Types of Within the Cartilage Bones Bone & Joints Functions BONUS10 Point 10 Point 10 Point 10 Point 10 Point20 Points 20 Points 20 Points 20 Points 20 Points30 Points 30 Points 30 Points 30 Points 30 Points40 Points 40 Points 40 Points 40 Points 40 Points50 Points 50 Points 50 Points 50 Points 50 Points
Long bones which are easily identified because of their extended longitudinal axes; an example is the femur of the thigh and Humerus of the arm Short bones are often described as cube- or box- shaped structures, which are as broad as they are long; an example is the carpals (wrist) and ankle bones (tarsal) Flat bones are generally broad and thin with a flattened and often curved surface; an example is the scapula and the sternumIrregular bones are often clustered in groups and come in various size and shapes; an example is the patella (1)
Inorganic Salts: the calcified nature and thus the hardness of bone results from the deposition of highly specialized chemical crystals of calcium and phosphate, called hydroxyapatite.Organic Matrix: is part of the bone and otherconnective tissues is a composite of collagenousfibers and an amorphous mixture of protein andpolysaccharides called ground substances. Theground substance of bone provides support andadhesion between cellular and fibrous elements andalso serves an active role in many cellularmetabolic functions necessary for growth, repair,and remodeling (1)
A bone fracture invariably tears and destroys blood vessels that carry nutrients to osteocytes. It’s this vasculardamage that initiates the repair sequence. Eventually, deadbone is either removed by osteoclastic resorption or serves as a scaffolding or framework for the deposition of a specialized repair tissue called callus.(1)
What is the first step of Bonefracture repair?
Vascular damage occurring immediately after a fractureresults in hemorrhage and the pooling of blood at the point of injury. The resulting blood clot is called a fracturehemotoma. As the hematoma is resorbed, the formation of specialized callus tissues occurs. It serves to bind the broken ends of the fracture on both the outside surface and along the marrow cavity internally. The rapidly growing callus tissue effectively “collars” the broken ends and stabilizes the fracture so that healing can proceed. If the fracture is properly aligned and immobilized and if complications do not develop, callus tissue will be actively “modeled” and eventually replaced with normal bone as the injury heals completely. (1)
What is the second step to bone fracture repair?
A new synthetic skeletal repair material called vitos is now available to facilitate fracture repair. It consists of a calcium sponge like matrix material riddled with microscopic holes. Vitos assists callus tissue in stabilizing the fracture site and in movement of bone repair cells andnutrients into the injured area. This new synthetic material is useful not only in treatment of fractures, but also in reducing the need for expensive and often surgically difficult bone grafts. Unlike metal stabilizers, vitos “patches” degrade naturally in the body after repair and do not require surgical removal. (1)
Endochondral ossification, is one of the two essential processes during fetal development of the mammalian skeletal system by which bone tissue is created. Unlikeintramembranous ossification, which is the other process by which bone tissue is created, cartilage is present during endochondral ossification. It is also an essentialprocess during the rudimentary formation of long bones, the growth of the length of long bones, and the natural healing of bone fractures. (22)
Osteoblasts: are small cells that synthesize and secrete specialized organic matrix, called osteoid, which is an important part of the ground substance of the bone. Osteoclasts: are giant multinucleate cells that are responsible for the active erosion of bone minerals. They are formed by fusion of several precursor cells and contain large numbers of mitochondria and lysosomesOsteocytes: are mature, non-dividing osteoblasts that have become surrounded by matrix and now lie within the lacunae. (1)
In intramembranous ossification, groups of cells in themembrane differentiate into osteoblasts. They secrete matrixmaterial and collagenous fibers. The Golgi apparatus of theseosteoblasts secrete a compound called mucopolysaccharide, andthe endoplasmic reticulum secretes collagen. Large amounts ofground substance accumulate around each osteoblast, andnumerous collagen fibers become embedded in the groundsubstance. This constitutes the organic matrix. As the matrixcalcifies, the trabeculae join in a network to form spongy bone.Eventually, the spongy bone will be covered by plates of compactbone. (1)
What is the development ofintramembranous ossification?
Lamellae: Concentric, cylinder- shaped layers of calcified matrix Lacunae: small spaces containing tissue fluid in which bone cells lie imprisoned between the hard layers of the lamellae Canaliculi: ultra-small canals radiating in all directions from the lacunae and connecting them to each other and into a larger canal, the Haversian canal Haversian Canal: extends lengthwise through the center of each Haversian system; contains blood vessels, and nerves from the Haversian canal; nutrients and oxygen movethrough the Canaliculi to the lacunae and their bone cells- a short distance about 0.1 mm or less (1)
What are themajor components of the Haversian Sys.?
