Chap 6 - Bones & Skeleton Tissues (definitions, concepts & practice questions)

Epiphyseal line

-A bony structure that replaces the hyaline cartilage when the bone stops growing in length at 18-21 years of age

Medullary (marrow) cavity

-A space within the diaphysis of long bones that contains yellow bone marrow

Articular cartilage

-A thin layer of hyaline carilage that covers areas of the epiphyses where bones articulate together (form synovial joints) -Functions to reduce friction and absorb shock at joints

Describe Protection (function of bone)

-ability of bone tissue to protect internal organs from injury -Ex: cranial bones of the skull protect the brain; vertebrae protect the spinal cord

Describe Assist in Movement (function of bone)

-ability of bone tissue to provide attachment sites for tendons of skeletal muscles -When skeletal muscles contract, they pull on the bones, which causes the body to move

Describe Support (function of bone)

-ability of bone tissue to serve as the structural framework for the body -supports soft tissues -provides sites for ligaments and tendons of most skeletal muscles

Epiphyseal plate

-aka growth plate -a layer of hyaline cartilage -fuctions to allow the diaphysis to grow in length -This "plate" is evident in growing bone between birth and 18-21 years of age

List the cells types that compose bone tissue

-osteogenic cells -osteoblasts -osteocytes -osteoclasts

________ cells are located in the inner cellular layer of the periosteum. A) Osteocyte B) Osteoclast C) Osteoid D) Osteoprogenitor E) Osteolytic

D) Osteoprogenitor

________ are squamous stem cells that develop into osteoblasts. A) Osteoclasts B) Osteocytes C) Osteomedullary cells D) Osteoprogenitor cells E) Osteoid cells

D) Osteoprogenitor cells

Bone is composed of ________ percent cells. A) 25 B) 10 C) 2 D) 15 E) 50

C) 2

Endosteum

-A thin, delicate, connective-tissue membrane that covers the trabeculae in the spongy bone tissue -Lines the central and perforating canals in compact bone tissue -Contains osteoblasts and osteoclasts, which function in bone building and bone breakdown

Periosteum

-A tough covering of dense irregular connective tissue that covers the bone's surface, except areas covered by articular cartilage -Functions to protect the bone's surface, provides an attachment site for tendons and ligaments -Assists in fracture repair and allows for appositional bone growth (increase in girth) due to the presence of osteoblasts and osteoclasts

Yellow bone marrow

-Adipose tissue located in the marrow cavity -Functions to store energy in the form of triglycerides

Veins

-Blood vessels that carry deoxygenated blood and waste products away from the bone tissue

Arteries

-Blood vessels that supply oxygenated blood and nutrients to bone tissue

Bone (osseous tissue) - describe bone structure

-Bone tissue is a specialized connective tissue composed of a hard extracellular with widely-distributed cells. -Extracellular matrix is approx. 25% water, 25% collagen fibers, and 50% crystallized mineral salts -The most abundant salt in the matrix is calcium phosphate. -The hard matrix forms when the mineral salts and ions interact together and crystallize between the collagen fibers

How does exercise affect bone tissue?

-Bone tissue is dynamic within limits as it can become stronger when exposed to changes in mechanical stress (i.e. pulling on bone tissue via concentration of skeletal muscles) -When mechanical stress is applied to bone tissue, it responds by increasing the production of collagen fibers and depositing additional mineral salts in the matrix -The response causes bone tissue to become stronger -Simple exercises, like brisk walking and moderate weight lifting, facilitate this process, which help to build and maintain the bone matrix and bone mass

How are bones classified? and List Types

-Bones are classified based on their shape and gross anatomical structure -Long bones -Short bones -Flat bones -Irregular bones -Sesamoid bones

Blood Supply of bone

-Bones have an extensive blood supply, and blood vessels are abundant in areas of bone containing red bone marrow -Contain arteries and veins

Spongy Bone vs Compact bone - compare

-Compact bone tissue is composed of osteons, & Spongy bone tissue is composed of trabeculae -Compact bone is denser that spongy tissue. It allows compact bone to provide strength and support to bones -Spongy tissue is less dense than compact bone tissue. It reduces bone weight to allow bones to move easier when they're being pulled by skeletal muscles -Trabeculae of spongy bone tissue support and protect the red bone marrow

Irregular bones - describe type and classification

-Complex shapes with variable amounts of compact bone and spongy bone tissues -EX: facial bones fo the skull, vertebrae, os coxae

Compact bone tissue (lamellar bone) - describe

-Composes about 80% of the human skeleton -Strongest bone tissue with microscopic spaces in the tissue -These spaces act as conduits from soft tissues to perforate through the bone -Located deep to the periosteum -basic unit of Compact Bone is an "osteon", which is also known as a "Haversian System". -forms the outer layer of all bones and most of the structure of "long bones" -Functions to resist torsion stress from movement and mechanical stress from weight -made of special cells called osteocytes. These cells are lined up in rings around the canals. Together, a canal and the osteocytes that surround it are called osteons.

