Musculo quiz 2 Flashcards
3 types of connective tissue
loose (binds skin to organs)
dense (tendons and ligaments)
cartilage (hyaline)
regular connective tissue
regularly arranged collagen fibers (deep fascia, aponeurosis, ligaments, tendons); resists tension well that is parallel to the fibers
irregular connective tissue
loose irregular (sheaths between muscles, subcutaneous, superficial fascia) and dense irregular (dermis, connective tissue, joint capsules)
2 things that make up extracellular matrix in connective tissue
ground substance (viscous gel that supports/strengthens) and collagen fibers (support/elasticity)
2 types of cells in connective tissue
resident (all the -blasts; synthesis/maintenance) OR circulating (-cytes,-phages; defense and clean up)
ultimate strain
strain to the point of failure (deformity)
ex) tendon rupture
tensile strain
maximum stress that a material can withstand while being stretch or pulled before breaking
hysteresis
loss of energy when forces is applied (energy dissipates)
Collagen I
main component of bone; skin, tendon, vascular binding, organs
Collagen II
main component of cartilage
Collagen III
main component of reticular fibers
Collagen IV
forms bases of cell membrane
Collagen V
cell surfaces, hair, placenta
in relaxed states, collagen fibers look
wavy/crimpy
tensile load
2 externally applied forces acting in opposite directions
tensile stress
tensile force applied in the direction of the applied force
function of ligament
attach bone to bone
biomechanical properties of ligaments
resists tensile forces in direction of fibers, reinforces joint capsule in areas of increased stress, provides stability, more or less elastic
function of tendon
attach muscle to bone
biomechanical properties of tendons
produce torque around joint, stablizies, slightly elastic, tensile strength is placed on the tendon with active contraction of associated muscle vs passive lengthening
Common to both ligaments and tendons
surrounded by loose areolar connective tissue that forms sheaths
open kinetic chain
gravity’s pull is most responsible
ex) bicep curl, bench press
closed kinetic chain
to depress and raise body against gravity
ex) pushing up from a chair
muscles that provide compressive forces on the humeral head
rotator cuff muscles (SITS): supraspinatus, infraspinatus, teres minor, subscapularis
scapula stabilizers
trapezius and serrates anterior
static stabilizers of GH joint
(end range, stop from hyper mobility)
ligaments/capsule, labrum
dynamic stabilizers of GH joint
(mid range)
rotator cuff SITS
3 dimensional motions of scapula
upward rotation, posterior tilt, from internal towards external rotation
3 dimensional motions of GH joint
spins, rolls, glides, external rotation
1st phase
0-60 degrees
GH joint: deltoid and supraspinatus
ST joint: upper trap and serratus anterior
2nd phase
60-120 degrees
GH: deltoid and ant/post cuff mx
ST: upper trap and serratus anterior
final phase
120-180 degrees
humerus disengages from scapula
scapular force couple - serratus anterior and upper trap provide upper components, and lower trap provides lower component to upwardly rotate scapula
Identify muscles that are involved with spasticity following a stroke
flaccid supraspinatus and posterior deltoid are primarily responsible; spacity of subscapularis and pectoralis major (inward rotators)
Joints at the elbow
medial (ulnar) collateral ligaments (tommy john surgery)
radial collateral ligament
annular ligament (stabilizer for rotation at forearm)
lateral ulnar collateral ligament
accessory lateral collateral ligament
at 1 DOF
elbow flexion (biceps brachii, brachialis, brachioradialis) and extension (triceps, anconeus), forearm pronation (proximal and distal radioulnar joints; pronator teres and quadratus) and supination (proximal and distal radioulnar joints; supinator and biceps) *brachioradialis is a pronator and supinator (at neutral it has no effect)
varus
distal bone towards the body
vagus
distal bone away from the body
Inhibition of elbow flexors
flexion of forearm in supination strongly activates biceps; flexion of forearm in pronation deactivates biceps and motion occurs mainly by brachialis
activities that create isometric contractions at the elbow
static hold of weight
activities that create concentric contractions at the elbow
bicep curl
activities that create eccentric contractions at the elbow
lowering a weight in bicep curl
contractile unit of muscle
myofibril: contractile unit in a muscle fiber
sarcomere: contractile unit of muscle fibers containing actin and myosin
golgi tendon organ
detects changes in muscle tension; located in origins and insertions
muscle spindle
detects change in length of muscle; receptors located within the body of muscle
active insufficiency
when a muscle contracts but isn’t strong enough; when a mx is not able to create its full excursion due to the muscle shortening and not having the available length
ex) arm in a cast
passive insufficiency
an opposing joint muscle is too short to allow full ROM (muscle is so tight it doesn’t have the length for the therapist to passively extend the muscles
slow twitch muscle fibers
resistant to fatigue and are contracted from aerobic activity (marathon runner)
fast twitch muscle fibers
lower resistance to fatigue and are anaerobic (sprinter)
fusiform
(strap) have parallel fibers to long axis to allow increase ROM (biceps)
unipennate
have fibers on one side of the tendon (flexor pollicis longus)
bipennate
have fibers on both sides of the tendon (rectus femoris)
multipennate
have fibers that converge on several tendons (deltoid)
spiral
fibers spiral around a long axis (latissimus dorsi)
common characteristic of connective tissue in bone - anisotropic
different values when measured in different directions; strength and elasticity vary based on orientation in space (ex. wood is stronger across its grain)
muscle actions at the proximal radiohumeral joint and elbow
pronation and supination, flexion and extension
common characteristic of connective tissue in bone - viscoelasticity
time dependent (ex. human tissue)
common characteristic of connective tissue in bone - hysteresis
loss of energy when force is applied (energy dissipates)
