BIO 1007 Lecture Outlines | BIO 1007 Resources | Mrs. Caley Opsal's Home | IVCC Home | Contact Us
I. Functions of Skeletal Muscle
A. Movement
B. Posture
C. Generate Heat
D. Stabilize Joints
II. Anatomy of Skeletal Muscle
A. Connective Tissue Coverings: See IP-CD: Muscular System, Skeletal Muscle Anatomy Review.
1. Fascia - fibrous connective tissue which separates individual muscles
2. Epimysium
3. Perimysium
4. Endomysium
5. Fascicle -
6. Tendons -
7. Aponeuroses -
B. Skeletal Muscle Fibers and Microscopic Anatomy: See IP-CD: Muscular System, Skeletal Muscle Anatomy Review.
1. Myofiber (muscle fibers or muscle cells)
2. Sarcolemma
3. Sarcoplasmic reticulum (SR)
4. Terminal cisternae of SR
5. Transverse tubules (T-tubules)
6. Mitochondria
7. Myofibrils
8. Cytosol (Sarcoplasm)
9. Sarcomere
a. Z lines
b. M line
c. A bands
d. I bands
e. H zone10. Myofilaments
a. Actin
i. Troponin
ii. Tropomyosinb. Myosin
C. Neuromuscular Junction - See IP-CD: Muscular System: Neuromuscular Junction section
1. Motor neuron (axon terminal)
2. Motor end plate of a myofiber (sarcolemma, nuclei & mitochondria)
3. Synaptic cleft
4. Neurotransmitter vesicles and neurotransmitter molecules (ACh)
D. Motor Units - A.D.A.M. Physiology: Contraction of Motor Units p. 3 only
1. Small motor units (fewer myofibers innervated)
2. Large motor units (more myofibers innervated)
III. Skeletal Muscle Physiology: See IP-CD: Sliding Filament Theory.
A. Summary of the Sliding Filament Model of Muscle Contraction
In your own words, write a brief summary of the process of muscle contraction.
1. _____________________________________________________________
2. _____________________________________________________________
3. _____________________________________________________________
4._____________________________________________________________
5. _____________________________________________________________
B. Muscle Relaxation: See A.D.A.M. Interactive Physiology: Neuromuscular Junction p. 10.
1. Acetylcholinesterase
2. Calcium-pump
Interesting Little Tidbit: Rigor mortis and muscle cramps occur due to a relative lack of ATP
C. Energy Sources for Contraction: See IP-CD: Muscle Metabolism
1. Quick Sources
a. Stored ATP
b. Creatine phosphate
2. Anaerobic Respiration
a. Glycolysis
b. Glucose
3. Aerobic Respiration
a. Kreb's Cycle and the Electron Transport System
b. Glucose
c. Fats
d. Proteins
Muscle fatigue usually occurs due to a build-up of ____________ acid from ____________________ respiration.
D. Oxygen Supply: Muscle Metabolism
1. Myoglobin
2. Lactic Acid
3. Oxygen debt = amount of oxygen needed for liver to convert lactic acid into glucose
E. Types of Muscle Fibers: See IP-CD: Muscle Metabolism.
White, Fast-twitch fibers
Red, Slow-twitch fibers
F. Muscle Mechanics: See IP-CD: Contraction of Whole Muscle (handout)
1. All-or-none Principal-
2. Frequency of Stimulation
a. Threshold stimulus - minimum amount of electrical stimulation needed to cause a muscle to contract
b. Twitch contraction (make sketch)
i. Latent Period
ii. Contraction Phase
iii. Relaxation Phase
c. Summation
d. Incomplete Tetanus
e. Complete Tetanus-
f. Fatigue
3. Number Muscle Fibers Involved
a. Motor units
b. Recruitment-
c. Muscle Tone-
d. Muscle Atrophy-
4. Isotonic contraction-
5. Isometric contraction-
G. Muscle Elongation
1. Passive process
2. Elastic forces
3. Antagonist muscle movements
IV. Skeletal Muscle Actions
A. Origin -
B. Insertion -
C. Prime mover-
D. Synergist-
E. Antagonist-
V. Naming Skeletal Muscles
A. Location
B. Action
C. Origin and Insertion
D. Shape
E. Size
F. Direction of fibers
G. Number of attachments
VII. Smooth Muscle and Cardiac Muscle
A. Smooth Muscle Fibers
1. No myofibrils, sarcomeres or striations
2. Cell-to cell transmission of impusles (anchoring sites connect adjacent cells)
3. Calcium binds to Calmodulin
4. Wave-like contractions (peristalsis)
5. Involuntary control and hormonally influenced
B. Cardiac Muscle
1. Automaticity of pacemaker cells
2. Contractions last 10x longer than skeletal muscle
3. Longer refractory period than skeletal muscle and cannot undergo tetany
4. Relies on aerobic respiration
Last Updated 10/08/07