Osteology Flashcards
The study of bone:
osteology
The skeletal system is composed of _______, ________, and ________ joined tightly to form a strong, flexible _______ for the body. ________, the forerunner of most bones, covers many joint surfaces in the mature skeleton.
bones, cartilages, ligaments, framework, Cartilage
__________ hold bones together at the joints.
ligaments
________ attach muscle to bone.
Tendons
The functions of the skeleton:
Support, protection, movement, electrolyte balance, acid-base balance, blood formation
Support: Bones of the lower limb, pelvis, and vertebral column ____ __ the body; nearly all bones provide support for the _______; the ______ and ______ support the teeth.
hold up, muscles, mandible, maxilla
Protection: Bones enclose and protect the ______, _____ _____, ______, and ______.
brain, spinal cord, heart, lungs
Movement: ______ movements, _______, and other movements are produced by the action of _____ on the bones.
limb, breathing, muscles
Electrolyte balance: the skeleton stores _____ and _____ ___ and releases them into the tissue fluid and blood according to the body’s physiological needs.
calcium, phosphate ions
Acid-base balance: Bone tissue buffers the blood against excessive ___ changes by absorbing or releasing alkaline salts such as calcium phosphate.
pH
Blood formation: ____ bone marrow is the major producer of blood cells, including cells of the immune system.
Red
Bone, or ______ _____, is a connective tissue in which the matrix is hardened by the deposition of ____ _____ and other minerals. The hardening process is called ________ or _________.
osseous tissue, calcium phosphate, mineralization, calcification.
Osseous tissue is only one of the tissues that make up a bone. Also present are ____, bone marrow, cartilage, adipose tissue, ______ tissue, and fibrous connective tissue.
blood, nervous
Osseous tissue continually _______ itself and interacts physiologically with all of the other organ systems of the body.
remodels
Long bones: Much of it is composed of an outer shell of dense white osseous tissue called ______ (______) _______. The cylinder encloses a space called the _________ _______, or _______ ______, which contains bone marrow.
compact (dense) bone, medullary cavity, marrow cavity
Long bones: At the ends of the bone, the central space is occupied by a more loosely organized form of osseous tissue called ______ (______) ______.
spongy (cancellous) bone
The skeleton is about ___ compact bone and ___ spongy bone by weight. Spongy bone is found at the _____ of the long bones and in the ______ of nearly all others. It is always enclosed by more durable ______ _____.
3/4, 1/4, ends, middle, compact bone
<p>
The principle features of a long bone are its shaft, called the \_\_\_\_\_\_\_, and an expanded head at each end called the \_\_\_\_\_\_\_. The \_\_\_\_\_\_ provides leverage, and the \_\_\_\_\_\_ is enlarged to strengthen the joint and provide added surface area for the attachment of tendons and ligaments.</p>
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| diaphysis, epiphysis, diaphysis, epiphysis</p>
Long bones: The joint surface where one bone meets another is covered with a layer of hyaline cartilage called the ____ ____. Together with a lubricating fluid secreted between the bones, this cartilage enable a joint to move ______.
articular cartilage, easily
Long bones: Blood vessels penetrate into the bone through minute holes called ________ ______.
nutrient foramina
Long bones: Externally, a bone is covered with a sheath called the _______. There is no _____ over the articular cartilage.
periosteum, periosteum
Long bones: The internal surface of a bone is lined with _______, a thin layer of reticular connective tissue with cells that dissolve osseous tissue and others that deposit it.
endosteum
In children and adolescents, an _______ _____ of hyaline cartilage separates the marrow spaces of the epiphysis and diaphysis. The ______ _____ is a zone where the bones grow in length.
epiphyseal plate, epiphyseal plate
In adults, the ______ _____ is depleted and the bones can grow no longer, but an ______ ____ marks where the plate used to be. This is also know as the ________ ______.
epiphyseal plate, epiphyseal line, metaphysis region
_____ _____ are conspicuously longer than wide. ____ ____ enclose and protect soft organs and provide broad surfaces for muscle attachment.
Long bones, Flat bones
Boney Prominences: _______: articular surface. ______: sides of joints.
Condyle, Epicondyle
Boney Prominences: ________: openings in bone/tissue. ______: narrow tube/channel.
Foramen, Canal
______ ______:enhance leverage and decrease joint stress.
Sesamoid Bones
Four principle types of bone cells:
osteogenic (osteoprogenator) cells, osteoblasts, osteocytes, osteoclasts
_______ are bone-forming cells. They are roughly cuboidal or angular, and line up in a single layer on the bone surface under the ______ and _______ and resemble a cuboidal epithelium.
Osteoblasts, endosteum, periosteum
________ synthesize the soft organic matter of the bone matrix, which then hardens by mineral deposition. Stress and fractures stimulate osteogenic cells to multiply more rapidly and quickly generate increased numbers of ______, which reinforce or rebuild the bone.
