Podcast
Questions and Answers
What is the main characteristic of skeletal muscle?
What is the main characteristic of skeletal muscle?
What is the specialized plasma membrane of a skeletal muscle fiber called?
What is the specialized plasma membrane of a skeletal muscle fiber called?
Which muscle type is exclusively found in the heart?
Which muscle type is exclusively found in the heart?
Which connective tissue layer encloses a single muscle fiber?
Which connective tissue layer encloses a single muscle fiber?
Signup and view all the answers
Which function is NOT associated with muscular tissue?
Which function is NOT associated with muscular tissue?
Signup and view all the answers
What role does ATP play in muscle contraction?
What role does ATP play in muscle contraction?
Signup and view all the answers
What distinguishes smooth muscle from skeletal muscle?
What distinguishes smooth muscle from skeletal muscle?
Signup and view all the answers
What is the function of the sarcoplasmic reticulum in a muscle cell?
What is the function of the sarcoplasmic reticulum in a muscle cell?
Signup and view all the answers
Which type of muscular dystrophy is mentioned as a specific condition?
Which type of muscular dystrophy is mentioned as a specific condition?
Signup and view all the answers
Which type of muscle fibers have a branched structure and intercalated discs?
Which type of muscle fibers have a branched structure and intercalated discs?
Signup and view all the answers
What is a characteristic of a contracture deformity?
What is a characteristic of a contracture deformity?
Signup and view all the answers
How is the function of smooth muscle primarily performed?
How is the function of smooth muscle primarily performed?
Signup and view all the answers
Which cellular structure is responsible for muscle cell contraction and contains myofilaments?
Which cellular structure is responsible for muscle cell contraction and contains myofilaments?
Signup and view all the answers
What is the role of muscle tissue in maintaining body temperature?
What is the role of muscle tissue in maintaining body temperature?
Signup and view all the answers
Which of the following best describes skeletal muscle fibers?
Which of the following best describes skeletal muscle fibers?
Signup and view all the answers
What is the primary purpose of blood vessels in skeletal muscle?
What is the primary purpose of blood vessels in skeletal muscle?
Signup and view all the answers
What is the primary function of dystrophin in muscle tissue?
What is the primary function of dystrophin in muscle tissue?
Signup and view all the answers
What initiates the contraction of skeletal muscle fibers?
What initiates the contraction of skeletal muscle fibers?
Signup and view all the answers
What is a motor unit?
What is a motor unit?
Signup and view all the answers
Which sequence correctly outlines the process of muscle contraction?
Which sequence correctly outlines the process of muscle contraction?
Signup and view all the answers
What role does acetylcholine play at the neuromuscular junction?
What role does acetylcholine play at the neuromuscular junction?
Signup and view all the answers
What occurs to the calcium ions during muscle contraction?
What occurs to the calcium ions during muscle contraction?
Signup and view all the answers
What happens to the myosin receptor sites in a relaxed muscle fiber?
What happens to the myosin receptor sites in a relaxed muscle fiber?
Signup and view all the answers
Which structure serves as the association site between the motor neuron's axon terminal and the skeletal muscle?
Which structure serves as the association site between the motor neuron's axon terminal and the skeletal muscle?
Signup and view all the answers
Study Notes
Learning Objectives
- Students should identify the main characteristic of skeletal muscle.
- Students should explain the function of muscle tissue.
- Students should list the three types of muscle tissue.
- Students should differentiate between smooth, cardiac, and skeletal muscle.
- Students should explain the term used to name skeletal muscle.
- Students should explain the functions of smooth, cardiac, and skeletal muscle.
Muscle Tissue
- Bones cannot move on their own. Movements are caused by the contraction and relaxation of muscle cells.
- Muscles make up about 40-50% of total body weight and are composed of highly specialized cells.
- There are 650 muscles and 187 joints in the human body.
The Muscular System
- The muscular system is a complex network of muscles that enable various body movements.
- The presentation covered different types of muscles (e.g., facial muscles, back muscles, muscles of the abdomen, leg muscles, forearm muscles, and hand muscles).
