Podcast
Questions and Answers
In anatomy, a muscle cell is referred to as a muscle _____
In anatomy, a muscle cell is referred to as a muscle _____
fiber
The _____ filament theory explains how muscle fibers shorten during contraction.
The _____ filament theory explains how muscle fibers shorten during contraction.
sliding
The muscle fibers in a circular muscle are _____ arranged around an opening or recess.
The muscle fibers in a circular muscle are _____ arranged around an opening or recess.
concentrically
What are the functions of muscle fibers?
What are the functions of muscle fibers?
Signup and view all the answers
What is the function of the sarcolemma?
What is the function of the sarcolemma?
Signup and view all the answers
What is the function of the sarcoplasm?
What is the function of the sarcoplasm?
Signup and view all the answers
What is the function of sarcoplasmic?
What is the function of sarcoplasmic?
Signup and view all the answers
What are T-tubules responsible for?
What are T-tubules responsible for?
Signup and view all the answers
What are the 3 main types of muscle in the body?
What are the 3 main types of muscle in the body?
Signup and view all the answers
The epimysium of a muscle surrounds the _____.
The epimysium of a muscle surrounds the _____.
Signup and view all the answers
After stimulation of ACh receptors, a muscle impulse spreads quickly along the _____ and into the muscle fiber along the T-tubules.
After stimulation of ACh receptors, a muscle impulse spreads quickly along the _____ and into the muscle fiber along the T-tubules.
Signup and view all the answers
Minimus refers to the _____ muscle.
Minimus refers to the _____ muscle.
Signup and view all the answers
Medius refers to the _____ muscle.
Medius refers to the _____ muscle.
Signup and view all the answers
Maximus refers to the _____ muscle.
Maximus refers to the _____ muscle.
Signup and view all the answers
Vastus refers to a muscle that is _____ than others.
Vastus refers to a muscle that is _____ than others.
Signup and view all the answers
Major refers to the _____ of two muscles.
Major refers to the _____ of two muscles.
Signup and view all the answers
The plasma membrane of a skeletal muscle fiber is called the _____.
The plasma membrane of a skeletal muscle fiber is called the _____.
Signup and view all the answers
What are fascicles?
What are fascicles?
Signup and view all the answers
What is a muscle fiber?
What is a muscle fiber?
Signup and view all the answers
What are myofibrils?
What are myofibrils?
Signup and view all the answers
What are myofilaments?
What are myofilaments?
Signup and view all the answers
The process of shortening of muscle cells is called _____.
The process of shortening of muscle cells is called _____.
Signup and view all the answers
What are the three main types of skeletal muscle actions?
What are the three main types of skeletal muscle actions?
Signup and view all the answers
The less mobile attachment of a muscle is called its _____.
The less mobile attachment of a muscle is called its _____.
Signup and view all the answers
What influences the speed, range, and force of movement?
What influences the speed, range, and force of movement?
Signup and view all the answers
Muscle contraction begins when a _____ impulse stimulates an impulse in a muscle fiber.
Muscle contraction begins when a _____ impulse stimulates an impulse in a muscle fiber.
Signup and view all the answers
The cytoplasm of a skeletal muscle cell is referred to as a _____.
The cytoplasm of a skeletal muscle cell is referred to as a _____.
Signup and view all the answers
Two types of muscle contraction are: a.____ contraction (when a muscle contracts but does NOT change length) and b._____ contraction (when muscle contracts and does change length).
Two types of muscle contraction are: a.____ contraction (when a muscle contracts but does NOT change length) and b._____ contraction (when muscle contracts and does change length).
Signup and view all the answers
Each _____ shortens as the muscle fiber contracts.
Each _____ shortens as the muscle fiber contracts.
Signup and view all the answers
A single motor neuron typically controls numerous _____ _____ in a muscle.
A single motor neuron typically controls numerous _____ _____ in a muscle.
Signup and view all the answers
What does a large muscle such as the biceps brachii have?
