A&P Lecture Exam 2
Medullary Cavity
Hollow cylindrical space in diaphysis Kids have red bone marrow Adults have yellow bone marrow
Amphiarthrosis
Slightly mobile joint movement classification
Synchondrosis
Cartilaginous joint No cavity Epiphyseal platr
Bone Repair
1. Fracture hematoma (blood clot) 2. Fibrocartilaginous (soft) callus is formed cartilage (fibrocartilage) fills in 3. Hard (bony) callus forms. Osteoblast produce spongy bone 4. Bone is remodeled. Osteoblast from compact bone. Osteoclast absorb spongy bone
Zone of calcified cartilage
2-3 layers of chondrocytes Minerals deposited into matrix between columns of lacunae Calcification destroys chondrocytes Chondrocytes die
Symphysis
Cartilaginous joint No cavity Intervertebral joint
Epiphyseal Line
Adult thin layer of compact bone
Lacunae
Body of "bug"
Osteoblast Cells
Bone forming Make bone matrix Formed from osteoprogenitor cells Form osteocyte cells Immature, build and create
Osteoporosis
Bone loss is not osteoporosis Osteoporosis is extreme loss of bone mass Osteoporosis is always loss of bone mass to the extreme
Diaphysis
Bone shaft that contains medullary cavity
Endrochondrial Ossification Step 5
Bones replaces all but articular cartilage and epiphyseal plate cartilage Bone is highly active and lengthens bone.
Osteoclast
Breaks down Remodels Reabsorbs Derived from fused bone marrow
Endrochondrial Ossification
Cartilage model is replaced by bone Occurs in long bones, pelvis, vertebrae
Hydroxyapatite
Calcium and phosphate 2:1
Endochondrial Ossification Step 2
Cartilage calcified and periosteal bone collar forms around diaphysis. Chondrocytes hyper trophy Osteoblasts create bone collar
Bone formation cells
Chondroblast - lays down matrix Chondrocytes - grow, gets larger, resorbs matrix to create holes, hardens and dies Osteoblast - builds Osteoclast - breakdown minerals
Zone of hypertrophic cartilage
Chondrocytes stop dividing Chondrocytes hypertrophy (enlarge) Chondrocytes resorb matrix
Zone of proliferating cartilage
Chondrocytes undergo rapid mitotic cell division Align like a stack of coins into longitudinal columns of flattened lacunae. Columns are parallel to diaphysis.
Osteoclast Cells
Derived from fused bone marrow cells Breakdown bones Remodel bones Reabsorb minerals
Epiphysis
End of long bones Thick layer of hyaline cartilage (articular) covering surface
Primary ossification center forms in diaphysis
Endochindrial Ossification Step 3 Periosteal bud forms - capillaries and osteoblasts Cartilage completely calcify (bone template) Osteoblasts forms osteitis (bone matrix) Primary ossification center - eventually makes diaphysis.
Secondary ossification center in epiphysis
Endrochondrial Ossification Step 4 Blood vessels enter epiphysis Forms as bone displaces cartilage Osteoclasts resorb bone matrix in diaphysis - creates medullary cavity.
Bones replaces all but articular cartilage and epiphyseal plate cartilage
Endrochondrial Ossification Step 5 Bone is highly active and lengthens bone.
Lengthwise growth continues until epiphyseal plate ossified and forms epiphyseal line.
Endrochondrial Ossification Step 6
Two places for hyaline cartilage
Epiphyseal Plate Articulating surface (epiphysis)
Long bone anatomy
Epiphysis Diaphysis Periosteum Endosteum Epiphyseal plate/line Articular cartilage
Zone of resting cartilage
Farthest from medullary cavity and nearest to epiphysis Composed of small Chondrocytes distributed throughout cartilage matrix Resembles mature and healthy hyaline cartilage Secures epiphysis to epiphyseal plate
Endochondrial Ossification Step 1
Fetal hyaline cartilage model develops Chondroblasts Perichondrium is formed
Structure Joint Classification
Fibrous - no joint cavity Cartilaginous joint - no joint cavity Synovial - fluid filled joint cavity
Suture
Fibrous joint No cavity Cranial bones
Syndesmosis
Fibrous joint No cavity Radius to ulna Tibia to fibula
Gomphosis
Fibrous joint No cavity Tooth to jaw
Synovial Joint
Fluid filled joint cavity Plane - intercarpal Hinge - elbow Pivot - radius/ulna Condylar - metacarpal/phalangeal Saddle - carpal/metacarpal Ball and Socket - hip
Bone Formation
Formation and development of new bone connective tissue. Chondroblast Chondrocyte Osteoblast Osteoclast
Intramembranous Ossification
Formation in a membrane Occurs in flat bones, facial bones, inner clavicles
Diarthrosis
Freely mobile joint movement classification
Osteon
Haversian Central Canal (center) lamellae (in-between circles) lacunae (bug body) canaliculi (bug legs)
Articular cartilage
Hyaline cartilage covering epiphysis Reduces friction
Osteoblast
Immature Builds Bone matrix
Synarthrosis
Immobile joint movement classification
Lamellae
In between circles surrounding haversion canal on osteon
Interstitial lamellae
Incomplete leftover in-between osteons some parts have been partially reabsorbed
Arthritis
Inflammation of a joint Osteoarthritis - from trauma, infection, aging Rheumatoid arthritis - autoimmune disease
Endosteum
Inner layer covering inside of long bone Protects inside of bone
Compact Bone
Lamellar matrix laid down in layers White smooth solid Osteons
Canaliculi
Legs of lacunae
Endrochondrial Ossification Step 6
Lengthwise growth continues until epiphyseal plate ossified and forms epiphyseal line.
