate in long bones hardens and stops producing new bone.
What is achondroplasia?
A congenital condition involving defective cartilage and endochondral bone growth, resulting in short limbs but normal-sized membrane bones.
What is a bony spur?
An abnormal projection from a bone due to bony overgrowth.
What does ostealgia refer to?
Pain in a bone.
What is osteogenesis imperfecta also known as?
Brittle bone disease.
What causes osteomyelitis?
Pus-forming bacteria that enter the body via a wound or spread from an infection near the bone.
What is the primary treatment for osteomyelitis?
Antibiotics, draining abscesses, and removing dead bone fragments.
What age group is most commonly affected by osteosarcoma?
10–25 years of age.
What is a pathologic fracture?
A fracture in a diseased bone involving slight or no physical trauma.
What is the purpose of traction in treating fractures?
To keep the parts of a fractured bone in proper alignment and prevent muscle spasms.
Achondroplasia
A congenital condition involving defective cartilage and endochondral bone growth, resulting in short limbs but normal-sized membrane bones; a type of dwarfism.
What is a bony spur?
An abnormal projection from a bone due to bony overgrowth, common in aging bones.
Ostealgia
Pain in a bone.
Osteitis
Inflammation of bony tissue.
Osteogenesis imperfecta
Also called brittle bone disease, a disorder where the bone matrix contains inadequate collagen, making bones prone to shattering.
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.
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.
Traction
Placing sustained tension on a body region to keep fractured bone parts in proper alignment and prevent muscle spasms.
What type of cartilage is the most abundant in the skeletal system?
Hyaline cartilage
Which type of cartilage contains abundant elastic fibers and supports the outer ear?
Elastic cartilage
What is the primary function of fibrocartilage?
Resisting compression and stretching
What are the two types of cartilage growth?
Interstitial and appositional growth
How are bones classified based on their shape?
Long, short, flat, irregular
What type of bone tissue is found in the diaphysis of a long bone?
Compact bone
Which cells are responsible for bone resorption?
Osteoclasts
What is the main inorganic component of bone matrix?
Hydroxyapatites (calcium salts)
Which process forms most of the bones in the body?
Endochondral ossification
What hormone is released when blood calcium levels decline?
Parathyroid hormone (PTH)
What is the sequence of bone repair after a fracture?
Hematoma, fibrocartilaginous callus, bony callus, remodeling
What condition is characterized by excessive and abnormal bone remodeling?
Paget’s disease
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.
What type of cartilage supports the outer ear and epiglottis?
Elastic cartilage
Fibrocartilage
A type of cartilage that contains thick collagen fibers, is highly compressible, and resists stretching. It forms intervertebral discs and knee joint cartilages.
What are the two methods of cartilage growth?
Interstitial growth and appositional growth
Osteoblasts
Cells that synthesize bone matrix and are responsible for bone formation.
What is the main function of osteoclasts?
Bone resorption (breaking down bone tissue)
Osteon
The structural unit of compact bone, consisting of a central canal surrounded by concentric lamellae of bone matrix.
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.
Intramembranous ossification
The process by which bone forms directly from mesenchymal tissue, primarily forming the clavicles and most skull bones.
Osteoporosis
A condition where bone resorption outpaces bone formation, leading to weak and porous bones.
What is the primary cause of osteomalacia and rickets?
Inadequate mineralization of bones, often due to insufficient vitamin D.
Bone remodeling
The continuous process of bone deposition and resorption in response to hormonal and mechanical stimuli.
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.
What type of fracture does Liliana have?
Open fracture
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
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.
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.
How likely is it that Liliana’s knee cartilage will regenerate?
Unlikely, because cartilage has limited ability to regenerate.
What type of fracture does Liliana have?
A fracture of the superior right tibia with a 3.5-cm laceration where the bone protrudes.
After the open reduction of Liliana’s tibia fracture, what problem should the nurse be especially alert for?
Infection
What might prevent Liliana’s leg from healing to its normal length?
Damage to the epiphyses.
Which cells are involved in Liliana’s leg healing?
Osteoclasts and osteoblasts.
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.
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.
What complications might arise from the damage to the nutrient artery in tibia?
Potential complications include delayed healing or nonunion of the fracture.
How likely is it that knee cartilage will regenerate?
