Skeletal system

____ ____ function primarily in movement and supporting body weight. They are rod shaped and are longer than they are wide. the extremities of a long bone(______) are covered in articular cartilage, and they are wider than the shaft(_______). most of the bones of the upper and lower limbs are long bones, as are the collar bones.

long bones, epiphyses, diaphysis

_____ ___ are roundish or cube-shaped. They have little to no role in the movement and instead function in support and stability. Examples of short bones include the carpals and tarsals of the worst and ankle, respectively.

short bones

____ ___ are flattened, thin bones that are usually curved, their broad shape is suited for protection, as well as muscle attachment. the scapulae, sternum, ribs, ilia of the pelvic girdle, and certain cranial bones are all flat bones.

flat bones

____ ____ have complex shapes that do not fit the classifications above, and their form is suited to their functions, examples are vertebrate and many facial bones.

irregular bones

_____ ___, such as the kneecap, are found embedded in tendons where there is considerable mechanical stress

sesamoid bones

_______(or cortical) bone is the hard, dense tissue that forms the outer surfaces of bones, as well as the shafts of long bones. it consists of cylindrical structures called ______, also called Haversian systems. Each osteon consists of a central _____ ___ that contains nerve fibers and blood vessels, and these canals connect to each other via _____ ____( or _____ ___). the Haversian canal is surrounded by concentric layers of calcified _______ with small spaces called _____, each of which contains an ________. tiny channels called ______ connect the lacunae to allow oxygen and nutrients to reach the osteocytes, and water to be removed.

compact, Haversian canal, perforating canals, volkmann’s canals, lamellae, lacunae, osteocyte, canaliculi

______(or cancellous) bone is the porous tissue found at the ends of long bones and side the vertebrae and flat bones. it is not as strong or abundant a compact bone, and does not contain osteons. instead, it consists of flattened, interconnected plates called _____. within the spaces of the trabecukae is the ____ ___ __ that produces blood cells. there are no central canals, but osteocytes do reside in lacunae that are connected by canaliculi

spongy, trabeculae, red bone marrow

bone consists of an ______ ____ that surrounds bone cells and function much like reinforced concrete. The matrix consists of about 2/3 _____ ___; mostly calcium phosphate(hydroxyapatite) with calcium carbonate and other minerals. The _____ ____ portion makes uo about 1/3 of the matrix and it consists mainly of collagen, which adds strength and flexibility to the matrix, as well as ground substance proteins such as glycosaminoglycans(GAGs)

extracellular matrix, inorganic matter, organic matter

There are three types of bone cells. ______(derived from osteoprogenitor cells) take calcium from the blood, and produce the matrix(including collagen fibers) that forms bone. when it is completely encased in matrix, the osteoblast differentiates into a mature bone cell called an _______, which are the most abundant bone cells that maintain the matrix by recycling calcium salts. _______ are large multinucleate cells that are formed by the fusion of monocytes(large white blood cells)

osteoblasts, osteocyte, osteoclasts

_____ are locations where two or more elements of the skeleton connect. they can be classified according to structure(material holding the joint together) and function(range of motion)

joints

_______ joints are held together by fibrous connective tissue

Suture: immovable, ex:skull

gomphosis: immovable, ex: teeth/mandible

syndesmosis: slightly movable, ex: distal tibiofibular joint

fibrous

_____ joints held together by cartilage

cartilaginous

Synchondrosis: hyaline cartilage, nearly immovable, ex: first rib/sternum

symphysis: fibrocartilage, slightly moveable, ex: intervertebral discs, pubic symphysis

