Chapter 6 Flashcards
Muscle fibers Definition
Muscle cells that are long cells
(made of long thin myofibrils)
Myoglobin Definition
Fascia Definition
Muscles covered by connective tissue
Fascicles Definition
Bundles of muscle cells
Myofibrils Definition
Bundles of myofilaments that contracts
Sacromere Definition
Involuntary Definition
Smooth muscles
Muscles found in the walls of many internal organs
*Aid in function of other organs
(digestive tract, respiratory system, blood vessels)
Cardiac muscles
Found only in the heart
*Functions by contracting to force blood from the heart into the arteries
Voluntary Definition
Skeletal muscles attached to the skeleton
- Usually work in pairs
Origin Definition
Muscle attached to the bone that remains stationary during movement
Insertion Definition
Muscle attached to bone that moves
Functions of Skeletal Muscles
(5)
1.Support the body – maintain our posture
2. Movement of bones, and other tissues
3. Help maintain a constant body temperature
– generates heat
4. Helps move blood through the veins and
lymphatic fluid through the lymphatic
vessels
5. Help to protect vital organs and stabilize
joints
Sacrolemma Definition
Plasma membrane
Sacroplasm Definition
Similar to cytoplasm, contains large amount of stored glycogen and myoglobin
Myoglobin Definition
Oxygen binding protein similar to hemoglobin, only found in muscles
Sarcoplasmic reticulum Definition
Similar to endoplasmic reticulum, one of its functions is to store Ca2+
(Calcium)
Transverse tubules (T tubules) definition
Extension of sarcolemma that come in contact with sarcoplasmic reticulum
Actin filaments Definition
Filaments that form by two strands of protein actin, Attached to Z line
Myosin Definition
Thick filaments of protein ,shaped like golf club , with found “head”
Cross-bridges Definition
Myosin heads bind and detach from thin actin filaments. When bound its called ->
Steps of muscle contraction
1-11
- Action potentials are transmitted through the neurons.
- At the end of the neurons neurotransmitters are released
- Neurotransmitters bind to receptor on the sarcolemma
- The receptors are ion channels that open
- An action potential travels through the T tubules
- The action potential goes to the sarcoplasmic reticulum
- The sarcoplasmic reticulum releases Ca2+.
- The calcium binds to the actin filament
- This opens up binding site for the myosin to attach
- Now the myosin binds to the actin
- ATP is needed for the myosin to slide past the actin
ATP definition
The bonds between phosphate groups are high energy bonds
