Anatomy: MSK 2
extrinsic ligaments
supporting bands
electrical excitability
the ability to respond to a stimulus and convert it into an action potential
types of cartilaginous joints
synchondrosis, symphysis
aponeurosis
A broad, flat tendon
pivot joints
C1-C2, rotation
extensibility
ability to be stretched
bursa
a fibrous sac between certain tendons and bones that is lined with a synovial membrane that secretes synovial fluid
ball-and socket joint
shoulder and hip, all actions
myofibrils
contractile elements of muscle fiber
elasticity
ability to return to original length after contraction
contractability
ability to shorten
contractile myofilaments
actin (thin) and myosin (thick)
epimysium
connective tissue surrounding entire muscle
sarcomere
contractile unit of a myofibril
types of myofilaments
contractile, regulatory, structural
sarcoplasm
cytoplasm of a muscle cell
terminal cisterns
dilated end sacs of the sarcoplasmic reticulum
articular disc
discs of fibrocartilage that divides synovial cavity
hinge joint
elbow and knee, flexion and extension
Properties of Muscular Tissue
electrical excitability, contractility, extensibility, elasticity
labrum
fibrocartilaginous lip, ball-and-socket joints
diathrosis
freely movable
plane joints
hand bones, flat/sliding/gliding
troponin
holds tropomyosin in place
articular cartilage
hyaline cartilage that covers ends of bones in synovial joints, NOT binding
meniscus
incomplete, fibrocartilaginous disc in the knee
hypertrophy
increase in muscle size; increase production of myofibrils
transverse (T) tubules
invaginations of sarcolemma; allow electrical impulses to travel deep into the cell
sarcoplasmic reticulum (SR)
membranous sacs that encircle each myofibril; stores Ca2+
isometric contraction
muscle tenses but does not shorten
synergist
muscle that aids a prime mover in a movement and helps prevent rotation
antagonist
muscle that opposes the prime mover
fixator
muscle that prevents a bone from moving
prime mover (agonist)
muscle that produces most of force during a joint action
isotonic contraction
muscles contract and shorten
gomphoses
peg-in-socket, teeth, periodontal ligament
crystal arthritis (gout)
sodium crystals deposited in joints
skeletal muscle
striated and voluntary
types of fibrous joints
sutures, syndesmoses, gomphoses
syndochondrosis
bones joined by hyaline cartilage; epiphyseal growth plates
fibrous joints
bones joined by solid mass of dense irregular CT
fibrous and cartilaginous joints
bones joined by solid masses of CT
ligaments
Connect bone to bone
tendons
Connect muscle to bone
perimysium
Connective tissue surrounding a fascicle
endomysium
Connective tissue surrounding a muscle fiber
sarcolemma
muscle plasma membrane
extension
Straightening of a joint, sagittal plan
insertion
attachment of tendon to moveable bone; distal/inferior
origin
attachment of tendon to stationary bone; proximal/superior
rheumatoid arthritis (RA)
autoimmune, attacks own joint lining/synovial membrane
abduction
away from the midline
flexion
bending a joint, sagittal plane
tropomyosin
blocks myosin head from binding to actin in relaxed muscle
rotation
bone revolves around its own longitudinal axis, internal or external
synovial joints
bones joined by a CT capsule surrounding a lubricated cavity
symphysis
bones joined by fibrocartilage; intervertebral discs
Osteoarthritis (OA)
breakdown of articular cartilage
fascia
dense irregular CT, wraps around groups of muscles or structures
syndesmosis
more substantial and longer fibrous connections, between forearms bones and leg bones
adduction
movement toward the midline
eccentric contraction
muscle lengthens
sutures
seams between bones of the skull
synovial membrane
secretes synovial fluid which reduces friction and absorbs shock
circumduction
the circular movement at the far end of a limb, all four movements
intrinsic ligament
the ligament that is binding the bones
synovial capsule
the outermost layer of dense irregular CT that resembles a sleeve as it surrounds the joint
saddle joint
thumb, everything except rotation
Ca2+ when released into sarcoplasm
triggers muscle contraction
regulatory myofilaments
troponin and tropomyosin
condyloid joint
wrist, everything except rotating