Module 1 Flashcards
What are the steps involved in muscle contraction?
- Brain sends electrical signal.
- Motor neuron activates.
- Signal crosses neuromuscular junction (acetylcholine).
- Muscle fiber depolarization.
- Sarcoplasmic reticulum releases calcium.
- Calcium binds to troponin.
- Tropomyosin moves off actin binding sites.
- Cross-bridge cycling occurs, generating force.
What changes occur within the muscle during exercise?
- PO2
- NAD:NADH
- AMPK
- ROS
- Calcium
- Tension
How do changes within the muscle during exercise differ between aerobic and resistance exercise?
aerobic
* PO2
* NAD:NADH
* AMPK
* ROS
* Calcium
Resistance
* calcium
* tension
What does the satellite cell niche refer to?
The microenvironment surrounding muscle stem cells, known as satellite cells.
Where do satellite cells reside in relation to muscle fibers?
Outside the sarcolemma but beneath the basal lamina.
What is the basal lamina primarily composed of?
Non-fibular collagen 4.
What are satellite cells considered to be?
Muscle stem cells with the capacity for self-renewal and differentiation.
What role do satellite cells play in muscle?
Muscle repair, regeneration, and potentially exercise adaptation.
What state are satellite cells typically in?
Quiescent (resting).
What happens to satellite cells upon activation?
They undergo proliferation.
What are myoblasts?
Cells that differentiate from proliferated satellite cells and fuse to form myotubes.
What do myotubes mature into?
Functional myofibers.
What is hyperplasia in the context of muscle fibers?
The formation of new muscle fibers.
What is hypertrophy in muscle adaptation?
The growth of existing muscle fibers.
What are Fibro adipo progenitor cells (FAP cells)?
Another type of stem cell in muscle that can differentiate into fibroblasts and adipocytes.
What do FAP cells contribute to after muscle injury?
Collagen deposition and extracellular matrix remodeling.
What are macrophages involved in?
Inflammation and tissue repair.
What are the two types of macrophages mentioned?
- M1 macrophages
- M2 macrophages
What is the role of M1 macrophages?
Involved in the initial inflammatory response.
What is the role of M2 macrophages?
Resolve inflammation and promote healing.
What do endothelial cells do?
Line blood vessels and are crucial for angiogenesis.
What is the extracellular matrix (ECM)?
The non-cellular component providing structural and biochemical support to tissues.
What is the ECM primarily composed of in muscle?
Collagen fibers.
What are the three types of collagen fibers in the ECM?
- Epimysium
- Perimysium
- Endomysium
