Muscles

Question 1

Function

Answer 1

1. Movement.
   - Locomotion: movement of whole body and body parts
   - movement of body contents: air, blood, digestions, defecation, unrination, childbirth
   - comunication: speech, writing, facial expression, body language.
2. Srtability
   - muscles provide stability by maintaining body posture, they resist the pull of gravity, and stabalize joints
3. Body heat production
   - skeletal muscle produc 85% of body heat
4. Control of openings and passage ways
   - muscles encircling the mouth, muscles of eyelids and pupils, internal rings (sphincters), and muscles of the ureathra and anus.
5. Glycemic control
   - skeletal muscles store and use large amounts of glucose.

Question 2

Skeletal Muscle

Answer 2

• Usually attached to bones
• Voluntary
• Somatic
• Striated

Question 3

Connective covering of a skeletal muslce

Answer 3

Fascia
• Tendons
• Aponeuroses
Muscle coverings:
• Epimysium –
surrounds whole muscle
• Perimysium –
surrounds fascicles 
within muscle
• Endomysium –
surrounds muscle fibers 
(cells) within fascicle

Question 4

Muscular Responses- Threshold stimulus

Answer 4

• Minimal strength required to cause contraction

Question 5

Muscular Responses

Answer 5

Twitch
• Latent period
• Period of contraction
• Period of relaxation
• Refractory period
• All-or-none response

Question 6

Types of contractions and examples

Answer 6

• Isotonic – muscle contracts and changes 
length
• Concentric – shortening contraction
• Eccentric – lengthening contraction
• Isometric – muscle contracts but does 
not change length

Question 7

Fast(white) twitch fibers

Answer 7

• Fast-twitch glycolytic fibers (Type IIa)
• White fibers (less myoglobin)
• Poorer blood supply
• Fewer michondria
• More SR
• Susceptible to fatigue
Fast-twitch fatigue-resistant 
fibers (Type IIb)
• Intermediate fibers
• Oxidative
• Intermediate amount of 
myoglobin
• Pink to red in color
• Resistant to fatigue

Question 8

Slow(Red) twitch fibers

Answer 8

• Slow-twitch fibers (Type I)
• Always oxidative
• Resistant to fatigue
• Red fibers
• Most myoglobin
• Good blood supply

Question 9

Levers

Answer 9

Four Basic Components of Levers:

1. Rigid bar – bones
2. Fulcrum – point on which bar moves; joint
3. Object - moved against resistance; weight
4. Force – supplies energy for movement; muscles

Question 10

Origin

Answer 10

immovable end

Question 11

Insertion

Answer 11

movable end

Question 12

Agonist

Answer 12

primarily responsible for

movement

Question 13

Synergist

Answer 13

assist prime mover

Question 14

antagonist

Answer 14

contraction causes movement in the opposite

direction of the prime mover

Question 15

Cardiac Muscle

Answer 15

• Wall of heart
• Involuntary
• Autonomic
• Striated

Question 16

Smooth Muscle

Answer 16

• Walls of most viscera, blood vessels and skin
• Involuntary
• Autonomic
• Not striated

Question 17

Structure of a skeletal muscle

Answer 17

• Organ of the muscular system
• Skeletal muscle tissue
• Nervous tissue
• Blood
• Connective tissues