Skeletal System PDF

Osseous Tissue & the Skeletal System FUNCTIONS OF BONE: There are seven important functions of bones: 1. _______________________ Support For body and soft organs 2. _______________________ Protection...

Osseous Tissue & the Skeletal System FUNCTIONS OF BONE: There are seven important functions of bones: 1. _______________________ Support For body and soft organs 2. _______________________ Protection ___________________ Protect brain, spinal cord, and vital organs 3. _______________________ Movement Levers for muscle ___________________ action Mineral and growth factor 4. _______________________ storage ___________________and Calcium ___________________, phosphorus and growth factors reservoir 5. _______________________ Blood Cell formation _______________________occurs Hematopoiesis in ___________________ red marrow cavities of certain bones 6. _______________________ Triglyceride (fat) storage ___________________ Fat , used for an energy source, is stored in bone ___________________ cavitives 7. _______________________ Hormone _______________________secreted Osteocalcin by bones helps to ___________________insulin regulate secretion, glucose levels, and metabolism CLASSIFICATION OF BONES: ___________________named 206 bones in human skeleton Divided into _________________ two groups based on location 1. ______________________________________________ Axial Skelton ___________________ Long axis of body ___________________, Skull ______________________________________, vertebral column ___________________ rib cage 2. ______________________________________________ Apppendicular skelton Bones of ___________________and upper ______________________________________ lower limbs ___________________attaching Girdles limbs to axial skeleton Bones are also classified according to one of four ___________________: shapes 1. _______________________ Long Bones ___________________than longer they are wide ___________________bones llimb 2. _______________________ Short Bones ______________________________________bones cube-shaped (in wrist and ankle) _______________________bones Seamoid form within tendons (example: patella) Vary in ___________________and size ___________________in number different individuals 3. _______________________ Flat Bones ___________________, Thin ___________________, slightly ___________________ Flat Curved  ___________________, Sternum ___________________, Scapulae ___________________, ribs most ___________________ skull bones 4. _______________________ Irregular ___________________shapes Complicated ___________________and Vertebrae ___________________bones Hip BONE STRUCTURE: Bones are ___________________because organs they contain different types of ___________________ tissues – ______________________________________ Bones (ossesous) tissue predominates, but a bone also has ___________________ nervous tissue, ___________________, cartilage ______________________________________ fibrous tissue, ___________________cells, muscle and ___________________cells epithelial in its blood vessels ______________ Three levels of structure – _______________________ Gross – _______________________ Microscopic – _______________________ Chemical GROSS ANATOMY: ___________________and Compact ___________________bone Spongy – ___________________bone: Compact dense ___________________ outer layer on every bone that appears ___________________ smooth and ___________________ solid  – ___________________ Spongy bone: made up of a ___________________ honeycomb of small, needle-like or flat pieces of bone called ___________ trabeculae ___________________ open spaces between trabeculae are filled with ______________________________________ red or yellow bone marrow Structure of ___________________, short ___________________, irregular and ___________________bones flat – Consist of thin ___________________of plates spongy bone (___________________ diploe )covered by ___________________bone compact – Compact bone ___________________between sandwiched ___________________tissue connective membranes _______________________covers Periosteum ___________________of outside compact bone, and _______________________covers endosteum ___________________portion inside of compact bone – Bone ___________________is marrow scattered throughout ___________________ spongy bone; no ___________________ defined marrow cavity – _______________________covers Hyaline Cartilage area of bone that is part of a ___________________ movable joint Structure of typical ___________________bone long – All long bones have a ___________________________________, shaft (diaphysis) _______________________________, bone ends (epiphyses) and _______________________ membrane _______________________: Diaphysis ___________________ tubular shaft that forms long axis of bone – Consists of ___________________bone compact surrounding central ___________________ medullary cavity that is filled with _______________________ yellow marrow in adults _______________________: Epiphyses ends of long bones