Cartilage has limited regenerative capacity, so it is unlikely to fully regenerate.
Open Reduction
A surgical procedure to realign broken bones.
Nutrient Artery
An artery that supplies blood to the bones.
Medial Meniscus
A fibrocartilage disc in the knee joint that acts as a cushion.
Osteoid
Unmineralized bone matrix.
Medullary cavity
Central cavity of a long bone. Contains yellow or red (bone) marrow.
Osteocytes
Mature bone cell.
Perichondrium
Fibrous, connective-tissue membrane covering the external surface of cartilaginous structures.
Spongy bone
Internal layer of skeletal bone. Also called trabecular bone.
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).
Osteon
System of interconnecting canals in the microscopic structure of adult compact bone; unit of bone; also called Haversian system.
Osteoblasts
Bone-forming cells.
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.
Diploë
The internal layer of spongy bone in flat bones.
Appositional growth
Growth accomplished by the addition of new layers onto those previously formed.
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.
Ossification
The process of bone formation; also called Osteogenesis.
Endosteum
Connective tissue membrane covering internal bone surfaces.
Fractures
A break in a bone.
Paget’s disease
Disorder characterized by excessive bone breakdown and abnormal bone formation.
Periosteum
Double-layered connective tissue that covers and nourishes the bone.
Hematoma
Mass of clotted blood that forms at an injured site.
Lamella
A layer, such as of bone matrix in an osteon of compact bone.
Osteoporosis
Decreased density and strength of bone resulting from a gradual decrease in rate of bone formation.
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.
Parathyroid hormone (PTH)
Hormone released by the parathyroid glands that regulates blood calcium level.
Hematopoiesis
Blood cell formation; hemopoiesis.
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.
Foramen
Hole or opening in a bone or between body cavities.
Endochondral ossification
Embryonic formation of bone by the replacement of calcified cartilage; most skeletal bones are formed by this process.
Calcitonin
Hormone released by the thyroid. Lowers blood calcium levels only when present at high (therapeutic) levels.
Bone resorption
The removal of osseous tissue; part of the continuous bone remodeling process.
Reduction
Chemical reaction in which electrons and energy are gained by a molecule (often accompanied by gain of hydrogen ions) or oxygen is lost.
Bone remodeling
Process involving bone formation and destruction in response to hormonal and mechanical factors.
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).
Epiphyses
The end of a long bone, attached to the shaft.
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
Diaphysis
Elongated shaft of a long bone.
Haversian system
System of interconnecting canals in the microscopic structure of adult compact bone; unit of bone; also called Haversian system.
Epiphyseal plate
Plate of hyaline cartilage at the junction of the diaphysis and epiphysis that provides for growth in length of a long bone.
Osteomalacia
Disorder in which bones are inadequately mineralized; soft bones.
Osteogenesis
The process of bone formation; also called ossification.
Osteoclasts
Large cells that resorb or break down bone matrix.
Lacunae
A small space, cavity, or depression; lacunae in bone or cartilage are occupied by cells.
Endochondral bone
Bone formed by using hyaline cartilage structures as models for ossification.
What is a key functional property of cartilage tissue?
It is very resilient and can return to its original shape after being compressed.
Why does cartilage not contain blood vessels?
To maintain a high water content and resilience without the need for direct blood supply.
How do cartilage cells receive nutrients?
Through diffusion from blood vessels in the surrounding perichondrium.
Which type of cartilage is most abundant in the skeletal system?
Hyaline cartilage
Where would you typically find fibrocartilage?
In the knee menisci and between vertebrae.
What distinguishes elastic cartilage from hyaline cartilage?
Elastic cartilage contains more stretchy elastic fibers.
How does appositional growth occur in cartilage?
Cartilage-forming cells in the perichondrium secrete new matrix against the existing cartilage.
What is a characteristic of interstitial growth in cartilage?
It involves the division of chondrocytes within the cartilage, expanding it from within.
When does cartilage typically stop growing?
During adolescence, when the skeleton stops growing.
What is a key difference between cartilage and bone?
Cartilage is surrounded by the perichondrium, while bone is surrounded by the periosteum.
Which cells are found in the lacunae of cartilage?
Chondrocytes
How does the extracellular matrix of bone compare to that of cartilage?