Short bones - describe the type and classification

-Cube shaped with a equal length and width -Consist primarily of psongy bone tissue with a superficial thin layer of compact bone tissue surrounding the spongy bone tissue -EX: carpals and tarsals

Describe Hematopoeisis - Blood cell production (function of bone)

-Facilitates the production, development, and maturity of blood cells (red blood cells, white blood cells, and platelets) in the red bone marrow

Organic chemical components of bone & their function

-Include cells and osteoid. -Osteoid makes up about 1/3 of the matrix, and it's composed of a ground substance (proteoglycans and glycoproteins) and collagen fibers -Functions to provide structure due to the hardness that resists compression

Inorganic chemical components of bone & their function

-Include mineral salts called hydroxylapatites, which are mainly calcium phosphates that crystallize in the matrix and around the collagen fibers -They function to provide structure due to the hardness that resists compression

Trabecula/Trabeculae

-Irregular arranged columns of lamellae (calcified extracellular matrix) -Function to resist physical stress -part of the spongy tissue

Osteoclasts

-Large cells that differentiate into macrophages (phagocytic cells) -Concetrated in the endosteum -Function to release powerful lysosomal enzymes and hydrochloric acid to catabolize proteins and minerals in the bone matrix -The action of these cells is important in bone development, growth, maintenance, and repair -Help maintain calcium-ion levels in the blood by catabolizing the matrix and releasing these ions into the blood supply

Long bones - describe the type & classification

-Long bones have a greater length than width. -Consist of a diaphysis & variable extremities (ir epiphyses & surface markings) -- which are curved to provide strength and absorb stress of body weight at different points to distribute weight evenly across the bone -Consist of compact bone tissue in th diaphysis and spongy bone tissue in the epiphyses -EX: humerus, radius, femur, ulna, tibia, fibula, and phalanges

Diaphysis

-Long, cylindrical structure of the long bone -Located between the epiphyses

Osteocytes

-Mature bone cells -Function to maintain the matrix and metabolism of bone tissue -Capable of detecting when bone tissue is damaged, stressed, or strained and communicate this with osteoblasts and osteoclasts in order to facilitate tissue repair

Canaliculus/Canaliculi (spongy tissue)

-Microscopic channels/canals that extend from the lacunae -Function to contain interstitial fluid -Interstitial fluid provides nutrients and removes waste products from the osteocytes in the lacunae

Canaliculus/Canaliculi

-Microscopic channels/canals that extend from the lacunae -Function to contain interstitial fluid -The interstitial fluid provides nutrients and removes waste products from the osteocytes in the lacunae -part of the compact bone

Lacuna/Lacunae

-Microscopic paces in the lamellae than function to contain osteocytes -part of the compact bone

Lacuna/Lacunae (spongy tissue)

-Microscopic spaces in the lamellae -Function to contain osteocytes

Interstitial lamella/lamellae

-Old, "broken" rings of calcified extracellular matrix, which are fragments from old osteons -They are located between new osteons -Function to provide strength to bone tissue -part of the compact bone

Osteon (Haversian system)

-Osteons are repeated structural units in compact bone tissue -They are composed of a central canal, concetric lamella, lacunae, osteocytes, and canaliculi -Function to provide strength to bone by acting as weight-bearing structures -Part of the compact bone

Circumferential lamella/lamellae

-Rings of calcified extracellular matrix -Located deep to the periosteum -Surround the entire bone -part of the compact bone

Concentric lamella/lamellae

-Rings of calcified extracellular matrix that surround the central canal -Function to resist torsion stress (twisting) on bone tissue -part of the compact bone

Perforating (Volkmann's) canals

-Spaces in the compact bone tissue that run horizontally and diagonally -They function to allow soft tissues and organs (ie blood vessels, lymphatic vessels, and nerves) to pass through the bone tissue -part of the compact bone

Spongy Tissue

-Spongy bone tissue composed about 20% of the human skeleton -Its name is derived from the very large spaces contained in the tissue -These spaces contributes to the light weight of bone

Describe Triglyceride storage (function of bone)

-Stores triglycerides in adipocytes contained in yellow bone marrow, which allow specific bones to function as a energy source

What are bone surface markings?

-Structural features that are adapted for specific functions -They are, typically, not present at birth and develop in response to force and mechanical stress as the human skeleton grows -Many surface markings function as attachment sites for tendons, ligaments, and muscles and serve as conduits for blood vessels, lymphatic vessels, and nerves to pass through bone.

