Skeletal system: bone structure & functions LearnSmart

Insufficient ossification is a condition known as?

Osteopenia

Name the four types of bone cells and their functions?

Osteoprogenitor = Precursor to bone cells. Osteoblasts = Bone-forming cell. Osteocytes = Bone cell in a lacuna within bone matrix. Osteoclasts = Large cell type that functions in the absorption and removal of bone connective tissue.

Osteitis deformans is also called__________disease

Paget

these bones has the entire interior made of spongy bone, and lacks a medullary cavity?

Short bone and irregular bone

Compare the gross anatomy of other bones to that of a long bone?

Short, flat, and irregular bones differ in their gross anatomic structure from long bones. The external surface generally is composed of compact bone, the interior is composed entirely of spongy bone, and there is no medullary cavity

the following steps in order to summarize appositional growth of cartilage?

Stem cells in the perichondrium undergo mitosis; Committed cells became chondroblasts; New matrix is produced at the periphery of the cartilage

The role of estrogen and testosterone on maintenance and bone growth is to?

Stimulate osteoblasts and promote epiphyseal plate growth and closure

Describe the composition of bone's matrix?

The matrix of bone connective tissue has both organic and inorganic components. The organic component is osteoid, which is produced by osteoblasts. The inorganic portion of the bone matrix is made up of salt crystals that are primarily calcium phosphate, Ca3(PO4)2

Which statements characterize canaliculi?

They extend from lacunae to lacunae; Nutrients pass through them; They contain osteocyte cytoplasmic extensions

Bones provide structural support for the body by serving as?

a framework for the entire body

Explain the general function of blood vessels and nerves that serve a bone?

a) Bone is highly vascularized (meaning it is supplied by many blood vessels), especially in regions containing spongy bone. Blood vessels enter bones from the periosteum. Typically, only one nutrient artery enters and one nutrient vein exits the bone via a small opening or hole in the bone called a nutrient foramen. Blood vessels supply nutrients and oxygen required by cells and remove waste products from bone cells. Nerves that supply bones accompany blood vessels through the nutrient foramen and innervate the bone as well as its periosteum, endosteum, and marrow cavity. These are mainly sensory nerves that signal injuries of the skeleton.

A bone's growth in diameter is called?

appositional growth

long bones

are greater in length than width. These bones have an elongated, cylindrical shaft (diaphysis). and is one of the major classes of bones

flat bones

are so named because they have flat, thin surfaces that may be slightly curved

A thin layer of hyaline cartilage covering an epiphysis of a long bone is called?

articular cartilage

hyaline cartilage

attaches ribs to the sternum (costal cartilage), covers the ends of some bones (articular cartilage), and is the cartilage within growth plates (epiphyseal plates). Hyaline cartilage also provides a model for the formation of most of the bones in the body.

bone formulation

begins when osteoblasts secrete the initial semisolid organic form of bone matrix called osteoid

Endochondral ossification?

begins with a hyaline cartilage model

The continual deposition of a new bone tissue and the removal of old bone tissue is called?

bone remodeling

ligaments connect?

bone to bone

examples of flat bones?

bones of the roof of the skull; shoulder blade bones; and the breastbone (sternum)

examples of short bones?

bones of the wrist and some bones of the foot

Tiny channels that connect lacunae to other lacunae in an osteon are called?

canaliculi

spongy bone is also called?

cancellous bone

the cells that produce the matrix of cartilage are called?

chondroblasts

An osteon is the basic functional and structural microscopic unit of ?

compact bone

cartilage is what type of tissue?

connective tissue

the elongated cylindrical shaft of a long bone is called its?

diaphysis

Bone remodeling begins?

during the embryologic development

The type of ossification that begins with a hyaline cartilage model is?

endochondral ossification

structure replaces the epiphyseal plate?

epiphyseal line

Which bones are produced by intramembranous ossification?

flat bones of the skull

which hormone stimulates the liver to produce somatomedin, which ultimately results in bone elongation?

growth hormone; high levels of cortisol increase bone loss

short bones

have a length nearly equal to their width. Examples of short bones include the carpals (wrist bones) and tarsals (bones in the foot).

irregular bones

have elaborate, sometimes complex shapes and do not fit into any of the preceding categories. The vertebrae; ossa coxae (hip bones); and several bones in the skull, such as the ethmoid, sphenoid, and sutural bones, are examples of irregular bones

the process of blood cell production is called?

hemopoiesis

example of an irregular bone?

hip bones

Articular cartilage, found on the ends of long bones, consists of?

hyaline cartilage

steps of endochondral ossification in the correct order?

hyaline cartilage model develops; periosteal bone collar forms; primary ossification center appears; secondary ossification center appears; epiphyseal plates become epiphyseal lines

When osteoblast activity outpaces osteoclast activity, bone mass

increases

Leftover parts of the osteons that have been partially resorbed are called ______ lamellae

interstitial

bone resorption

is a process whereby bone matrix is destroyed by substances released from osteoclasts into the extracellular space adjacent to the bone. Proteolytic enzymes released from lysosomes within the osteoclasts chemically digest the organic components (collagen fibers and proteoglycans) of the matrix, while hydrochloric acid (HCl) dissolves the mineral parts (calcium and phosphate) of the bone matrix

fibrocartilage

is a weight-bearing cartilage that withstands compression. It forms the intervertebral discs, the pubic symphysis (cartilage between bones of the pelvis), and cartilage pads of the knee joints (menisci).

