chapter 6

Bone-forming cells originate from __________.

Osteoprogenitor cells

Which bone disorder is characterized by excessive and haphazard bone deposit and resorption?

Paget's disease

Which of the following bone disorders is not treatable with increased calcium and vitamin D?

Paget's disease

Osteoporosis occurs most often in ____________________.

Postmenopausal women

bone disorders: what is rickets

Results in bowed legs and other bone deformities because bones ends are enlarged and abnormally long - Cause: vitamin D deficiency or insufficient dietary calcium

what type of bone is the vertebrae

irregular bone

bone resorption: what is resorption

is a function of osteoclasts

Correctly match the bone type with its example: Sesamoid bone.

patella (knee)

Correctly match the bone type with its example: Irregular bone.

vertebra, spinal column

compact: what are perforating canals (volkmann's)

* perpendicular* *allow two central canals to connect* canals linked with endosteum that occur at right angles to central canal - they connect blood vessels and nerves of periosteum, medullary cavity, and central canal *they link central canal with other canals*

chemical composition of bone: what are the inorganic components of bone

*Hyrdoxyapatites (mineral salts)*

endochondral ossification process

*begins 8-week pregnancy to childhood adolescence* 1. bone collar forms around diaphysis of the hyaline cartilage 2.cartilage calcifies (hardens) in the center of the diaphysis and then develops cavities 3. the periosteal bud invades internal cavities and forms spongy bone 4. the diaphysis elongates and a medullary cavity forms. secondary ossification centers appear in the epiphysis 5. the epiphyses ossify(turn into bone tissue). when ossification is complete hyaline cartilage remains only in the epiphyseal plates and articular cartilages

cells: osteoclasts

*cells that destroy bone for remodeling* responsible for dissolving bone* become active if calcium levels drop too low they eat up bone - derived from the same hematopoietic stem cells that become macrophages - giant, multinucleate cells function in bone resorption -when active, cells are located in *depressions called resorption bays* - cells have ruffled borders that serve to *increase surface area for enzyme degradation* of bone and also helps seal off area from surrounding matrix

compact: what is a central canal and what does it consist of

*central (Haversian) canal runs through core of an osteon* - *contains blood vessels (arteries and veins) and nerve fibers*

formation of the bony skeleton: intramembranous ossification

*growth of clavicle, skull, facial bones* - *bone develops from fibrous membrane* - *bones are called membrane bones* - flat bones of the skull, some facial bones, part of clavicle

describe fibrocartilage (what does it do, what is it made of, and where is it found)

*has great tensile strength; thick collagen fibers* found in - - pads of pubic bones - pads of knee (menisci of knee) - pads of vertebral discs

compact: what is an osteon what does it consist of

*looks like bullseye* - an osteon is the structural unit of compact bone - *builds strength to bone* - it consists of an elongated cylinder that runs parallel to long axis of bone and acts as tiny weight-bearing pillars - it also consists of several rings of bone matrix called lamellae

functions of bones: what is hormone production

*osteocalcin(calcium-binding protein)* secreted by bones helps to regulate insulin secretion, glucose levels, and metabolism

formation of the bony skeleton: what is endochondral ossification

*replacing of the hyaline cartilage* - *bones are called cartilage (endochondral) bones* - *form most of skeleton (long bones)* - mesenchymal cells specialize into osteoblasts - begins at primary ossification center

The bones in the long axis of the body make up the __________.

Axial

describe medullary cavity (what is looks like, what it contains)

- hallow, cylindrical space within the diaphysis - contains red bone marrow in children - contains yellow bone marrow in adults

Which of the following is true regarding bone remodeling?

Every year 5 to 10 percent of the skeleton is replaced.

All of the following belong to spongy bone, except __________.