List Long Bone structures and membranes

-Structures: Diaphysis; Epiphysis; Metaphysis; Medullary (marrow) canal -Membranes: Articular cartilage; Periosteum; Edosteum

List the Functions of Bones

-Support -Protection -Assist in Movement -Mineral Homeostasis -Blood cell protection (hematopoiesis) -Triglyceride storage -Hormone production

Processes - describe the bone surface markings

-Surface markings are raised, rough areas that result from enw bone tissue being deposited in response to mechanical stress (tension) on the bone surface. -Function to help form joints and to serve as attachment sites for connective tissues (ie tendons and ligaments) -EX: Condyte(s); Facet(s); Head(s); Crest(s); Epicondyle(s); Spinous process; Trochanter(s); Tubercle(s); Tuberosity

Depressions & openings - describe the bone surface markings

-Surface markings that function to help form joints and to allow soft tissues (ie blood vessels, lyphatic vessels, and nerves) to pass through bone -EX: Fissure(s); Foramen/Foramina; Fossa/Fossae; Sulcus/Sulci; Meatus/Meatuses

Endochondrial Ossification

-The MOST COMMON type of bone formation -Involves bone tissue forming within hyaline cartilage -Most bones form via this process

Metaphysis (-ses)

-The areas of mature bone, where the diaphysis and epiphyses join together -Each long bone has a proximal and distal metaphysis -The epiphyseal plate and epiphyseal line are located in the metaphyses

Osteoblasts

-The bone-building cells of bone tissue -Function to produce and secrete collagen fibers and other molecules that compose the extracellular matrix -Also initiate calcification of the matrix and eventually, mature into osteocytes

Central (Haversian) Canal

-The central canal is a space located in the center of the osteon and runs longitudinally on compact bone tissue -Functions to allow soft tissues and organs (ie blood vessels, lyphatic vessels, and nerves) to pass through the bone tissue -part of the compact bone

Nerves (nerve supply of bones)

-The periostium has an extensive nerve supply and sensory nerve endings (receptors) -Function to mediate sensations of pain (i.e. detect tearing or extreme tension on bone tissue)

Ossification or osteogenesis

-The process of bone formation -It occurs via two methods, typically, during the sixth week of embryonic development -Both methods involve replacing pre-existing connective tissue with bone

Calcification

-The process of the mineral salts and ions crystallizing to form the hard matrix

Epiphysis (-ses)

-The proximal and distal ends of the long bone

Intramembranous Ossification

-The simplest type of bone formation -Invovles bone tissue forming directly withing the mesenchyme -As the bone tissue forms, it's arranged in sheet-like layers forming the flat bones of the skull and the mandible -EX Fontaneis ("soft spots" on baby's head) harden via this process

Flat bones - describe type and classification

-Thin and composed of two parallel plates of compact bone tissue, which surrounds an inner core of spongy bone tissue. -EX: cranial bones of the skull, scapulae, sternum and ribs

Sesamoid bones - describe type of classification

-Unique bones that develop in tendons, where friction, tension, and mechanical/physical stress in common. -Function to protect tendons from mechanical stress -Change the direction of how tendons are pulled to improve the mechanical advantage at a joint EX: patellae

Osteogenic cells

-Unspecialized stem cells -Located in the periosteum and endosteum -Function to undergo somatic cell division -Some of these cells develop into osteoblasts

Describe Mineral homestasis (function of bone)

-stores minerals, especially calcium ions and phosphorus, which help strengthen bone tissue -Body tissue releases these minerals into the blood supply in order to maintain mineral balance and to distribute these minerals to cells of the body

Intramembranous Ossification - Describe step 1 (with picture)

1) Ossification centers appear in the fibrous connective tissue -Selected centrally located mesenchymal cells cluster and differentiate into osteoblasts, forming an ossification center that produces the first tribeculae of spongy bone

Describe 4 steps of Intramembranous Ossification

1) Ossification centers appear in the fibrous connective tissue -Selected centrally located mesenchymal cells cluster and differentiate into osteoblasts, forming an ossification center that produces the first tribeculae of spongy bone 2) Osteoid is secreted within the fibrous membrane and calcifies -Osteoblasts begin to secrete osteoid, which calcifies in a few days -Trapped osteoblasts become osteocytes 3) Woven bone and periosteum form -Accumulating osteoid is laid down between embryonic blood vessels in a manner that results in a network (instead of concentric lamellae) of trabeculae called woven bone -Vascularized mesenchyme condenses on the external face of the woven bone and becomes the periosteum 4) Lemellar bone replaces woven bone, just deep to the periosteum. Red bone marrow appears -Trabeculae just deep to the periosteum thicken. Mature lamellar bone replaces them, forming compact bone plates. -Spongy bone (diploe), consisting of distinct trabeculae, persists internally and its vascular tissue becomes red marrow

Intramembranous Ossification - Describe step 2 (with picture)

2) Osteoid is secreted within the fibrous membrane and calcifies -Osteoblasts begin to secrete osteoid, which calcifies in a few days -Trapped osteoblasts become osteocytes

Intramembranous Ossification - Describe step 3 (with picture)

