-
fascia cell composition
- 1) Static - fibroblasts, fat, fixed macrophages,
- mast cells
- 2) Mobile - other macrophages i.e. PMNs and
- other wandering cells (cytotoxic killer T cells)
-
fascia fibers
1) Collagen - structural integrity
2) Elastin - elasticity
3) Reticular - support/rigidity (type of collagen)
-
function of fascia
a. Adds strength
- b. Provides continuity to structures
- covered\encircled by fascia
- c. Provides ease of movement by allowing
- structures to move easily over one another
-
superficial fascia
- connective tissue layer found directly beneath the skin composed of two fairly indistinct
- layers: a more superficial layer composed mostly of fat, referred to as the
- "fatty layer"; a deeper, more membranous reinforcing layer referred
- to as the "membranous layer". In the abdomen, these layers are more
- distinct and are referred to as Camper's and Scarpa's fascia, respectively
-
deep fascia
- a "stocking‑like" vestment of fibrous connective tissue, devoid of fat,
- located deep to the superficial fascia. It surrounds the body musculature,
- forms sheaths for nerves and vessels and provides for general compartmentation
- by attaching to bony prominences. Also, provides accessory attachments of
- muscle to bone.
-
-
a narrow band of deep fascia associated with a joint which
- functions to hold tendons close to bones as the joint is moved; prevents
- “bowstringing” of tendons across joints
-
intermuscular septum
- a specialization of deep fascia that forms a partition between muscular groups in
- such areas as the upper and lower limbs and neck. These partitions assist in
- delineating muscular compartments that are most often named for the major
- function of the muscles located within the compartment. Intermuscular septa may also increase the
- strength of a muscle by providing areas of attachment for muscular fibers.
-
neurovascular sheath
- a tubular sheath of deep fascia that surrounds arteries, veins, lymphatics and
- nerves that traverse and/or feed a muscular compartment.
-
bursa
- connective tissue membranes which surround tendons as sheaths, overlay boney prominences,
- and surround organs as bursal sacs, i.e., pleura, pericardium, and peritoneum. Their
- linings secrete serous fluid which reduces the frictional component of structures
- moving within or over them.
-
bone functions
a. Support and protection of soft tissues
- b. Provides a system of levers for the action of
- skeletal muscles
c. Blood producing organ
d. Storage site for calcium and phosphorus
-
cortex
- outer mantel of compact bone;
- responsible for shape
-
cancellous
- inner supportive layer of trabeculated "spongy" bone; responsible for
- strength
-
medullary cavity
- innermost "hollow" area filled with marrow; may be "yellow"
- serving as a fat storage department or "red" serving as a blood forming organ
-
periosteum
connective tissue layer surrounding bone which:
- 1) sends fibers (Sharpey) into the bone for
- anchoring purposes
- 2) possesses an inner layer of osteoprogenitor
- cells which participate in bone growth and repair
3) is highly innervated
-
endosteum
lines
medullary spaces, is less well developed than periosteum, however, does possess
osteoprogenitor cells.
- lines medullary spaces, is less well developed than periosteum, however, does possess
- osteoprogenitor cells.
-
axial skeleton
skull, vertebral column, rib cage
-
appendicular skeleton
limbs and bones of "girdle" which attach them to the axial skeleton.
-
short bones
carpals and tarsals
-
irregular bones
vertebrae, os coxa (hip), irregular bones of the skull, i.e., sphenoid, ethmoid, etc.
-
flat bones
- scapula, sternum, ribs, flat bones of skull, i.e., parietal, occipital, frontal,
- etc.
-
sesamoid bones
- develop within tendons where they cross long bones
- of the limbs. They help to reduce erosion of the tendons and help to provide the
- muscle with a greater mechanical advantage by changing the angle of approach
- of a tendon to its insertion
-
head, condyle
- expanded smooth articulating portions located at the ends
- of long bones
-
Line, ridge, crest, tubercle, tuberosity, spine, and trochanter
areas of relief in order of increasing size; provide sites for muscle attachment
-
facet
smooth articulating surface
-
pi, fovea, fossa
depressions listed in increasing depth
-
appositional bone growth
- width: appositional growth is the result of synergistic activity of osteoclasts and osteoblasts to alternately remove bone
- from the wall of the medullary cavity and form new bone on its external
- surface.