Osteons

cells: describe osteogenic cells (also called osteoprogenitor)

- mitotically active stem cells in periosteum and endosteum - when stimulated they differentiate into osteoblasts or bone lining cells, some remain as osteogenic stem cells

compact: what is a canaliculi

*smaller canals that radiate out from center canal - tiny blood vessels that take blood from a central canal to osteocytes* - hairlike canals that connect lacunae to each other and to central canal *small pathways that allow osteocytes to share nutrients* - osteoblasts that secrete bone matrix maintain contact with each other and osteocytes via cell projections with gap junctions - when matrix hardens and cells are trapped the canaliculi forms - allow communication between all osteocytes of osteon and permit nutrients and wastes to be relayed from one cell to another

compact: what is a lacunae and what does it consist of

*the name of the small spaces where bone cells (osteocytes) are found* they are *small cavities* that contain osteocytes *house of osteocyte*

long bone: what does the epiphyseal plate consists of

*this plate is in metaphysis* - growth plate - thin layer of hyaline cartilage provides for lengthwise bone growth

cells: describe bone lining cells

- *all cells die by apoptosis* *if they don't die they become bone lining* *regulate calcium* - flat cells on bone surfaces are believed to also help maintain matrix - on the *external bone surface*, *lining cells are called periosteal* - on the *internal surfaces*, they are *called endosteal cells*

cells: describe osteoblasts

- *responsible for bone growth* *lay down bone tissue* - *bone-forming cells that secrete unmineralized bone matrix* called osteoid - are actively mitotic *committing to becoming bone tissue*

bone resorption

- Dig depressions or grooves as they break down matrix - Secrete lysosomal enzymes and protons (H+) that digest matrix - Acidity converts calcium salts to soluble forms Osteoclasts also phagocytize demineralized matrix and dead osteocytes - Digested products are transcytosed across cell and released into interstitial fluid and then into blood - Once resorption is complete, osteoclasts undergo apoptosis • Osteoclast activation involves PTH (parathyroid hormone) and immune T cell proteins

spongy: what is spongy bone

- appears poorly organized but is actually *organized along lines of stress to help bone resist stress* - *location of red bone marrow* - trabeculae like cables on a suspensions bridge confer strength to bone

endosteum: what does it do

- covers trabeculae of spongy bone - lines canals that pass through compact bone - like periosteum, it contains osteogenic cells that can differentiate into other bone cells

compact: what is the circumferential lamellae

- deep to periosteum but superficial to endosteum - these layers of lamellae extend around entire surface of diaphysis - help long bone to resist twisting

endosteum: what is it

- delicate connective tissue membrane covering internal bone surface

long bone: describe diaphysis (what is looks like, what it does)

- elongated, usually cylindrical shaft - provides leverage and weight support - compact bone with spongy bone extending inward

long bone: what does the articular cartilage(joint) consist of

- only at the ends of bones - covers the joint surface - thin layer of hyaline cartilage - reduces friction - absorbs shock in moveable joints

describe hyaline cartilage (what does it do, what is it made of, and where is it found)

- provides support, flexibility, and resilience - *most abundant type; *contains collagen fibers only* found in - - articular cartilage (joints) - costal cartilage (ribs) - nasal cartilage (nose tip)

long bones: what is the metaphysis

- region of mature bone between diaphysis and epiphysis

describe elastic cartilage (what is it made of, and where is it found)

- similar to hyaline cartilage, but *contains elastic fibers* found in - - external ear - epiglottis(flap of windpipe)

what are some general functions of bones

- support and protect organs - structure - nutrients store calcium and makes red blood cells

compact: what is interstitial lamellae

-this lamellae is not part of the osteon *fill gaps between osteons* - some fill gaps between forming osteons; others are remnants(small quantities) of osteons cut by bone remodeling

fracture treatment and repair: process

1. *hematoma formation:* Torn blood vessels hemorrhage, forming mass of clotted blood called a hematoma The site is swollen, painful, and inflamed 2. *fibrocartilaginous callus formation:* Capillaries grow into (clotted blood) hematoma - Phagocytic cells clear debris - Fibroblasts secrete collagen fibers to span break and connect broken ends - Fibroblasts, cartilage, and osteogenic cells begin reconstruction of bone ▪ Create cartilage matrix of repair tissue ▪ Osteoblasts form spongy bone within matrix - This mass of repair tissue is called fibrocartilaginous callus 3. *bony callus formation:* - within one week, new trabeculae appear in fibrocartilaginous callus - Callus is converted to bony (hard) callus of spongy bone 4. *Bone remodeling* - Begins during bony callus formation and continues for several months -Excess material on diaphysis exterior and within the medullary cavity is removed - Compact bone is laid down to reconstruct shaft walls

