Skeletal System (Lecture) Flashcards
Hyaline Cartilage
Frosted glass appearance. Avascular. Strong but flexible. ex: costal cartilage, trachea, & joints
Elastic cartilage characteristic
Not as strong, but very elastic. ex: ears, epiglottis
Fibrocartilage
Strongest cartilage able to withstand strong compression and tension forces but is not flexible. No perichondrium. Ex: Intervertebral discs, pubic symphysis, knee menisci
Bone Cells
Osteoblasts - Lay down bone matrix
Osteocytes - mature bone cells (located in lacunae)
Osteoclasts - Demineralize bone matrix
Extracellular Matrix
Layed down by chondrocytes
- Tricalcium phosphate (hydroxyapatite), calcium carbonate, and other minerals
- Reinforcing collagen fibers
Cartilage Appositional Growth
Growth from the outside. Chondroblasts inside perichondrium.
Cartilage Interstitial Growth
Growth from within. Chondrocytes divide within the cartilage.
Compact Bone
a. Osteon - a unit of compact bone
b. central canal - artery, vein, nerve, lymphatic vessel
c. perforating canal-connect blood vessels and nerves between osteons
d. canaliculi-get O2 and nutrients to osteocytes
e. concentric lamellae-ECM of the bone (Tricalcium Phosphate and Calcium Carbonate)
f. interstitial lamella(e)-incomplete lamellae that fill space between osteons
g. Osteocytes- lay down ECM
h. Lacuna(e)-protect osteocyte
Spongy bone
a. Trabecula(e)-Honeycomb-like structure in spongy bone containing yellow or red bone marrow
b. Osteocyte-lay down ECM
c. Lacuna(e)-Protect osteocyte
d. canaliculi- get O2 and nutrients to osteocytes
e. Endosteum-covers internal bone surface
I. Osteoblast
II. Osteoclast
Diaphysis
I. Compact Bone
II. Medullary cavity-center of diaphysis containing yellow bone marrow
III. Yellow bone marrow-site of fat storage
Epiphysis
I. Spongy Bone
II. Red Marrow-Blood cell formation
Epiphyseal Plate/Line
Disc of hyaline cartilage that grows during childhood to lengthen the bone
Articular Cartilage
Hyaline cartilage that covers the joint surface of the epiphysis
Nutrient Foramina
Hole in the wall of diaphysis that allow arteries and veins to pass-through
Periosteum
Dense irregular fibrous tissue that covers the entire outer surface of each bone except on the ends of epiphysis where articulation occurs
Bone growth
- Bone Collar forms around the diaphysis of hyaline cartilage model
- Cartilage calcifies and develops cavities
- Periosteal bud invades internal cavities and spongy bone begins to form
- Diaphysis elongates and medullary cavity is formed.
- epiphyses ossify. Hyaline cartilage remains only in epiphyseal plates and articular cartilage
Bone Remodeling
- Resorption of bone matrix by osteoclasts
2. deposition of new bone by osteoblasts
Fracture Stages
- Hematoma forms
- Fibrocartilaginous callus forms
- Bony callus forms
- bone remodeling occurs
Comminuted Fracture
Bone fragments in three or more pieces
Compression Fracture
The bone is crushed. Common in porous bones
Greenstick Fracture
Incomplete fracture where one side of the shaft breaks and the other bends. Common in children since bones are more flexible
Open (Compound) Fracture
Bones protrude through the skin during fracture
Spiral Fracture
occur when excessive twisting forces are applied to the bone. Common in sports
Stress Fractures
tiny cracks typically in weight-bearing bones that occur from repeated impact
Osteoporosis
Characterized by low bone mass and deterioration of bony skeleton architecture
Purpose of skeletal system
- Physical support
- Protects vital organs
- Allows for movement by connecting to skeleton
- Mineral storage (Ca)
Plagiocephaly-skull flattened on one area
Brachycephaly-short wide head
Scaphocephaly-long narrow head
Purpose of cranial orthosis
Fix cranial deformities
