Skeleton Flashcards
What is Compact Bone
Dense bone filled with osteons.
Resists Compression
Outer, smooth layer that we see.
Spongy Bone
Honeycomb structure of needle like structures. Spaces are also known as trabeculae and are filled with yellow or red bone marrow
What is the mesh of bony spine called
Trabeculae
What makes up the axial skeleton
Skull, vertebral column, and rib cage(thoracic cavity)
What’s the appendicular skeleton
Bones of limbs and girdles. ( Shoulder bones and hip bones) Movement and manipulation of environment
What’s a long bone and example
Longer than is wide usually limb bones like a femur or phalanges (even if small they are long).
What’s a short bone/ example
Roughly cubed shape. Ex: Tarsal and Carpal.
Sesamoid Bone
Type of short bone formed in tendons. Can alter direction or suppress friction/modify pressure.
Flat bone and example
Thin, flattened bone like sternum, scapulae, ribs, and most cranial bones.
Irregular Bones and example
Complicated shapes that don’t match other classes. Like vertebrae and coxal bones.
Appositional Growth
New matrix against previous matrix Cartilage and bone grow this way.
Interstitial Growth
Chondrocytes replicate and create new matrix from within. Only happens with cartilage.
Hematopoietic Tissue and where it’s found
Tissue that makes blood cells
Infant: red bone marrow in medullary cavity and spongy bone
Adults: Cavities between trabeculae in sternum flat bones, hip bones vertebrae, and heads of femur and humerus
Osteoprogenitor Cell
Stem cells - differentiate into osteoblasts,cytes, and class ( flattened squamous cells)
Osteoblast
Synthesizes bone matrix and helps bone grow secrete ground collagen
Osteocyte
Maintains bone matrix. Is a mature bone cell
Osteoclast
Bone resorption same WBC as macrophage
Osteon
Found in compact bone and is the tunnel where nerves, and blood vessels run through.
Lamella
Matrix tube around osteon, helps withstand torsional stresses.
Circumferential lamellae
Extend around the diaphysis. Lamellae around the whole bone.
Lacunae
Spaces where osteocytes occupy
Canaliculi
Thin crack like canals that connect lacunae to each other and to the central canal (osteon)
Hydroxyapatites
Mineral salts, mostly calcium phosphates
Why bones are left when someone dies (takes longer to decompose)
Ossification/ Osteogenesis
Bone tissue formation. Plays a role in skeletal development in embryos and bone growth later. Also for remodeling and repair
Endochondral Ossification
Bone replaces hyaline cartilage. Uses hyaline cartilage model bones as a model for bone construction.
Membranous Bone
Develops from fibrous membrane.
Steps to endochondral Ossification
1st: Bone Collar forms
2nd: Cartilage calcified in center of diaphysis
3rd: periosteal bud invades and spongy bone
4th: diaphysis elongates and medullary cavity formed
5th: epiphysis ossifies
Medullary Cavity
Marrow cavity with no bone tissue and contains yellow marrow in adults.
Postnatal Bone growth steps
1st: Proliferation Zone - Cells at top multiply push epiphysis
2nd: Hypertrophic - older cartilage cells stack and enlarge
3rd: Calcification Zone - chondrocytes die and blood vessels invade (matrix deteriorates)
4th: Ossification - new bone formed by osteoblasts.
Intra membranous ossification and steps
1: Ossification center develops in connective fibrous tissue
2: Osteon secreted and calcified
3: immature spongy bone and periosteum form
4: Compact bone replaces immature bone and red marrow develops
Step 1 of Fracture Repair
Hematoma Forms ( blood clots)
Step 2 of Fracture Repair
Fibrocartilaginous callus forms because of chondroblasts and fibroblasts
Step 3 Fracture Repair
Hard callus forms new bone develops from osteoblasts.
Step 4 of Fracture Repair
Bone Remodeling - osteoblasts make compact bone and bone is almost identical to pre-fracture bone.
Type of fracture in which bone fragments into 3 or 4 pieces. Common with aging
Comminuted Fracture
Bone is crushed. From extreme trauma
Compression
Broken from twisting bone. Ragged break
Spiral Fracture
Epiphysis separates from diaphysis along epiphyseal plate
Epiphysis Fracture
Dent in the fracture. (Bone pushed inwards)
Depressed Fracture
One side of shaft breaks kind of like a crack. Common in children
Green stick fracture
Osteomalacia
Bone disorders which result from lack of minerals. Inadequate calcium salts.
Rickets
Ends of long bone enlarge in children. Caused by deficient vitamin D
Osteoporosis
Bone resorption outpaced bone deposition resulting in declining bone mass
What can contribute to osteoporosis?
Lack of Vit D or protein
Smoking
Genetics
Less androgens and estrogen
Insufficient bone streds
Coronal Suture
Suture between parietal and frontal bone
Parietal meets superiorly at cranial midline
Sagittal
Lamboid
Where parietal meets occipital posteriorly
Squamous
Where parietal and temporal meet laterally
Keystone bone of cranium
Sphenoid
Ethmoid
Lies between sphenoid and nasal bones.
Mandible
Chin bone or lower jawbone ( strongest bone of the face)
Maxillae
Keystone bones of facial skeleton. Upper jaw and central portion of facial skeleton.
Zygomatic bones
Cheekbones
Lacrimal Bone
Medial wall of orbit behind nasal bone. Wear tear sacs are.
Hyoid
Only bone that isn’t articulated(connected) to other bones
Paranasal sinuses
Container in ethmoid, sphenoid, Frontal, maxillary
Vertebral Column in order:
Cervical: 7
Thoracic: 12
Lumbar: 5
Sacral: 5
Coccyx: 4