-
fibrous joints
synarthrosis: joints united by fibrous tissue
-
artilaginous joints
amphiarthrosis: joined by cartilage
-
suture joint
1) Occur only between bones of the skull
- 2) In the adult, bones united by sutures may be
- slightly moveable
-
syndesmosis
- 1) Union between two bones is accomplished by a fibrous
- sheet or ligament, i.e., tibiofibular & tympanostapedial joints
- 2) Joints of this type vary in their degree of
- movement.
-
synchondrosis
joints united by hyaline cartilage
1) Epiphyseal plate
2) Normally immovable
-
symphysis
- joints
- united by fibrocartilage
- 1) Symphysis pubis, joints between
- intervertebral bodies
2) Partially movable
-
characteristics of synovial joints
most common type of joint:
- 1) Articular surfaces covered by hyaline
- cartilage
- 2) Presence of a joint capsule surrounding a
- joint cavity
- 3) Joint capsule lined by a synovial membrane
- that secretes synovial fluid important for joint lubrication and is nutritive
- to the articular cartilage
- 4) Joint capsule reinforced with capsular
- ligaments
- 5) May possess a fibrocartilaginous articular
- disk or interarticular ligaments
6) Joints are freely mobile
-
describe the blood supply of synovial joint
- A rich network of vessels surrounds the joint supplying the epiphysis, joint capsule
- and synovial membrane, all areas except the articular cartilage.
-
innervation of synovial joints
- Joints are highly innervated, nerve endings being located in the articular
- capsule and synovial membrane.
- In general, nerves which supply muscles moving a specific
- joint also provide innervation to the overlying skin as well as to the interior of
- that joint.
-
plane/gliding joint
- small articular surfaces slide one upon the other.
- Examples:
- facet joints of the vertebral column, intercarpal and intermetacarpal joints
-
hinge joint
actions of flexion and extension allowed around a single transverse axis.
(elbow,interphalangeal joints of the fingers and toes)
-
pivot joint
- a process of bone serves as a pin and is surrounded by an osseofibrous ring;
- allows rotational movement longitudinally oriented about a single axis.
(proximal radioulnar joint, atlantoaxial joint)
-
condyloid joint
- modified ball and socket employing a shallow
- ellipsoidal socket and a ball that is not exactly round; allows movement in two planes (biaxial) at right
- angles to one another.
Examples: wrist joint (radiocarpal), metacarpophalangeal and metatarsophalangeal joints.
-
saddle (sellar) joint
- biaxial articulation where the surfaces of each articulating
- bone lie in opposite directions (concave in one direction, convex in another
- [like a saddle]) and the two bones reciprocally fit precisely with one another.
Examples: carpometacarpal joint of the thumb
-
ball and socket
- a convex head fits a concavity, more or less,
- precisely, allows greater freedom of motion
Examples: shoulder and hip joints
-
muscle contraction/relaxation
Muscles act upon articulated elements of the skeleton to provide movement only through contraction. A muscle exerts no action when it relaxes.
-
retinaculum/fibrous sheaths
- connective tissue structures which hold tendons close to bones which they traverse,
- thereby preventing them from "bow-stringing" and facilitating their
- action by acting as pulleys.
-
bursae/synovial sheaths
- fluid filled sacs which lie between tendons and underlying bone or encircle tendons;
- prevents erosion of the tendon and facilitates its movement.
-
fusiform muscles
parallel fibers longitudinally oriented; weakest
-
multipennate muscles
many feathers next to one another; strongest
-
fast twitch muscles
- Muscles that can be contracted maximally for a short duration before fatiguing, i.e.
- gastrocnemius (jumping muscle)
-
slow twitch muscles
muscles that can be contracted for long durations before fatiguing; soleus (running muscle).
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