3) Woven bone and periosteum form -Accumulating osteoid is laid down between embryonic blood vessels in a manner that results in a network (instead of concentric lamellae) of trabeculae called woven bone -Vascularized mesenchyme condenses on the external face of the woven bone and becomes the periosteum

Intramembranous Ossification - Describe step 4 (with picture)

4) Lemellar bone replaces woven bone, just deep to the periosteum. Red bone marrow appears -Trabeculae just deep to the periosteum thicken. Mature lamellar bone replaces them, forming compact bone plates. -Spongy bone (diploe), consisting of distinct trabeculae, persists internally and its vascular tissue becomes red marrow

Which statement is true regarding calcium in bone matrix? A) Calcium is found in crystals called hydroxyapatite. B) Calcium is secreted by osteoblasts into the matrix. C) Once deposited, calcium cannot be removed from bone. D) Calcium provides flexibility to the bone matrix. E) Calcium is the organic part of the matrix.

A) Calcium is found in crystals called hydroxyapatite

Which of the following statements about Marfan's syndrome is false? A) It results in short, stubby fingers. B) It results from a mutation. C) It affects connective tissue structures. D) It affects epiphyseal cartilages. E) It may also cause cardiovascular problems

A) It results in short, stubby fingers

________ hormones stimulate osteoblasts to produce bone matrix. A) Sex B) Growth C) Thyroid D) Parathyroid E) Pancreatic

A) Sex

Which of the following is a characteristic of bone? A) The bone matrix is very dense and contains deposits of calcium salts. B) The matrix of the bone contains osteoclasts and chondroblasts. C) Narrow channels pass through the matrix to allow for muscle attachment. D) The matrix of bone is mostly collagen with very little calcium. E) For strength, compact bone is organized into a meshwork of matrix called trabeculae

A) The bone matrix is very dense and contains deposits of calcium salts.

Suppose that epiphyseal lines appear in a 10-year-old's long bones. Which of the following statements is, therefore, true? A) The epiphyseal plates have ossified and further growth in length is not possible. B) Administration of growth hormone will stimulate future bone growth in length. C) Osteoclasts will dissolve the metaphysis so length growth can continue until adulthood. D) More growth will occur during the teenage years as sex hormones stimulate rebuilding of growth plates. E) Intramembranous ossification will enable further growth in length.

A) The epiphyseal plates have ossified and further growth in length is not possible.

Elevated levels of calcium ion in the blood stimulate the secretion of the hormone A) calcitonin. B) thyroid hormone. C) parathyroid hormone. D) growth hormone. E) testosterone.

A) calcitonin

The layers of bone tissue immediately deep to the periosteum are A) circumferential lamellae. B) osteoid plates. C) trabeculae. D) concentric lamellae. E) epiphseal ridges

A) circumferential lamellae

The lining of the medullary cavity is called the A) endosteum. B) periosteum. C) epiosteum. D) mediosteum. E) paraosteum

A) endosteum

The proximal and distal ends of a long bone are called the A) epiphyses. B) diaphyses. C) epiphyseal plates. D) metaphyses. E) periphyses.

A) epiphyses.

A shallow depression on a bone is termed a A) fossa. B) sulcus. C) facet. D) fissure. E) line.

A) fossa

When cartilage is produced at the epiphyseal side of the metaphysis at the same rate as bone is deposited on the opposite side, bones A) grow longer. B) grow wider. C) become shorter. D) become more porous and weaker. E) become thicker.

A) grow longer

The expanded articular end of an epiphysis that is separated from the shaft by a narrower neck is called a A) head. B) crown. C) capitulum. D) corona. E) bulb.

A) head

Osteoclast-activating factor does all of the following except that it A) is released in large amounts early in life. B) increases the number of osteoclasts. C) increases the activity of osteoclasts. D) produces a severe osteoporosis. E) is released by some cancer tumors.

A) is released in large amounts early in life.

The humerus is an example of a(n) ________ bone. A) long B) short C) flat D) irregular E) sesamoid

A) long

Adipose tissue is stored within the A) medullary cavity. B) metaphysis. C) spongy bone. D) epiphysis. E) diaphysis

A) medullary cavity

Blood is distributed from the surface of a bone to deeper central canals through channels known as A) perforating canals. B) canaliculi. C) interstitial canals. D) concentric ducts. E) concentric canals

A) perforating canals

Intramembranous ossification A) produces flat bones, as in the bones of the roof of the skull. B) explains how a juvenile's bone can grow in length. C) occurs in the diaphysis of a long bone. D) occurs inside a bag of cartilage. E) occurs in all bones before birth

A) produces flat bones, as in the bones of the roof of the skull.

Bone tissue formation begins when osteoblasts secrete A) protein fibers. B) mesenchyme. C) silica. D) hydroxyapatite. E) calcium.

