LECTURE 5

study of bone tissue as well as the study of the individucal bones of the skeleton

is a major tissue component of the named bones of the body, third hardest substance in the body, hardness comes from high mineral content.

consists of same three general components of other connective tissues: cells, fibers and ground substance.

osteoblasts, osteocytes, and osteoclasts

single nucleated, metabolically active cells found on the surface of bone tissue. They secrete the fibers and the organic part of the ground substance.

the organic part of the matrix of bone, fibers of bone are collagenous in nature and ground substance is a protein/polysaccharide

relatively sedentary cells which are entrapped within the extracellular matrix.  Former osteoblasts which became imprisoned in the products of the own secretion

large, multinucleated cells which are active in bone reabsorption.

most common form of calcium phosphate (which is the mineral portion of bone).  bone mineral s are deposited on the collagenous fibers after the osteoblasts manufacture and extrude them

small cavities in the extracellular matrix. when osteoblasts get imprisoned they become osteocytes. Mitotic division of osteoblasts prevent # from decreasing

alternating layers of entrapped osteocytes and matrix, four types: concentric, interstitial, and external and internal circumferential lamellae

also called osteonal, lamellae that surround neurovascular channels within the cortex of the bone

a neurovascular structure surrounded by a set of concentric (osteonal) lamellae. functional subunits of bone. new osteons are formed after osteoclasts "cut" channels through the bone by reabsorbing it (process called bone remodeling) this process helps maintain proper blood calcium levels

in long bones, the neurovascular passageways where most osteons are longitudinally oriented

(perforating canals) nurovascular passageways that pass through bone perpendicular to the long axis often lacking surrounding lamellae

tiny channels through the lamellae, contain cytoplasmic processes of the osteocytes and allow those located close to the vessels to exchange nutrients and wastes with those located farther from the vessels

incomplete remnants of concentric and external circumferential lamellae

the several layers of lamellae that surround (encase) a whole bone

corresponding layers of lamellae that line the medullary cavities of mature bones

spongy and compact

also called cortical bone, known as dense bone, relatively solid and forms the majority of the substance of most bones

also called "cancellous" bone. consists of slender spicules and reinforcing struts which lend strength w/o excessive bulk. Found btwn inner and outer layers of compact bone of braincase, also on the ends of long bones where it provides reinforcement for overlaying articular surfaces

214, divided into two groups based on position in body. Appendicular and axial skeleton

includes all of the bones associated with the limbs.

the clavicle, scapula, humerus, radius, ulna, eight carpal bones, 5 metacarpal bones, 14 phalanges and two sesamoid bones (at the base of the thumb

os coxae (hip bone), femur bone, patella (a sesamoid bone) tibia, fibula, seven tarsal bones, five metatarsal bones, 14 phalanges and two more sesamoid bones (at base of big toe)

divided into several groups consisting of those found within the head, the vertebral column, ribs, and sternum

include 8 that form the cranial cavity, 14 that form the face, 3 pairs of auditory ossicle and a single hyoid bone

26 components that represent 33 originally separate vertebrae. 12 pairs of ribs and cartilaginous extensions from all but inferior two pairs extend to make direct or indirect contact with sternum

at junction of the appendicular and axial skeletons, some bones from each form the skeletal support for free limbs. these supporting bones comprise the pectoral girdle and the pelvic girdle

supports the free parts of the superior limbs which begin at the shoulders and extend distally. Includes sternum, clavicles and scapulaes

supports free parts of the inferior limbs, begin at the hip joint and extend distally.  includes bony sacrum (irregular bone from the axial skeleton) and right and lift os coxae (flat bones of the appendicular skeleton)

long bones, short bones, flat bones, irregular bones, sesamoid bones

those which are elongated in one dimension, found ONLY IN LIMBS where they act as supporting columns and articulate with each other to form joints and levers for locomotion.  88 long bones (44 pairs) and 56 of them are phalanges

include the 8 carpal bones within each wrist and seven tarsal bones within each ankle. 30 total. Most are somewhat cuboidal in shape

significantly reduced in one dimension, include clavicles, scapulae, ribs, sternum, ossa coxae (bones of the pelvis) and many bones of the head

characterized by jutting processes, include vertebrae and several bones of the head

small (seedlike) bones embedded in some tendons, function as bearing surfaces and protect the tendons from frictional deterioration. largest is patella, total number is 10

end  - a general term applying to only long bones. typically enlarged in comparison to the diaphysis in order to create larger weight-bearing surfaces for articulations (joints)

