Exercise 9 Flashcards
Skeleton
The body’s framework; Constructed of cartilage and bone
Functions of the skeleton
- support and protect
- system of levers with the skeletal muscles
- store lipids and minerals
- hematopoiesis (blood cell formation)
What are the two divisions of the skeleton?
Axial: bones that lie around the body’s center of gravity
Appendicular: bones of the limbs or appendages
Name the 7 most important skeleton cartilages
- ) Articular: cover the bone ends at movable joints
- ) Costal: found connecting the ribs to the sternum (breastbone)
- ) Laryngeal: largely constructs the larynx (voice box)
- ) Tracheal and bronchial: reinforce other passageways of the respiratory system
- ) Nasal: support the external nose
- ) Intervertebral discs: separate and cushion bones of the spine (vertebrae)
- ) Cartilage of the ear
What is the dense connective tissue covering in cartilage called?
Perichondrium
What are the three cartilage tissue types?
Hyaline: sturdy support with some resilience
Elastic: more flexible, tolerates bending better
Fibrocartilage: great tensile strength, can withstand heavy compression
Compact bone
Smooth and homogeneous
Spongy bone
Composed of small trabeculae (bars) of bone and lots of open space
Long bones
Longer than they are wide, shaft with heads at either end
Short bones
Typically cube shaped, contain more spongy bone than compact bone
Flat bones
Generally thin, with two waferlike layers of compact bone sandwiching a layer of spongy bone
Irregular bones
Bones that do not fall into one of the other bone categories
Sesamoid bones
Special types of short bones formed in tendons
Wormian (sutural) bones
Tiny bones between cranial bones
How many bones are in an adult?
206
Bone markings
Where bones from joints with other bones, where muscles, tendons, and ligaments were attached, and where blood vessels and nerves passed
What are the categories of bone markings?
Projections: processes that grow out form the bone and serve as sites of muscle attachment or help form joints
Depressions (cavities): indentations or openings in the bone that serve as conduits for nerves and blood vessels
Tuberosity
(Site of muscle and ligament attachment) Large rounded projection; may be roughened
Crest
(Site of muscle and ligament attachment) Narrow ridge of bone; usually prominent
Trochanter
(Site of muscle and ligament attachment) Very large, blunt, irregularly shaped process (only in femur)
Line
(Site of muscle and ligament attachment) Narrow ridge of bone; less prominent that a crest
Tubercle
(Site of muscle and ligament attachment) Small rounded projection or process
Epicondyle
(Site of muscle and ligament attachment) Raised area on or above a condyle
Spine
(Site of muscle and ligament attachment) Sharp, slender, often pointed projection
Process
(Site of muscle and ligament attachment) Any bony prominence
Head
(Help form joints) Bony expansion carried on a narrow neck
Facet
(Help form joints) Smooth, nearly flat, articular surface
Condyle
(Help form joints) Rounded articular projection
Ramus
(Help form joints) Armlike bar of bone
Groove
(Passage of blood vessels and nerves) Furrow
Fissure
(Passage of blood vessels and nerves) Narrow, slitlike opening
Foramen
(Passage of blood vessels and nerves) Round or oval opening through a bone
Notch
(Passage of blood vessels and nerves) Indentation at the edge of a structure
Meatus
(Others) Canal-like passageway
Sinus
(Others) Bone cavity, filled with air and lined with mucous membrane
Fossa
(Others) Shallow, basinlike depression in a bone, often serving as an articular surface
Endochondral ossification
Except for the collarbones, all bones of the body inferior to the skull form in the embryo by this process
Where does endochondral ossification begin?
Primary ossification center of the shaft of a developing bone
What is another name for the shaft of a bone?
Diaphysis
Periosteum
Fibrous membrane covering the bone surface
Perforating (Sharpey’s) fibers
Fibers of the periosteum that penetrate into the bone
Osteoblasts
Bone-forming cells
Osteoclasts
Bone-destroying cells
Epiphysis
The end of a long bone
Epiphyseal plate
Thin area of hyaline cartilage that provides for longitudinal growth during youth
Epiphyseal lines
Replace the epiphyseal plate
What is the central cavity of the shaft called and what does it do?
Medullary cavity; Stores adipose tissue (yellow marrow)
Where is red marrow found?
In infants, the marrow cavities; In adults, confined to the interior of the epiphyses
Endosteum
Lines the trabeculae of spongy bone and the canals of compact bone
Central (Haversian) canal
Runs parallel to the long axis of the bone; Carries blood vessels, nerves, and lymph vessels (nerve, vein, artery)
Osteocytes
Mature bone cells
Lacunae
Chambers with contain osteocytes
Concentric lamellae
The arrangement of the osteocytes and lacunae around the central canal
Osteon (Haversian system)
Cental canal and all the concentric lamellae
Canaliculi
Tiny canal radiating outward from a central canal to the lacunae of the first lamella and then from lamella to lamella
Perforating (Volkmann’s) canal
Run into the compact bone and marrow cavity from the periosteum at right angles to the shaft; Complete the communication pathway between interior and exterior of bone