what are the three levels of bone structure

1. Gross 2. Microscopic 3. Chemical

interstitial growth (length) process

1. Resting (quiescent) zone- - Area of cartilage on *epiphyseal side* of epiphyseal plate that is relatively inactive *inactive area* cells grow 2. Proliferation (growth) zone- *cartilage cells undergo mitosis* - Area of cartilage on diaphysis side of epiphyseal plate that is rapidly dividing - New cells formed move upward, pushing epiphysis away from diaphysis, causing lengthening 3. Hypertrophic zone *older cartilage cells enlarge* - Area with older chondrocytes closer to diaphysis - Cartilage lacunae enlarge and erode, forming interconnecting spaces 4. Calcification zone *matrix becomes hardened; cartilage cells die; matrix begins deteriorating* - Surrounding cartilage matrix calcifies; chondrocytes die and deteriorate 5. Ossification zone *new bone is forming* - Chondrocyte deterioration leaves long spicules of calcified cartilage at epiphysis- diaphysis junction - Spicules are then eroded by osteoclasts and are covered with new bone by osteoblasts - Ultimately replaced with spongy bone - Medullary cavity enlarges as spicules are eroded

intramembranous ossification process

1. ossification centers develop in fibrous connective tissue membrane. *(mesenchymal cells cluster and differentiate into osteoblasts, forming ossification center)* 2. osteoid is secreted and calcifies(hardens) *(osteoblasts continue to secrete osteoid, which calcifies in a few days. trapped osteoblasts become osteocytes)* 3. immature spongy bone and periosteum form *(accumulating osteoid is laid down between embryonic blood vessels, forming a honeycomb of immature spongy bone. vascularized mesenchyme condenses on the external face of the bone and becomes the periosteum)* 4. compact bone replaces immature spongy bone just deep to the periosteum. red marrow develops *(trabeculae deep to the periosteum are remodeled and replaced with compact bone. the immature spongy bone in the center is remodeled into mature spongy bone that is eventually filled with red bone marrow

cells: five major cell types

1. osteogenic cells 2. osteoblasts 3. osteocytes 4. bone-lining cells 5. osteoclasts

how many bones are in the human skeleton

206 bones

bone remodeling: what percent of bone mass is recycled each week

5-7%

Match the following function of bone to its description: Anchorage.

As a result, we can walk, grasp objects, and breathe

what percent of collagen makes up bone protein

90%

Select the statement that best describes most long bones at the time of birth.

A bony diaphysis with a widening medullary cavity, and two cartilaginous epiphyses

Match the type of cartilage to its correct description: Fibrocartilage.

Able to withstand heavy loads and absorb shock

bone disorders: what is osteomalacia

Bones are poorly mineralized - Osteoid is produced, but calcium salts not adequately deposited - Results in soft, weak bones - Pain upon bearing weight

Bones serve as an important reservoir for __________.

Calcium

Hydroxyapatites in bone matrix that give bone its hardness are primarily composed of __________.

Calcium phosphates - inorganic component

Osteocytes maintain contact allowing them to communicate and permitting nutrients and wastes to be relayed from one osteocyte to the next through __________.

Canaliculi

A patient is brought to the emergency room with a broken bone. According to the x-ray, the bone is fragmented into three pieces. This would be considered a __________.

Comminuted fracture

what is diploe

Diploë is the spongy bone structure of the internal part of short, irregular, and flat bones.

In a car accident, the injuries to the driver include a fractured femur. Part of the broken end of the diaphysis of the femur is visibly penetrating through the skin in the thigh area. Which of the following properly classifies this fracture?

Displaced, complete, open (compound)

Paget's disease of bone

Excessive and haphazard bone deposit and resorption cause bone to grow fast and develop poorly - Called Pagetic bone - Very high ratio of spongy to compact bone and reduced mineralization • Usually occurs in spine, pelvis, femur, and skull • Rarely occurs before age 40 • Cause unknown: possibly viral • Treatment includes calcitonin and bisphosphonates

The padlike menisci of the knee joints contain __________.

Fibrocartilage

Before eight weeks, the skeleton of the human embryo is composed of __________.

Fibrous membranes and hyaline cartilage

A narrow, slitlike opening in a bone is referred to as a __________.

Fissure

Match the following: Respiratory cartilages.

Form the skeleton of the larynx and reinforce other respiratory passages

Grove

Furrow

Select the correct sequence of fracture repair steps.