that consist of compact bone ___________________ externally and spongy bone ___________________ internally  – Articular ___________________covers cartilage articular ___________________ joint surfaces Between ___________________ diaphysis and ___________________ epiphysis is _______________________ epiphyseal lines – Remnant of childhood _______________________where eiphyseal plate bone ___________________ growth occurs Membranes: two types (______________________________________________) periosteum and endosteum – _______________________: Periosteum white, double-layered membrane that covers ___________________ external surfaces except joints _______________________: Fibrous Layer ___________________layer outer consisting of dense irregular connective tissue consisting of _______________________that Sharpey’s fibers secure to bone matrix _______________________: Osteogenic Layer ___________________ inner layer touching bone and containing primitive ______________________________________________ osteogenic stem cells that gives rise to most all bone cells Contains many ___________________ nerve fibers and ___________________ blood vessels that continue on to the shaft ___________________ Anchorning points for tendons and ligaments – _______________________ Endosteum ___________________ Delicate connective tissue membrane covering ___________________ internal bone surface Covers ___________________of trabeculae spongy bone Lines ___________________ canals that pass through ___________________bone compact  Like periosteum, contains osteogenic cells that can differentiate into other bone cells ___________________ Hematopoietic tissue in bones – _______________________is Red marrow found within trabecular cavities of ___________________bone spongy and _______________________of diploe flat bones, such as ___________________ sternum In newborns, _______________________and medullary cavities all spongy bone contain ___________________ red marrow marrow In adults, ___________________ red marrow is located in heads of __________________________________________, femur and humerus but most active areas of hematopoiesis are flat bone ___________________ diploe and some ___________________ irregular bones (such as the hip bone) ___________________ Yellow marrow can convert to red, if person becomes ___________________ anemic Bone ___________________ Markings – Sites of ___________________, muslce ___________________, and ___________________ ligmaments tendon attachment on ___________________surfaces external – Areas involved in ___________________ joint formation or ___________________ conduits for blood vessels and nerves – Three types of markings: _______________________: Projection outward bulge of bone – May be due to ___________________ increased stress from muscle pull or is a ___________________ modificatiion for joints _______________________: Depression bowl- or groove-like cut-out that can serve as ___________________ passageways for vessels and nerves, or plays a role in joints  _______________________: Opening hole or canal in bone that serves as ___________________for passageways blood vessels and nerves MICROSCOPIC ANATOMY: ___________________ Cells of bone tissue – ___________________ Five major cell types, each of which is a specialized form of the ______________________________________ same basic cell type 1. _______________________ Osteogenic Cells – Also called ___________________ Osteoprogenitor cells – ___________________ Mitotically active stem cells in ___________________ periosteum and ___________________ endosteum – When ___________________, stimulated they ___________________ differentiate into osteoblasts or bone-lining cells – Some remain as osteogenic ___________________ stem cells 2. _______________________ Osteoblasts – Bone-forming cells that ___________________ secrete unmineralized bone matrix called _______________________ osteoid _______________________is Osteoid made up of ___________________ collagen and ___________________ calcium -binding proteins Collagen makes up ___________________ 90% of bone ___________________ proteins – Osteoblasts are actively ___________________ mitotic 3. _______________________ Osteocytes  – ___________________ Mature bone cells in lacunae that no longer ___________________ divide – ___________________ Miantaining bone matrix and act as stress or strain ___________________ sensors Respond to ___________________ mechanical stimuli such as ___________________ increased force on bone or ___________________ weightless Communicate information to _______________________and osteoblasts _______________________ osteoclasts (cells that destroy bone) so bone ___________________ remodeling can occur 4. _______________________ Bone-lining cells – ___________________ Flat cells on bone surfaces believed to also help ___________________ maintain matrix (along with ___________________) osteocytes – On ___________________ external bone surface, ___________________ lining cells are called _______________________ periosteal