What does a large muscle such as the biceps brachii have?
Signup and view all the answers
Although muscle fibers obey the all-or-none principle, the force and precision of muscle movement can be varied, depending on how many _____ and motor units are _____.
Although muscle fibers obey the all-or-none principle, the force and precision of muscle movement can be varied, depending on how many _____ and motor units are _____.
Signup and view all the answers
The functional contractile unit of a skeletal muscle fiber is known as a _____.
The functional contractile unit of a skeletal muscle fiber is known as a _____.
Signup and view all the answers
Thick filaments are assembled from bundles of the protein called _____.
Thick filaments are assembled from bundles of the protein called _____.
Signup and view all the answers
What does the M-line serve as?
What does the M-line serve as?
Signup and view all the answers
What are myofibrils responsible for?
What are myofibrils responsible for?
Signup and view all the answers
What is the function of thick filaments?
What is the function of thick filaments?
Signup and view all the answers
What is the function of thin filaments?
What is the function of thin filaments?
Signup and view all the answers
Study Notes
Muscle Cells and Contraction
- A muscle cell is known as a muscle fiber.
- The sliding filament theory explains how muscle fibers shorten during contraction.
- Muscle fibers in circular muscles are arranged concentrically around openings.
Functions of Muscle Components
- Muscle fibers are responsible for metabolic activities and contraction.
- The sarcolemma regulates the entry and exit of materials in muscle cells.
- Sarcoplasm is the site of metabolic processes essential for muscle fiber activities.
- Sarcoplasmic reticulum stores calcium ions necessary for muscle contraction.
Structural Components
- T-tubules transport muscle impulses from the sarcolemma throughout the entire muscle fiber.
- The three main types of muscles in the body are skeletal, cardiac, and smooth.
- The epimysium surrounds the entire skeletal muscle.
- The sarcolemma is the plasma membrane of a skeletal muscle fiber.
- Fascicles refer to bundles of muscle fibers within a muscle.
Muscle Fiber Characteristics
- Muscle fibers are elongated, multinucleated, and cylindrical cells.
- Myofibrils are long, cylindrical contractile elements found within muscle cells.
- There are two types of myofilaments: thick and thin, responsible for contraction.
Muscle Contraction Process
- The process of muscle fibers shortening is called contraction.
- Muscle actions occur through three types: agonists, antagonists, and synergists.
- Muscle contraction begins with a nerve impulse stimulating the muscle fiber.
Muscle Attachments and Mechanics
- The origin of a muscle is its less mobile attachment.
- The attachment's location affects the speed, range, and force of movement.
- Muscle contraction can vary depending on the number of muscle fibers and motor units activated.
Motor Units and Force Generation
- A single motor neuron typically controls numerous muscle fibers.
- Larger muscles, like the biceps brachii, have many motor units, each controlling various fibers.
- Muscle fibers follow the all-or-none principle, where movement force and precision depend on the number of activated fibers and motor units.
Contractile Units and Filaments
- The sarcomere is the functional contractile unit of a skeletal muscle fiber.
- Thick filaments are made from bundles of the protein myosin.
- The M-line serves as an attachment site for thick filaments, keeping them aligned during contraction and relaxation.
- Myofibrils contain myofilaments that are essential for muscle contraction.
- Thick filaments bind to thin filaments to initiate contraction, while thin filaments bind to thick filaments to facilitate the process.
Muscle Contraction Types
- Two types of muscle contraction include:
- Isometric contraction: Muscle contracts but does not change length.
- Isotonic contraction: Muscle contracts and changes length.
Additional Terminology
- Terms such as minimus (smallest), medius (intermediate), maximus (largest), vastus (even larger), and major (largest of two muscles) help classify muscle sizes and characteristics.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Test your knowledge on muscle cells, their structure, and the mechanisms of contraction. This quiz will cover the sliding filament theory, the role of various muscle components, and the different types of muscle fibers. Perfect for students studying biology or anatomy.
