Podcast
Questions and Answers
What triggers depolarization and repolarization in action potential generation?
What triggers depolarization and repolarization in action potential generation?
A stimulus reaching threshold
What connects a motor neuron to a muscle fiber?
What connects a motor neuron to a muscle fiber?
Neuromuscular junction (NMJ)
Which neurotransmitter is released into the synaptic cleft?
Which neurotransmitter is released into the synaptic cleft?
The smooth muscles control movement within ______.
The smooth muscles control movement within ______.
Signup and view all the answers
Skeletal muscles are under involuntary control.
Skeletal muscles are under involuntary control.
Signup and view all the answers
What binds to troponin on actin during excitation-contraction coupling?
What binds to troponin on actin during excitation-contraction coupling?
Signup and view all the answers
What is the appearance of cardiac muscle?
What is the appearance of cardiac muscle?
Signup and view all the answers
What is required for cross-bridge formation and movement?
What is required for cross-bridge formation and movement?
Signup and view all the answers
The complex that covers myosin binding sites on actin returns to its original position during muscle ______.
The complex that covers myosin binding sites on actin returns to its original position during muscle ______.
Signup and view all the answers
Study Notes
Muscle Function
- Skeletal Muscle: Attached to bones, voluntary control, responsible for movement, posture, respiration
- Smooth Muscle: Found in the walls of hollow organs and blood vessels, involuntary control, responsible for movement of substances and blood flow regulation
- Cardiac Muscle: Located in the heart, involuntary control, responsible for pumping blood
Muscle System Functions
- Body Movement: Voluntary movements like walking and running
- Posture Maintenance: Maintains muscle tone for stability
- Respiration: Muscles in the thorax assist with breathing
- Heat Production: Muscle contractions generate heat for temperature regulation
- Communication: Facial expressions and speech
- Organ Constriction: Smooth muscles control movement within organs and blood vessels
- Heartbeat Regulation: Cardiac muscle drives heartbeats
Neuromuscular Junction (NMJ)
- Connects a motor neuron to a muscle fiber
- Composed of the presynaptic terminal, synaptic cleft, and motor end-plate
- Neurotransmitter Release: Acetylcholine (ACh) is released into the synaptic cleft, binding to receptors on the muscle fiber, causing depolarization
- Acetylcholinesterase: Breaks down ACh to prevent continuous stimulation
Excitation-Contraction Coupling
- Action Potential Propagation: Action potentials travel along the sarcolemma and T tubules, triggering Ca2+ release from the sarcoplasmic reticulum (SR)
- Calcium Binding: Ca2+ binds to troponin on actin, moving the troponin-tropomyosin complex to expose myosin binding sites
Cross-Bridge Cycle
- Formation and Movement: Myosin heads attach to actin, perform a power stroke, pulling filaments towards the sarcomere center, and release. ATP is needed for each cycle to detach the myosin head and reset it
- Energy Use: ATP is essential for cross-bridge formation and movement. It also allows the myosin head to return to its original position
Muscle Relaxation
- Calcium Reuptake: Ca2+ is actively transported back into the SR, decreasing its concentration in the sarcoplasm
- Troponin-Tropomyosin Complex: Returns to its original position, covering the myosin binding sites on actin, resulting in muscle relaxation due to decreased cross-bridge cycling
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
This quiz covers the three types of muscle tissue: skeletal, smooth, and cardiac. It explains their functions related to movement, posture, respiration, and other vital processes. Test your understanding of the neuromuscular junction and how muscles interact with the nervous system.
