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Skeletal System
Review for written test on skeletal system
Question | Answer | |||
---|---|---|---|---|
What are the factors influencing the stability of a joint? | shape, size, arrangement of articular surfaces, number & positioning of ligaments, and muscle tone | |||
What are the functional classifications of joints? 1 | synarthroses, amphiarthroses, Diarthroses | |||
What are the structural classifications of joints? 1 | fibrous, cartilaginous, synovial | |||
Name and describe the classifications of fibrous joints 3 | sutures: found only in skull, short connective fibers ossify in adulthood creating bony joint | syndesmoses: sheet of fibrous tissue connects the bone | Gomphosis: found only where teeth are anchored into alveolar socket | |
name and describe the classifications of cartilaginous joints 2 | syncondroses: untied by hyaline cartilage | symphses: united by articular cartilage which is fused to an intervening pad of fibro cartilage | ||
what structures make up the terrible triad 1 | Tibial collateral ligament, medial meniscus, and anterior cruciate ligament | |||
name and describe the types of angular movements 3 | Flexion: angle between bones decreases Extension: angle between bones increases | Hyperextension: beyond normal extension circumduction: combination of flexion, abduction, extension, and adduction so that limb describes a cone in space | abduction: movement away from midline adduction: movement towards midline | |
name and describe the types of special movements 3 | Dorsiflexion: pointing toes up Plantar flexion: pointing toes down supination: moving forearm so that palm faces anteriorly | pronation: moving forearm so that palm faces posteriorly inversion: sole of foot is turned medially eversion: sole of the foot is turned laterally | protraction: forward movement in plane retraction: backward movement in plane elevation: moving superiorly along frontal plant depression: moving inferiorly along frontal plane | |
what is a bursae? 1 | Flattened fibrous sacs lined with synovial membrane and containing a thin film of synovial fluid | |||
what are the 3 types of bone cells? 1 | Osteoblasts, osteocytes, osteoclasts | |||
what are the functions of the skeletal system? 1 | support, protection, movement, storage (fat & minerals), and blood cell formation | |||
describe the steps in intramembranous ossification 3 | 1) Formation of spongy bone within fibrous membrane: usually has only 1 ossification center 2) Osteoblasts secrete matrix which mineralizes and traps the cells into lacunae (osteocytes) | 3) formation of periosteum- mesenchyme condenses on the outside of membrane and becomes the periosteum | 4) Formation of compact bone plates: area between the trabeculae becomes filled with concentric lamellae and becomes mineralized, compact bone encloses medullary cavity | |
Primary ossification 4 | 1) osteoblasts of the periosteum secrete matrix: matrix mineralizes and traps the osteoblasts so that they are now osteocytes: this later of compact bone is called bone collar | 2) Chondrocytes in the shaft hypertrophy and secrete alkaline phosphatase to mineralized the matrix: as the matrix calcifies, nutrients are unable to diffuse in and the chondrocytes die alone with cartilage matrix: cavities form in bone | 3) Cavities are quickly invaded by blood vessels, lymph vessels, nerves, red marrow elements, osteoblasts, and osteoclasts: there are collectively called periosteal bud, osteoblasts secrete matrix to form trabeculae | 4) Ossification centers spread proximally and distally: osteoclasts break down spongy bone to form the medullary cavity 5) at birth, long bones have a bony diaphysis surrounding a medullary cavity the epiphyses are made of cartilage |
secondary ossification 3 | Secondary ossification centers appear in the epiphyses | secondary ossification is the same as primary ossification except that the spongy bone in the interior is retained | when secondary ossification is complete, cartilage remains only as articular cartilage and epiphyseal plate | |