Hematoma forms, fibrocartilaginous callus forms, bony callus forms, bone remodeling occurs

Osteoblasts release which of the following?

Matrix vesicles studded with the enzyme alkaline phosphatase

Bone Disorders: Osteoporosis

Most common bone disease -Porous bone -Loss of bone density -Often brittle and break easily -Vertebrae compress -The moral to the story is higher bone density now mea less risk later

bone development: birth to young adulthood

Most long bones begin ossifying by 8 weeks, with primary ossification centers developed by week 12 Birth to Young Adulthood- • At birth, most long bones ossified, except at epiphyses • Epiphyseal plates persist through childhood and adolescence • At ~ age 25, all bones are completely ossified, and skeletal growth ceases

interstitial growth

Near end of adolescence, chondroblasts divide less often • Epiphyseal plate thins, then is replaced by bone • Epiphyseal plate closure occurs when epiphysis and diaphysis fuse • Bone lengthening ceases - *Females: occurs around 18 years of age* - *Males: occurs around 21 years of age*

bone deposit

Occurs where bone is injured or added strength is needed; Requires a diet rich in protein; vitamins C, D, and A; calcium; phosphorus; magnesium; and manganese New bone matrix is deposited by osteoblasts • Osteoid seam: band of unmineralized bone matrix that marks area of new matrix • Calcification front: abrupt transition zone between osteoid seam and older mineralized bone • Trigger for deposit not confirmed but may include: - Mechanical signals (stress on the bone) - Increased concentrations of calcium and phosphate ions for hydroxyapatite formation - Matrix proteins that bind and concentrate calcium - Appropriate amount of enzyme alkaline phosphatase for mineralization

Determine the scenario that reduces the mass of a long bone.

Osteoclast activity is greater than osteoblast activity.

Bone is broken down by __________.

Osteoclasts

The cells that maintain mature compact bone marix are __________.

Osteocytes

The lacunae of bone contain __________.

Osteocytes

A bone disorder that affects adults and has symptoms that are similar to rickets is called __________.

Osteomalacia

If a breastfeeding mother becomes vitamin D deficient, what disease is most likely to develop in the nursing infant?

Rickets

Correctly match the opening or depression in bone with its correct name: Foramen.

Round or oval opening through a bone

In adolescence, the "growth spurt" that is observed is mainly attributed to an increase in __________.

Sex hormones

Correctly match the opening or depression in bone with its correct name: Fossa.

Shallow, basinlike depression in a bone, often serving as an articular surface

Correctly match the term and description: Epiphyseal plate.

Site of length increase in long bones

Correctly match the description of the projection with its name: Tubercle.

Small rounded projection or process

During a football game, a player fractures his leg bone when his foot plants into the turf, but several opposing players continue to push him forward. The doctor explains that the diagonal break across the bone was due to intense twisting forces. Select the type of fracture involved in this example.

Spiral

Match the description to the correct stage of intramembranous ossification: Immature spongy bone and periosteum form.

Stage 3

Mary is 50 years old. During a checkup, a bone scan reveals that portions of her skeleton show signs of osteoporosis. After reviewing the test results, her physician suggests that she take all of the following courses of action except?

Start taking synthetic parathyroid hormone

hormonal regulation of bone growth: what is testosterone and estrogen

Testosterone (males) and estrogens (females) at puberty: promote adolescent growth spurts

Red bone marrow in adults is only found in the cavities between trabeculae of spongy bones in:

The flat bones of the skull, as well as the sternum, ribs, clavicles, scapulae, hip bones, and vertebrae The heads of the femur (thigh bone) and humerus (long bone of the arm)

Select the true statement regarding appositional growth of a long bone.

The long bone increases in thickness, or diameter.

T/F Despite the environmental factors that influence bone density, genetics still plays the major role in determining bone density.

True

T/F Hypocalcemia leads to hyperexcitability.

True

T/F Osteocytes are bone forming cells that secrete the bone matrix

True

Correctly match the description of the projection with its name: Trochanter.

Very large, blunt, irregularly shaped process

Rickets can be caused by a deficiency of __________.

Vitamin D

The bones of the skeleton store energy reserves as fat in __________.

Yellow marrow

what does the perichondrium consist of

a layer of dense connective tissue surrounding cartilage like a girdle - that consists of blood vessels for nutrient delivery to cartilage - helps cartilage resist outward expansion

what is a sesamoid bone

a specialized short bone that occurs within a tendon, such as the patella (kneecap).

