Questions and Answers
The __________ is described as two strands of actin molecules wrapped together.
thin filament
Which of the following happens as actin and myosin filaments slide past each other during muscle contraction?
Which of the following statements about the 'heads' of the myosin molecules is true?
Muscle contractions are initiated by the binding of __________ to __________.
Signup and view all the answers
During muscle contractions, cross-bridges form between the _________ and the __________.
Signup and view all the answers
Which of the following is the site of ATP binding and hydrolysis?
Signup and view all the answers
During contraction of a muscle, calcium ions bind to the __________.
Signup and view all the answers
The bond between the active site on actin and the myosin head is broken when an __________.
Signup and view all the answers
The sequence of cross-bridge formation and myofilament movement will be repeated as long as calcium ions and ATP are present.
Signup and view all the answers
An action potential causes calcium ions to diffuse from the ________ into the ________.
Signup and view all the answers
Which of the following best describes the role of Ca2+ in muscle contraction?
Signup and view all the answers
Which of the following is not a filamentous protein?
Signup and view all the answers
An action potential enters the depths of a muscle fiber by way of __________.
Signup and view all the answers
Which structure do the calcium ions bind to when muscle contraction is initiated?
Signup and view all the answers
Cross-bridges form between the __________ and the __________.
Signup and view all the answers
Which of the following is not an example of an autonomic receptor?
Signup and view all the answers
Study Notes
Muscle Contraction Basics
- Thin filament consists of two strands of actin molecules twisted together.
- During muscle contraction, neither actin nor myosin filaments shorten; they slide past each other.
Myosin Molecule Characteristics
- Myosin heads attach to various sites on actin filaments, allowing for flexibility.
- Myosin is the site of ATP binding and hydrolysis, essential for muscle movement.
Calcium's Role in Muscle Contraction
- Calcium ions initiate contractions by binding to troponin, leading to changes that allow myosin heads to attach to actin.
- An action potential prompts calcium ion release from the sarcoplasmic reticulum into the sarcoplasm.
Cross-Bridge Formation
- Cross-bridges form between myosin heads and actin filaments during contraction.
- The connection between the active site on actin and the myosin head is disrupted when an ATP molecule binds to the myosin head, facilitating muscle relaxation.
Filamentous and Non-Filamentous Proteins
- Troponin is not considered a filamentous protein; it functions differently within muscle contraction processes.
T Tubules
- An action potential travels into muscle fibers via T tubules, helping coordinate contraction.
Reflex Mechanisms
- The response to increased body temperature involving thermoreceptors and sweat glands exemplifies a reflex mechanism that maintains homeostasis in the body.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Prepare for your muscle physiology exam with these flashcards. Test your knowledge on the components of muscle contraction, specifically focusing on actin and myosin filaments. Perfect for students studying human anatomy and physiology.