Which of the following is a function of bone?

is production of organs.

bone marrow

is the soft connective tissue of bone that includes red bone marrow and yellow bone marrow

statements characterize the microscopic arrangement of spongy bone?

it contains lacunae and canaliculi; it contains no osteons; it contains parallel lamellae

which statements are true regarding cartilage?

it is found in the head, arms, legs, and trunk of the body; it is more flexible than bone; it contains cells and a matrix.

statements characterize the functions of cartilage?

it provides a gliding surface at joints; it supports soft tissues; and it provides a model for the formation of bones

osteoclasts are ?

large phagocytic cells found in bone

the bones formed through endochondral ossification?

lower limb bones, vertebrae, and upper limb bones

choose the bones formed through endochondral ossification?

lower limb bones; upper limb bones; and vertebrae

another name for the calcification of a bone is?

mineralization

functions of bones

movement; support and protection; flexibility; storage of mineral and energy reserves

spongy bone

(also called cancellous or trabecular bone) is located internal to compact bone, appears porous, and makes up approximately 20% of the total bone mass.

compact bone

(also called dense or cortical bone) is a relatively dense connective bone tissue that appears white, smooth, and solid. It makes up approximately 80% of the total bone mass

red bone marrow

(myeloid tissue) is hemopoietic (blood cell forming) and contains reticular connective tissue, immature blood cells, and fat

Steps in order to summarize interstitial growth of cartilage?

1. Chondrocyte in lacuna undergoes mitosis 2. Two cells occupy one lacuna 3. Two cells in one lacuna begin to produce new matrix

Which statements characterize the effects of exercise on bones?

1. Exercise increases the production of the hormone calcitonin 2. Exercise promotes bone remodeling 3. Regular weight bearing exercise can increase total bone mass

Which characterizes the process of bone resorption?

1. HCl dissolves minerals of bones 2. Lysosomes dissolve the organic parts of bone matrix

Which statements characterize lamellar bone?

1. It becomes the spongy bone of flat bones 2. It becomes the compact bone of flat bones 3. It replaces trabeculae of woven bone 4. It is also called secondary bone

Which statements describe the inorganic components of the matrix of bone?

1. It contains hydroxyapatite crystals 2. It gives the bone its hardness

Which statements characterize intramembranous ossification?

1. Ossification centers appear around the 8th week of development 2. Osteoid formation is followed by calcification 3. Some osteoprogenitor cells become osteoblasts

Which statements characterize perforating canals of bone?

1. They run perpendicular to central canals 2. They connect multiple central canals 3. They contain blood vessels and nerves

the zones of an epiphyseal plate in their correct order is?

1. zone of resting cartilage 2. zone of proliferating cartilage 3. zone of hypertrophic cartilage 4 . zone of calcified cartilage 5. zone of ossification

the mineral called phosphate is stored by the bone and is needed for?

ATP utilization among other things

Glucocorticoids are released from the?

Adrenal cortex

The release of parathyroid hormone increases?

Blood calcium levels

describe the general functions of bone?

Bones perform several basic functions: support and protection, movement, hemopoiesis, and storage of mineral and energy reserves

Hyaline cartilage consists of specialized cells called ________ that produce a matrix surrounding themselves. When matrix surrounds these cells they become ______that are trapped in lacunae.

Chondroblasts; chondrocytes

Ring of bone directly internal to the periosteum of a bone are called external _________ lamellae?

Circumferential ***rings of bone immediately internal to the periosteum of the bone (external circumferential lamellae) or internal to the endosteum (internal circumferential lamellae). Both external and internal circumferential lamellae run the entire circumference of the bone itself

The rings of bone connective tissue that surround the central canal of an osteon are called?

Concentric lamellae

this bone has the entire interior made of spongy bone, lacks medullary cavity and has dipole?

Flat bone

Seretonin is a:

Hormone and neurotransmitter

Calcium phosphate and calcium hydroxide interact to form ______ in the matrix of bone

Hydroxyapatite crystals

Donor bone marrow is most commonly harvested from the?

