Exam 12: Muscles

Smooth muscle cells of blood vessels are described as integrating centers.Outline the various inputs that affect smooth muscle cells and how those are integrated.

The heavy chain of myosin contains 2 important regions: the first acts as ________ to convert energy into movement whereas the second binds to ________.

The speed with which force is developed by skeletal muscles is determined by the

________ is the backup energy molecule that can be rapidly converted to ATP in active skeletal muscle.

Compared to skeletal muscle,contraction of smooth muscle cells is

Match from the following list. -The lightest color bands of the sarcomere,comprised only of thin filaments.

Match from the following list. -The letter assigned to this structure stands for the German word for middle; it is the attachment site for the thick filaments.

The graph below was generated by students in a physiology lab.The top trace (myogram)shows contraction force,the bottom (EMG)shows the electrical stimulus.On the graph,label a muscle twitch.What property of muscle is being tested here? What caused the increase in force (and subsequent decrease)?

A contraction that generates enough force to move a load is known as ________,whereas one that generates force that equals the load is known as ________.

The calcium release channel in the smooth muscle sarcoplasmic reticulum that is opened by increases in phospholipase C activity is the

A construction worker entered the emergency room after an accident in which his leg was crushed by falling beams.A color of the urine sample is noticeably reddish brown.Assuming that color is related to the accident,what molecule could have been released from the damaged muscle cells that colored the urine? What is the function of this molecule?

Myasthenia gravis is a disease characterized by reduction in the number of acetylcholine receptors on skeletal muscles.Which physiological process would be affected? What would someone afflicted by this disease experience? How may this disease be treated?

As a muscle cell undergoes an eccentric contraction,sarcomere length will ________ as the length of the A band ________.

Before the entire muscle can change length,the force generated by the muscle must stretch the

The molecular event that occurs immediately after the power stroke is the

Which fibers generate more force?

The thick filament of the myofibril is composed of ________ molecules whereas ________ is a protein that makes up the thin filaments.

Motor units that control skeletal muscles involved with fine motor movements (eye muscles or the hands)have ________ muscle fibers than motor units that control more gross movements (gastrocnemius muscle of the lower leg).

The force generated by a single muscle fiber can be increased by

The relaxation of skeletal muscle relies on the activity of the ________,which decreases cytoplasmic calcium concentration.