cells – On ___________________ internal surfaces, they are called _______________________ endosteal cells 5. Osteoclast _______________________ – Derived from same ___________________ hematopoietic stem cells that become ___________________ macrophages – ___________________, Giant ___________________ multinucleate cells function in ______________________________________________ bone resorption (breakdown of bone) – Cells have ___________________ ruffled borders that serve to ___________________ increase surface area for enzyme ___________________ degradation of bone ___________________ Compact bone – Also called ___________________ lamellar bone  – Consists of: Osteon (Haversian system) Canals and canaliculi ___________________ Interstitial and ___________________ circumferential lamellae 1. ___________________ Osteon (___________________ Haversian system) – An osteon is the ___________________ Structual unit of ___________________ copact bone – Consists of an ___________________ elongated cylinder that runs ___________________ parallel to long axis of bone Acts as tiny ______________________________________ weight-bearing pillars – An osteon cylinder consists of several ___________________ rings of bone matrix called ___________________ lamellae Lamellae contain ___________________ collagen fibers fibers that run in different ___________________ directions in adjacent rings Withstands ___________________ stress and resist ___________________ twisting Bone ___________________ salts are found between ___________________ collagen fibers 2. ___________________ Canals and ___________________ canaliculi – ___________________ central (___________________) haversian canal runs through core of ___________________ osteon Contains ______________________________________ blood vessels and nerve fibers  – ___________________ Perforating (___________________) Volkmann’s canals: canals lined with ___________________ endosteum that occur at ___________________ right angles to central canal ___________________ connect blood vessels and nerves of ___________________, periosteum _____________________________________, medullary cavity and ___________________ central canal – ___________________: Lacunae small cavities that contain ___________________ osteocytes – ___________________ Canaliculi : hair-like canals that connect ___________________ lacunae to each other and to ___________________ central canal 3. ___________________ Interstitial and ___________________ circumferentail lamellae – ___________________ Interstitial lamellae Lamellae that are not part of ___________________ osteon Some fill gaps between forming ___________________; osteons others are ___________________ remnants of osteons cut by bone ___________________ remodeling – ___________________ Circumferential lamellae Just deep to ___________________, periosteum but superficial to ___________________, endosteum these layers of lamellae extend around ___________________ entire surface of diaphysis Help long bone to resist ___________________ twisting CHEMICAL COMPOSITION: Bone is made up of both ___________________ organic and ___________________ inorganic components – ___________________ Organic components Includes ___________________ ostrogenic cells, ___________________, oteoblasts ___________________, osteocytes bone- lining cells, ___________________, osteoclasts and ___________________ osteoid  – Osteoid, which makes up ___________________ one-third of organic bone matrix, is ___________________ secreted by osteoblasts Consists of _____________________________________ ground substance and ______________________________________ collagen fibers , which contribute to ___________________ high tensile strength and ___________________ flexibilty of bone – ___________________ Inorganic components ___________________ Hydroxyapatities (mineral salts) – Makeup ___________________ 65% of bone by mass – Consist mainly of tiny ______________________________________ calcium phosphate crystals in and around ___________________ collagen fibers – Responsible for ___________________ hardness and ___________________ resistance to compression Bone is half as strong as steel in ___________________ resisting compression and as strong as steel in resisting ___________________ tension Lasts long after ___________________ death because of ___________________ mineral composition Can reveal ___________________ information about ___________________ ancient people SKELETAL CARTILAGES: The human skeleton initially consists of just ___________________, which is replaced by ___________________ , except in areas requiring ___________________ ___________________ cartilage: made of highly ___________________, molded cartilage tissue that consists primarily of ___________________ – Contains ______________________________________ or ___________________  ___________________: layer of dense connective tissue surrounding ___________________ like a ___________________ – Helps cartilage resist ____________________________________ – Contains blood