WEEK 5 - muscle physiology Flashcards
what is the structure function breakdown of the muscle ?
- muscle
- mundle of muscle fibers
- single muscle fiber (cell)
- myofibril
- sarcomere
where is the muscle fiber ?
in the muscle belly
where do muscle fibrils run ?
throughout the whole length (is the contracting unit)
TRUE OR FALSE
muscle fibre = muscle cell
TRUE
TRUE OR FALSE
muscle fibers have the same functional parts of the muscle cell
TRUE
what are the parts of the sarcomere ?
- thick and thin filament
- z-disk
- a-band
-I-band
what do crossbridges allow ?
allows muscle to change length (amount go overlap either increases or decreases) ; shortening or lengthening
what are the stricture function steps of the skeletal muscle ?
→ crossbridge binds → crossbridge rotates → crossbridge unbinds → crossbridge resets
what does each crossbridge contain ?
- 1 ATP
- 3.4 pN force
- 10nm length change
define muscular strength :
force a muscle or muscle group can exert in one maximal effort
define muscular endurance :
ability of muscles or muscle groups to perform repeated or sustained contractions
what is muscular strength determined by ?
muscle size and neural drive
what does bigger muscle = ?
more crossbridges
what does more crossbridges = ?
more force
what is muscle endurance determined primarily by ?
- increased capillarization (more blood flow)
- increased mitochondria dir density/function
what does endurance do ?
maintain those muscle contractions (need oxygen; provides the muscle with ATP) ; how well can we utilize oxygen to make ATP
what does increased mitochondria density / function lead to ?
- increased ATP
- increased crossbridges
- increased density
what is contractile function of muscle dependent on ?
fiber type
in humans, what are skeletal muscle characterized by ?
fast and slow twitch muscle fibers
what are the two types of fast (type 2) :
- type IIx (fastest)
- type IIa (fast)
define the fatigue resistance of type I (slow) :
high
define the fatigue resistance of type IIa :
moderate
define the fatigue resistance of type IIx :
low
define the ATPase activity of type I (slow) :
low
define the ATPase activity of type IIa :
high
define the ATPase activity of type IIx :
high(er)