A) protein fibers

The type of bone that is adapted to withstand stresses that arrive from many directions is ________ bone. A) spongy B) osteon C) compact D) lamellar E) irregular

A) spongy

Which of the following are not components of the skeletal system? A) tendons B) bones C) ligaments D) cartilage E) other tissues that connect bones

A) tendons

When stress is applied to a bone, A) the minerals in the bone produce a weak electrical field that attracts osteoblasts. B) osteoclast activity increases and osteoblast activity decreases. C) the bone becomes thin and brittle and ultimately fractures. D) the bone compensates by becoming thinner in the region of stress. E) blood supply through the nutrient artery diminishes and thus remodeling proceeds at a much slower rate.

A) the minerals in the bone produce a weak electrical field that attracts osteoblasts.

After a fracture of the diaphysis has healed, the thickened region that results is called the A) epiphyseal plate. B) external callus. C) dense tuberosity. D) condyle. E) fracture facet.

B) external callus

A hole through a bone is called a A) ramus. B) foramen. C) linea. D) tubercle. E) facet.

B) foramen

Cells that are found in small depressions on the endosteal surfaces are the A) osteolytic cells. B) osteoclasts C) osteoblasts. D) osteocytes. E) osteogenic cells

B) osteoclasts

Cells that free calcium from bone to maintain blood calcium levels are called A) osteolytics. B) osteoclasts. C) osteoblasts. D) osteogenics. E) osteocytes

B) osteoclasts

The lacunae of osseous tissue contain A) blood cells. B) osteocytes. C) chondroblasts. D) bone marrow. E) capillaries.

B) osteocytes

The organic component of the matrix in developing or repairing bone is called A) osteon. B) osteoid. C) hydroxyapatite. D) mesenchymal tissue. E) calcium phosphate

B) osteoid

A condition in which bone becomes riddled with holes is called A) osteopenia. B) osteoporosis. C) osteomyelitis. D) osteitis. E) osteomalacia.

B) osteoporosis

A fracture at the ankle involving both lower leg bones is often called a ________ fracture. A) compression B) Pott's C) displaced D) greenstick E) Colles

B) Pott's

________ bones develop inside tendons, commonly near the knees, hands, and feet. A) Irregular B) Sesamoid C) Short D) Long E) Flat

B) Sesamoid

The space occupied by an osteocyte is called A) Volkmann's canal. B) a lacuna. C) a trabecula. D) a Haversian canal. E) a canaliculus.

B) a lacuna

In normal adult bones, A) there is no turnover of minerals. B) a portion of the protein and mineral content is replaced each year. C) osteoblast activity exceeds osteoclast activity, once bone has been formed. D) osteoclasts continue to be active long after osteoblast activity ceases. E) exercise will have no effect on bone remodeling.

B) a portion of the protein and mineral content is replaced each year

The trabeculae of spongy bone A) are organized parallel to the long axis of the bone. B) are organized along stress lines. C) are composed mostly of cartilage. D) will collapse under stress. E) are concentrated in the cortex of the diaphysis.

B) are organized along stress lines

When production of sex hormones increases at puberty, epiphyseal plates A) widen. B) become narrower. C) increase slowly. D) accelerate rapidly, but mostly in thickness. E) are hardly affected

B) become narrower

During appositional growth A) bones grow longer. B) bones grow wider. C) cartilage replaces bone. D) the epiphysis fuses with the diaphysis. E) compact bone replaces spongy bone

B) bones grow wider

Bone growth in length occurs by mitosis of A) concentric lamellae. B) cartilage cells in the epiphyseal side of the metaphysis. C) growth of trabeculae. D) osteoblasts in the endosteum. E) cartilage cells in the diaphyseal side of the metaphysis

B) cartilage cells in the epiphyseal side of the metaphysis.

Endochondral ossification begins with the formation of a(n) A) fibrous connective-tissue model. B) cartilage model. C) membranous model. D) calcified model. E) osteoid model.

B) cartilage model

The condition known as osteopenia A) affects mostly women. B) causes a gradual reduction in bone mass. C) is caused by too much vitamin D in the diet. D) is rarely seen as people age. E) only affects the femur.

B) causes a gradual reduction in bone mass.

The ________ interactions allow bone to be strong, somewhat flexible, and highly resistant to shattering. A) collagen-fiber B) protein-crystal C) mineral-crystal D) protein-protein E) hydroxyapatite-crystal

B) protein-crystal

The patella is an example of a(n) ________ bone. A) irregular B) sesamoid C) sutural D) sagittal E) flat

B) sesamoid

The carpal bones are examples of ________ bones. A) long B) short C) flat D) irregular E) sesamoid

B) short

A chamber within a bone normally filled with air is a A) foramen. B) sinus. C) fossa. D) canal. E) meatus.

B) sinus

The interconnecting tiny arches of bone tissue found in spongy bone are called A) osteons. B) trabeculae. C) concentric lamellae. D) interstitial lamellae. E) lacunae.