_____ joint is the most common type of joint; characterized by a joint cavity filled with synovial fluid

synovial

pivot: allows rotation, ex: atlantoaxial joint

hinge: allows movement in one plane ex; knee

saddle: allows pivoting two planes and axial rotation, ex; metacarpal/trapezium

gliding: allows sliding, ex: carpals

condyloid: allows pivoting in two planes but no axial rotation, ex; radoiocarpal joint

ball and socket: have the highest range of motion, ex; hip

______ joint is immovable either fibrous or cartilaginous, ex; skull sutures, teeth/mandible

synarthrosis

_______ joint have a slight range of motion—- either fibrous or cartilaginous, ex; intervertebral discs, distal tibiofibular joint

amphiarthrosis

_________ joint moves freely—- always synovial, ex; wrist, knee, shoulder

diarthrosis

when calcium levels are high, bone forming cells called _______ remove calcium from the blood and deposit it into the bone along with other components of matrix. eventually, these cells become surrounded by the hard, calcium-rich secretion and differentiate into mature bone cells called _______. if blood calcium is low, cells called _____ can break down bone and put calcium back into the blood. in a healthy individual, there is a balance between the amount of calcium deposited and the amount removed. homeostatic imbalances result in hypercalcemia or hypocalcemia

osteoblasts, osteocytes, osteoclasts

a ____ ____ is when the bone breaks but does not puncture through the skin and protrude to the outside. an _____ ___ is when the bone breaks and punctures the skin protruding to the outside of the body. a ____ ___ is when the bone breaks in multiple areas(seen in car accidents and sports). a ____ ___ is when part of the bone bends and does not fully break(seen in kids, bones are flexible and soft). a ____ ___ is when the bone is twisted or rotated like a corkscrew. an _____ ___ is when a tendon or ligament is taxed and pulled too hard causing it to pull away and break the bone. an ___ ___ is a break at an angle caused by the outside force coming at a right angle to the bone. a _____ ___ is when the fracture is perpendicular to the shaft of the bone. a _____ _____ is caused by disease making the bone so weak that is may break without warning simply by putting minimal pressure on it

closed fracture, open fracture, comminuted fracture, greenstick fracture, spiral fracture, avulsion fracture, oblique fracture, transverse fracture, pathological fracture

_______ is a connective tissue with a matrix that is flexible yet resistant to stretching. cartilage is not innervated, nor does it have a blood supply, except for the ________ that forms the surfaces of nearly all cartilage. the immature cartilage cells that secrete the matrix are called _______, which give rise to mature cells called ________ that reside in lacunae

cartilage, perichondrium, chondroblasts, chondrocytes

there are three types of cartilage; ____ ___ is the most common cartilage in the body. it consists of evenly distributed collagen fibrils that explain its glassy appearance. it is found in locations that require strong support with some pliability, such as th ribs, nose, trachea, and articular surfaces. _____ ___ is similar to hyaline cartilage but is more flexible due to the presence of elastic fibers. it is found in the epiglottis and external ear. _____ has collagen arranged into thick fibers, which allows it to withstand tension and compression. IT is found in the jaw, knee, and between vertebrae

Hyaline cartilage, elastic cartilage, fibrocartilage

______ connect bones to bones and help stabilize joints. ______ connect muscles to bones or other structures, such as eyeballs, and facilitate movement. they are both composed of ____ ___ ___ ___, which consists of bundles of collagen fibers as well as elastic fibers. this gives them strength and resistance to stretching. the collagen fibers of tendons are more densely packed than those of ligaments. they are also arranged in parallel bundles, while the fibers of many ligaments are not. tendons are tougher, but ligaments are more elastic. the yellowish color of certain ligaments results from the protein elastin

ligaments, tendons, dense regular connective tissue

the kidneys produce 1,25-hydroxyvitamin D, a biologically active form of vitamin D also known as _____. this hormone regulates levels of calcium by promoting the absorption of dietary calcium in the intestines, which increases the level of calcium in the blood. calcitriol also stimulates osteoclasts to break down bone, which moves calcium into the blood. when blood calcium is high, the peptide hormone _____ is secreted by the parafollicular cells of the thyroid gland. calcitonin inhibits the activity of osteoclasts, and stimulates the activity of bone-forming osteoblasts. when blood calcium is low, parathyroid glands secrete a peptide hormone known as _______ _____. this increases the quantity and also the activity of osteoclasts

calcitriol, calcitonin, parathyroid hormone(PTH)