click below
click below
Normal Size Small Size show me how
Physiology
Skeletal Muscle Fiber Anatomy - Test 4
Question | Answer |
---|---|
What layer of connective tissue connects the two ends of the skeletal muscle fiber? | The endomysium layer. |
A tendon attaches muscle to bone, what is the tendon made of? | Collagen and Elastin fibers that merge with the endomysium |
Is a muscle fiber uninucleated? | No, it is multinucleated. |
True or False, the skeletal muscle cell body is one of the largest cell bodies? | True |
What is a myofibril? | series of sarcomeres running the length of the fiber. |
How many T-Tubules are there per a sarcomere? | 2 |
What mineral does the sarcoplasmic reticulum? | Ca++ |
What is the thick fibers of the sarcomere called? | Myosin = Thick, Actin = Thin |
Tropomysin complex is consists of Troponin and which type of fiber? | Actin |
Tropomyosin is a THIN long fiber that covers and spans how many monomers? | 7 actin monomers |
How many globular proteins? | 3 Globular Proteins - C, T, I as in aCTIn. |
Which of the 3 globular proteins binds to actin? | I |
Which of the 3 globular proteins binds to tropomyosin? | T |
Which of the 3 globular proteins binds to calcium? | C |
How many subunits is myosin composed of? | 6 protein subunits - 2 long thin units twisted together and 4 light chains |
What type of fibers span the I band? | Only Actin |
What protein structure supports the actin fibers? | The Z-Disc |
True or False, the A Band changes length during muscle contraction? | False, the A Band does NOT change length |
What are T-Tubules? | Invaginations of the sorcolemma |
How does the action potential effect levels of Calcium in the sarcoplasm? | It increases it 1000X |
How many Ca++ ions bind to Tropin C? | 4 |
During muscle contraction the myosin head and ADP - P binds to what? | The Actin binding site |
When the ADP and P group are released from the myosin head it causes the myosin head to flex from ____ degrees to _____ degrees? | 90 degrees to 45 degrees which in turns moves the actin fiber across the myosin. |
How far does the actin move across the myosin in each flexion of the myosin head? | 10nm |
What happens when ATP binds to the myosin head? | The myosin head releases the actin |
What enzyme splits ATP into ADP - P causing the myosin head to return to its original 90 degree orientation? | MyosinATPase |
What is the normal level of Ca++ ion concentrations in the sarcoplasm? | 0.00000007 molar |
How many Ca++ ions is transported into the sarcoplasmic reticulum for every ATP burned? | 2 this is accomplished by Sarcoplasmic reticular Ca++ ATPase |