Chapter Preview Muscles (Chapter 6)---Anatomy &
Physiology
Name_________________________
System
Muscular
1. There are three types of muscles. What are the
differences in control and structure?
Voluntary/Invol
Shape of one cell
Smooth-----Involuntary
spindle
shaped
Skeletal-----shaped
Voluntary
cigar or tube
Cardiac------
Involuntary
branched
2. Define the following;
Tendon----tough c.t. cord that holds muscle to bone
and muscle to muscle
Aponeurosis---a flattened out tendon
Actin---thin protein fiber in muscle that helps it
contract
Myosin---thick protein fiber in muscle that helps it
contract. The heads on myosin are attracted to
the receptor sites on actin
3. What is the difference between:
Endomysium---c.t.sheath around one muscle fiber (cell)
Perimysium----c.t.sheath around a group of muscle fibers
(fascicle)
Epimysium-----c.t.sheath around on entire muscle
4. What is the difference between irritability and
contractility? irritability is the readiness of muscle to
contract and contractility is the ability of muscle to
contract
5. What is acetylcholine?
this is a neurotransmitter that stimulates muscle to
contract
6. What is an action potential?
this is an electrical wave moving down a nerve or muscle
7. What is the last ion to enter the muscle before a
contraction?
sodium
8. Why do we have muscle twitches? (tics)
the muscle or nerve to the muscle is irritated or damaged.
Too much caffeine or a lack of sleep can do this
9. Explain how muscles receive energy for contraction?
Include both aerobic and anaerobic pathways in your
answer.
you have 4 to 6 seconds of stored ATP
then you have 20 seconds of creatine phosphate that can
be converted to ATP
then you go into aerobic metabolism till the oxygen runs
out
then you go into a lactic acid cycle
10. What is the difference between how isotonic exercise
and isometric exercise affects our muscles? isotonic
exercise builds endurance but isometric exercise builds
muscle size and strength
11. How is muscle fatigue and oxygen debt related to
exercise?
oxygen debt, which is a lack of oxygen, leads to fatigue
12. What is a muscle’s origin and insertion? the origin
is the fixed or nonmovable end while the insertion is the
movable end
13. Define the following. They each have to do with a
type of muscle:
a. prime movers--the main muscle that causes a
movement
b. synergists--a group of muscles that work together
c. fixators--muscles that stabilize joints
d. antagonists--muscles that pull against each other like
biceps and triceps
e. flexors--muscles that close the angle of joints
f. extensors--muscles that open the angle of joints
14. What are myasthenia gravis and muscular dystrophy?
myasthenia gravis is a muscle disease which is thought to
be caused by an autoimmune process. Symptoms
include a drooping eyelid and progressive muscle
weakness
muscular dystrophy is a group of muscle diseases
resulting in progressive muscle wasting and atrophy
Know your major muscles and major movements for the
test.