Molnar Anatomy Lecture Exam 2 cards

deep invaginations of the sarcolemma that run between each pair of terminal cisterns

• Structure: "end sacs" for perpendicular A-I junctions
• Function: store large quantities of calcium to be released when the muscle is stimulated to contract

Structure: cluster of enlargements at the end of the axonal process

Function: the point at which the nerve ending and the muscle fiber meet which signals the muscle fiber to contract.

When a nerve impulse reaches the axon terminal

It binds to the receptor molecules on the sarcolemma, where it induces an impulse that initiates fiber contraction.

Troponin changes confirmation and that causes tropomyosin to be dislodged from the sites. Myocin heads interact with actin and pull actin towards the M-line.

where the rigid elements of the skeleton meet. (also known as articulations)

By function or structure

• Function - amount of movement
• Structure - based on materials that bind bones together

• 1) Snyarthroses - unmovable
• 2) Amphiarthroses - slightly movable
• 3) Diarthroses - freely movable

• 1) Fibrous
• 2) Cartilagenous
• 3) Synovial

• 1) Articular cartilage
• 2) Joint cavity (synovial cavity)
• 3) Articular capsule
• 4) Synovial fluid
• 5) Reinforcing ligaments
• 6) Nerves and vessels

• 1) Articular disc (meniscus)
• 2) Bursa
• 3) Tendon sheath

covers surface of articulating bones

filled with synovial fluid

fibrous capsule and synovial membrane

lubricates free surfaces

joint reinforcements

for feeling and nutrients

• 1) Shape of the articular surfaces
• 2) Number and position of stabilizing ligaments
• 3) Muscle tone

• Plane joints - non axial
• Hinge joints - uni axial
• Pivot joints - uni axial
• Condyloid joints - bi axial
• Saddle joints - bi axial
• Ball & Socket joints - tri axial

They are both a flattened fibrous sac lined by a synovial membrane. Bursae occur where ligaments, muscles, skin, tendons or bones overlie and rub together. Tendon sheaths only occur in tendons.

flat articular surfaces, gliding joints

vertebra to vertebra; ribs to vertebrae

cylindrical end of one bone fits into a trough surface on another bone

ulna to humerus; elbow joint

rounded end of one bone fits into a ring that is formed by another bone plus an encircling ligament

C-1 to C-2; radius to ulna

egg-shaped articular surface of one bone fits into oval concavity of another

radius, knuckles

articular surface has concave and convex

ball of thumb

spherical head in round socket

shoulder and hip

• 1) Linear
• 2) Rotation
• 3) Angular

Linear, Angular, Rotation and Special movements

• 1) Heat generation
• 2) Movement
• 3) Posture
• 4) Joint stability

• 1) Contractibility
• 2) Excitability
• 3) Extendibility
• 4) Elasticity

plasma membrane

cytoplasm

endoplasmic reticulum of the muscle fiber

cells of skeletal tissue

surrounds entire skeletal tissue

composed of DICTP

defines fascicles

composed of fibrous CT

what surrounds each muscle fiber

reticular fibers

Tendon is a cord of DRCT that attaches muscle to bone.

• origin - where muscle starts
• insertion - where muscle ends

Origin is on the less movable bone and insertion is on the more movable bone

The smallest contractible unit of skeletal and cardiac muscle; the part of a myofibril between 2 Z-discs. Basic unit of contraction in skeletal muscle.

proteins found within myofibril

• myofilaments;
• actin=thin, myosin=thick

spring-like elastic filaments attached to myosin

the boundaries at the end of each sarcomere

dark bands; full length of thick filament

region on either side of the A-bands that contain only filaments

central part of A-band with only myocin

the center of the H-zone