Yellow marrow is useful as __________.

a tissue that may revert back to red marrow if a person needs more red blood cells

cells: describe osteogenic cells

also called osteoprogenitor cells mitotically active stem cells in periosteum and endosteum chemical messenger- when stimulated they differentiate into osteoblasts or bone lining cells

what are the two ways cartilage grows

appositional growth (width) interstitial growth (length)

Cartilage can grow in which of the following ways?

appositional growth and interstitial growth

what are flat bones

are thin, and they curve at the edges like frontal bone and sternum

what is spongy bone

at the ends of bones - a honeycomb of small needle-like or flat pieces of bone called trabeculae - open spaces between trabeculae are filled with red or yellow bone marrow

how is the human skeleton divided?

axial skeleton and appendicular skeleton

interstitial growth (length): describe

begins during embryonic development and dependent on cartilage in the epiphyseal plate

what are hematopoiesis

blood cell formation in red bone marrow

what does bone remodeling consist of

bone deposit and bone resorption

cells: describe osteocytes

bone maintenance *monitors and maintains mineralized bone matrix* - *mature bone cells* in lacunae that no longer divide - *maintain bone* matrix and act as stress or strain sensors - respond to mechanical stimuli (increased force on bone) - communicate info to osteoblasts and osteoclasts so bone remodeling can occur

what is scattered throughout spongy bone; no defined marrow cavity

bone marrow

What is osseous tissue?

bone tissue

what are long bones

bones are longer than they are wide

what are short bones

bones that are long as they are wide, making them cube-shaped

what is the appendicular skeleton and what does it consist of?

bones that support appendages consists of - - arms and legs - girdles attaching limbs to the axial skeleton

chemical composition of bone: what is bone made out of

both organic(cells and protein- osteoid gelly like) and inorganic components

Match the description to the correct zone in longitudinal growth of a long bone: Dead cartilage cells appear; matrix begins deteriorating.

calcification zone

Select the hormone that lowers blood calcium levels when administered at high pharmacological doses.

calcitonin

functions of bones: what is mineral and growth factor storage

calcium and phosphorus, and growth factors reservoir

Correctly match the opening or depression in bone with its correct name: Meatus.

canal-like passageway

Which of the following are tiny canals that connect the central canal of an osteon to the osteocytes?

canaliculi

Correctly match the bone type with its example: Short bone.

carpal (wrist)

skeletal cartilage: what does the human skeleton initially consist of

cartilage, which is then replaced by bone

Correctly match the opening or depression in bone with its correct name: Sinus.

cavity within a bone

describe appositional growth (surface) (width)

cells in perichondrium secrete matrix against external face of existing cartilage - lay down new matrix on surface of cartilage

Cartilage tissue features __________ within small cavities called lacunae.

chondrocytes

describe interstitial growth (within) (length)

chondrocytes in the lacunae divide and secrete new matrix, allowing the cartilage to grow from within. - new matrix within cartilage

what is cartilage made up of

chondrocytes, cells encased in small cavities (lacunae) within jelly-like extracellular matrix

Match the description to the correct answer regarding bone tissue: Major organic fiber of bone.

collagen

what is gross anatomy consist of

compact and spongy bone

Match the following: Costal cartilages.

connect the ribs to the sternum

compact: what does compact bone consist of (also called lamellar bone because its layered which offers strength)

consists of - - osteon (haversian system) - canals and canaliculi - interstitial and circumferential lamellae

what does an osteoid consist of

consists of ground substance and collagen fibers, which contribute to high tensile strength and flexibility of bone

hormone regulation of bone growth: what is calcitonin and parathyroid hormone (PTH)

control blood calcium levels by inhibiting (calcitonin) or promoting (PTH) osteoclast activity

Match the following: Articular cartilages.

cover the ends of most bones at moveable joints

what is compact bone

dense outer layer of bone that appears smooth and solid

long bones: what is the distal epiphysis

end of bone farthest from trunk - composed of outer layer of compact bone - inner region of spongy bone

long bones: what is the proximal epiphysis

end of the bone closest to the body trunk

Correctly match the definition and term: Replacement of hyaline cartilage with bony tissue to form a bone.

