Podcast
Questions and Answers
What is the function of the T tubule and Terminal Cisternae in muscle contraction?
What is the function of the T tubule and Terminal Cisternae in muscle contraction?
Which component denotes the length of a sarcomere?
Which component denotes the length of a sarcomere?
What is the role of acetylcholine at the neuromuscular junction?
What is the role of acetylcholine at the neuromuscular junction?
How does the resting membrane potential change during an action potential?
How does the resting membrane potential change during an action potential?
Signup and view all the answers
What is the main function of calcium in muscle contraction?
What is the main function of calcium in muscle contraction?
Signup and view all the answers
What is the primary function of the Endomysium within skeletal muscle structure?
What is the primary function of the Endomysium within skeletal muscle structure?
Signup and view all the answers
What is the role of ATP in muscle contraction's cross bridge cycling process?
What is the role of ATP in muscle contraction's cross bridge cycling process?
Signup and view all the answers
Where are Golgi tendon organs located, what stimulates them, and what do they result in?
Where are Golgi tendon organs located, what stimulates them, and what do they result in?
Signup and view all the answers
What occurs during the power stroke in muscle contraction's cross bridge cycling process?
What occurs during the power stroke in muscle contraction's cross bridge cycling process?
Signup and view all the answers
Which receptors are located in the muscle belly, respond to muscle stretch, and generate tension?
Which receptors are located in the muscle belly, respond to muscle stretch, and generate tension?
Signup and view all the answers
In muscle contraction's cross bridge cycling process, what happens during cross bridge detachment?
In muscle contraction's cross bridge cycling process, what happens during cross bridge detachment?
Signup and view all the answers
Which part of the nervous system sends signals to skeletal muscles via 12 cranial nerves and 31 spinal nerves?
Which part of the nervous system sends signals to skeletal muscles via 12 cranial nerves and 31 spinal nerves?
Signup and view all the answers
Study Notes
Skeletal Muscle Organization
- Epimysium is the outermost layer of connective tissue, covering the entire muscle
- Perimysium surrounds each fascicle, a group of muscle fibers
- Endomysium is the layer of connective tissue between individual muscle fibers
- Myofibril is the organelle within muscle fibers responsible for contraction
- Myofilament is composed of actin and myosin proteins
Muscle Triad
- Muscle triad components include T-tubules and two terminal cisternae of the sarcoplasmic reticulum (SR)
- Function of muscle triad is to regulate excitation-contraction coupling
Sarcomere Components
- Sarcomere is the functional unit of muscle contraction, consisting of myofilaments, lines, bands, and zones
- Actin is a thin/light strand, making up the I-band
- Myosin is a thick/dark strand, making up the A-band
- Z-line denotes the length of a sarcomere
- M-line is the middle of a sarcomere
- H-zone surrounds the M-line, running from the end of one actin to the end of another actin within the same sarcomere
Actin and Myosin
- Myosin uses cross-bridge cycling to "pull" actin towards the M-line, causing contraction
- Components of actin and myosin are essential for muscle contraction
Motor Unit
- A motor unit consists of one alpha motor neuron and the muscle fibers it innervates
- Alpha motor neuron structure and function involve depolarization and the release of acetylcholine (ACh)
- Function of the motor unit is to send a signal to trigger muscle contraction
Neurotransmission
- Neuromuscular junction (NMJ) is the junction between the motor neuron and skeletal muscle
- Motor end plate is the area of the muscle fiber with a high concentration of ACh receptors
- Acetylcholine (ACh) is the neurotransmitter released to create a skeletal muscle action potential
Resting Membrane Potential
- Resting membrane potential is a negative charge, typically -70 mV in neurons and -80 mV in skeletal muscle
- Sodium-potassium pump maintains the ion gradient, pumping Na+ out and K+ in
Action Potential
- Depolarization occurs when Na+ channels open, and Na+ moves in, making the cell more positive
- Repolarization occurs when K+ moves out of the cell, making it more negative
Calcium in Muscle Contraction
- Calcium is released from the terminal cisternae of the sarcoplasmic reticulum
- Calcium attaches to tropomyosin, moving it off of troponin, making myosin heads available to bind
ATP in Muscle Contraction
- ATP binds to the cross-bridge, detaching it and hydrolyzing to energize the cross-bridge
Cross-Bridge Cycling Process
- Cross-bridge formation: actin and myosin bind
- Power stroke: myosin pulls actin towards the center/M line
- Cross-bridge detachment: ATP binding breaks the bond
- Reactivation of myosin: ATP hydrolysis causes reactivation, where myosin "cocks head" to bind to actin again
Sliding Filament Model
- The sliding filament model describes the movement of actin and myosin filaments during muscle contraction
Peripheral Nervous System
- The peripheral nervous system consists of 12 cranial nerves and 31 spinal nerves that send signals to skeletal muscles
Mechanoreceptors
- Muscle spindles are located in the muscle belly, stimulated by muscle stretch, and respond with tension
- Golgi tendon organs are found within tendons, sense the strength of contraction in the tendon, and inhibit muscle contraction if too much force is applied
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Study guide covering skeletal muscle organization, connective tissue layers, myofilament levels, muscle triad components and roles. Includes key terms from a Taboo Slide show for review.
