Muscle Contraction Flashcards
Types of tissue
Epithelial
Connective
Nervous
Muscular
Types of muscle tissue
Skeletal, cardiac, smooth.
Muscle cells
Thanks to their unique protein arrangement they can contract
Skeletal muscle tissue
Long, multinucleate, stritated. Can be up to 30 cm in length
Smooth muscle
Sickle shaped
No striations
Muscle of involuntary nervous system.
Can constrict airways and blood vessels. Can move food down via peristalsis.
Involuntary
Single nucleus
What causes striations?
Sarcomeres: highly organized protein structures
Cardiac muscle
Striated
Only one nucleus
Have highly organized actin myosin sarcomeres
Branched
Sometimes a capillary between branching
Have intercalated discs.
Lots of sarcomeres
Huge number of mitochondria. Can make up 35-40% of cell
Dark lines are intercalated discs
Intercalated discs
Looks like egg cartons together
Has lots of gap Junctions and desmosomes
Beats in syncytium.
Creates cytoplasm to cytoplasm connections between all cardiac muscle cells. Anchoring junctions prevents shear stress
Ability to repair of muscle tissues
Skeletal muscle: a little bit
Smooth muscle: best ability to repair itself
Cardiac muscle : not at all. Amitotic. Causes higher risk of ischemia(stop blood flow) and hypoxia (lack of oxygen).
Cardiomyocyte
Cardiac muscle cell death.
That section of heart dies that lost its oxygen supply. Gets filled with connective tissue. Limits heart capacity
Muscle fiber is
Muscle cell
Fuse together early on
Can be up to 30 cm in length.filled with cables called myofibrils
Myofibrils
Made up of myofilaments (smallest units) like myosin and actin.
Have lots of mitochondria. Needed for muscle movement.
Smallest structure in a muscle cell is
Myofilaments. Bundle together to make myofibrils
Endomysium
Layer or connective tissue that covers muscle fiber.
Satellite cells in muscles
Help muscles grow.
Grow by enhancing or creating more of the myofibrils of the muscle fiber itself.
Muscle fascicle
Group of muscle cells together. Column of muscle cells.
Perimysium
Around fascicles peri-around
Groups of fascicles together
Belly of muscle itself
Surrounded by epimysium
Deep fascia
Wraps in and around groups of muscles and organs above epimysium
Possible length of smooth muscle
200 micrometers in length
Sarcolemma
Plasma membrane around q skeletal muscle cell
Sarcolemma=cell membrane
Myosin
Thick filament
Actin
Thin filament
-in
Protein suffix