describe longitudinal growth 3 | 1) mitosis occurs at the distal face of the epiphyseal plate 2) chondrocytes at the proximal face hypertrophy and die: the matrix deteriorates | 3) Osteoblasts in the medullary cavity ossify the cartilage spicules to form spongy bone 4) spongy bone is eventually digested by the osteoclasts | the epiphyseal plate will eventually be replaced by bone: growth stops when the bone of the epiphyses and diaphysis fuse | |
what are the ages that longitudinal growth stops? 1 | Females- 18 males-21 | |||
describe appositional growth 3 | 1) osteoblasts beneath the periosteum secrete matrix: grooves on the bone surface form the central canals of the Haversian canals | 2) osteoclasts destroy compact bone closest to the medullary cavity, but slower rate | 3) BC process is slow, it produces stronger, thicker bones, but keeps them from becoming too heavy | |
what four hormones control longitudinal growth 1 | T3, T4, growth hormone, and somatomedin | |||
what is the osteoid seam? 1 | unmineralized band of bone matrix that reveals the site of new matrix deposition | |||
what is the calcification front? 1 | abrupt transition between osteoid seam and old bone | |||
Describe the negative feedback hormonal mechanism that controls bone remodeling 1 | PTH is release from parathyroid glands, inhibits reabsorption, increases CA in blood, stimulates release of Calcitonin, stimulates reabsorption, decreased CA in blood, stimulates release of PTH | |||
what are the normal blood and body calcium levels? 1 | Blood: 9-11 mg/100 ml of blood Body: 1200-1400 g | |||
Describe wolff's law | bone grows or remodels in response to the forces or stressors placed on it | |||
give evidence that supports wolff's law 3 | Long bones are thickest midway along the shaft | Curved bones are thickest where they are most likely to buckle | fetuses and bedridden ppl have featureless bones | |
describe the repair process of bone 1 | 1) hematoma formation 2) fibrocartilaginous callus formation 3) bony callus formation 4) remodeling | |||
spine disorders 2 | Scoliosis: abnormal lateral curvature kyphosis: dorsally exaggerated thoracic curvature Lordosis: accentuated lumber curvature | Herniated disc: usually involved rupture of the annulus fibrosis followed by protrusion of the nucleus pulposis: can press on cord and cause numbness, pain, or destruction of nervous structures | ||
hip dysplasia 1 | Acetabula are incomplete so the heads of femurs can slip out of the hip joints | |||
cleft palate 1 | palatine processes of the maxillae and palatine bones fail to fuse medially can cause aspiration pneumonia | |||
sprain 1 | ligaments reinforcing a joint are stretched or torn | |||
dislocation 1 | bone is forced out of its normal position in a joint cavity | |||
bursitis 1 | inflammation of a bursa caused by excessive stress or friction | |||
tendonitis 1 | inflammation of tendon sheaths | |||
osteomalacia 1 | bones are inadequately mineralized | |||
rickets 1 | osteomalacia in children: causes bowed legs and deformed pelvis | |||
osteoporosis 1 | bone reabsorption outpaces bone deposition: bones become more porous and more susceptible to fracture | |||
paget's disease 1 | excessive and abnormal bone reabsorption and formation: pagetic bone has lots of spongy bone and as much compact bone: eventually osteoclasts cease functioning and causes bone thickening and filly of medullary cavity with bone | |||
3 types of arthritis 1 | Osteoarthritis rheumatoid arthritis gouty arthritis | |||
crepitus 1 | crunching noise resulting from contact of roughened articular surfaces | |||
What is rheumatoid arthritis 1 | Chronic inflammatory disorder: synovial membrane thickens and synovial fluid accumulates causing joint swelling: eventually the cartilage erodes and fibroblasts make fibrous tissue that connects bone ends | |||
(Rheumatoid arthritis) age of onset and symptoms 1 | 30-40 anemia, osteoporosis, muscle atrophy, and cardiovascular problems | |||
pannus 1 | abnormal tissue that clings to the articular cartilage | |||
ankylosis 1 | tissue ossifies and bones become fused | |||
what are the functions of the fontanels? 1 | accommodate brain growth and allow infant head to be compressed during birth | |||
when do the fontanels close? 1 | occipital, sphenoidal, and mastoid close by age 1 and frontal close by age 2 | |||
Primary curvatures 1 | Thoracic and sacral | |||
secondary curvatures and when do they develop? 1 | Cervical: baby holds head up lumbar: baby stands and walks |