Anatomy: Chapter 9

Lab books are available both in lab rooms and in the library.
Textbooks are accessible online through Access Pearson, which students have paid for.
Importance of being knowledgeable about Access Pearson and its features.
- Masterying A&P is a useful resource.
- Inquiry about students using Access Pearson and its effectiveness.

Importance of utilizing Kaltura for studying, as it contains recorded lectures and important information.
Kaltura's usage tracking suggests its effectiveness for students studying from it.
- Instructor can check engagement and time spent studying on Kaltura.
Mention of potential technical issues with sound and the need for batteries.
- Importance of addressing these technical issues for better learning experience.

Entry into Chapter Nine of the textbook, focusing on muscles, their definitions, and features.
Topics covered will include:
- Terminology related to muscles: "sarco", "myo"
- Basic structural and functional units, parts of muscles, and definitions critical for lab and lecture tests.

Definitions:
- Sarcomere: Basic functional unit of striated muscle.
- Sarcolemma: Plasma lemma of muscle cells.
- Sarcoplasmic reticulum: Homologous to endoplasmic reticulum in muscle cells.
Concept of muscle cell being synonymous with muscle fiber.
Muscle fibers can vary in length significantly.
- Role in understanding how muscles function in the body.

Also called voluntary striated muscle due to its striped appearance from sarcomeres.
Some functions include:
- Skeletal muscle can function involuntarily (e.g., diaphragm).
- Pumps blood back to the heart without conscious effort.

Considered to be involuntary muscle.
- Striated appearance.
- Heart rate can be controlled using biofeedback.

Nonstriated muscle that is involuntary.
- Found in areas such as blood vessels and internal organs.
- Functions automatically without conscious control.

Layers of muscle tissue:
- Epimysium: Dense irregular connective tissue surrounding the entire muscle.
- Perimysium: Surrounds fascicles (bundles of muscle fibers).
- Endomysium: Surrounds individual muscle fibers.
Fascicles: Bundles within the muscle, containing multiple muscle fibers.

Z discs: Boundaries of sarcomeres, connecting the actin filaments.
Thin filaments: Comprised of actin.
Thick filaments: Comprised of myosin.
M line: Center line of the sarcomere where myosin is anchored.
A band: The part of the sarcomere that contains both thick and thin filaments, does not change size during contraction.
I band: Area containing thin filaments but no thick filaments, shortens during contraction.
H band: Area where there are only thick filaments, also decreases in size during contraction.
Zones of overlap: Regions where thick and thin filaments overlap, crucial for muscle contraction.

Sliding Filament Theory: Muscle contraction occurs when the actin and myosin filaments slide past each other, causing the muscle to shorten.
Importance of Calcium: Calcium ions are released from the sarcoplasmic reticulum triggering contraction by binding to troponin.
Regulatory Proteins:
- Troponin and tropomyosin: Proteins that regulate the interaction between actin and myosin.

Differences between muscle fibers and their properties affecting fatigue:
- Fast-twitch fibers: (White meat) Quick contractions but fatigue easily.
- Slow-twitch fibers: (Dark meat) Slower contractions but more resistant to fatigue due to more myoglobin and mitochondria.

Learning about origins, insertions, and actions (OIA)
- Origin: Fixed point of muscle attachment to the body.
- Insertion: Movable point (characteristically distal in limbs).
- Action: The resultant movement performed by the muscle.
Recognition of anatomical terminology related to muscle classification (e.g. biceps brachii, triceps, flexors, extensors, etc.).

Questions on muscle anatomy will be on upcoming tests focusing on:
- Key structures and functions of muscles.
- Definitions and terminology such as sarcomeres, muscle fibers, and types of muscle tissue.

Future classes will continue with Chapter Ten of the textbook covering additional anatomy and physiology concepts related to muscles.
Students are encouraged to review materials regularly and utilize provided resources to aid in their understanding of the material covered.
Students should feel free to reach out with any questions or concerns outside of class hours.