Podcast
Questions and Answers
What occurs in Step 1 of muscle contraction?
What occurs in Step 1 of muscle contraction?
What neurotransmitter is released by the motor neuron in Step 2?
What neurotransmitter is released by the motor neuron in Step 2?
Acetylcholine (ACH)
In Step 3, ACH binds to muscle receptor sites.
In Step 3, ACH binds to muscle receptor sites.
True
What happens to sodium channels in Step 4?
What happens to sodium channels in Step 4?
Signup and view all the answers
What creates the action potential in Step 5?
What creates the action potential in Step 5?
Signup and view all the answers
The action potential travels down the muscle cell in Step 6.
The action potential travels down the muscle cell in Step 6.
Signup and view all the answers
What does the release of Ca++ cause in Step 7?
What does the release of Ca++ cause in Step 7?
Signup and view all the answers
How do Ca++ ions influence myosin and actin in Step 8?
How do Ca++ ions influence myosin and actin in Step 8?
Signup and view all the answers
What does the myosin do during contraction in Step 9?
What does the myosin do during contraction in Step 9?
Signup and view all the answers
What happens when the action potential ends in Step 10?
What happens when the action potential ends in Step 10?
Signup and view all the answers
Study Notes
Steps of Muscle Contraction
- Nerve Impulse reaches the neuromuscular junction, triggering muscle activation.
- Motor neuron releases Acetylcholine (Ach), a neurotransmitter, into the synaptic gap, facilitating communication between nerve and muscle cells.
- Ach binds to muscle receptor sites, initiating the muscle contraction process.
- Binding of Ach stimulates receptors, leading to the opening of sodium (Na+) channels in the muscle cell membrane.
- Influx of Na+ ions alters the cell's polarity, generating an electrical current known as an Action Potential.
- The Action Potential travels along the sarcolemma, spreading across the muscle fiber to initiate contraction.
- The Action Potential triggers the sarcoplasmic reticulum to release stored calcium ions (Ca++) into the muscle cell and surrounding sarcomeres.
- Increased Ca++ levels enable myosin heads to attach to actin filaments within the sarcomeres, forming cross-bridges essential for contraction.
- Myosin heads pull actin filaments towards the center of the sarcomere, resulting in sarcomere shortening and muscle contraction.
- When the Action Potential ceases, Ca++ is reabsorbed by the sarcoplasmic reticulum, allowing myosin and actin to return to their original positions, leading to muscle relaxation.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Test your knowledge on the 10 steps of muscle contraction with this quiz. Each step includes key processes involved in how muscles respond to nerve impulses. Perfect for students of biology or anatomy.