The matrix of bone is rigid due to inorganic calcium salts.
Which of the following best describes the support function of bones?
Bones provide a framework that supports the body and cradles its soft organs.
How do bones protect vital organs in the human body?
The fused bones of the skull protect the brain.
What role do bones play in movement?
Bones serve as points of attachment for muscles, allowing for the movement of the body.
Which minerals are primarily stored in the bones?
Calcium and phosphate.
Where does most blood cell formation occur in the human body?
In the red marrow of certain bones.
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.
Which hormone is produced by bones and helps to regulate insulin secretion, glucose homeostasis, and energy expenditure?
Osteocalcin.
Which part of the human skeleton is primarily responsible for protection, support, and carrying other body parts?
Axial skeleton
The appendicular skeleton is essential for:
Locomotion and manipulation of the environment
What does the axial skeleton include?
Skull, vertebral column, and rib cage
Which of the following is a characteristic of long bones?
They have a shaft and two expanded ends
Sesamoid bones, like the patella, are classified as:
A special type of short bone
Which type of bone is typically involved in protecting internal organs?
Flat bones
The bones that make up the wrist and ankle are classified as:
Short bones
An example of an irregular bone is:
The vertebrae
Why are long bones such as the femur designed to be hollow?
To provide maximum strength with minimum weight
Flat bones like the scapulae are important for:
Protection of internal organs and providing large areas for muscle attachment
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.
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.
What is the function of articular cartilage in long bones?
To cushion the opposing bone ends during movement and absorb stress.
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.
Which category of bone markings includes surfaces that form joints?
Surfaces that form joints.
What is the role of osteocytes in bone tissue?
To monitor and maintain the bone matrix and act as stress or strain sensors.
Which cells are responsible for forming new bone tissue?
Osteoblasts.
How do nutrients reach the osteocytes in compact bone?
Through the central canal in each osteon.
What is the primary organic component of the bone matrix that contributes to bone’s flexibility and tensile strength?
Osteoid, including collagen fibers.
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.
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.
Which of the following best describes intramembranous ossification?
A bone develops from a fibrous membrane.
Endochondral ossification is primarily responsible for the formation of which type of bones?
Long bones below the base of the skull, excluding the clavicles.
What initiates the process of ossification in intramembranous ossification?
Mesenchymal cells specializing into osteoblasts.
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.
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.
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.
How do long bones grow in length?
By interstitial growth of the epiphyseal plate cartilage.
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.
Which hormone is most important for stimulating epiphyseal plate activity during infancy and childhood?
Growth hormone.
What effect do sex hormones have on bone growth during puberty?
They induce epiphyseal closure, ending longitudinal bone growth.
How do bones grow in width (thickness)?
By appositional growth, with osteoblasts adding bone matrix externally.
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.
What is the primary location where bone is deposited and removed in the adult skeleton?
At the endosteal surface
Which cells are responsible for bone resorption by breaking down the bone matrix?
Osteoclasts
What initiates the calcification of the newly deposited osteoid during bone deposition?
The release of matrix vesicles containing alkaline phosphatase by osteoblasts
How does parathyroid hormone (PTH) primarily affect bone remodeling?
By indirectly stimulating osteoclasts to resorb bone
Which hormone is thought to have a negligible effect on calcium homeostasis in humans under normal conditions?
Calcitonin
What is the primary role of mechanical stress in bone remodeling?
To direct remodeling where it strengthens the bone
What is the main purpose of maintaining calcium homeostasis in the blood through bone remodeling?
To ensure proper muscle contraction and nerve function
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
What is the outcome when the balance between bone deposit and resorption is lost?
It can lead to bone diseases due to imbalance
Which of the following best describes a nondisplaced fracture?
The bone ends retain their normal position.
What characterizes a complete fracture?
The bone is broken through.
An open (compound) fracture is distinguished by which of the following?
The bone ends penetrate the skin.
What is the first step in treating a fracture?
Reduction, the realignment of the broken bone ends.
Which method involves the surgical securing of bone ends with screws and plates?
Open (internal) reduction.
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.
What occurs immediately after a bone breaks?
A hematoma forms.
During the second step of bone repair, what type of callus forms?
Fibrocartilaginous callus.
