Chapter 10- Musculoskeletal System: Anatomy & Physiology
temporal bones
-2 of these, 1 on each side of the skull, form part of the lower cranium -each has a complicated shape that contains various cavities and recesses associated with the internal ear -projects downward to form the mastoid process
lacrimal bones
-2 thin, paired bones -located at the corner of each eye -unite to form the groove for the lacrimal sac and canals through which the tear ducts pass into the nasal cavity
cranium (skull)
-8 bones that enclose and protect the brain and the organs of hearing and equilibrium -its bony structure consists of cranial bones and facial bones, almost all of which are joined together by sutures -connected to muscles to provide head movements, chewing motions, and facial expressions
periosteum
-a dense, white, fibrous membrane that covers the remaining surface of the long bones -contains numerous blood and lymph vessels and nerves, as well as osteoblasts in its inner layer -provides a means for bone repair and general bone nutrition -serves as a point of attachment for muscles, ligaments, and tendons
trochanter
-a non-articulating surface -very large, irregularly shaped process found only on the femur -example: greater ___ of the femur
tubercle
-a site of muscle and ligament attachment -small, rounded process -example: ___ of the femur
articular cartilage
-a type of elastic connective tissue that provides a smooth surface for movement of joints -covers the epiphyses -reduces friction and absorbs shock at the freely movable joints
fontanel (soft spot)
-an unossified membrane in an infant's skull (incomplete bone formation) -lies between the cranial bones -allows the bones to move as the fetus passes through the birth canal during the delivery process -with age, they begin to fuse together and become immobile in early childhood
appendage
-any body part attached to a main structure -examples include the arms and legs
aponeurosis
-attachment when the fibrous attachment spans a large area of a bone -found in the lumbar region of the back -sometimes it penetrates the bone itself -these are flattened
flat bones
-bones that provide broad surfaces for muscular attachment -provide protection for internal organs -examples: bones of the skull, shoulder blades, and sternum
irregular bones
-bones with complex shapes -includes bones that cannot be classified as short or long -examples: vertebrae and bones of the middle ear
pectoral (shoulder) girdle
-consists of 2 bones: the anterior clavicle and posterior scapula -attaches the bones of the upper limbs to the axial skeleton -provides attachments for muscles that aid upper limb movements
muscles
-contribute to posture, produce body heat, and act as a protective covering for internal organs -make up the bulk of the body -have the ability to be excited by a stimulus, contract, relax, and return to their original shape and size -primary responsibility is movement
axial skeleton
-divided into 3 major regions: skull, rib cage, and vertebral column -contributes to the formation of body cavities -provides protection for internal organs -provides central support for the body
ligaments
-flexible bands of fibrous tissue that are highly adapted for resisting strains -one of the principal mechanical factors that hold bones close together in a synovial joint -connect bone to bone
fleshy attachments
-in these, muscle fibers arise directly from bone -distribute force over wide areas -weaker than the other attachment -it is contractile
fibrous attachments
-in these, the connective tissue converges at the end of the muscle to become continuous and indistinguishable from the periosteum -non-contractile and inelastic
cruciate ligaments
-ligaments that cross each other, forming an X within the notch between the femoral condyles -along with other structures, they help secure and stabilize the knee -prevent anterior-posterior displacement of the articular surfaces
cardiac muscle
-muscle found only in the heart and makes up most of the heart's wall -unique for its branched interconnections -it is striated, but produces rhythmic involuntary contractions
smooth (involuntary or visceral) muscles
-muscles whose actions are involuntary -found principally in the visceral organs, walls of arteries and respiratory passages, and urinary and reproductive ducts -their contraction is controlled by the autonomic nervous system
head
-projection that forms joints -prominent, rounded, articulating end of a bone -example: ___ of the femur
condyle
-projection that forms joints -rounded, articulating knob -example: ___ of the humerus
bones
-provide the framework of the body -storehouse for minerals -produce blood cells in marrow -protect and support organs -provide points of attachment for muscles, tendons, and ligaments -assist in body movement
sinus
-site for blood vessel, nerve, and duct passage -cavity or hollow space in a bone -example: ___ of the frontal sinus containing a duct
fissure
-site for blood vessel, nerve, and duct passage -narrow, slit-like opening -example: ___ of the sphenoid bone
meatus
-site for blood vessel, nerve, and duct passage -opening or passage into a bone -example: external auditory ___ of the temporal bone
foramen
-site for blood vessel, nerve, and duct passage -rounded opening through a bone -example: ___ of the skull through which cranial nerves pass
tuberosity
-site of muscle and ligament attachment -large, rounded process -example: ___ of the humerus
short bones
-somewhat cube-shaped bones -consist of cancellous bone -examples: bones of ankles, wrists, and toes
mandible
-the lower jaw bone -its movement is needed for speaking and chewing -contains sockets for the roots of the teeth
maxillae
-the paired upper jawbones that are fused in the midline by a suture -form the upper jaw and hard palate -contain sockets for the roots of the teeth
epiphyses
-the two ends of long bones -have a somewhat bulbous shape to provide space for muscle and ligament attachments near the joints -covered with articular cartilage -made up largely of spongy bone surrounded by a layer of compact bone
surface features
-these are rarely smooth -may be rounded, sharp, narrow, or contain ridges -consist of projections, depressions, and openings that provide sites for muscle and ligament attachment -provide pathways and openings for blood vessels, nerves, and ducts
