Card Set Information
What are the 3 types of muscle mass in the body?
(1) Skeletal - voluntary, attached to bones
(2) Cardiac - involuntary, in the heart
(3) Smooth - involuntary, in the walls of the hollow visceral organs (not the heart)
What are the 4 functions of muscle mass and which type of muscle play a role in each?
Skeletal - locomotion and manipulation
Cardiac - provides pressure for movement of blood
Smooth - helps maintain BP
(2) Postural Maintenance
Skeletal - maintain posture
(3) Joint Stability
Skeletal - contribute
(4) Heat generation
Skeletal - responsible for most of heat generation
(muscles generate heat when contract)
What are elasticity and plasticity?
Elasticity = ability of a muscle to STRETCH
Plasticity = ability to take new stretched form
What is the role of the T-tubules?
Transfer-tubules = allow nerve impulses to transfer from one side of the muscle to the other
Explain the role of ATP and Ca in contraction and relaxation
ATP required for both
ATP = energy supply for contraction - required for sliding of the filaments
= required for separation of actin and myosin (relaxing)
Ca triggers muscle contraction, if ATP is present, the muscle will contract
What are the 6 phases of muscle contraction?
(1) Ca influx exposes binding sites on actin
(2) Actin and myosin bind
(3) Power stroke filaments slide over each other
(4) ATP binds to x-bridges releasing actin
(5) Hydrolysis of ATP to ADP and Pi
(6) Ca transported to SR