Meh 2

Movement

Function of skeletal muscles involving contraction to pull on bones for limb, trunk, and head movement.

Posture

Function of skeletal muscles aiding in maintaining body upright and balanced.

Body Temperature Regulation

Function of skeletal muscles generating heat to regulate body temperature.

Stabilization

Function of skeletal muscles stabilizing joints during movement.

Storage

Function of skeletal muscles storing glycogen and amino acids.

Epimysium

Outermost connective tissue layer surrounding the entire muscle.

Perimysium

Connective tissue surrounding bundles of muscle fibers.

Endomysium

Delicate connective tissue surrounding individual muscle fibers.

Tendon

Tough connective tissue connecting muscle to bone.

Ligament

Tough connective tissue connecting bone to bone.

Fascicle

Bundle of muscle fibers surrounded by perimysium.

Muscle Fiber (Myocyte)

Individual muscle cell.

Myofibril

Thread-like bundle of protein filaments within a muscle fiber.

Sarcomere

Basic contractile unit of a myofibril.

Thick filaments (Myosin)

Protein filaments arranged in the center of the sarcomere.

Thin filaments (Actin)

Protein filaments found on either side of the thick filaments.

Z-lines

Thin lines marking the ends of the sarcomere.

A-band

Dark region in the center of the sarcomere where thick filaments overlap thin filaments.

I-band

Lighter region containing only thin filaments.

M-line

Line in the middle of the A-band anchoring thick filaments.

Neural Impulse

Nerve signal traveling to the neuromuscular junction.

Calcium Release

Triggering release of calcium ions from the sarcoplasmic reticulum.

Calcium Binding

Calcium binding to troponin on thin filaments, uncovering myosin binding sites.

Cross-bridge Formation

Myosin heads binding to actin, forming cross-bridges.

Power Stroke

Myosin heads bending, pulling thin filaments towards the sarcomere center.

Detachment and Reattachment

Myosin heads detaching, re-cocking with ATP, and reattaching to actin.

Neuromuscular Junction (NMJ)

Specialized synapse between motor neuron and muscle fiber.

Botulism

Illness caused by toxin blocking acetylcholine release at NMJ, leading to muscle paralysis.

Rigor Mortis

Stiffening of muscles after death due to ATP depletion.

Tetanus

Bacterial infection.

Fast Twitch Muscle Fibers

Fibers that contract quickly but fatigue rapidly. Used for quick and powerful movements like sprinting. Rely on anaerobic metabolism.

Incomplete Tetanus

a state of sustained muscle contraction with partial relaxation between stimuli. It occurs when muscle fibers partially relax between stimuli, leading to a sustained but wavering contraction.

Complete Tetanus

fused tetanus. During ____ tetanus, there's no relaxation period between muscle contractions.

Isotonic Contractions

involve muscle length changes with constant tension. They can be either concentric (muscle shortens) or eccentric (muscle lengthens).

Isometric Contractions

occur when muscles generate force without changing length, such as pushing against an immovable object. This type of contraction does not result in movement at the joint.

Muscle Fatigue

the decline in muscle's ability to generate force. It can be caused by factors like accumulation of lactic acid, depletion of energy stores, and buildup of metabolites. Recovery involves rest, hydration, and proper nutrition.

Agonist

A substance that binds to a receptor and activates it.

Antagonist

A substance that binds to a receptor and blocks its activation.