body - general turn applying to only long bones

envelope of connective tissue proper which all bones are encased in, covers the outer aspects except for articular surfaces, attachments of tendons, ligaments, and joint capsules, and ports of entry of nerves and vessels

composed of collagen,microscopic,  firmly anchors the periosteum to the underlying bone tissue

the hollow, inner portion of the bone

thin layer of connective tissue proper that lines the medullary cavity, houses the bone marrow tissue

bone marrow tissue, actively hemopoietic in young individuals

(fatty) bone marrow which changes yellow with age

bone marrow tissue with senility

the bone tissue btwn the endosteum and periosteum in most areas of most bones which is compact bone. penetrated by neurovascular structures in several locations

nutrient foramen are external openings in the cortex of the bone, the rest of the passageway is called the nutrient canal. They contain nerves and vessels which supply the medullary tissue AND small branches from them form the neurovascular components within the central canals of the osteons

found in freely moving (synovial) joints of the body, a specialized type of hyaline cartilage

34 total: 2 flat bones (clavicle, scapula), 22 long bones (humerus, radius, ulna, 5 metacarpal bones, 14 phalanges), 8 short bones (carpal bones) and two sesamoid bones (base of thumb)

the only point btwn the bones of the superior limb and the axial skeleton

the incomplete ring of skeletal components formed by the two scapulae, two clavicles, and the intervening manubrium of the sternum. supports the free parts of the superior limbs and provides extensive attachments for muscles which attach to the limb to the trunk

most frequently fractured bone in the body, classified as flat bone and resembles a long bone. consists of central body, sternal extremity, acromial extremity and conoid tubercle

triangularly-shaped bone with three named borders (superior, medial, and lateral), three angles (superior, inferior and lateral) , and two surfaces (anterior and posterior)

largest bone in the superior limb, forms the skeleton within the brachium

diaphysis

33 bones form the inferior limb; one flat bone (os coxae), 22 long bones (femur bone, tibia, fibula, five metatarsal bones, 14 phalanges), 7 short bones (tarsal bones) and 3 sesamoid bones

formed by the two ossa coxae and the bony sacrum. supports the free parts of the inferior limbs and is a site of origin for muscles which act on the limb. Passageway through the pelvic girdle is commonly called the "pelvic canal"

degenerative, anomalous, metabolic, neoplastic, infectious, and traumatic... which are the six major etiological categories of disease

degenerative disorder, excessive skeletal demineralization, major problem among the elderly

(anomalous for A in DAMNIT) include complete failure of certain bones to develop and abnormal sizes, positions, and shapes of skeletal components

nutritional and homonal

a metabolic disorder in adults, deficiency in vit D which causes demineralization

that portion of the skeleton associated with the limbs. Includes the clavicles, scapulae, ossa coxae, and all of the bones in the free parts of the limbs

the hyaline cartilage that covers those load bearing surfaces of bones that are involved in synovial joints.

the sternum and ribs, and the bones of the vertebral column and head.  All these bones are flat or irregular in shape

those bones that are obviously flattened in one dimension (sternum, ribs, scapulae, clavicles, ossa coxae, and many bones of the skull)

the principal inorganic component of bone tissue, complex calcium phosphate salt, primary mineral in enamel, cementum, and dentin of teeth

the vertebrae and several bones of the head which have jutting processes. Exact #'s of irregular and flat bones typically not states because some bones have parts that are flat and other portions are irregular

88 long bones; each superior limb (humerus, radius, ulna, 5 metacarpal bones, and 14 phalanges) and each inferior limb (femur bone, tibia, fibula, five metatersal bones, and 14 phalanges)

the space within a bone that contains bone marrow tissue, adipose tissue, and blood.  The connective tissue proper that lines the medullary cavity is called endosteum

the tiny spaces within bone tissue that contain osteocytes. Osteocytes in neighboring lacunae communicate physically and metabolically by extending cytoplasmic processes through tiny passageways called osseous canaliculi

a layer of mineralized osteoid. Those parellel and adjacent to the periosteum and endosteum are called external and internal circumferential lamellae.  Those in the intervening compact bone are called concentric (osteonal) and interstitial lamellae

the non-cellular organic portion of bone tissue. manufactured by osteoblasts and consists of collagenous fibers embedded in a protein/polysaccharide ground substance

the dense, irregular connective tissue proper that forms the outer encasement of the bones.  covers most external surfaces

the carpal and tarsal bones. 30 total, 8 in each wrist and 7 in each ankle

bone tissue formed of small spicules between intervening region of bone marrow tissue.  found within the ends of long bones and also called "cancellous" bone tissue