endochondral ossification

what covers the inside portion of compact bone

endosteum

Correctly match the definition and term: Expanded portion of the long bone at its ends.

epiphysis

functions of bones: what is triglyceride (fat storage)

fat, used for an energy source, is stored in bone cavities

Match the description to the correct stage of bone repair: Activity of fibroblasts and osteoblasts creates an overgrown splint around the fracture site.

fibrocartilage callus

Intramembranous ossification is mostly responsible for forming which type of bone?

flat bone

what type of bone is the sternum

flat bone

Correctly match the opening or depression in bone with its correct name: Groove.

furrow

what happens to bones during appositional growth

growing bones widen as they lengthen bones thicken in response to increased stress from muscle activity or added weight osteoblasts beneath periosteum secrete bone matrix on external bone osteoclasts remove bone on endosteal surface usually more building up than breaking down which leads to thicker, stronger bone that is not too heavy

During infancy and childhood, the single most important stimulus of epiphyseal plate activity is __________ from the anterior pituitary gland.

growth hormone

Correctly match the description of the bony projection with its name: Bony expansion carried on a narrow neck.

head

what is the process of blood cell formation

hematopoiesis

Which function of bone tissue occurs in the red bone marrow?

hematopoiesis - blood cell formation

functions of bones: what is blood cell formation

hematopoiesis occurs in red marrow cavities of bones

What is hypercalcemia?

high levels of calcium cause non-responsiveness

what is skeletal cartilage made of

highly resistant, molded cartilage tissue that consists of water (no blood vessels or nerves)

When problems with blood forming tissue are suspected, clinicians obtain tissue samples from the _____________ because the red bone marrow in this location is highly active in hematopoiesis.

hip bone

three types of cartilage

hyaline, elastic, fibrocartilage

Match the description to the correct zone in longitudinal growth of a long bone: Older cartilage cells enlarge.

hypertrophic zone

long bone: what is the epiphyseal line and where

in adults, the epiphyseal line is the remnant (small quantity) of the epiphyseal plate

chemical composition of bone: what do organic components include

includes- - osteogenic cells - osteoblasts - osteocytes - bone lining cells - osteoclasts - osteoid

periosteum: what is the osteogenic layer

inner layer abutting bone and contains primitive osteogenic stem cells that give rise to most all bone cells bone stem cells are being made stem cells are baby cells that mature

Which of the following is not composed of hyaline cartilage?

intervertebral discs - fibrocartilage

Match the description to the correct answer: Bone with a complex shape.

irregular bone

hematopoiesis: where is red bone marrow found (for newborns and adults)

is found within trabecular cavities of spongy bone and diploe of flat bones such as sternum - in *newborns* medullary cavities and all spongy bone contains red marrow - in *adults* red bone marrow is located in heads of femur and humerus but most areas of hematopoiesis are flat bone diploe and some irregular bones (such as hip bone)

bone development: what is ossification (osteogenesis)

is the process of bone tissue formation

what is an osteoid and what is it made of?

it is an *unmineralized bone matrix* *made up of* - - collagen and *calcium-binding proteins* - collagen makes up 90% of bone protein

long bone: what is the epiphysis?

knobby region at each end of long bone

postnatal bone growth: how do long bones grow

lengthwise by interstitial (longitudinal) growth of epiphyseal plate

functions of bones: what is movement

levers for muscle action

Match the type of cartilage to its correct description: Elastic cartilage.

located in the external ear and epiglottis

what is the axial skeleton and what does it consist of?

long axis of the body consists of - - skull - vertebral column - rib cage

Match the description to the correct answer: Has a length greater than width.

long bone

what type of bone is the humerus

long bone

What is hypocalcemia?

low calcium levels in the blood cause hyper-excitability

what portion of bone plates contain epiphyseal plate

meda

Correctly match the definition and term: Hollow space in the shaft of a long bone.

medullary cavity

what portion of bone plates contain epiphyseal plate

metaphysis

hormonal regulation of bone growth: what is thyroid hormone

modulates activity of growth hormone, ensuring proper proportions

Which of the following is true with respect to hyaline cartilage?

most abundant skeletal cartilage

hormonal regulation of bone growth: what is growth hormone

most important hormone in stimulating epiphyseal plate activity in infancy and childhood

Correctly match the description of the projection with its name: Crest.