tendon
-when connective tissue fibers form a cord or strap -localizes a great deal of force in a small area of bone -connects muscle to bone
nasal bones
2 thin, nearly rectangular bones that lie side-by-side and are fused medially, forming the shape and the bridge of the nose
vertebrae
26 bones that compose the vertebral column
coccyx
4 or 5 fragmented fused vertebrae that makes of the tail of the vertebral column
sacrum
5 sacral vertebrae that are fused into a single bone in the adult
lumbar vertebrae
5 vertebrae that are situated in the lower back area and carry most of the weight of the torso
cervical vertebrae
7 of these form the skeletal framework of the neck
medullary (marrow) cavity
a central canal in long bones that contains fatty yellow marrow in adults, consisting primarily of fat cells and a few scattered blood cells
cleft palate
a congenital defect that results if the maxillary bones do not fuse properly before birth
nucleus pulposus
a fibrocartilaginous substance with a gelatinous mass in the center that composes the intervertebral disks
vomer
a single, thin bone that forms the lower part of the nasal septum
ethmoid bone
a very light and spongy bone that forms most of the bony area between the nasal cavity and parts of the orbits of the eyes
clavicle
also known as the collar bone
scapula
also known as the triangular shoulder blade
sphenoid bone
bone located at the middle part of the base of the skull that forms a central wedge, which joints with all other cranial bones and holds them together
compact bone
bone that forms a cylinder and surrounds the medullary cavity in long bones, as well as encloses cancellous bone in short bones
osteoblasts
bone-forming cells contained in the inner layer of the periosteum in growing bones
zygomatic bones (cheekbones)
bones located on the side of the face below the eyes and form the higher portion of the cheeks below and to the sides of the eyes
long bones
bones that are found in the appendages of the body and consist of 3 main parts
girdles
bony rings that attach the limbs to the axial skeleton
paranasal sinuses
cavities located within the cranial and facial bones that open into the nasal cavities and are lined with ciliary epithelium
vertebral column
composed of vertebrae and supports the body, as well as provides a protective bony canal for the spinal cord
thoracic cage (rib cage)
consists of 12 pairs of ribs that are all attached to the spine and encloses and protects the internal organs of the thorax
appendicular skeleton
consists of bones of the upper and lower limbs and their girdles and enables the body to move
fibers
contractile cells that compose muscle tissue and provide movement of an organ or body part
flexion
decreases the angle of a joint
dorsiflexion
elevates the foot
intervertebral disks
flat, rounded structures that separate the vertebrae and are composed of nucleus pulposus
forehead
forms the anterior portion of the skull
frontal bone
forms the anterior portion of the skull and the roof of the bony cavities that contain the eyeballs
musculoskeletal system
includes muscles, bones, joints, and related structures, such as the tendons and connective tissue that function in support and movement of body parts and organs
extension
increases the angle of a joint
upper limb
its skeleton framework includes the arm, forearm, and hand and is adapted for mobility and flexibility
cancellous
latticelike arrangement of bony plates occurring at the ends of long bones
ciliary epithelium
lines the paranasal sinuses and is continuous with the mucosa of the nasal cavities
plantar flexion
lowers the foot (points the toes)
rotation
moves a bone around its own axis
abduction
moves away from the midline
adduction
moves closer to the midline
inversion
moves the sole of the foot inward
eversion
moves the sole of the foot outward
skeletal (voluntary or striated) muscles
muscles whose action is under voluntary control, such as those that moved the eyeballs, tongue, and bones
skeletal system
of a human adult, it consists of 206 individual bones
articulation, joint
place of union between two or more bones
hematopoiesis
production and development of blood cells, normally in the bone marrow
mastoid process
provides a point of attachment for several neck muscles
parietal bone
situated on each side of the skull just behind the frontal bone and meets the frontal bone along the coronal suture
cancellous bone
spongy bone that makes up the core of short bones, is enclosed in a thin surface layer of compact bone, and contains red bone marrow
mastication
term for chewing
sternum
term for the breastbone
atlas
the 1st cervical vertebrae that supports the skull
axis
the 2nd cervical vertebrae that makes possible the rotation of the skull on the neck
false ribs
the costal cartilage of these 5 pairs of ribs is not fastened directly to the sternum
internal ear
the essential part of the organ of hearing associated with the temporal bones
true ribs
the first 7 pairs of ribs that are attached directly to the sternum by a strip of costal cartilage
floating ribs
the last 2 pairs of false ribs that are not joined directly or indirectly to the sternum, but attach posteriorly to the thoracic vertebrae
sutures
the lines of junction between 2 bones, especially of the skull, and are usually immovable
hard palate
the roof of the mouth
diaphysis
the shaft, main portion of a bone that consists of compact bone surrounding the medullary cavity
coronal suture
the suture where the parietal bone meets the frontal bone
red bone marrow
this is contained in spongy bone, richly supplied with blood and consists of immature and mature blood cells in various stages of development
occipital bone
this single bone forms the back and base of the skull and contains an opening in its base through which the spinal cord passes
thorax
this term refers to the entire chest and includes the heart and lungs, which are enclosed and protected by the thoracic cage
pronation
turns the palm down
supination
turns the palm up
thoracic vertebrae
under the 7th cervical vertebra are these, which support the chest and serve as a point of articulation for the ribs