vessels for nutrient ___________________ to ___________________ Cartilage is made up of ___________________, cells encased in small cavities (lacunae) within jelly-like ______________________________________ Cartilage grows in ___________________ ways: – ___________________ growth Cartilage-forming cells in ___________________ secrete matrix against ___________________ face of existing cartilage – New matrix laid down on ___________________ of cartilage – ______________________________________ Chondrocytes within lacunae ___________________ and ___________________ new matrix, expanding cartilage from within – New matrix made ___________________ cartilage BONE DEVELOPMENT: ___________________ Ossification (___________________) osteogenesis is the process of bone tissue ___________________ formation – Formation of bony skeleton begins in ___________________ month 2 of development – ___________________ postnatal bone growth occurs until early adulthood – Bone remodeling and repair are ___________________ lifelong FORMATION OF THE BONY SKELETON: Up to about week 8, ___________________ fibrous membranes and ___________________ hyaline cartilage cartilage of fetal skeleton are replaced with ___________________ bone tissue There are _________ two methods of ossification: 1. ___________________ Endochondral ossification – Forms essentially all bones ___________________ inferior to base of skull, except ___________________ clavicles – Begins ___________________ late in month 2 of development – Uses ___________________ previously formed hyaline cartilage models – Requires ___________________ breakdown of hyaline cartilage prior to ossification – Begins at ________________________________________________________ primary oddification center in center of shaft Blood vessels infiltrate ___________________, perichondrium converting it to ___________________ periosteum ___________________ Mesenchymal cells specialize into osteoblasts – ____________ five main steps in the process of ossification: 1. Bone collar forms around ___________________ diaphysis of cartilage model 2. Central cartilage in diaphysis ___________________, calcifies then develops ___________________ cavities 3. ___________________ Periosteal bud invades cavities, leading to formation of ___________________ spongy bone – Bud is made up of blood vessels, ___________________ nerves , red marrow, ___________________ osteogenic cells, and ___________________ osteoclast 4. Diaphysis ___________________, elongates and ___________________ medullary cavity forms  – ___________________ Secondary ossification centers appear in ___________________ epiphyses 5. ___________________ Epiphyses ossify ossify – Hyaline cartilage remains only in ___________________ epiphyseal plates and ___________________ articular cartilages 2. ___________________ Intramembranous ossification – Begins within ___________________ fibrous connective tissue membranes formed by ___________________ mesenchymal cells cells – Forms ___________________, frontal ___________________, parietal occipital ___________________, temporal ___________________, and ___________________ clavicle bones bones – ____________ Four major steps are involved: centers 1. Ossification ___________________ cluster are formed when mesenchymal cells ___________________ and become ___________________ osteoblast 2. Osteoid is ___________________, secreted then ___________________ calcified 3. ___________________ Spongy bone is formed when osteoid is laid down around blood vessels, resulting in ___________________ trabeculae Mesenchyme ___________________ periosteum layer of woven bone forms ___________________ 4. ___________________ Compact red bone replaces woven bone, and ___________________ marrow appears GROWTH IN LENGTH OF LONG BONES: Long bones grow ___________________ lengthwise by interstitial (longitudinal) growth of ___________________ epiphyseal plate plate epiphyseal Interstitial growth requires presence of ___________________ epiphyseal cartilage in the ___________________ plate  Epiphyseal plate consists of ___________________ five zones: 1. ___________________ Resting Zone zone – Area of cartilage on epiphyseal side of epiphyseal plate that is relatively ___________________ inactive 2. ___________________ Proliferation zone – Area of cartilage on diaphysis side of epiphyseal plate that is rapidly ___________________ dividing – New cells formed move ___________________, upward pushing epiphysis away from diaphysis, causing ___________________ lengthening 3. ___________________ Hypertrophic zone – Area with older ___________________ chondrocytes closer to diaphysis – Cartilage lacunae ___________________ enlarge and ___________________, erode forming interconnecting spaces 4. ___________________ Calcification zone – Surrounding cartilage matrix ___________________; calcifies chondrocytes ___________________ die and ___________________ deteriorate 5. ___________________ Ossification zone – Chondrocyte ___________________ deterioration leaves long ___________________ spicules of calcified cartilage at epiphysis-diaphysis junction – Spicules are then ___________________ eroded by osteoclasts and are ___________________ covered with new bone by osteoblasts – Ultimately replaced with ___________________ spongy bone  Near end of ___________________, adolescence chondroblasts divide ___________________ less often Epiphyseal plate ___________________, thins then is ___________________ replaced by bone ______________________________________ Epiphyseal plate closure occurs when epiphysis and diaphysis ___________________ fuse Bone lengthening ___________________ caeses – Females: occurs around ___________________ 18 years years of age – Males: occurs around ___________________ 21 years years of age GROWTH IN WIDTH OF BONES: Growing bones ___________________ widen as they ___________________ lengthen through appositional growth – Can occur ___________________ throughout life Bones ___________________ thicken in response to ___________________ increased stress from muscle activity or added ___________________ weight Osteoblasts beneath periosteum ___________________ secrete bone matrix on external bone Osteoclasts ___________________ remove bone on endosteal surface Usually more ___________________ building up than ______________________________________ breaking down which leads to thicker, stronger bone that is not too ___________________ heavy HORMONE REGULATION OF BONE GROWTH: ___________________ Growth hormone: most important hormone in ___________________ stimulating epiphyseal plate activity in infancy and childhood  ___________________ Thyroid hormone: ___________________ modulates activity of growth hormone, ensuring proper proportions ___________________ Testesterone (males) and ___________________ estrogens (females) at puberty: promote adolescent growth spurts – ___________________ end growth by ___________________ inducing epiphyseal plate closure ___________________ Excesses or ___________________ deficits of any hormones cause ___________________ abnormal skeletal growth BONE REMODELING: About ___________________ 5-7% of bone mass is recycled each ___________________ week – Spongy bone replaced ~ every ___________________ 3-4 years – Compact bone replaced ~ every ___________________ 10 years ___________________ Bone remodeling consists of both bone ___________________ deposit and bone ___________________ resorption – Occurs at surfaces of both ___________________ periosteum and ___________________ endosteum – ___________________ Remodeling units: packets of adjacent ___________________ osteoblast and ___________________ osteoclast coordinate remodeling process BONE DEPOSIT: ___________________ Deposti of new bone matrix is done by ___________________ osteoblasts ___________________ Trigger for deposit not confirmed but may include: – ___________________ Mechanical signals  – ______________________________________ Increased concentrations of calcium and phosphate ions – Matrix proteins that ___________________ bind and ___________________ concentrate calcium – Appropriate amount of ___________________ enzyme alkaline phosphatase for ___________________ mineeralization BONE RESORPTION: ___________________ Resorption is function of ___________________ osteoclasts – Dig ___________________ depressions or ___________________ grooves as they break down matrix – ___________________ secrete lysosomal enzymes and protons (H+) that ___________________ digest matrix – ___________________ Acidity converts calcium salts to ___________________ soluble forms Osteoclasts also phagocytize ___________________ demineralized matrix and ___________________ dead osteocytes – Digested products are ___________________ transcytosed across cell and released into ___________________ interstitial fluid and then into ___________________ blood – Once ___________________ resorption is complete, osteoclasts undergo ___________________ apoptosis (controlled cell death) CONTROL OF REMODELING: Remodeling occurs ___________________ continuously but is regulated by ___________________ genetic factors and ___________________ two control loops 1. ___________________ Hormonal controls – ___________________ Parathyroid hormone (___________________): PTH produced by ___________________ parathyroid glands in response to ______________________________________ low blood calcium levels Stimulates ___________________ osteoclasts to resorb bone  ___________________ Calcium is released into blood, raising levels PTH ___________________ secretion stops when homeostatic ___________________ calcium levels are reached – ___________________: Calcitonin produced by ___________________ parafollicular cells of thyroid gland in response to ______________________________________ high levels of blood calcium levels Effects are ___________________, negligible but at high pharmacological doses it can lower blood calcium levels ___________________ temporarily 2. _____________________________________ Response to mechanical stress – Bones reflect ___________________ stressese