Week 5 Muscles 1 Flashcards
What are the myofilaments?
Thin actin filaments and thick filaments of myosin
Movement is achieved by?
Contraction of myofilaments
Muscle responsibility
Movement of body parts
Do all of our cells have actin and myosin?
Yes. It’s only a matter of how they organize and assemble it in the cytoplasm. Most HIGHLY characterized in muscle
Types of muscle
1) Striated
2) Smooth
Examples of striated muscle?
1) Skeletal
2) Visceral striated muscle
3) Cardiac
Examples of special visceral striated muscle?
Tongue, pharynx, upper part of esophagus
What is the biggest way to differentiate smooth and striated muscle?
Smooth muscle doesn’t have striations
What are the myofilaments?
Actin and myosin
What is myofibril?
The muscle fiber that makes up tissue; made of myofilaments (actin and myosin)
Myofibrils are formed from?
Myoblast precursors, it’s a fusion of cells, so it is multinucleated
Myofibrils are multinucleated or singular?
Multinucleated bc of the fusion of myoblast precursors
Myofibrils bundle together to form a?
Muscle fiber
Muscle fibers are different form what other fibers? How?
ECM fibers. ECM are individual proteins. Muscle fibers are fused multinucleated long cells
Skeletal muscle is many muscle fibers held together by?
Connective tissue: Endomysium, perimysium, epimysium
Endomysium?
Delicate reticular fibers surrounding individual muscle fibers
Perimysium?
Thicker connective tissue surrounding groups of fibers to form a bundle or fascicle
Epimysium? What is found here?
Sheath of dense connective tissue surrounding the collection of fascicles. MAJOR vascular and nerve supply are found here
What is a muscle fascicle?
A bundle of muscle fibers grouped together by perimysium
List fascicle, myofibril, actin/myosin, and fiber in order
actin/myosin < myofibril < muscle fiber < muscle fascicle
What connective tissue surrounds fascicle, myofibril, and fiber?
Endomysium (myofibril) < Perimysium (fiber)
All muscles end with what connective tissue?
Tendons
What are the 3 types of skeletal muscle fibers?
1) Type 1 (slow oxidative)
2) Type 2a (fast oxidatiove glycolytic fibers)
3) Type 2b (fast glycolytic fibers)
Type 1 striated skeletal muscle?
slow oxidative small fibers, RED, high myoglobin content, SLOW TWITCH, fatigue resistant
Type 2a striated skeletal muscle
fast oxidative glycolytic fibersIntermediate fibers- pink, many mitochondria, high myoglobin contant, FAST TWITCH FATIGUE RESISTANT, generate HIGH peaks of muscle tension
Type 2b striated skeletal muscle
fast glycolytic fibers, large and light color, less myoglobin and few mitchodondria, FAST TWITCH FATIGUE PRONE fibers, generate high muscle tension in short bursts
What type of striated skeletal muscle has HIGH mitochondria?
Type 2a
What type of striated skeletal muscle generate high tension?
Type 2a and Type 2b (more)
What type of striated skeletal muscle is slow twitch?
Type 1
What type of striated skeletal muscle is fast glycolytic fibers, slow oxidative, & fast oxidative glycolytic fibers?
Slow oxidative= Type 1
fast oxidative glycolytic fibers=Type 2a
fast glycolytic fibers=Type 2b
What type of striated skeletal muscle have high myoglobin?
Type 1 and Type 2a
What type of striated skeletal muscle generated the highest amount of muscle tension?
Type 2b
