Study Guide

Muscular System

ANS 215 Anatomy and Physiology of Domestic Animals

1. Classification, Arrangement, Harnessing
1. What kinds of nerves are associated with the activity of smooth, cardiac and skeletal muscle?
2. What is the principle distinguishing characteristic between smooth muscle and cardiac and skeletal muscle?
3. What is the function of an intercalated disc in cardiac muscle?
4. What is the functional difference between red and white skeletal muscle fibers?
5. What is the difference between an adductor and an abductor skeletal muscle?
6. What is the difference between the origin and insertion of a skeletal muscle?
7. Differentiate between epimysium,perimysium and endomysium. Which of these is associated most intimately with individual muscle fibers?
2. Microstructure of Skeletal Muscles
1. Is a muscle fiber the same as a muscle cell?
2. Understand the division of a muscle fiber into myofibrils; myofibrils into sarcomeres; sarcomeres into myofilaments; and myofilaments into actin and myosin.
3. Be able to sketch a sarcomere and the spatial arrangement of the myofilaments.
4. Relate the striations(banding) of skeletal muscle to the myofilaments.
5. Which tubule set of the sarcotubular system opens to the outside of the muscle fiber and contains the extracellular fluid?
6. What is the location of the sarcoplasmic reticulum relative to T tubules and myofibrils?
7. What is the function of the sarcotubular system?
8. What is a neuromuscular junction and how many are there for each muscle fiber?
9. What is a motor unit?
3. Skeletal Muscle Contraction
1. Describe the chain of events that initiate muscle fiber membrane depolarization.
2. What is the association of Ca++ to Ach release? How is this related to milk fever in cattle?
3. What is the trigger for release of Ca++ release from the sarcoplasmic reticulum? Where do the Ca++ go following their release?
4. Study the molecular basis fo muscle contraction with emphasis on sequence and related to shortening and relaxation of muscle fibers.
5. What molecule appears to be necessary for relaxation?
6. What causes rigor mortis?
7. What is muscle tetany? Is this a reflection of motor unit or wave summation?
8. How is the bacterial disease tetanus related to CNS neurotransmitters?
9. What characteristic of muscle contraction is generally similar among smooth .cardiac and skeletal muscle fibers?
10. Differentiate harnessing, innervation, and stimulus conduction between cardiac and skeletal muscle.
11. Do smooth muscle fibers have actin and myosin, a neuromuscular junction, a harnessing system, and a sarcotubular system?
12. What is the difference between hyperplasia and hypertrophy?
13. How do skeletal muscle fibers hypertrophy (grow in size) after birth?
14. Is regeneration of skeletal , cardiac and smooth muscle fibers possible?
15. What is muscle atrophy?