- Diagrams illustrate the various muscles.
Functions of Muscular Tissue
- Produce body movements (e.g., lifting, peristalsis, heart beating, bladder contraction).
- Maintain body posture (muscles contract continuously)
- Store and move substances within the body by smooth muscle contraction and relaxation.
- Produce heat. Muscle contraction accounts for approximately 80% of body heat production.
Types of Muscle Tissues
-
Cardiac muscle:
- Involuntary.
- Found only in the heart.
- Cylindrical and striated.
- Cells branch and interconnect to form a complex network.
- Points where cells attach are called intercalated discs.
- Has only one nucleus per cell.
-
Smooth muscle:
- Involuntary.
- Non-striated.
- Small cells with one nucleus.
- Lines the walls of hollow organs.
- Tubular structure for transporting substances through the tract
- Moves in a wave-like contraction.
-
Skeletal muscle:
- Voluntary muscle.
- Striated muscle.
- Attached to bone by tendons.
- Moves bones.
- Muscle fibers are cylindrical in shape.
- Movement is controlled.
Muscle Structure
- Skeletal muscle tissue is composed of muscle fibers (cells).
- Muscle tissues comprise of:
- Endomysium - surrounds individual muscle fibers
- Perimysium - surrounds bundles (fascicles) of muscle fibers,
- Epimysium - surrounds the entire muscle.
- Tendon - connects muscle to bone.
- Sarcolemma- specialized plasma membrane of muscle fiber.
- Myofibrils - long organelles within the muscle fiber, composed of sarcomeres.
- Sarcoplasm - the cytoplasm of the muscle cell.
- Sarcoplasmic reticulum - specialized smooth endoplasmic reticulum; stores calcium ions and releases them during muscle contraction.
Sarcomere
- The smallest functional unit of a myofibril.
- Contains thick and thin filaments arranged in compartments.
- Filaments overlap to create striations.
- These filaments (thick and thin filaments) and their interaction cause contraction
Myofilaments
-
Thick Filaments (myosin):
- Composed of myosin proteins that form a rod-like tail and globular heads.
- Heads act as cross-bridges, binding to actin filaments during contraction.
-
Thin Filaments (actin):
- Composed of actin protein arranged in helixes.
- Specific binding sites for myosin heads.
- Regulated by tropomyosin and troponin.
-
The organization of filaments within a sarcomere influences the muscle contraction process
Muscle Contraction
- Initiated by nerve impulses.
- Nerves release acetylcholine (ACh), a neurotransmitter at the neuromuscular junction.
- ACh binds to receptors on the sarcolemma and triggers an action potential.
- This leads to calcium ion release from the sarcoplasmic reticulum, exposing active sites on actin.
- Myosin heads bind to actin, and the sliding filament mechanism shortens the sarcomere and generates muscle contraction.
- Muscle contraction requires energy (ATP)
- Energy sources include: Creatine phosphate (CP), Glucose, and Glycolysis.
Nerve and Blood Supply to Skeletal Muscles
- Skeletal muscle fibers need an impulse from nerve cells to contract,
- Blood vessels deliver the necessary nutrients and oxygen to produce ATP,
- Blood vessels remove waste products produced by the muscles.
Muscular Dystrophy
- A group of inherited diseases that damage and weaken muscles over time.
- The damage and weakness is caused by a lack of a protein called dystrophin.
- Dystrophin supports the muscle fibers and helps them function normally. Without it, the muscles weaken and degenerate over time.
- Various types exist (e.g., Duchenne muscular dystrophy, Becker muscular dystrophy).
Contraction Deformity
- The result of stiffness or constriction in muscles, joints, tendons, ligaments, or skin.
- Limits normal movement.
- Develops when connective tissues become less flexible.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
This quiz focuses on the characteristics and functions of muscle tissue in the human body. Students will explore the three types of muscle: skeletal, smooth, and cardiac, and will learn how these muscles work to facilitate movement. Prepare to differentiate between these muscle types and understand their specific roles in the muscular system.
