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 1. Properties and Functions of Muscle Tissue

Muscle tissue is specialized for ___________________________________________________________________________. The main properties include:

- Excitability: Ability to _______________________to stimuli, typically from motor neurons.

- Contractility: Ability to ______________________________________________when stimulated.

- Extensibility: Ability to _______________________without being _______________________.

- Elasticity: Ability to _______________________to _______________________length after stretching or contracting.

Functions:

- _______________________: Muscles produce _______________________of the body (skeletal), pump blood (cardiac), and move contents through hollow organs (smooth).

- Posture and Stability: Muscles help _______________________body posture and stabilize _______________________.

- Heat Production: Muscle _______________________generate heat, which helps regulate ______________________________________________.

- Support of Soft Tissues: Muscles in the _______________________wall support _______________________organs.

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 2. Types of Muscle Tissue

- _______________________: Long, cylindrical fibers with striations. The function is voluntary movement. They are multinucleated and have clear connective tissue coverings (endomysium, perimysium, epimysium).

- _______________________: Branched fibers, also striated, with a central nucleus and intercalated discs that enable coordinated contraction of the heart.

- _______________________: Non-striated with spindle-shaped fibers. Found in the walls of hollow organs such as intestines and blood vessels, involved in involuntary movements.

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 3. Histological Identification

- Skeletal Muscle: Long, striated fibers, multiple _______________________at the periphery.

- Cardiac Muscle: Striated, _______________________fibers with _______________________located nuclei and______________________________________________.

- Smooth Muscle: ______________________________________________ cells with no striations and a _______________________, centrally located nucleus.

Look for striations in skeletal and cardiac muscles, intercalated discs in cardiac muscle, and dense bodies in smooth muscle tissue slides.

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 4. Levels of Organization of Skeletal Muscle

- Muscle Organ: Surrounded by the _______________________, it contains bundles of _______________________.

- Fascicle: Surrounded by the _______________________, a fascicle is a bundle of ______________________________________________(cells).

- Muscle Fiber (Cell): Each fiber is surrounded by the _______________________and contains many _______________________.

- Myofibril: _______________________ units inside the muscle fiber that contain _______________________.

- Sarcomere: The _______________________unit of _______________________in muscle tissue, containing thick (myosin) and thin (actin) filaments.

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 5. Muscle Cell and Sarcomere Structure

Key parts to label on a diagram or model:

-______________________________________________ (cell): The basic cellular unit of muscle.

- _______________________: Connective tissue surrounding each muscle fiber.

- _______________________: A bundle of muscle fibers within a muscle.

- _______________________: Connective tissue surrounding each fascicle.

-______________________________________________: The entire muscle, covered by epimysium.

- _______________________: Connects muscle to bone, transmitting force.

 Muscle Fiber Structures:

- _______________________: Skeletal muscles have multiple peripheral nuclei; cardiac has 1-2 central nuclei.

- _______________________: The plasma membrane of the muscle cell.

- _____________________________________________________________________: Specialized smooth endoplasmic reticulum that stores calcium ions.

- _______________________: Provide energy for muscle contraction.

- Myofilaments:

  - Thin filaments: Composed of _______________________.

  - Thick filaments: Composed of _______________________.

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 6. Specialized Structures in Muscle Tissue

- Skeletal and Cardiac Muscle:

  - Transverse (T) Tubules: _______________________of the _______________________that allow _______________________impulses to reach deep into the muscle fiber.

  - _______________________: The repeating structural unit, bounded by Z discs.

  - _______________________: The boundary of each sarcomere.

  - _______________________: Contains only thin filaments (actin).

  - _______________________: The region containing thick filaments (myosin) with some overlap of thin filaments.

  - _______________________: The center of the sarcomere.

  - _______________________: The center part of the A band, containing only thick filaments (in both skeletal and cardiac muscle).

 Skeletal Muscle Specific:

- _____________________________________________________________________: Where the motor neuron contacts the muscle fiber.

- ______________________________________________: The specialized region of the sarcolemma at the NMJ.

- Motor Neuron: Transmits _______________________from the _____________________________________________________________________to the muscle fiber.

 Cardiac Muscle Specific:

- Intercalated Discs: Specialized _______________________between _______________________muscle cells that facilitate ______________________________________________.  

 Smooth Muscle Specific:

- Dense Bodies: The _______________________of Z discs in _______________________muscle, where _______________________ filaments attach.