Iliac crest

based on shape, bones that have elaborate, complex shapes are classified as?

Irregular bones

Statements characterize endosteum?

It contains osteoblasts; It lines medullary cavities; It is active during bone repair; It contains osteoclasts

statements characterize articular cartilage?

It covers an epiphysis; It is composed of hyaline cartilage; It functions to reduce friction in joints

Statements characterize periosteum?

It helps to heal bone fractures; It functions to anchor blood vessels to the surface of bones; It covers the outer surface of the diaphysis of a long bone; It is composed of dense irregular connective tissue

Statements describe an osteon?

It is also called a haversian system; It contains a central canal; It is microscopic; It runs parallel to the diaphysis of a long bone

Statements characterize lamaellar bone?

It is also called secondary bone; It replaces trabeculae of woven bone; It becomes the compact bone of flat bones; It becomes the spongy bone of flat bones

Statements characterize woven bone?

It is replaced by lamellar bone; It is formed during intramembranous ossification; It is not well organized

Statements characterize bone remodeling?

It occurs at the periosteal and endosteal surfaces of a bone; It helps maintain calcium and phosphate levels in body fluids; It can be stimulated by stress on a bone

the most common bone shape, has a diaphysis, and has a medullary cavity?

Long bone

List the structural components of a long bone and state their function?

Long bones support soft tissues in the limbs. (a) A typical long bone, such as the humerus, contains both compact and spongy bone. (b) The endosteum lines the internal surface of the bone along the edge of the medullary cavity. (c) The periosteum lines the external surface of the bone shaft

Descriptions of the part of a long bone

Medullary cavity = hollow, cylindrical space within the diaphysis, and contains bone marrow Metaphysis = contains the growth plate and region between diaphysis and epiphysis Endosteum = Layer of cells that covers all internal surfaces of the bone. Periosteum = Dense irregular connective tissue covering the outer surface of bone.

yellow bone marrow

Much of the red bone marrow degenerates as children mature into adults, and the marrow primarily in the medullary cavities of long bones turns into a fatty substance

Which components of bone matrix provides its tensile strength?

Organic components

Tissue types are found in bones are?

Osseous connective tissue; Nervous tissue; Blood

calcification

or mineralization, subsequently occurs to the osteoid when hydroxyapatite crystals deposit in the bone matrix

the process of bone formation is called?

ossification

intramembranous ossification?

ossification that develops from mesenchyme

this has bone-building cells, involved with bone deposition, calcitonin causes these cells to become, and increase activity when blood calcium levels are high?

osteoblasts

Bone connective tissue contains?

osteoblasts and osteocytes

these are bone resorbing cells, and are massive multinucleate cells?

osteoclasts

mature bone cells are called?

osteocytes

this bone cells encased in matrix are?

osteocytes

when osteoclasts become entrapped in the matrix they produce, they become cells called?

osteocytes

which has stem cells?

osteoprogenitor cells

a tough fibrous layer covering the outer surface of a long bone is called ?

periosteum

where does hemopoiesis occur?

red bone marrow

bones of the skeleton function as a system of levers that are pulled when?

skeletal muscles contract

cancellous or trabecular bone is also called?

spongy bone

the region of cartilage between the diaphysis and an epiphysis of a long bone during endochondral ossification is called?

the Epiphyseal plate

Blood vessel supplies the diaphysis of a long bone is?

the Nutrient artery

Long bones include?

the bones of the fingers; the bones of the palm; the bones of the toes; and the thigh bone

the cylindrical channel that lies in the center of the osteon is?

the central canal

the secondary ossification centers form in?

the epiphyses of long bones

based on shape, the most common type of bone is ?

the long bone

the cylindrical space within the diaphysis of a long bone is called?

the medullary cavity

The region of a mature bone between the diaphysis and epiphysis is?

the metaphysis

osteoprogenitor cells are located in?

the periosteum; the endosteum

The region in the diaphysis of a long bone where bone replaces cartilage through endochondral ossification is called?

the primary ossification center; it is the first major center of bone formation.

the epiphysis of a long bone closest to the body trunk is?

the proximal epiphysis

statements characterize osteoclasts?

they are phagocytic; they have ruffled borders; and they reabsorb bone matrix

statements characterize osteocytes?

they maintain bone matrix; they detect mechanical stress on bone; they reside in lacunae; they reabsorb bone matrix; they are phagocytic; they have ruffled borders

the bones of the upper and lower limbs are produced?

through endochondral ossification

Lengthwise bone growth is complete?

when epiphyseal lines form

in intramembranous ossification, newly formed bone that is immature and not well organized is called?

woven bone

In the epiphyseal plate, the microscopic zone in which chondrocytes undergo rapid cell division and become aligned into longitudinal columns of flattened lacunae is called the?

zone of proliferating cartilage