they encounter Bones are stressed when ___________________ weight bears on them or ___________________ muscles pull on them – ___________________ Wolf’s Law states that bones ___________________ grow or ___________________ remodel in response to ___________________ demands placed on them Stress is usually off ___________________, center so bones tend to ___________________ bend ___________________ Bending compresses one side, ___________________ stretches other side – ___________________ Diaphysis is thickest where bending stresses are ___________________ greatest ___________________ Handedness (right- or left-handed) results in ___________________ thicker and ___________________ stronger bone of the corresponding upper limb Curved bones are ___________________ thickest where most likely to ___________________ buckle Trabeculae form ___________________ trusses along lines of stress Large, bony ___________________ projections occur where ___________________, heavy ___________________ active muscles attach  – Weight lifters have enormous thickenings at muscle attachment ___________________ sites of ___________________ most used muscles Bones of ___________________ fetis and ___________________ bedridden people are featureless because of lack of ___________________ stress on bones Mechanical stress causes ___________________ remodelign by producing electrical signals ______________________________________ when bone is deformed Hormonal controls determine ___________________ whether and ___________________ when remodeling occurs in response to changing blood ___________________ calcium levels, but mechanical stress determines ___________________ determines it occurs FRACTURES: ___________________ Fractures are breaks in bone – During youth, most fractures result from ___________________ trauma – In old age, most result from ___________________ weakness of bone due to bone v thinning ___________________ Three fracture classifications: 1. Position of bone ends ___________________ after fracture ___________________: Nondisplaced ends retain normal position ___________________: Displaced ends are out of normal alignment 2. ___________________ Competeness of break ___________________: Complete broken all the way through Incomplete ___________________: not broken all the way through  3. Whether skin is ___________________ penetrated ___________________ Open (___________________): compound skin is penetrated ___________________ Closed (___________________): simple skin is not penetrated BONE REPAIR-FRACTURES: Treatment involves ___________________, reduction the ___________________ realignment of broken bone ends – ___________________ Closed reduction: physician ___________________ manipulates to correct position – ___________________ Open reduction: surgical ___________________ pins or wires secure ends – ___________________ Immobilization of bone by cast or traction is needed for healing ___________________ Time needed for repair depends on break ___________________, severity ______________________________________, bone broken and ___________________ age of patient Repair involves ___________________ four major stages: 1. ___________________ Hematoma formation – Torn blood vessels ___________________, hemorrhage forming mass of ___________________ clotted blood called a ___________________ hematoma – Site is ___________________, swollen ___________________, painful and ___________________ inflames 2. ___________________ Fibrocartilaginous. callus ___________________ formation – Capillaries grow into ___________________ hematoma – ___________________ Phagocytic cells clear debris – Fibroblasts ___________________ secrete collagen fibers to span break and connect ___________________ broken ends  – ___________________, Fibroblasts ___________________, cartilage and ___________________ osteogenic cells begin reconstruction of bone – This mass of repair tissue is called ______________________________________ fibrocartilaginous callus 3. ___________________ Bony Callus Formation ___________________ formation – Within ___________________, one week new ___________________ trabeculae appear in fibrocartilaginous callus – Callus is converted to ___________________ bony (hard) callus ___________________ of spongy bone – Bony callus formation continues for about ___________________ 2 monthes until firm union forms 4. ___________________ Bone remodeling ___________________ – Begins during ___________________ bony callus ___________________ formation and continues for ______________________________________ several months – Excess material on diaphysis ___________________ exterior and ___________________ within medullary cavity is ___________________ removed – ___________________ Compact bone is laid down to ___________________ reconstruct shaft walls – ___________________ Final Structure structure resembles ___________________ orgiginal structure Responds to same ___________________ mechanical stressors BONE DISORDERS: ___________________ Imbalences between bone ___________________ deposti and bone ___________________ resorption underlie nearly every disease that affects the human skeleton.  