Muscles Flashcards
on exam one
What are the three types of muscle?
cardiac, smooth, skeletal
A muscle is made up of ____ which are made of ____ which are made up of _____
fascicles; fibers; myofibrils
Endomysium
inner covering of myofibrils
Perimysium
covers fasicles
Epimysium
covers muscle
The endomysium, perimysium, and epimysium make up what?
the fascia
What is the cell membrane of a muscle cell/fiber called?
sarcolemma
Where is calicum stored?
the sarcoplasmic reticulum
T-tubules
where electrical signals travel down
Basement membrane of the sarcolemma?
plasmalemma
Where are the receptors for acetylcholine?
plasmalemma
When an electrical signal travels down the t-tubules and depolarization occurs what happens with the sarcoplasmic reticulum?
it releases calcium
What is a myofibril made up of?
tiny contractile units called sarcomeres
How many major proteins does each sarcomere have?
four
What are the four proteins?
actin, myosin, troponin, tropomyosin
Which two proteins are directly responsible for muscle contraction?
actin and myosin
Which protein has calcium receptors to tell them to move?
troponin
Troponin has to move in order for what to happen?
for tropomyosin to unravel
What are the three types of muscle contractions?
isometric, isotonic, isokinetic
What is an isometric contraction?
force is applied but no movement occurs; it’s a static contraction
What is an isotonic contraction?
force is applied and there is movement
What is an isokinetic contraction?
force is applied and movement occurs, but there is no sticking point (constant velocity)
What is the best contraction type for rehab?
isometric
What contraction type needs specialized equipment?
isokinetic
What is the main contraction type when working out in the gym?
isotonic
Isotonic has two phases of contraction
concentric and eccentric
Concentric
shortening a muscle
Eccentric
making a longer muscle (returning it to normal)
Which phase causes the most damage to a muscle?
eccentric
What are the five characteristics of a muscle?
contractibility, extensibility, elasticity, excitability, all or nothing principle
Contractibility
ability to contract/shorten
Extensibility
ability to lengthen
Elasticity
ability to stretch
Excitability
ability to be stimulated by nervous system
All or nothing principle
a muscle either contracts all the way or not at all
What is burned up every time actin hooks to myosin?
ATP is used and calories are burnt
Another name for the motor unit
excitation-contraction coupling
Type 1 fibers
-slow twitch, endurance
-aerobic
-lots of myoglobin
-red
-burn fat
Type 2 fibers
-fast twitch, sprint
-anaerobic
-very little myoglobin
-white
-burns carbs
What enzyme splits ATP
ATPase
Which fiber type has a more highly developed sarcoplasmic reticulum?
type 2
Which fiber type has a smaller cell body?
type 1
Which fiber type hypertrophies more readily?
type 2
What principle says that we always start with type 1 fibers then type 2 takes over
principle of orderly recruitment or the size principle
