Term
| Four major functional characteristics of muscle |
|
Definition
Extensibility: stretched out
Elasticity: recoil after extended
Contractility: shorten forcefully
Excitability: stimulated by nerves and hormones |
|
|
Term
| Three functions of muscle |
|
Definition
Posture
Heat production
Movement |
|
|
Term
|
Definition
|
|
Term
|
Definition
Striated
Voluntary
Multinucleate |
|
|
Term
|
Definition
Only in heart
Striated
Single nucleus
Involuntary |
|
|
Term
|
Definition
Non striated
involuntary
Single nucleus |
|
|
Term
| Skeletal muscle structures from small to large |
|
Definition
Microfilaments of actin or myosin
Sarcolemma, sarcoplasmic reticulum, myofibrils
Muscle fiber cell surrounded by endomysium
Fascicle with perimysium
Muscle wrapped in epimysium |
|
|
Term
|
Definition
| Repeating units of myofibrils |
|
|
Term
| 5-step cycle of a sarcomere contraction |
|
Definition
1. Active sites on the actin myofilaments are not exposed, so the heads of the myosin myofilaments are ready.
2. Ca++ bind to troponin which makes the proteins in the actin myofilaments rearrange to expose the active sites where the myosin heads can bind. Phosphate is the ejected.
3. Power Stroke: The heads bend which pull the actin myofilaments in the direction of the bend. ADP is ejected.
4. ATP molecules bind to the heads, causing them to release the active sites. The actin myofilament has moved.
5. Return stroke: ATP molecules break down into ADP and P which remain bound to the mysoin heads which release energy for the heads to spring back again. |
|
|
Term
|
Definition
| Proteins in the actin myofilament. Tropomyosin wraps around the actin molecules while the troponin lie across the troponin. |
|
|
Term
| The myosin filament is formed from... |
|
Definition
|
|
Term
| The actin filament is formed from... |
|
Definition
|
|
Term
| Which filament is thicker and darker? |
|
Definition
|
|
Term
| which filament "surrounds" the other? |
|
Definition
|
|
Term
| There are certain active sites on the ____ and the combination of a _____ _____ with the active site of an _____ ________ is called a cross bridge. |
|
Definition
| Actin, myosin head, actin myofilament |
|
|
Term
|
Definition
|
|
Term
|
Definition
| Actin myofilament (no myosin!) |
|
|
Term
|
Definition
| "Boundary"of sarcomere that serve as a place to which the actin myofilaments can be anchored. |
|
|
Term
|
Definition
| Area in between the ends of the actin myofilaments |
|
|
