Anatomy and Physiology 101: Chapter 9, Muscular System
I.
Overview
A. List 6 functions of muscles
1.
2.
3.
4.
5.
6.
II.
Types of Muscles
A. Smooth Muscles
1.List three characteristics of smooth muscles
1.
2.
3.
2.List three locations of smooth muscles
1.
2.
3.
B. Cardiac Muscle
1.List four characteristics of cardiac muscles
1.
2.
3.
4.
2.Name 1 location of cardiac muscle:
C. Skeletal Muscles
1.List four characteristics of skeletal muscles
1.
2.
3.
4.
III.
Structure of Skeletal Muscles
A. Connective tissue attachments
1.What is fascia?
2.What is a tendon? How does it differ from a ligament?
3.What are aponeuroses?
B. Connective tissue coverings
1.Skeletal muscle fibers are organized into bundles called ___________.
2.Distinguish between the epimysium, perimysium, and endomysium.
C. Levels of organization within a skeletal muscle from largest to smallest
1.Muscle
2.
3.
4.
5.
6.Actin and myosin
IV.
Skeletal Muscle Fibers
A. Cell membrane is called:
B. Cytoplasm is called:
C. Network of membranous channels corresponding to ER:
D. SR are large storage tanks for:
E. Membranous channels that run transversely from the surface into the sarcoplasm:
F. Enlarged portions of SR:
G. What is a triad?
H. Filaments
1.Thin filaments are:
2.Thick filaments are:
I. Striation Patterns
1.The I bands are composed of:
2. The A bands are composed of:
J. Sarcomere
1.What is a sarcomere?
2. Which filaments are attached to Z-lines?
3. What happens to Z-lines during a muscle contraction?
4.Cross-bridges are located on which filaments?
V.
Skeletal Muscle Contractions
A. Motor Neurons
1.What is a motor neuron?
2.Define a motor unit:
3. Explain the synapse, and describe how neurons communicate through a synapse.
4. The gap at the synapse is called __________________________.
5. The site where an axon and a muscle fiber meet is called a ___________________.
6. What is the motor end plate?
VI.
Stimulus for Contraction
A. Which neurotransmitter is used to stimulate muscle contractions?
B. Explain eight steps that occur with the initiation of a contraction.
1. Nerve impulse (action potential) reaches axon terminal.
2.
3.
4.
5.
6.
7.
8. SR releases ______, which initiates a muscle contraction.
VII.
VIII.
Excitation Contraction Coupling
A. Explain the role of Calcium in initiating a muscle contraction. What role does the troponintropomyosin complex play?
Sliding Filament Theory of Contraction
A. Explain the sliding filament theory of contraction.
B. What happens to the I-bands during a contraction?
C. What happens to the Z-lines during a contraction?
IX.
Cross-Bridge Cycling
A. Draw a Myosin filament with a Cross-Bridge in the cocked position
B. Draw a Myosin filament with a cross-bridge in the sprung position
1.Include arrows depicting the power stroke and the recovery stroke
2.Which enzyme provides the energy required to recock the cross-bridges during the
recovery stroke?
C. Describe the 6 events during cross-bridge cycling. Note when ATP, ADP, or neither is attached
to the cross-bridge.
1.Muscle is relaxed. Tropomyosin hides the actin filaments from myosin. ADP and P are
attached to cross-bridge (from previous cycle).
2.
3.
4.
5.
6.
X.
Muscle Relaxation
A. Describe the two events that lead to muscle relaxation
1.
2.
XI.
Energy Sources for Contractions
A. What is the only source of energy that can be used to directly power muscle contractions?
B. Creatine Phosphate
1.What reaction releases energy from creatine phosphate?
2. What is the energy from creatine phosphate used for?
3.How much energy is available from creatine phosphate?
C. Glycolysis
1.Is glycolysis anaerobic or aerobic respiration?
2.How many ATP are produced from glycolysis?
3.Why is glycolysis the primary source of energy for intense exercise as opposed to aerobic
respiration?
4.What product accumulates in muscles as a result of anaerobic respiration?
5. What is meant by Oxygen Debt?
6. Which organ converts lactic acid back to glucose once oxygen supplies are available?
D. Aerobic Respiration
1.How many ATP can be produced from aerobic respiration?
2. Is aerobic respiration more or less efficient than anaerobic respiration?
3. Aerobic respiration occurs in which part of the cell?
E. Muscle Fatigue
1.Where is hemoglobin located, and what is its function?
2.Where is myoglobin located, and what is its function?
3.Define muscle fatigue. What is the greatest cause of muscle fatigue?
4. Define a cramp.
XII.
Muscular Responses
A. Define threshold stimulus:
B. Define twitch:
C. Draw a Myogram recording of a twitch and label the three periods of the twitch:
D. Summation
1.What is summation?
2.What is a tetanic contraction?
E. Recruitment of Motor Units
1.Describe what is meant by recruitment of motor units. Do individual muscle fibers
increase their force of contraction with recruitment?
XIII.
Types of Contractions
A. Define an Isotonic contraction and give an example.
1.How does a concentric contraction differ from an eccentric contraction?
B. Define an isometric contraction and give an example.
C. What is muscle tone?
XIV.
Slow and Fast Twitch Fibers
A. Provide four characteristics of Slow twitch (type I) fibers
1.
2.
3.
4.
B. Provide three characteristics of Fast twitch, type IIb fibers
1.
2.
3.
C. Provide two characteristics of Intermediate, Type IIa fibers
1.
2.
D. Which fibers are fatigue resistant?
E. Which fibers are glycolytic, which are oxidative?
F. Which fibers contain numerous mitochondria and a good blood supply?
G. Which fibers are red, which are white?