Module 8 - Muscle Tissue

Question 1

Properties of Muscle

Answer 1

Properties of Muscle
Excitability – respond to stimulation or impulses or hormones
Contractility – shorten or contract with force
Extensibility – stretch beyond resting length
Elasticity – returns to resting length

Question 2

Functions of Muscle

Answer 2

Functions of Muscle
Produce Movement
Stabilize
Regulate organ volume
Move substances
Generates heat

Question 3

Structural Classifications

Answer 3

Structural Classifications
Skeletal Muscle – attached to bones – striated and voluntary
Cardiac Muscle – walls of heart – striated and involuntary
Smooth Muscle – viscera – nonstriated and involuntary

Question 4

Cardiac Muscle

Answer 4

Cardiac Muscle
Heart wall
Fibers connect to fibers by intercalated discs – desmosomes and gap junction
Long contractions – prolonged calcium ions from sarcoplasmic reticulum and extracellular fluid
Autorhythmic fibers
Perimysium and endomysium cover
Regulating proteins – troponin and tropomyosin
Moderate contraction speed
Regulated by:
Hormones
Acetylcholine and norepinephrine of autonomic motor neurons

Question 5

Smooth Muscle

Answer 5

Smooth Muscle
Single unit of hollow viscera and small blood vessels
Joined by gap junctions – contract as single unit
Network for action potentials
Multiunit – large blood vessels, large airways, arrector pili muscles, and iris
Individual fibres
Own neuron terminals – few gap junctions
Autorhythmic
Spindle-shaped
No sarcomeres – nonstriated
Contain myosin and actin myofilaments
No troponin
Endomysium cover only
Slow contraction
Regulated by:
Hormones
Acetylcholine and norepinephrine of autonomic motor neurons
Local chemical changed
Stretching