Chapter 9&10

Each individual muscle cell (fiber) is surrounded by the

Endomysium

Several muscle cells are bundled together into a

Fascicle

Several muscle cells are bundled together into a fascicle by the

Perimysium

All fascicles that make up a muscle are, in turn, enclosed by the

Endomysium

Interconnected connective tissues taper down and connect to

Tendons or other connective tissues

Interconnected connective tissues do what

Attach muscle to bone or other structure to be moved

What supports soft tissue

Muscle contraction

What muscle contraction do for heat

Generate

What is contraction of diaphragm muscle responsible for

Respiratory system, breathing

What does muscles in throat do

Assist with swallowing

General name of the muscle that provides most force for a given muscle action

Agonist

General name of the muscle that have opposite action of agonist; allows for modulation and control of agonist movement

Antagonist

General name of the muscle that aid agonists by supplying supplemental force, minimizing unwanted movement, and by helping to stabilize joints

Synergist

General name of the muscle that provide stabilizing force that anchors a bone, protection from injury due to unnecessary movements

Fixator

What is anchoring point on a bone, not involved directly with movement of joint

Origin

Moving end of muscle whose tendon attaches to a bone or other structures

Insertion

Muscle tension

Basic function common to each muscle tissue type

Skeletal muscle tissue

Voluntary control, multinuclear

Cardiac muscle tissue

Branching, uninuclear, involuntary

Smooth muscle tissue

Spinal shape, uninuclear, involuntary, ex: arrector pili

Ability to contract where proteins in the cell draw closer together

Contractility

Ability of a cell to respond to a stimulus

Excitability

Ability of a cell to conduct electrical changes across the plasma membrane

Conductivity

Ability of a cell that allows it to be stretched without being ruptured

Extensibility

Ability of a cell that allows it to return to its original length

Elasticity

Name of muscle cells

Myocytes

The muscle cell’s cytoplasm

Sarcoplasm

The muscle cell’s plasma membrane

Sarcolemma

Bundles of specialized proteins, including those involved in muscle contraction

Myofibrils

Modified smooth endoplasmic reticulum that forms a weblike network surrounding each myofibril

Sarcoplasmic Reticulum (SR)

What does Sarcoplasmic Reticulum (SR) do

Stores/releases calcium

What do mitochondria create

ATP or energy

Inward extensions of sarcolemma that surround each myofibril is named

Transverse tubules (T-tubules)

Thick filaments

Myosin

Thin filaments

Actin, tropomyosin, troponin

Elastic filaments

Titin

Muscles that regulates contraction

Tropomyosin, troponin

Muscle that look like spring

Titin

What theory explains how tension is generated during muscle contraction

Sliding filament

Functional unit where contraction occurs

Sarcomere

What happens to the I band and the H zone while sliding filament theory.

Narrow

What happens to the A band while sliding filament theory.

Remains unchanged

What happens to the Z-disc while sliding filament theory.

Closer together, shortening the sarcomere

What is neuromuscular junction

is the synapse where a motor neuron communicates with a skeletal muscle fiber.

Motor neuron is

related to muscle only, a nerve cell that carries signals from your brain or spinal cord to a muscle, telling it to contract.

What is axon terminal

The end of motor neuron

What synaptic vesicles filled with

Acetylcholine (ACh)

What is synaptic cleft

The small gap between the axon terminal and the muscle fiber

Motor end plate is

Region of sarcolemma the receives signals

Three phases of muscle contractions

Excitation, excitation-contraction, contraction

Acetylcholine is released, electrical signal that travels along the sarcolemma and down the T-tubules.

Is excitation

The electrical signal causes the sarcoplasmic reticulum (SR) to release Ca²⁺. Calcium binds to troponin, which shifts tropomyosin and exposes the myosin-binding sites on actin.

Is excitation-contraction

Myosin binds to actin and pulls it, shortening the sarcomere. ATP binds to myosin, making it detach, and ATP breakdown resets the myosin head. The cycle repeats while calcium and ATP are available.

Is contraction (cross-bridge cycle)

ACh is broken down, and Ca²⁺ is pumped back into the SR. Tropomyosin covers the binding sites again, cross-bridge cycling stops, and muscle tension falls.

Is relaxation

____ can immediately regenerate enough ATP for 10 sec

Creatine phosphate

Immediate cytosolic reactions, Glycolytic catabolism,
Oxidative catabolism generate

ATP and they are sources of energy for muscle contraction