Bone-Bones grow in diameter by the combined action of osteoclasts and osteoblasts. Osteoclasts enlarge the diameter of the medullary cavity. Osteoblasts from theperiosteum build new bone around the outside of the bone. (208)
Hyaline- Is the most common cartilage and has a glassyappearance, it covers the articular surfaces of bones. Formsthe costal cartilages, cartilage rings in the trachea, bronchi of the lungs and the tip of the nose. It forms fromspecialized cells in centers of chondrification, which secrete matrix material.(208) Elastic- forms the external ear, Epiglottis and Eustachian tubes. Large number of elastic fibers confers elasticity and resiliency.(208)Fibro- Occurs in symphysis pubis and intervertebral disks, small quantities of matrix and abundant fibrous elements, Fibrocartilage are strong and rigid. (208-209)
Cartilage- There is 2 different types of growth with cartilage Interstitial or endogenous growth and Appositional or exogenous growth. Interstitial growth is when the cartilage cells divide and secrete additional matrix, it is seen during childhood and early adolescencewhile cartilage is still soft and capable of expansion within. Appositional growth is when the chondrocytes in the deeplayer of the perichondrium divide and secrete matrix. New matrix is deposited on the surface, increasing its size. It is unusual in early childhood, but once initiated, continues throughout life. (209)
Structural- joints are named according to the type of connective tissue that joins bones together (fibrous or cartilaginous joints) and the presence of a fluid-filled joint capsule (synovoial joint) (275) Functional classification- joints are named according to degree of movement allowed. Synarthroses- immovablejoint. Amphiarthroses-slightly moveable. Diarthroses- freely moveable (275) Synovial joints- are freely movable joints
Cartilage: Collagenous fibers embedded in a rubbery ground-substance called Chondrin, which is a protein- carbohydrate complex. The chondron is secreted by chondrocytes. Bone: mineralized connective tissue. Cells called osteocytes deposit a matrix of collagen and calcium-phosphate which harden to form crystals of a substance called hydroxyapatite. Mammalian bone is constructed fromrepeated units called Haversian Units.The process of making new bone is called ossification. (23)
What are thestructural units of Cartilage and Bone?
Support- bones serve as the supporting framework of the body,much as steel girders are the supporting framework of our modernbuildings. They contribute to the shape, alignment, and positioningof the body parts.(1)
Mineral storage- bones serve as the major reservoir for calcium, phosphorus, and certain other minerals. Homeostasis of blood calcium concentration- essential for healthy survival- depends largely on changes in the rate of calcium movement between the blood and bones. If, for example, blood calcium concentration increases above normal, calcium moves more rapidly out of the blood intobones and more slowlu in the opposite direction. The result? Blood calcium concentration decreases- usually to its homeostatic level(1)
Hematopoiesis- or blood cell formation is a vital processcarried on but red bone marrow or myeloid tissue. Myeloid tissue in the adult is located primarily in the ends, or epiphyses, of certain long bones, in the flat bones of the skull, in the pelvis, and in the sternum and ribs.(1)
Hinge- elbow joint, spool-shaped process fits into concave sockets, Flexion and Extension onlyPivot- Joint between 1st and 2nd cervical vertebrae, arch- shaped process firsts around peglike process, Rotation
Saddle- Thumb joint between first metacarpal and carpalbones, Saddle-shaped bone fits into socket that is concave- covex-cocave, FlexionCondyloid- Joint between the radius and carpal bones, oval condyle fits into elliptical socket, Flexion
Ball and socket- Shoulder joint and hip, Ball-shaped process fits into concave socket, widest range of movements Gliding- joints between articular facts or adjacent vertebrae; joints between carpal and tarsal bones, relatively flat articulating surfaces.
Mineral Storage: Normally this bone function is responsible for maintaining the homeostatic level of bloodcalcium. If there is too much calcium in the blood, calcium is stored in the bone. If there is too little calcium in the blood calcium is removed from the blood. Hematopoiesis: This bone function is responsible for the formation of blood cells. This function is carried out by the myeloid tissue or bone marrow. (1)
Which two bone functions areinterrupted by osteoporosis?
Epiphyseal plates are areas of developing cartilage tissuenear the ends of long bones. The plates regulate and helps determine the length and shape of a mature bone. Since children’s bones are still growing, when the plate isbroken it is very likely that their limbs will be crooked or of unequal length.
Why is a bone fracture along the epiphyseal plateharmful to childrenand young adults?
With aging comes bone loss, because the body producescells which absorb bones. They become thinner and more porous. Two inches of height are lost for the reason that compression of vertebrae, changes in posture, and increased curvature of the hips and knees take place.Osteoporosis is one which has the leading role to much of these bone degenerations.
What are the changes of theskeletal system for older adults and how does it affect them?