60 terms

Chapter 6: Bones and Skeletal Tissue

T/F The term osteoid refers to the organic part of the matrix of compact bones.
For intramembranous ossification to take place, which of the following is necessary?
An ossification center forms in fibrous connective tissue
_______ are not one of the four cell types that populate bone tissue in adults.
mesenchymal cells
T/F Each consecutive bone lamellae has collagen fibers that wrap in alternating directions.
T/F In newborn infants, the medullary cavity and all areas of spongy bone contain yellow bone marrow.
Ossification of the ends of long bones ______.
is produced by secondary ossification centers.
T/F Bones are classified by whether they are weight-bearing or protective in function.
Yellow bone marrows contain a large % of _______.
The process of bones increasing in width is ______.
appositional growth.
Bones are covered and lined by a protective tissue called periosteum. The inner layer consists primarily of ______.
osteoblasts and osteoclasts.
T/F Compact bone is replaced more often than spongy bone.
Cranial bones develop ________.
within fibrous membranes
Wolff's law is concerned with _____________.
the thickness and shape of a bone being dependent on stresses placed upon it.
Growth of bones is controlled by a symphony of hormones. Which hormone is important for bone growth during infancy and childhood?
growth hormone
T/F All bones formed by intramembranous ossification are irregular bones.
The canal that runs through the cone of each osteon (the Haversion canal) is the site of ___.
blood vessels and nerve fibers.
T/F The structural unit of compact bone osteon resembles the growth rings of a tree trunk.
Osteogenesis is the process of _____.
bone formation
The periosteum is secured to the underlying bone by dense connective tissue called _____.
Perforating (Sharpey's) fibers
In the epiphysial plate, cartilage grows ________.
By pushing the epiphysis away from the diaphysis.
T/F Short, irregular, and flat bones have large marrow cavities in order to keep the weight of bones light.
T/F Bone tissue in the skeleton of a human fetus is completely formed at six months gestation.
The universal loss of mass seen in the skeleton which begins at age 40 ______.
reflects incomplete osteon formation and mineralization.
Which fracture would be least likely to happen in a 90 yr old?
Spongy bones are made up of a framework called _______.
A bone fracture perpendicular to the bones axis is called a(n) ____ fracture.
T/F The periosteum is a tissue that serves only to protect the bone because it is not supplied with nerves or blood vessels.
Ostealgia is ________.
pain in a bone.
Yellow bone marrow contains a lot of ____.
A _____ exhibits chondrocytes housed in lacunae within the extracellular matrix. It contains large amounts of water, lacks nerve fibers, is avascular, and is surrounded by a fibrous perichondrium that resists expansion.
Skeletal cartilage
________ appear glassy; the fibers are collagenic. They provide support with flexibility and resilience and are the most abundant skeletal cartilages, accounting for the articular, costal, respiratory, and nasal cartilages.
Hyaline cartilages
________ cartilages contain abundant elastic fibers, in addition to collagen fibers, and are more flexible than hyaline cartilages. They support the outer ear and epiglottis.
________, which contain thick collagen fibers, are the most compressible cartilages and are resistant to stretch. They form intervertebral discs and knee joint cartilages.
T/F Cartilages grow from within (interstitial growth) and by addition of new cartilage tissue at the periphery (appositional growth).
Bones are classified as ______ on the basis of their shape and their proportional of compact or spongy bone.
Short, flat, or irregular
Name the functions of bones.
Bones give the body shape, protect and support body organs, provide levers for muscles to pull on, store calcium and other minerals, and are the site of blood cell production.
A ______ is composed of a diaphysis and epiphyses. The medullary cavity of the diaphysis contains yellow marrow; the epiphyses contain spongy bone.
long bone
____ consist of 2 thin plates of compact bone enclosing a spongy bone layer.
Flat bones
T/F In adults, red marrow is found within the diploe of flat bones and occasionally within the epiphyses of long bones.
The structural unit of ______, consists of a central canal surrounded by concentric lamellae of bone matrix.
Compact bone
________ has slender trabecullae containing irregular lamellae which encloses red-marrow filled cavities.
Spongy bone
What is bone composed of?
living cells (osteogenic cells, osteoblasts, osteocytes, and osteoclasts) and matrix.
The organic substances in bone matrix ______, while the inorganic components ______.
give the bone tensile strength, make bone hard
_______ forms the clavicles and most skull bones.
Intramembranous ossification
T/F Long bones increase in length by interstitial growth of the epiphyseal plate cartilage an its replacement by bone.
______ growth increases bone diameter/thickness.
Together, these processes constitute bone remodeling.
Hormonal and mechanical stimuli
What helps the skeleton maintain skeletal strength?
Mechanical stress and gravity
______ are often treated by open or closed reduction.
What is the most frequent cause of Osteomalacia and rickets (soft and deformed bones)?
inadequate vitamin D
________ is any condition in which bone breakdown outpaces bone formation, causing bones to become weak and porous.
T/F Postmenopausal women are particularly susceptible to osteoporosis.
_______ is characterized by excessive and abnormal bone remodeling.
Paget's disease
T/F Longitudinal long bone growth continues until the end of adolescence.
A bone with approximately the same width, length, and height is most likely a______.
short bone
The shaft of a long bone is properly called the______.
The flat bones of the skull develop from_____.
fibrous connective tissue
The remodeling of a bone is the function of which cells?
Osteoblasts and osteoclasts
Bone modeling in adults is directed mainly by ____ and ____.
mechanical stress and PTH
T/F The dividing cartilage cells in the epiphyseal plate are located farthest from the shaft.