narrow ridge of bone

Correctly match the term and description: Bone-building cell.

osteoblast

Correctly match the term and description: Mature bone cell.

osteocyte

chemical composition of bone: which makes up one-third of organic bone matrix and is secreted by osteoblasts

osteoid

Correctly match the term and description: Bone stem cell.

osteoprogenitor cell

periosteum: what is the fibrous layer

outer layer consisting of dense irregular connective tissue consisting of sharpeys fibers that secure to bone matrix lots of collagen fibers for protections

What are remodeling units?

packets of adjacent osteoblasts and osteoclasts coordinate remodeling process

The hormonal control of bone remodeling primarily involves which of the following?

parathyroid hormone

When Ca2+ concentration in the blood becomes lower than normal, __________.

parathyroid hormone is released

what are lining cells called

periosteal cells

Correctly match the definition and term: Fibrous connective tissue membrane that covers the outer surface of long bone.

periosteum

what contains many nerve fibers and blood vessels that continue on to the shaft through nutrient foramen openings

periosteum

what is a white double layered membrane that covers compact bone, external surfaces except joints

periosteum

Where does bone remodeling occur?

periosteum and endosteum

Correctly match the term and description: Diaphysis.

primary ossification center

Match the description to the correct zone in longitudinal growth of a long bone: Cartilage cells undergo mitosis.

proliferation zone

functions of bones: what is protection

protect brain, spinal cord, and vital organs

Collagen fibers do not __________.

provide for bone hardness

Which of the following bones belong to the axial skeleton?

ribs

compact: what is a lamellae and what does it consist of

rings of bone matrix - contain collagen fibers that run in different directions in adjacent rings - withstands stress and resist twisting - bone salts are found between collagen fibers

Match the description to the correct answer: Sesame seed-shaped bone formed in a tendon.

sesamoid bone

Correctly match the description of the projection with its name: Spine.

sharp, slender, often pointed projection

Match the description to the correct answer: Approximately equal in length and width.

short bone

what type of bone is the carpal bone

short bone

what type of bones have a length nearly equal width

short bones

Correctly match the definition and term: Location of red bone marrow in an adult.

spongy bone

where is red bone marrow found in the adult skeleton

spongy bone and head of femur and humerus

bone remodeling: when is spongy and compact bone replaced

spongy bone replaced every 3-4 years compact bone replaced every 10 years

Correctly match the bone type with its example: Flat bone.

sternum (breastbone)

functions of bones: what is support

support for body and soft organs

Match the following: Nasal cartilage.

supports external nose

where are chondrocytes found

they are encased in small cavities which are called the lacunae and the lacunae is within jelly-like extracellular matrix

why are bones organs

they contain different types of tissues

what are irregular bones

they have complicated shapes, so its hard to classify

Correctly match the definition and term: A hormone that modulates the activity of growth hormone, ensuring proper bone formation.

thyroid hormone

T/F Excesses or deficits of any hormones cause abnormal skeletal growth

true

T/F Sustained high blood calcium levels can lead to deposits of calcium salts in blood vessels or kidneys and formation of kidney stones

true

T/F bone remodeling and repair are lifelong

true

T/F formation of bony skeleton begins in month 2 of development

true

T/F hyaline cartilage covers area of bone that is part of a moveable joint

true

T/F is compact bone sandwiched between connective tissue membranes

true

T/F postnatal bone growth occurs until early adulthood

true

T/F short, irregular, flat bones consist of thin plates of spongy bone (diploe) covered by compact bone

true

T/F • Bones increase thickness through appositional growth

true

T/F • Bones stop growing during adolescence

true - Some facial bones continue to grow slowly through life

Correctly match the description of the projection with its name: Large, rough, rounded projections.

tuberosity

what happens to yellow marrow if person becomes anemic

turns red to make blood cells

formation of the bony skeleton: at what week are fibrous membranes and hyaline cartilage of fetal skeleton replaced with bone tissue

week 8

Which of the following is classified as a short bone?

wrist bone

T/F is bone bloody

yes

chemical composition of bone: what does Hyrdoxyapatites consist of and what does it do

▪ Makeup 65% of bone by mass ▪ Consist mainly of tiny calcium phosphate crystals(from diet) in and around collagen fibers ▪ Responsible for hardness and resistance to compression