Three major bone diseases: ___________________ Osteomalacia and rickets – Bones are poorly ___________________ mineralized – Osteoid is ___________________, produced but calcium salts not adequately ___________________ deposited – Results in ___________________, soft ___________________ weak bones ___________________ Rickets (osteomalacia of children) – Results in ___________________ bowed legs and other bone ___________________ deformities because bones ends are ___________________ enlarged and abnormally ___________________ long – Cause: vitamin D ___________________ deficiency or ___________________ insufficient dietary ___________________ calcium ___________________ Osteoporosis – a group of diseases in which bone ___________________ resorption exceeds ___________________ deposit – Matrix remains ___________________, normal but bone mass ___________________ declines – Most often seen in ___________________, aged ___________________ postmenopausal women ___________________ Estrogen plays a role in bone density, so when levels drop at ___________________, menopause women run higher risk – Additional risk factors for ___________________: osteoporosis ___________________ Petite body form ___________________ Insufficient exercise to stress bones Diet poor in ___________________ calcium and ___________________ protein  ___________________ smoking ___________________ Hormone -related conditions ___________________ Immobility Males with ___________________ prostate cancer taking ___________________ androgen -suppressing drugs ___________________ Paget’s disease – ___________________ Excessive and haphazard bone deposit and resorption cause bone to be made ___________________ fast and ___________________ poorly Called ______________________________________ Pagetic Bone Very high ratio of ___________________ spongy to ___________________ compact bone and reduced ___________________ moneralization – Usually occurs in ___________________, spine ___________________, pelvis ___________________, femur and ___________________ skull – Rarely occurs ___________________ before age 40 – Cause unknown: possibly ___________________ viral JOINTS ___________________, Joints also called ___________________: articulations sites where two or more bones ___________________ meet  Functions of joints: give skeleton ___________________ mobility and ___________________ hold skeleton together Two classifications: 1. ___________________: structural three types based on what material ___________________ binds the joints and whether a cavity is ___________________ present ___________________ Fibrous ___________________ Cartilaginous ___________________ Synovial 2. ___________________: Functional three types based on movement joint allows ___________________: Synarthroses immovable joints ___________________: Amphiarthroses slightly movable joints ___________________: Diarthroses freely movable joints Structural classifications are more clear cut, so these will be used here STRUCTURAL CLASSES: 1. ___________________ Fibrous joints – Bones joined by ___________________ dense fibrous connective tissue – No joint ___________________ cavity – Most are ___________________ immovable Depends on ___________________ length of connective tissue fibers – Three types of fibrous joints  a) ___________________ Sutures b) ___________________ Syndesmoses c) ___________________ Gomphoses 2. ___________________ Cartilaginous joints – Bones united by ___________________ cartilage – Like ___________________ fibrous joints, have no joint ___________________ cavity – Not highly ___________________ movable – Two types a) ___________________ Synchondroses b) ___________________ Symphyses 3. ___________________ Synovial joints – Bones ___________________f separated by luid-filled joint cavity – All are ___________________ diarthrotic (freely movable) – Include almost all ___________________ limb joints Synovial joints have _______________ six general features: 1 ___________________ Articular Cartilage ___________________: consists of hyaline cartilage covering ends of bones Prevents ___________________ crushing of bone ends 2 ___________________ Joint (___________________) synovial ___________________: cavity small, fluid-filled Potential space that is unique to synovial joints  3 ___________________ Articular (___________________) joint ___________________: capsule two layers thick ____________________________ External Fibrous Layer __________: dense irregular connective tissue ______________________________________: Inner Synovial membrane loose connective tissue that makes synovial fluid 4 ___________________: Synovial Fluid viscous, slippery filtrate of plasma and hyaluronic acid ___________________ Lubricates and ___________________ nourishes articular cartilage Contains ___________________ phagocytic cells to ___________________ remove microbes and debris 5 Different types of ___________________ reinforcing ligaments ___________________: Capsular thickened part of fibrous layer ___________________: Extracapsular outside the capsule ___________________: Intracapsular deep to capsule; covered by synovial membrane 6 ___________________ Nerves and ___________________ blood vessels Nerves detect ___________________; pain monitor joint ___________________ position and ___________________ stretch Capillary beds ___________________ supply filtrate for synovial fluid Other features of some ___________________ synovial joints: – ______________________________________ Fatty pads For ___________________ cushioning between fibrous layer of capsule and synovial membrane or bone – ___________________ Articular Disc (menisci) ___________________ (___________________)  ___________________ Fibrocartilage separates articular surfaces to improve “fit” of bone ends, stabilize joint, and reduce ___________________ wear and ___________________ tear – Bags of synovial fluid that act as ___________________ lubricating “ball bearing” – ___________________: Bursae reduce friction where ligaments, muscles, skin, tendons, or bones rub together – ______________________________________: Tendon Sheaths elongated bursae wrapped completely around tendons subjected to ___________________ friction ___________________ Three factors determine stability of joints to prevent ___________________: dislocation – ___________________ Shape of ___________________ articular surface (minor role) ___________________ Shallow surfaces ___________________ less stable than ball-and-socket – ___________________ Ligament number and ___________________ locationb (limited role) The more ___________________, ligament the stronger the ___________________ joint – ______________________________________ Muscle tone keeps tendons taut as they cross joints (most important) Extremely important in ___________________ reinforcing shoulder and knee joints and ___________________ arches of the foot There are _______________ six different types of ___________________ synovial joints – Categories are based on ___________________ shape of articular surface, as well as ___________________ movement joint is capable of a) ______________________________________ Plane b) ______________________________________ Hinge c) ______________________________________ Pivot  d) ______________________________________ Condylar e) ______________________________________ Saddle f) ______________________________________ Ball and Socket COMMON JOINT INJURIES Cartilage tears ______________________________________ stress – Due to ___________________ compression and shear ___________________ – arthroscopic surgery Repaired with ______________________________________ Sprains ___________________ stretched torn – Reinforcing ligaments are ___________________ or ___________________ vascularization – Partial tears repair very slowly because of poor ___________________ Surgery grafts immoblization – ___________________, ___________________, and/or ___________________ used to repair Dislocation ___________________ (luxations) alignment – Bones forced out of ___________________ Suluxation portail ___________________: ___________________ dislocation of a joint INFLAMMATORY & DEGENERATIVE CONDITIONS Bursits ___________________ Inflammation blow friction – ___________________ of bursa, usually caused by ___________________ or ___________________ Tendonitis ___________________ overuse Inflammation – ___________________ of tendon sheaths, typically caused by ___________________  ___________________ Arthritis – Symptoms: ___________________, pain ___________________, stiffiness and ___________________ swelling of joint – Acute forms: caused by ___________________, bacteria treated with ___________________ antibiotics – Chronic forms: ___________________, osteoarthritis ______________________________________, rheumatoid arthritis and ___________________ gouty arthritis ___________________ ARTHRITIS ______________________________________ Osteoarthrits – ___________________ Most common type of arthritis – Irreversible, ___________________ degenerative (“wear-and-tear”) arthritis – Cartilage is _______________________________ broken down faster than it is ___________________ replaced – By age ___________________, 85 half of Americans develop OA, more ___________________ females than ___________________ men ______________________________________ Rheumatoid Arthritis – Chronic, inflammatory, _____________________________________ autoimmune disease of unknown cause Immune system attacks ___________________ own cells – Usually arises between ages ___________________, 40-50 but may occur at any age; affects ___________________ three times as many women as men ___________________ Gouty arthritis ___________________ – Deposition of ___________________ uric acid crystals in joints and soft tissues, followed by ___________________ inflammation  men – More common in ___________________ base great toe – Typically affects joint at ___________________ of ___________________