Chp 6 Flashcards
Skeletal System
Bones (skeleton)
Cartilages
Ligaments (bone to bone)
Tendons (bone to muscle)
Skeletal System Functions
Assistance in Movement Support (structure) mineral homeostasis Storage of fats Protection of internal organs site of blood cel production
What is the name of the growth plate found in children’s bones during endochondral ossification?
Epiphyseal plate (once ossified: epiphyseal line)
Long bone
Longer than they are wide, has shaft plus two ends
ex// all limb bones except patella, wrist, and ankle bones
Short bone
cube shaped ex// bones of ankle and wrist
Flat bones
Composed of 2 layers of compact tissue ex// sternum, scapulae, ribs, most skull bones
Irregular bones
complicated shapes ex// vertebrae and hip bones
Sesamoid bones
Type of short bone embedded in a tendon (shaped like a sesame seed) ex// patella
Sutural bone
interlocking joints of tiny, irregularly shaped bones that unite all bones of adult skull ex// coronal, sagittal, squamous, lambdoid
Tuberosity
Large rounded projection, may be roughened
Site of muscle and ligament attachement
Crest
Narrow ridge of bone, usually prominent
Site of muscle and ligament attachment
Trochanter
Very large, blunt, irregularly shaped process (only example: on femur)
Site of muscle and ligament attachment
Line
Narrow ridge of bone, less prominent than a crest
site of muscle/ligament attachment
Tubercle
small rounded projection or process
site of muscle/ligament attachment
epicondyle
raised area on or above a condyle
site of muscle/ligament attachment
Spine
sharp, slender, often pointed projection
site of muscle/ligament attachment
Process
Any bony prominence
site of muscle/ligament attachment
Head
Bony expansion carried on a narrow neck
projection that helps form joints
Facet
Smooth, nearly flat articular surface
projection that helps form joints
Condyle
rounded articular projection
projection that helps form joints
Ramus
armlike bar of bone
projection that helps form joints
Groove
Furrow
depression/opening that allows passage of blood vessels and nerves
Fissure
Narrow, slitlike opening
depression/opening that allows passage of blood vessels and nerves
Foramen
Round or oval opening through a bone
depression/opening that allows passage of blood vessels and nerves
Notch
Indentation at the edge of a structure
Meatus
canal-like passageway
Sinus
Cavity within a bone, filled with air and lined with mucous membrane
Fossa
Shallow, basinlike depression in a bone, often serving as an articular surface
Compact Bone
Dense outer layer, solid mass
aka “lamellar bone”
functional unit = osteon (Haversian system)
Cancellous/ Spongy Bone
Honeycomb of trabeculae filled with red or yellow marrow
Periosteum
White, double-layered membrane that covers the external surface of entire bone except for the joint surfaces
Provides anchoring points for tendons and ligaments
Outer fibrous layer is made of connective tissue, inner osteogenic layer consists of osteogenic stem cells
Sharpey’s Fibers
“Perforating fibers”: tufts of collagen fibers that extend from its fibrous layer into the bone matrix- secure the periosteum to the underlying bone
Endosteum
Delicate connective tissue membrane that covers internal bone surfaces
Contains osteogenic cells
Location of hematopoietic tissue (red marrow)
Infants: in medullary cavity and all areas of spongy bone
Adults: in diploe of flat bones, sternum, and head of femur and humerus
Yellow marrow can convert to red marrow in anemic persons
What are the 4 major types of cells in bones?
Osteogenic, osteoblasts, osteocytes, osteoclasts
Osteogenic cells
Undergo cell division, resulting cells develop into osteoblasts
Osteoblasts
Bone-building cells, synthesize extracellular matrix of bone tissue
Osteocytes
Mature bone cells, exchange nutrients and wastes with blood
Osteoclasts
Release enzymes that digest the mineral components of bone matrix (resorption)
Regulate blood calcium level
Chemical composition of bone
25% water [inorganic]
25% collagen fibers, proteoglycans, glycoproteins [organic]
50-65% crystallized mineral salts [inorganic]; mainly hydroxapatites (deposited and calcified by osteoblasts)
Wolff’s Law
Bone increases in mass in proportion to the stresses placed on it by muscles ex// right handed people will have heavier bones in the right hand, bones of weight lifters (such as clavicles) are large, astronauts/bedridden patients suffer bone loss from lack of stress on bones
Open Fracture
break in teh skin and underlying soft tissue leading directly into or communicating with the fracture and its hematoma
Closed Fracture
“simple” fracture, does not break the skin
Comminuted Fracture
Bone is splintered, crushed, or broken into pieces
Greenstick Fracture
Partial fracture, one side of bone is broken and other side bends (common in chidren whose bones have relatively more organic matrix and are more flexible than those of adults)
Impacted Fracture
One end of the fractured bone is forcefully driven into another
Pott’s Fracture
Fracture of the fibula, with injury of the tibial articulation
Colle’s Fracture
Fracture of the radius, with displacement of distal fragment
Stress Fracture
A series of microscopic fissures in bone
Bone Mass
Peak bone mass: by age 20, maintain until 35-40
Women lose bone at accelerated rate during first ten years after menopause (2-5% per year)
Men lose bone more slowly with higher rate of loss after 65 years
4 Factors that Contribute to Bone Health
Genetics, physical activity, hormones, nutrition
2 main effects of aging on bone tissue
- Loss of Bone mass: loss of calcium from bone matrix
2. Brittleness: results from decreased rate of protein synthesis, loss of tensile strength
Osteomalacia
Inadequately mineralized bones, “soft bones”
Insufficient dietary calcium/insufficient vit D
RIckets
Children’s form of osteomalacia
More detrimental, bowed legs, deformities of pelvis, ribs, skull
Osteoporosis
Decreased bone mass/bone mineral density resulting in porous bones
44 million US women and men (50 Y and older)
most common fracture sites: hip (femur), spine, wrist