What role do osteoblasts play in bone repair?
They begin forming spongy bone within the repair tissue.
In the final stage of bone repair, what process occurs?
Bone remodeling.
Which treatment has been suggested to potentially hasten the repair and healing of fractures?
Daily ultrasound treatments or electrical stimulation of fracture sites.
What is a common symptom of osteomalacia?
Pain when weight is put on the affected bones
Rickets is most analogous to which condition in adults?
Osteomalacia
What are common causes of osteomalacia and rickets?
Insufficient calcium in the diet or vitamin D deficiency
Which group is most often affected by osteoporosis?
Postmenopausal women
What are common risk factors for developing osteoporosis?
Decreased sex hormones and insufficient bone stress
Which parts of the skeleton are most often involved in Paget’s disease?
Spine, pelvis, femur, and skull
What is a common treatment for Paget’s disease?
Bisphosphonates and calcitonin
How can osteoporosis be prevented or delayed?
Minimizing controllable risk factors like diet and exercise
Which category of drugs is used to treat osteoporosis by inhibiting osteoclasts?
Bisphosphonates
What is a recommended lifestyle change for preventing bone disorders like osteomalacia?
Increasing vitamin D intake and sunlight exposure
At what stage of development do most long bones begin ossifying?
8 weeks after conception
What is the primary role of the epiphyseal plates in bone development?
To provide for long bone growth during childhood and adolescence
By what age are nearly all bones in the human body completely ossified, marking the cessation of skeletal growth?
25 years
In which age group does bone formation exceed bone resorption?
Children and adolescents
Which factor plays the major role in determining a person’s bone density changes over a lifetime?
Genetics
What is the trend in bone mass as individuals enter their fourth decade of life?
Bone mass decreases
Which demographic is generally known to experience faster age-related bone loss?
White females
What qualitative change occurs in bones as people age?
More osteons remain incompletely formed, and mineralization is less complete
Why do fractures heal more slowly in older adults?
Because of a diminished blood supply to the bones
What is a characteristic feature of achondroplasia?
Short limbs with normal-sized membrane bones
Achondroplasia results from which of the following?
Defective cartilage and endochondral bone growth
What is a bony spur?
An abnormal projection from a bone due to overgrowth
Bony spurs are most commonly associated with which of the following conditions?
Aging bones
What does ostealgia refer to?
Pain in a bone
Osteitis is characterized by:
Inflammation of bony tissue
Osteogenesis imperfecta puts bones at risk for:
Shattering due to inadequate collagen
Osteomyelitis is primarily caused by:
Pus-forming bacteria entering through a wound
A common treatment for osteomyelitis includes:
Antibiotics and draining abscesses
Osteosarcoma is a form of:
Bone cancer
The survival rate for osteosarcoma, if detected early, is approximately:
50%
A pathologic fracture occurs due to:
Disease weakening the bone, leading to fracture with minimal trauma
The purpose of traction in medical treatment is to:
Keep parts of a fractured bone in proper alignment
What is the primary function of the large amounts of water found in the extracellular matrix of skeletal cartilage?
To provide resilience
Which type of skeletal cartilage is characterized by its glassy appearance and collagenous fibers?
Hyaline cartilage
Fibrocartilages are best suited for which of the following functions?
Resisting stretching and being highly compressible
How does interstitial growth contribute to the growth of cartilage?
By growing from within the cartilage
Appositional growth of cartilage involves which of the following processes?
The addition of new cartilage tissue at the periphery
Which of the following is NOT a function of bones?
To conduct nerve impulses
Bones that are classified as “flat” are primarily characterized by:
Two thin plates of compact bone enclosing a layer of spongy bone
The axial and appendicular classifications of bones are based on:
Their location in the body
What triggers the release of parathyroid hormone (PTH) during bone remodeling?
A decline in blood calcium levels
The initial step in the bone healing process after a fracture is:
Formation of a hematoma
Which condition is characterized by excessive and abnormal bone remodeling?
Paget’s disease
Intramembranous ossification is responsible for forming:
Most of the skull bones and clavicles
Osteoporosis is a condition in which:
Bone breakdown outpaces bone formation, leading to weak and porous bones
A key factor in the development of osteomalacia and rickets is:
Inadequate vitamin D
