Chapter 11 - Muscle Tissue Flashcards
What is the primary role of muscle?
Contraction
What are the two types of contractile cell apperances?
- Striated
- Smooth
Muscle cells are characterized by aggregates of elongated cells arranged in parallel array
True
What are the two types of myofilaments in muscle cells?
- Actin
- Myosin
Skeletal muscle characteristics
Light and dark staining cells
Muscle fibers
Multinucleated myocytes
Voluntary, strong, discontinuous movements
Cardiac Muscle Characteristics
Light and dark staining
individual myocytes
Interculated discs
Nucli centrally located
Smooth Muscle Characteristics
Tappered Ends
Central Nucli
Oblique angles connect filaments to the membrane
weak, slow, involuntary movements
Where is smooth muscle located (2)?
Visceral Organs
Blood Vessels
What are the 3 layers of CT in skeletal muscle?
- Epimysium
- Perimysium
- Endomysium
What does the epimysium surround?
Surronds collection of fascicles of skeletal muscle
What does the perimysium surrond?
Surronds group of fibers to form a bundle (fascicle) in skeletal fibers
What does the endomysium surround?
Surronds muslce fibers in skeletal and other muscle types
What do the layers of CT help the skeletal muscle do?
The CT helps transmitt force as 1 section
What type of fibers are prevalent in the CT in skeletal muscle?
Reticular fibers
What is a muscle fiber?
A skeletal muscle cell
What are the three types of skeletal muslce?
Type I
Type IIa
Type IIb
What are the characteristics of type I skeletal muscle fibers?
Red, Slow
Oxidative phosphorylation
Why does oxidative phosphorylation help the muscle with long standing contractions?
Decreases waste production (in comparison to glycolysis) so the muscle doesn’t tire out
What are the characteristics of type IIa skeletal muscle fibers?
Oxydative phosphoylation and glycolysis
Get some byproducts
Decrease endurance, increase in speed
What are the characteristics of type IIb muscle fibers?
Fast movements
Glycolysis
Increase waste products
What type of animals/where doe you find type I skeletal muscle?
Limbs of mammals
Migratory birds
Back Muscles
Where do you find/what type of person type IIa skeletal muscle fiber?
Middle-distance swimmers
Hockey players
What type of athletes do you find type IIb skeletal muscle fibers?
Sprinters
Weightlifters
What is the subunit of muscle fibers?
Myofibrils
What are myofibrils composed of?
myofilaments
The organization of ______ in muscle fibers give a cross-striated apperance
Myofibrils
A-band
Thick and thin overlap
I band
Thin band only
Z line
Bisects the I band
Sarcomere
Z line to Z line
What are alpha actininins responsbile for?
Help attach actin to the Z line
H band
Just myosin filaments
M line
In the H band
Most high density
What is titin? What is its function?
Protien
Attaches myosin to the Z line so they stay in register
What is tropomyosin? What is its function?
Protien
Helical
Mask myosin binding site on actin
When muscles contract and relax what band(s) shrink/grow? What band(s) never change?
I band and H band increase during stretch
A band never changes
What are the three parts of the troponin complex?
TnC
TnT
TnI
What is the function of TnC?
Binds calcium
Initiates contraction
What is the function of TnT?
Binds direclty to tropomyosin