B) trabeculae

A large proximal projection on a bone is called the A) ramus. B) trochanter. C) tuberosity. D) tubercle. E) condyle

B) trochanter

Factors that are necessary for proper bone formation include all of the following, except A) vitamin A. B) vitamin E. C) vitamin C. D) the hormone thyroxine. E) vitamin D.

B) vitamin E

Describe Hormone production (function of bone)

Bones produce osteocalcin, a hormone that helps regulate insulin secretion, glucose homeostasis, and energy expenditure

The following are major steps in the process of intramembranous ossification: Clusters of osteoblasts form osteoid that becomes mineralized. Osteoblasts differentiate within mesenchymal connective tissue. Spicules of bone radiate out from the ossification centers. Mesenchymal cells aggregate. What is the correct order for these events? A) 4, 1, 2, 3 B) 2, 1, 3, 4 C) 4, 2, 1, 3 D) 2, 3, 1, 4 E) 3, 4, 2, 1

C) 4, 2, 1, 3

________ bone reduces the weight of the skeleton and reduces the load on muscles. A) Short B) Irregular C) Spongy D) Compact E) Long

C) Spongy

Hundreds of years ago, explorers often died of scurvy. How can this bone-related disease be prevented? A) Supplement the diet with more calcium from meat. B) Increase levels of testosterone to stimulate bone repair. C) Supplement the diet with fresh fruit rich in vitamin C. D) Drink more water to promote bone remodeling and repair. E) Amputate fractured limbs to prevent the spread of scurvy.

C) Supplement the diet with fresh fruit rich in vitamin C.

Through the action of osteoclasts, A) new bone is formed. B) an organic framework is formed. C) bony matrix is dissolved. D) osteoid is calcified. E) fractured bones regenerate

C) bony matrix is dissolved

The deposition of calcium salts in bone tissues is referred to as A) hardening. B) ossification. C) calcification. D) osteogenesis. E) remodeling.

C) calcification

The narrow passageways that contain cytoplasmic extensions of osteocytes are called A) central canals. B) lacunae. C) canaliculi. D) medullary cavities. E) foramina.

C) canaliculi

The shaft of long bones is called the A) epiphysis. B) metaphysis. C) diaphysis. D) paraphysis. E) endophysis

C) diaphysis

Accelerated closure of the epiphyseal plates could be caused by A) high levels of vitamin D. B) too much calcium in the diet. C) elevated levels of estrogen. D) too little thyroxine. E) an excess of growth hormone

C) elevated levels of estrogen

Mary is 50 years old and has entered menopause. During a checkup, a bone scan reveals the beginnings of osteoporosis. Her physician suggests hormone therapy. What hormone might she prescribe for Mary? A) thyroid hormone B) growth hormone C) estrogen D) parathyroid hormone E) calcitonin

C) estrogen

A rib is an example of a ________ bone. A) long B) short C) flat D) sutural E) sesamoid

C) flat

A calcified skeletal muscle is an example of A) bone spurs. B) osteoporosis. C) heterotopic bone formation. D) osteodysplasia. E) osteomalacia.

C) heterotopic bone formation

The articular cartilage of a typical long bone is composed of what type of cartilage? A) elastic cartilage B) synovial cartilage C) hyaline cartilage D) fibrocartilage E) osseous cartilage

C) hyaline cartilage

In bone, the calcium phosphate forms crystals of A) osteoid matrix. B) calcium carbonate. C) hydroxyapatite. D) calcitriol. E) proteolytic enzymes

C) hydroxyapatite

Secondary ossification centers occur A) in the diaphysis. B) at the periosteum. C) in the epiphyses. D) in the metaphyses. E) in dermal bones

C) in the epiphyses

Aging has what effect on the skeletal system? A) progressive loss of processes and tuberosities B) fusion of joints, especially in the vertebral column C) loss of calcium and collagen fibers from matrix D) increase in the number of cranial foramina E) increase in adipose tissue in epiphyses

C) loss of calcium and collagen fibers from matrix

Which of the following labels best matches osteocyte? A) stem cell B) dissolves matrix C) mature bone cell D) secretes organic matrix E) immature bone cell

C) mature bone cell

Intramembranous ossification begins with differentiation of ________ cells. A) osteoclast B) osteolytic C) mesenchymal D) osteoblast E) osteocyte

C) mesenchymal

During the process of ________, an existing tissue is replaced by bone. A) phosphorylation B) resorption C) ossification D) osteopropagation E) remodeling

C) ossification

Cells that secrete protein fibers in bone are called A) osteolytic cells. B) osteoclasts. C) osteoblasts. D) osteocytes. E) osteogenic cells

C) osteoblasts

Cells that secrete the organic components of the bone matrix are called A) osteocytes. B) osteoprogenitor cells. C) osteoblasts. D) osteoclasts. E) osteoid cells.

C) osteoblasts

The structural units of mature compact bone are called A) trabeculae. B) osteocytes. C) osteons. D) canaliculi. E) lamellae

C) osteons.