Osteoblasts, osteoblasts
________ are former osteoblasts that have become trapped in the matrix they deposited. They reside in tiny cavities called _______, which are interconnected by slender channels called _______.
Osteocytes, lacunae, canaliculi
_________ have multiple functions. Some resorb bone matrix and others deposit it, so they contribute to the homeostatic maintenance of both bone density and blood concentrations of calcium and phosphate ions. Perhaps even more importantly, they are _____ _____: they secrete biochemical signals that may regulate _____ _____.
Osteocytes, strain sensors, bone remodeling
________ are bone-dissolving cells found on the bone surface. Bone remodeling results from the combined action of these bone-dissolving ________ and bone-depositing _______.
Osteoclasts, osteoclasts, osteoblasts
The matrix of osseous tissue is, by dry weight, about ____ organic and _____ inorganic matter. The organic matter, synthesized by the _______, includes collagen and various protein-carbohydrate complexes such as glycosaminoglycans, proteoglycans, and glycoproteins.
1/3, 2/3, osteoblasts
The matrix of osseous tissue: the inorganic matter is about 85% ________, a crystalized calcium phosphate salt, 10% ______ ______, and lesser amounts of magnesium, sodium, potassium, fluoride, sulfate, carbonate, and hydroxide ions.
hydroxyapatite, calcium carbonate
Bone is in a class of materials that engineers call a ________ – a combination of two basic structural materials, in this case a ceramic and a polymer. A ________ can combine the optimal mechanical properties of each component.
composite, composite
In bone, the polymer is the ______ and the ceramic is the ________ and other minerals. The ceramic components enables a bone to ______ the weight of the body. The protein component gives bone a degree of ______.
collagen, hydroxyapatite, support, flexibility
______ _____ forms the outer shell of all bone and also the shafts in long bones.
Compact bone
The basic structural unit of ____ ____ are long cylinders around a central canal. Helices coil in one direction in one lamella and in the opposite direction in the next lamella for added _____.
compact bone, strength
The skeleton receives about half a liter of blood per minute. Blood vessels, along with nerves, enter the bone tissue through _____ _____ on the surface.
nutrient foramina
Along their length, central canals are joined by transverse or diagonal passages called ______ (_____) ______.
perforating (Volkmann) canals
The inner and outer boundaries of dense bone are arranged in ________ _____ that run parallel to the bone surface. Between osteons, we can find irregular regions called _____ ______, the remains of old osteons that broke down as the bone grew and remodeled itself.
circumferential lamellae, interstitial lamellae
Spongy bone consists of a lattice of delicate slivers of bone called ______ (rods or spines) and ______ (thin plates).
spicules, trabeculae
Although calcified and hard, ____ ____ is named for its spongelike appearance. It is permeated by spaces filled with _____ ______.
spongy bone, bone marrow
The matrix of spongy bone is arranged in lamellae like those of compact bone, but there are few ______. _____ _____ are not needed here because no osteocyte is very far from the marrow.
osteons, Central canals
Spongy bone is well designed to impart ______ to a bone while adding a minimum of ______. Its trabeculae are not randomly arranged as they might seem at a glance, but develop along the bone’s lines of _____.
strength, weight, stress
_______ _______ is a general term for soft tissue that occupies the marrow cavity of a long bone, the spaces amid the trabeculae of spongy bone, and the larger central canals.
Bone marrow
In a child, the marrow cavity of nearly every bone is filled with ____ _____ _____ (______ ____). This is often described as _____ _____ – tissue that produces blood cells – but it is actually composed of multiple tissues in a delicate but intricate arrangement, and is properly considered an organ unto itself.
red bone marrow (myeloid tissue), hemopoietic tissue
In adults, most of the red marrow turns to fatty _____ _____ ______, which no longer produces _____.
yellow bone marrow, blood
In adults, ____ ____ is limited to the skull, vertebrae, ribs, sternum, part of the pelvic (hip) girdle, and the proximal heads of the humerus and femur.
red marrow
The formation of bone is called _______ or ______. In the human fetus and infant, bone develops by two methods called ______ and ______ ______.
ossification, osteogenesis, intramembranous, endochondral ossification.
______ _______: embryonic connective tissue up to the 6th week of fetal development. Fetal cartilage template of skeleton made of _____ _____.
Intramembranous Ossification, fibrous membranes
_______ ______ is a process in which a bone develops from a preexisting model composed of hyaline cartilage.
Endochondral Ossification
_______ ______ begins around the sixth week of fetal development and continues into a person’s 20s.
Endochondral Ossification
Most bones of the body, including the vertebrae, ribs, sternum, scapula, pelvis, and bones of this limbs, develop this way.
