Lecture 4

Question 1

2 Types of Muscle Contraction

Answer 1

Isometric- length of the muscle does not change

Isotonic- Length of muscle changes/tone does not

Question 2

2 Types of Isotonic Contraction

Answer 2

Concentric- Bicep curl

Eccentric- Pull-ups on the way down

Question 3

Fiber Arrangement

Answer 3

Straight

Fusiform (A)

Unipennate (B)

Bipennate (C)

Multipennate (D)

Question 4

Terms related to muscle function

Answer 4

Agonist

Antagonist

Synergist

Fixator

Unijoint

Multijoint

Insufficiency

Question 5

Agonist

Answer 5

Muscle doing the desired action

Question 6

Antagonist

Answer 6

Muscle that opposes the agonist

Question 7

Synergist

Answer 7

Muscle that eliminates unwanted action by the agonist

Stabilizes the joint around which the muscle is moving

Question 8

Fixator

Answer 8

Muscle that stabilizes base of attachment of agonist

Question 9

Unijoint

Answer 9

Muscle that crosses only one joint

Question 10

Multijoint

Answer 10

Muscle that crosses more than one joint

Question 11

Insufficiency

Answer 11

Inability of a multijoint muscle to contract maximally over all joints crossed simultaneously

Active insufficiency

• Refers to the agonist

Passive Insufficiency

• Refers to the antagonist

Question 12

Active Insufficiency

Answer 12

The diminished ability of a muscle to produce/maintain active tension. This is due to the muscle being elongated to the point where there is no overlap between myofilaments.

Question 13

Passive Insufficiency

Answer 13

Occurs when the inactive antagonist muscle is of insufficient length to allow a force to complete the full range of motion available.

Mostly applies to multi-joint muscles

Question 14

3 Classifications of Muscle Tissues

Answer 14

Appearance

• Striated
• Smooth

Arrangement of nuclei

• Multinucleated
• Mononucleated

Function

• Voluntary
• Involuntary

Question 15

3 Types of Muscle Tissue

Answer 15

Skeletal

Smooth

Cardiac

Question 16

Skeletal Muscle

Answer 16

Striated

Voluntary

Multinucleated- nuclei are arranged on the periphery of the muscle fibers

Question 17

Smooth Muscle

Answer 17

Involuntary

Mononucleated

Question 18

Cardiac Muscle

Answer 18

mononucleated- Nuclei are found in the center

Striated

Intercalated Disks

Question 19

Hierarchical Structure of Skeletal Muscle

Answer 19

Muscle

Fascicle- bundle of myofibers

Myofiber- bundle of myofibrils

Myofibril- chain of sarcomeres

Myofilament

Question 20

Skeletal Muscle Connective Tissue Supports

Answer 20

Endomysium- Surrounds each muscle fiber

Perimysium- Surrounds each fascicle

Epimysium- Surrounds each muscle

Question 21

Myofiber Type

Answer 21

Dark, Slow (Red Fibers)

While, Light (Fast Fibers)

Question 22

Dark, Slow Fibers

Answer 22

Fatigue resistant (Marathon runners)

Use Oxidative Phosphorylation

Contract slowly

Many Mitochondria

Many Myoglobin

Low ATPase conc.

Question 23

White, Light Fibers

Answer 23

Fatigue Easily (Sprinters)

Use Glycolysis

Low Mitochondria

Low Myoglobin

High ATPase conc.