If osteoclasts are more active than osteoblasts, bones will become A) denser. B) thicker. C) osteopenic. D) stronger. E) calcified

C) osteopenic

In relationship to the diaphysis of a long bone, the osteons are A) radial. B) anterior. C) parallel. D) proximal. E) diagonal

C) parallel

A lack of exercise could A) cause bones to become thicker. B) cause bones to store more calcium. C) result in porous and weak bones. D) cause bones to become longer. E) cause bones to lose their medullary cavity

C) result in porous and weak bones

Small bones that fill gaps between bones of the skull are called ________ bones. A) irregular B) sesamoid C) sutural D) sagittal E) tendon

C) sutural

A ________ is a smooth, grooved bone process shaped like a pulley. A) tubercle B) trochanter C) trochlea D) tuberosity E) trabeculae

C) trochlea

Which of the following bones is classified as "irregular" in shape? A) patella B) frontal C) vertebra D) metatarsal E) ulna

C) vertebra

________ prevents damaging bone-to-bone contact within movable joints. A) A synovial membrane B) Elastic cartilage C) A serous membrane D) Articular cartilage E) Serous fluid

D) Articular cartilage

What is the appendicular skeleton?

Comprised of 126 bones that are attached to the axial skeleton via the pectoral (shoulder) and pelvic (hip) girdles. Include the bones of the upper and lower extremities

The femur can withstand ________ times the body's weight without breaking. A) 3 B) 5 to 10 C) 8 D) 10 to 15 E) 30

D) 10 to 15

The adult skeleton contains ________ major bones. A) 88 B) 115 C) 174 D) 206 E) 251

D) 206

How would removing hydroxyapatite from bone matrix affect the physical properties of a bone? A) The bone would be less flexible. B) The bone would be stronger. C) The bone would be more brittle. D) The bone would be more flexible. E) The bone would be less compressible

D) The bone would be more flexible

How is vitamin D (vitamin D3) related to calcium homeostasis in bone? A) Vitamin D provides a framework for calcium in the matrix. B) Vitamin D is regulated by osteoclast activity. C) Vitamin D is produced by osteoblasts during endochondral ossification. D) Vitamin D is involved in calcium absorption by the digestive tract. E) Vitamin D replaces calcium in the skeleton

D) Vitamin D is involved in calcium absorption by the digestive tract

The central canal of an osteon contains A) bone marrow. B) osteocytes. C) concentric lamellae. D) blood vessels. E) lacunae.

D) blood vessels

A child with rickets often has A) oversized facial bones. B) long fingers. C) frequent bruises. D) bowed legs. E) inadequate muscle development.

D) bowed legs

Bone plays a central role in the regulation of blood levels of A) potassium. B) iron. C) sulfate. D) calcium. E) sodium.

D) calcium

The most abundant mineral in the human body is A) sodium. B) potassium. C) phosphorus. D) calcium. E) hydrogen.

D) calcium

Which of the following chemicals is not present in bone? A) calcium phosphate B) collagen fibers C) calcium carbonate D) chondroitin sulfate E) hydroxyapatite

D) chondroitin sulfate

The smooth, rounded articular process of a bone is termed a A) crest. B) ridge. C) head. D) condyle. E) trochlea.

D) condyle

The hormone calcitonin functions to A) stimulate osteoclast activity. B) decrease the rate of calcium excretion. C) decrease the rate of calcium absorption. D) decrease the level of calcium ion in the blood. E) stimulate osteoblasts and inhibit osteoclasts.

D) decrease the level of calcium ion in the blood

A ________ is a rounded passageway for passage of blood vessels and/or nerves. A) sinus B) fossa C) meatus D) foramen E) cavernosa

D) foramen

Excessive growth hormone prior to puberty could result in A) osteoporosis. B) osteopenia. C) rickets. D) gigantism. E) dwarfism.

D) gigantism

While on a school skiing trip in Colorado, Heidi falls and breaks her tibia and fibula in a Pott's fracture. What would you expect as a prominent part of her clinical assessment several hours after the fall? A) hypertension B) tachycardia C) erythema D) hematoma E) cyanosis

D) hematoma

What type of tissue is replaced in the embryo during endochondral ossification? A) connective tissue membranes B) fibrocartilage C) mesenchymal tissue D) hyaline cartilage E) Wharton's jelly

D) hyaline cartilage

When the epiphyseal plate is replaced by bone, A) puberty begins. B) interstitial bone growth begins. C) appositional bone growth begins. D) long bones have reached their adult length. E) the bone becomes more brittle.

D) long bones have reached their adult length

The region of a long bone between the end and the shaft is known as the A) diaphysis. B) epiphysis. C) osseophysis. D) metaphysis. E) medullary cavity

D) metaphysis

The superficial membrane of a bone is called the A) endosteum. B) ectosteum. C) cortical membrane. D) periosteum. E) osteoid collar

D) periosteum

A small rough bump on bone where a tendon attaches is called a A) tubercle. B) trochanter. C) trochlea. D) tuberosity. E) trabecula.