Endochondral Ossification
Endochondral Ossification: Blood vessels penetrate the bony collar and invade the primary ossification center. As the center of the model is hollowed out and filled with blood and stem cells, it becomes the _____ _____ _____.
primary marrow cavity
Primary Ossification Center: In the primary marrow cavity, various stem cells introduced with the blood give rise to ____ and ____. ____ line the cavity, begin depositing osteoid tissue, and calcify it to form a temporary network of bony _______.
osteoblasts, osteoclasts, Osteoblasts, trabeculae
Primary Ossification Center: As the bony collar under the periosteum thickens and elongates, a wave of cartilage death progresses toward the _____ of the bones. ______ in the marrow cavity follow this wave, dissolving calcified cartilage remnants and enlarging the marrow cavity of the diaphysis.
ends, Osteoclasts
Primary Ossification Center: The region of transition from cartilage to bone at each end of the primary marrow cavity is called a ______.
metaphysis
Primary Ossification Center: Chondrocyte enlargement and death occur in the epiphysis of the model as well, creating a _______ _______ ______.
secondary ossification center
The secondary ossification center becomes hollowed out by the same process as the diaphysis, generating a _____ _____ _____ in the epiphysis. This cavity expands _____ from the center, in ___ directions.
secondary marrow cavity, outward, all
During infancy and childhood, the ______ fill with spongy bone. Cartilage is then limited to the articular cartilage covering each joint surface, and to an _________ _____, a thin wall of cartilage separating the primary and secondary marrow cavities at one or both ends of the bone. The ____ ____ persists through childhood and adolescence and serves as a growth zone for bone elongation.
epiphyses, epiphyseal plate, epiphyseal plate
By the late teens to early twenties, all remaining cartilage in the ______ ____ is generally consumed and the gap between the ______ and _____ closes. The ____ and ____ marrow cavities then unite into a single cavity, and the bone can no longer grow in length.
epiphyseal plate, epiphysis, diaphysis, primary, secondary
_______ does not end at birth, but continues throughout life with the growth and remodeling of bones. Bones grow in two directions: _____ and ____.
Ossification, length, width
The _______ ______ is a region of transition from cartilage to bone, and functions as a growth zone where the bones elongate.
epiphyseal plate
The epiphyseal plate consists of typical ____ cartilage in the middle, with a transitional zone on each side where cartilage is being replaced by bone. The transitional zone, facing the marrow cavity, is called the ______.
hyaline, metaphysis
Bone elongation is really a result of cartilage growth. Cartilage growth from within, by the multiplication of chondrocytes and deposition of new matrix in the interior, is called _____ _____.
interstitial growth
Bones also continually grow throughout life in diameter and thickness. This involves a process called _____ _____, the deposition of new tissue at the surface.
appositional growth
In addition to their growth, bones are continually ______ throughout life by the absorption of old bone and deposition of new. The process replaces about ___ of the skeletal tissue per year. It repairs microfractures, releases minerals into the blood, and reshapes bones in response to use and disuse.
remodeled, 10%
____ ____ of ____ states that the architecture of a bone is determined by the mechanical stresses placed upon it, and the bone thereby adapts to withstand those stresses.
Wolff’s law of bone
Bone remodeling comes about through the collaborative action of ______ and _____.
osteoblasts, osteoclasts
The most common bone disease is ______, a severe loss of bone density.
osteoporosis
Osteoporosis affects especially ____ ___, since this is more metabolically active than dense bone and has more surface area exposed to bone-dissolving osteoclasts.
spongy bone
In osteoporosis, the bones become _____ and highly subject to pathologic ____ from stresses as slight as sitting down too quickly. Fractures occur especially in the ____, ____, and ____ ___.
brittle, fractures, hip, wrists, vertebral column
In osteoporosis, as the vertebrae lose bone, they become compressed and the spine is often deformed into a condition called ____ (“_____ ____”).
kyphosis, widow’s hump
In osteoporosis, complications of the resulting loss of mobility are ______ and _____.
pneumonia, thrombosis
What types of people are at the greatest risk of osteoporosis?
postmenopausal white women
White women begin loosing bone density as early as age _____. By age 70, the average white woman looses ____ of her bone tissue.
35, 30%
Other than age, race, and sex, some other risk factors for osteoporosis include ______, ______ _____, ___ ____, and inadequate ____ ____ ____.
smoking, diabetes mellitus, poor diet, weight-bearing excercise
Osteoporosis: Until menopause, _____ maintains bone density by inhibiting ______.
estrogen, osteoclasts
Osteoporosis is common in young female athletes. The percentage of body fat is so low that they stop _____ and ovarian _____ _____ is low.
ovulating, estrogen secretion
Treatments for osteoporosis are aimed at slowing the rate of _____ _____. ______ replacement therapy is out of favor because it increases the risk of breast cancer, stroke, and coronary artery disease. The bisphosphonates (Fosamax, Actonel), among the current preferred treatments, act by destroying _______.
bone resorption, Estrogen, osteoclasts
The best treatment for osteoporosis is ______. Exercise and _____ and _____ intake are good bone building tools.
prevention, calcium, vitamin D
Osteoporosis drug side effects include:
osteonecrosis of the jaw, atypical fractures of the femur, gastric ulcers, and thick brittle bones.
