Chapter 10 Flashcards
Properties of muscle tissue
Contractability
Excitability
Conductivity
Extensibility
Elasticity
Functions of muscle tissue
Body movement
Movement of internal substances
Open and close body passages
Maintain posture and body stability
Generate heat
3 Types of muscle tissue
Skeletal, cardiac, and smooth
Skeletal muscle
Attaches to bone
Voluntary, striated, and multinucleated
Cardiac muscle
Found in the heart
Striated and involuntary
Smooth muscle
Found in the walls of hollow organs, blood vessels, and the digestive tract
Involuntary and not striated
Fleshy muscle attachments
Short fibers, muscle appears to attach directly into bone
Indirect muscle attachments
Long fibers of connective tissue connect muscle to bone via tendons or aponeuroses
Origin
The attachment on the less movable bone; remains relatively fixed
Insertion
The attachment on the bone that moves
Contractile proteins
Actin and myosin
Actin
Thin filament that extends from the z-discs
Myosin
Thick filament that contains ATPase and binds to actin to produce movement
Regulatory proteins
Troponin and tropomyosin
Troponin
Rests on tropomyosin and binds to calcium ions to move tropomyosin
Tropomyosin
Covers actin binding sites when not contracting
Structural Protein
Titin
Functions to provide proper alignment, elasticity, and extensibility
Organization of muscle tissue
Largest
Muscle- Organ
Fascicle- Bundle
Fiber- Cell
Myofibril- Contractile organelle
Sarcomere- Contractile unit
Smallest
Epimysium
Connective tissue that surrounds entire muscles
Perimysium
Connective tissue that surrounds and divides fascicles
Endomysium
Surrounds individual muscle fibers
Z disc
Border of the sarcomere
Move closer together during contraction
A band
Full length of myosin filament
Does not change during contraction
H zone
The Center of the A band, contains no actin
Shortens/disappears during contraction
M line
Rods in the center of the sarcomere that hold myosin together
Not impacted during contraction
I Band
Ends of adjacent sarcomeres with only actin
Shortens during contraction
Sarcolemma
Plasma membrane of muscle fibers
Transverse (T) Tubules
Deep extensions of the sarcolemma that deliver nerve impulse to deep myofibrils
Sarcoplasmic reticulum
Specialized smooth ER that contains and releases calcium ions when stimulated that triggers sliding filament mechanism
Concentric contraction
Produce force while shortening
Eccentric contraction
Produce force while lengthening
Motor unit
One motor neuron and all of the muscle fibers it innervates
All fibers contract when the neuron fires
