Skeletal System Flashcards
3 types of cartilage
Hyaline
Elastic
Fibrocartilage
Hyaline
Forms most of the embryonic skeleton
(Covers the ends of long bones and joint surfaces; trachea, larynx, nose)
Elastic
External ear, epligottis
Fibrocartilage
Pubic symphysis, intervertebral discs, menisci
Bones
Provide stable levers on which muscles act to generate movement
Highly vascularized
What is the human skeleton divided into? What are they?
2 to 3 subunits; axial skeleton & appendicular skeleton (maybe skull)
Axial Skeleton
Skeleton of the trunk:
- Ribs
- Sternum
- Vertebrae
- Pelvis*
- Coccyx
Appendicular Skeleton
Skeleton of the limbs:
- Pelvic and shoulder girdles
- Long bones, irregular bones, short bones
Takeaway:
Skeletal muscles attach and move the limbs
Long bones
Longer than they are wide, tubular
Ex. Humerus, femur
Short bones
Cube-shaped bones of the wrist and ankle
Bones that form within tendons- sesamoid
Ex. Patella
Flat bones
Thin, flattened, slightly curved
Ex. Sternum, ribs, and most skull bones
Irregular bones
Bones with complex shapes
Ex. Hip bones and vertebrae
Tuberosity
Large rounded projection; may be roughened
Crest
Narrow ridge of bone; usually prominent
Trochanter
Very large, blunt, irregularly shaped process
Ex. only examples are in femur
Line
Narrow ridge of bone; less prominent than a crest
Tubercle
Small rounded projection or process
Epicondyle
Raised area on or above a condyle
Spine
Sharp, slender, often pointed projection
Process
Any bony prominence
Head
Bony expansion carried on a narrow neck
Facet
Smooth, nearly flat articular surface
Condyle
Rounded articular projection, often articulates with a corresponding fossa
Foramen
Round or oval opening through a bone
Groove
Furrow
Fissure
Narrow, slitlike opening
Notch
Indentation at the edge of a structure
Fossa
Shallow basin like depression in a bone, often serving as an articular surface
Meatus
Canal-like passageway
Sinus
Cavity within a bone, filled with air and lined with mucous membrane
Muscle and ligament attachment points
- Tuberosity
- Trochanter
- Tubercle
- Epicondyle
- Spine
- Process
Depressions and openings (passageways)
- Foramen
- Fissure
- Fossa
- Sinus
Projections that help form joints
- Condyle
- Facet
- Head
Compact bone
Dense outer layer that appears smooth and is solid to the naked eye
Spongey (trabecular) bone
Found internally deep of compact bone layer, spaces are filled with red or yellow bone marrow, plenty of small pointed/flat pieces called trabeculae
Diaphysis
Tubular “shaft” of a bone
Epiphysis
Ends of a bone, covered with articular cartilage
How much % of the bone tissue is well vascularized
Between 3-11% of blood vessels
Medullary cavity
Filled with bone marrow
Periosteum
Well innervated and vascularized CT membrane that covers the outer surface of each bone, except the epiphyseal ends
Diploë
Internal spongy bone of flat bones
What causes the bone to compress on one side and stretch (tense) it on the other?
Bending
What are at their greatest at the external surfaces?
Compression and tension
From the spongy bone, what aligns along the stress lines in a support pattern?
Trabeculae
Material that unites the joint (structural)
- Fibrous
- Cartilaginous
- Synovial
Degree of movement (functional)
- Synarthrosis
- Amphiarthrosis
- Diarthrosis
Fibrous Joints
Bones united by fibrous CT
Ex. Cranial vault sutures, syndesmoses, gomphoses
Cartilaginous joints
Bones united by hyaline cartilage (synchondroses) or fibrocartilage (symphyses)
Synovial
Bones are separate and are connected by a fibrous joint capsule lined with a synovial membrane (forms a synovial cavity
Synarthrosis
Immovable
Ex. Cranial vault sutures
Amphiarthrosis
Slightly movable
Ex. IV discs, pubic symphysis of pelvis
Diarthrosis
Bone articulation permits free motion in a joint
Ex. Glenohumeral joint
Plane Joints
Allow short gliding movements
Hinge Joints
Allow angular movements
Pivot Joints
Allow rotational movements
Condyloid Joints
Allow flexion and extension, abduction and adduction movements
Saddle Joints
Allow flexion and extension, abduction and adduction movements
Ball and Socket Joints
Allow movements in all directions
Trade-off between Joint Mobility and Stability
Least Mobile: Uniaxial
Most Stable: Uniaxial
Most Mobile: Multiaxial
Least Stable: Multiaxial
In between: Biaxial
Ossification (osteogenesis)
Bone-tissue formation; begins in the embryo and proceeds through childhood and adolescence as the skeleton grows, as you progress it gets slower
Prior to 8 weeks of development, what happens?
The embryo consists only of hyaline cartilage and some membranes of mesenchyme, bone tissue develops in week 8 and replaces most cartilage and mesenchymal membranes
Membrane bones
Formed directly from mesenchyme; all bones of the skull except some bones of the skull base
Intramembranous Ossification
All other bones inferior to the basicranium, except for clavicles, initially develop as hyaline cartilage which is eventually replaced through a process named Endochondrial Ossification
Simple Fracture
The bone breaks cleanly but does not penetrate the skin
Compound fracture
Broken ends of the bone protrude through the skin
Bones lengthen entirely by growth of what?
Epiphyseal plates
Comminuted Fractures
Bone fragments into three or more pieces
Compression
Bone is crushed
Spiral
Ragged break occurs when excessive twisting forces are applied to a bone
Epiphyseal
Epiphysis separates from the diaphysis along the epiphyseal plate
Depressed
Broken bone portion is pressed inward
Greenstick
Bone breaks incompletely, only one side of the shaft breaks; other side bends