Interstitial growth
Long bones grow in length Zone of resting cartilage Zone of proliferating cartilage Zone of hypertrophic cartilage Zone of calcified cartilage Zone of ossification
Tissue bone composed of
Mainly connective tissue (also epithelia and nervous) CT: bone, hyaline cartilage, fibrocartilage, dense fibrous adipose
Bone Storage
Matrix - calcium and phosphate Bone Marrow - Yellow (adults) Red (Children)
Osteocyte
Mature Maintain bone
Osteocyte cells
Mature Maintain the bone matrix Derived from osteoblasts
Haversion Canal
Middle of osteon
Fibrous Joint
No Joint Cavity Gomphosis - tooth to jaw Suture - cranial bones Syndesmosis - tibia to fibula
Cartilaginous Joint
No Joint Cavity Synchondrosis - epiphyseal plate Symphysis - intervertebral joint
Bone blood supply
Nutrient foramen - arteries and veins enter/exit Arteries carry nutrients to bone Veins carry waste away from bone Nerves supply bones - go in through nutrient foramen
Bone Remodeling Cells
Osteoblasts - increase osteoid synthesis Osteoclasts - resorption (takes calcium and phosphate out of bone and puts into blood) Occurs at periosteal and endosteal
Bone cells
Osteogenic - stem cells (give rise to others) Osteocytes - mature, maintain Osteoblast - immature, builds bone matrix Osteoclast - breakdown, remodel, reabsorb, derived from fused bone marrow cells
Bone Growth Cells
Osteoprogenitor cells Osteoblast Osteocyte Osteoclast
Circumferential lamellae
Outer rings of compact bone surrounding all osteons internal to periosteum or endsteum
Spongy Bone
Porus Red or yellow bone marrow No osteons Lacunae are present Trabeculae - lattice, narrow rods, plates of bones
Endochondrial Ossification Step 3
Primary ossification center forms in diaphysis. Periosteal bud forms - capillaries and osteoblasts Cartilage completely calcify (bone template) Osteoblasts forms osteitis (bone matrix) Primary ossification center - eventually makes diaphysis.
Bone Resorption
Process by which osteoclasts break down bone and release minerals. Osteoclast.
hematopoiesis
Production of blood cells. Occurs in red bone marrow connective tissue.
Concentric lamellae
Rings of compact bone surrounding central canal - bulk of osteon
diploe
Sandwich of compact and spongy bone Compact on outer surface Found in short, irregular and flat bones
Endrochondrial Ossification Step 4
Secondary ossification center in epiphysis Blood vessels enter epiphysis Forms as bone displaces cartilage Osteoclasts resorb bone matrix in diaphysis - creates medullary cavity.
Osteogenic
Stem cell
Osteoprogenitor Cells
Stem cells Mature to become osteoblast
Fetal hyaline cartilage model develops
Step 1 for endrochondrial ossification Chondroblasts: makes cartilage matrix for format, makes cartilage model Peri hindering is formed - this surrounds hyaline cartilage model
Cartilage calcified and periosteal bone collar forms around diaphysis
Step 2 for endrochondrial ossification Chondrocytes hyper trophy (divide) and resort matrix to create holes then harden and die. Blood vessels enter holes to make vascularization. Osteoblasts create periosteal bone collar. Perichondrium become periosteum.
Skeletal System Functions
Support Protection Storage Produce blood cells Movement
Movement Joint Classification
Synarthrosis - immobile Amphiarthrosis - slight mobile Diarthrosis - freely mobile
Saddle
Synovial joint Fluid filled cavity Carpal/metacarpal
Hinge
Synovial joint Fluid filled cavity Elbow
Ball-and-socket
Synovial joint Fluid filled cavity Hip
Plane
Synovial joint Fluid filled cavity Intercarpal
Condylar
Synovial joint Fluid filled cavity Metacarpal/phalangeal
Pivot
Synovial joint Fluid filled cavity Radius/ulna
Epiphyseal plate
Thin layer of hyaline cartilage Lengthwise growth Grows from end towards middle
Periosteum
Tough health covering long bones Anchor for tendons, blood, lymph, nerves 2 layers: outer dense irregular fibrous CT, inner osteogenic cells (makes new bone)
Factors to counteract bone loss
Vitamin D Calcium Bisphosphonates Estrogen Therapy Exercise
Zone of ossification
Walls breakdown between lacunae in columns and this forms longitudinal channels Spaces invaded by capillaries and osteoprogenitor cells from medullary cavity New matrix of bone is deposited on remaining calcified cartilage matrix
Appositional Growth
Widening of the bones at the periosteum Osteoblasts produce and deposit bone matrix within layers parallel to the surface. As rings increase, strength increases. As new bone lays down, osteoclasts resorb bone matrix along medullary cavity. More exercise/force - wider bone gets.
Bone loss factors
With age, more resorption, less formation Vitamin D Calcium from diet Sex steroids Exercise - stimulates formation and bones get bigger
Bone matrix
hydroxyapatite (calcium and phosphate 2:1)