Muscle System I Chapter 13 Flashcards
Cylindrical
Striated (striped)
Multiple nuclei
Voluntary
Found in muscles attached to skeleton
Skeletal
Spindle (narrow cylinder, pointed ends)
Not striated (striped)
Single nuclei
Involuntary
Found in blood vessel walls and digestive tract walls
Smooth
Tubular
Striated (striped)
Single nuclei
Involuntary
Found in wall of heart
Cardiac
_____ muscles
Help us remain upright/support
Help us move our bodies and breathe
Help us release heat
Help us keep fluids circulating
Help us protect organs and hold bones together
skeletal
The plasma membrane of muscle fiber that forms T Tubules
Sarcolemma
Bundle of myofilaments that contracts
Myofibrials
Myofibrils divided vertically
Sarcomere
The smooth endoplasmic reticulum of a muscle fiber that stores Ca^2+
Sarcoplasmic reticulum
Formed by sarcolemma
penetrates into cells/ muscle fiber and conveys impulses that cause Ca^2+ to be released from SR
T Tubule
What thick myofilaments are made up of
A protein
Myosin
What thing myofilaments are made up of
a protein
Actin
1Action Potential to Skeletal muscle cell
Action potential is conducted from nervous system to the _______
Motor neurons secrete ________
This binds to receptors on sarcolemma
tissue
Acetylcholine/ACh
2Action potential on cell surface to Cell interior
Action potential travels along the sarcolemma and travels down into the membrane through a ______.
This triggers the release of ______from the ____________
Calcium ions flood the interior of the cell and find the sarcomeres
axon
Ach
Acon terminal
2.5On the ____ filaments, a protein called ___________ covers the myosin binding sites
________ is a protein bound to tropomyosin
Myosin
Tropomyosin
Troponin
3Calcium binds to _______ which pulls ______________ away, exposing the myosin binding sites.
troponin
tropomyosin
4_______ heads bind to the actin filaments to form a ___________
myosin
cross bridge
5_______ pulls _____ ________ inwards in a “power stroke.”
myosin
axon filament
6________ binds to ______ head and detaches it from actin filaments
ATP
myosin
_______ gives the energy to cock the _____ head into the power stroke position. Head reattaches _______ to start the cycle again.
ATP–ADP
myosin
myosin
_______ will continue to shorten as long as the motor neuron’s ____ _____ ______
sarcomeres
muscle fiber contracts
When the signals stop, ____ is actively transported back into the __________. ________ covers myosin binding sites and the sarcomere relaxes.
ATP
myosin head
Tropomyosin