D) tuberosity

The disease osteomalacia causes calcium loss from the skeleton, which would result in bones that are A) more resistant to compression. B) stronger and heavier. C) stronger and contain more spongy bone. D) weaker and more flexible. E) weaker and more brittle

D) weaker and more flexible

What is the correct sequence of steps in bone repair? Cartilage in the external callus is replaced by bone. A hematoma occurs. An internal callus forms at the site of injury. Osteoclasts and osteoblasts remodel the bone at the site of repair. A) 1, 2, 3, 4 B) 2, 1, 3, 4 C) 3, 1, 4, 2 D) 4, 2, 3, 1 E) 2, 3, 1, 4

E) 2, 3, 1, 4

The following are important steps in the process of endochondral ossification. What is the correct order for these events? Enlarged chondrocytes die. Osteoblasts replace calcified cartilage with spongy bone. Chondrocytes enlarge and the surrounding matrix begins to calcify. Blood vessels grow around the edges of the cartilage. Perichondrial cells become osteoblasts and produce a superficial layer of bone. A) 3, 1, 5, 4, 2 B) 1, 3, 5, 4, 2 C) 1, 5, 3, 4, 2 D) 2, 3, 1, 5, 4 E) 3, 1, 4, 5, 2

E) 3, 1, 4, 5, 2

1) Which of following is a function of the skeletal system? A) body support B) calcium homeostasis C) protection of internal organs D) blood cell production E) All of the answers are correct.

E) All of the answers are correct

Mary is 50 years old and has entered menopause. During a checkup, a bone scan reveals the beginnings of osteoporosis. Her physician suggests nutritional therapy. What might she recommend for Mary? A) vitamin C B) vitamin D C) calcium supplements D) dairy products E) All of the answers are correct

E) All of the answers are correct

If a tumor secretes high levels of osteoclast-activating factor, which of the following would you expect to occur as a result of this condition? A) increases in blood levels of calcium B) bone fragility C) decreased bone density D) increased osteoclast activity E) All of the answers are correct

E) All of the answers are correct.

________ account(s) for almost two-thirds of the weight of bone. A) Water B) Calcium carbonate C) Collagen fibers D) Fluoride E) Calcium phosphate

E) Calcium phosphate

________ fibers are stronger than steel when stretched. A) Calcium B) Mineral C) Elastic D) Carbon E) Collagen

E) Collagen

________ marrow is found between the trabeculae of spongy bone. A) Blue B) Yellow C) White D) Gray E) Red

E) Red

Why does osteoporosis affect more women than men? A) Women typically do not get enough calcium in their diet. B) Men do not remodel the skeleton as fast as women. C) Pregnancy causes deossification of bones in women and will lead to osteoporosis. D) Men exercise more than women and therefore have less osteoporosis. E) Women have a decrease in sex hormones after menopause

E) Women have a decrease in sex hormones after menopause

Primary ossification centers develop in long bones in the A) proximal epiphysis. B) periosteum. C) metaphysis. D) distal epiphysis. E) diaphysis.

E) diaphysis

Damage to a bone because of extreme load, sudden impact, or stresses applied from an unusual direction is called a A) dislocation. B) contortion. C) rupture. D) fragmentation. E) fracture

E) fracture

Parathyroid hormone functions in all of the following ways except A) stimulating osteoclast activity. B) increasing the rate of calcium absorption. C) decreasing the rate of calcium excretion. D) raising the level of calcium ion in the blood. E) inhibiting calcitonin secretion

E) inhibiting calcitonin secretion

The most abundant cell type in bone is A) osteoclasts. B) osteoblasts. C) osteolytes. D) osteoprogenitor cells. E) osteocytes.

E) osteocytes

The natural age-related loss of bone mass is called A) osteogenesis imperfecta. B) osteoporosis. C) osteomalacia. D) osteodysplasia. E) osteopenia.

E) osteopenia

The ongoing process of tearing down and rebuilding bone matrix is called A) restoration. B) osteolysis. C) resorption. D) ossification. E) remodeling.

E) remodeling

Where in the body does the production of precursors for the synthesis of calcitriol occur? A) bone B) kidneys C) small intestine D) liver E) skin

E) skin

Which of the following is formed by intramembranous ossification? A) roof of the skull B) carpal bones C) femur D) clavicle E) the roof of the skull and the clavicle

E) the roof of the skull and the clavicle

What is the axial skeleton?

The axial skeleton is comprised of 80 bones that form the longitudinal axis of the body. Include the cranial and facial bones of the skull, hyoid bone, sternum, ribs and vertebrae of the vertebral column.

How is the human skeleton classified?

The human skeleton is comprised of 206 bones, which are divided into the axial skeleton and appendicular skeleton.