Week 2 Flashcards
of bones in axial skeleton
80
of bones in appendicular skeleton
126
skeletal functions
- protection of heart, lungs, brain, etc…
- support to maintain posture
- movement by serving as points of attachment for muscles and acting as levers
- mineral storage such as calcium and phosphorus
- hemopoiesis- in vertebral bodies, femurs, humerus, ribs, and sternum
types of bones
long bones- humerus, fibula short bones- carpals, tarsals flat bones- skull, scapula irregular bones- pelvis, ethmoid, ear ossicles sesamoid bones- patella
Long bones
composed of long, cylindrical shaft with relatively wide, protruding ends
shaft contains medullary canal
short bones
small, cubical shaped, solid bones that usually have a proportionally large articular surface in order to articulate with more than one bone
flat bones
usually have a curved surface and vary from thick where tendons attach to very thin
Irregular bones
include bones throughout entire spine and ischium, pubis, and maxilla
sesamoid bones
small bones embedded within tendon of a musculotendinous unit that provide protection and improve mechanical advantage of musculotendinous units
DIaphysis
long, cylindrical shaft
cortex
hard, dense compact bone forming walls of diaphysis
periosteum
dense, fibrous membrane covering outer surface of diaphysis
endosteum
fibrous membrane that lines the inside of the cortex
medullary (marrow) cavity
between walls of diaphysis, containing yellow or fatty marrow
epiphysis
ends of long bones formed from cancellous (spongy or trabecular) bone
epiphyseal plate
growth plate. thin cartilage plate that separates diaphysis and epiphyses
articular (hyaline) cartilage
covering the epiphysis to provide cushioning effect and reduce friction
Longitudinal bone growth
continues as long as epiphyseal plates are open. Shortly after adolescence, plates disappear and close. Most close by age 18, but some may be present until 25. Growth in Diameter of bone continues throughout life
mechanisms of bone growth
internal layer of periosteum builds new concentric layers on old layers. Simultaneously, bone around sides of the medullary cavity is resorbed so that diameter is continually increased
osteoblasts
cells that form new bone. Blast=Build
osteoclasts
cells that resorb old bone
Bone properties
Bone size and shape are influenced by the direction and magnitude of forces that are habitually applied to them.
Bones reshape themselves based upon the stresses placed upon them.
Bone mass increases over time with increased stress.
Wolf’s law.
Processes (elevations and projections) that form joints
condyle, facet, head
Processes (elevations and projections) to which ligaments, muscles, or tendons attach
crest, epicondyle, line, process, spine (spinous process), suture, trochanter, tubercle, tuberosity
Cavities (depressions)
facet, foramen, fossa, fovea, meatus, sinus, sulcus (groove).
Articulation
connection of bones at a joint usually to allow movement between surfaces of bones
3 FUNCTIONAL classifications of joints
Synarthroidal, amphiarthroidal, diarthroidal
3 STRUCTURAL classifications of joints
Fibrous, cartilaginous, synovial
Synarthroidal joints
immovable joints.
sutures such as skull sutures
Gomphosis such as teeth fitting into mandible or maxilla. (Gomphosis is synarthroidal and fibrous).
Amphiarthroidal joints
Slightly movable joints.
- Syndesmosis
- Symphysis
- Synchondrosis
Syndesmosis
Amphiarthroidal. Fibrous.
Two bones joined together by a strong ligament or an interosseus membane that allows minimal movement between the bones.
Bones may or may not touch each other at the actual joint.
Example: distal tibiofibular joint.
Symphysis
Amphiarthroidal. Cartilaginous.
Joint separated by a fibrocartilage pad that allows very slight movement between the bones.
Example: symphysis pubis and intervertebral discs
Synchondrosis
Amphiarthroidal. Cartilaginous.
Type of joint separated by hyaline cartilage that allows very slight movement between the bones.
Example: costochondral joints of the ribs with the sternum.
DIarthroidal Joints
Known as synovial joints. Freely movable. Composed of joint capsule which secretes synovial fluid to lubricate the joint cavity. Have motion possible in one or more planes.
Slowly absorbs synovial fluid during joint unloading
Secretes synovial fluid during subsequent weight bearing & compression maintaining and utilizing a joint through its normal ROM.
Capsule thickenings in diarthroidal joints
form tough, non-elastic ligaments that provide additional support against abormal movement or joint opening.
Type of cartilage in diarthroidal joints
Articular or hyaline. It covers the articular surface ends of the bones inside the joint cavity.
absorbs shock
protects the bone
Fibrocartilage discs in diarthroidal joints
Some diarthroidal joints have specialized fibrocartilage discs.
- medial and lateral menisci
- glenoid labrum
- acetabular labrum
Arthroidal (gliding) joints
-2 planes or flat bony surfaces which touch each other.
-little motion possible in any 1 joint articulation.
-usually work together in a series of articulations.
Ex: vertebral facets in spinal column, intercarpal and intertarsal joints.
Motions are flexion, extension, abduction, adduction, diagonal abduction and adduction, & rotation (circumduction).
Hinge joint
Diarthroidal
-uniaxial articulation
-articular surfaces allow motion in only one plane
Ex: elbow, knee, talocrural (ankle)
Trochoid (pivot, screw) joint
Diarthroidal
Uniaxial articulation
Ex: atlantoaxial joint - odontoid which turns in a bony ring, proximal and distal radio-ulnar joints.
Condyloid (knuckle joint)
Diarthroidal
Biaxial ball and socket joint.
One bone with an oval concave surface received by another bone with an oval convex surface.
Ex: 2nd, 3rd, 4th, and 5th metacarpophalangeal joints, wrist articulation between carpals and radius.
Flexion, extension, abduction, adduction, circumduction.
Enarthroidal joint
Diarthroidal
Miltiaxial or triaxial ball and socket joint.
Bony rounded head fitting into a concave articular surface.
Ex: hip and shoulder joints.
Flexion, extension, abduction, adduction, diagonal abduction and adduction, rotation, and circumduction.
Sellar (saddle) joint
Diarthroidal.
Unique triaxial joint.
2 reciprocally concave and convex articular surfaces.
Only example is 1st carpometacarpal joint at thumb.
Flexion, extension, adduction and abduction, circumduction and slight rotation.
Movements in joints
Some joints permit only flexion and extension.
Others permit a wide range of movements, depending largely upon the joint structure.
Goniometer is used to measure amount of movement in a joint or measure of joint angles.
Using a goniometer
Goniometer is placed even with the axis of rotation at the joint line.
As the joint is moved, goniometer arms are held in place either along or parallel to long axis of bones on either side of joint.
Joint angle is then read from goniometer.
