Hayward's Lectures

Question 1

Adaptations to improve speed

Answer 1

• Elongation of limbs
  
  • proximal distribution of muscle mass
  • disproportional growth of distal bones
    
    • walking on toes
    • loss of digits (decr. manipulative skills)
• Flexibility of spine

Question 2

Hypertrophy

Answer 2

• Incr. diameter of muscle fiber
• Synthesis of new myofibrils
• Incr. force-generating capacity

Question 3

Moment Arm

Answer 3

Perpendicular distance from an axis to the line of application of a force

Question 4

Isotonic Contraction

Answer 4

Muscle shortens at constant velocity (movement of joint)

Internal force exceeds external force

Question 5

Hyperplasia

Answer 5

• Formation of more muscle cells (very limited in differentiated muscle)
• Incr. force-generating capacity

Question 5

Isometric Contraction

Answer 5

Force generated at a constant length (no joint movement)

(ex. try to lift something too heavy, you exert force, but arm doesnt move)

Question 6

Antagonist Muscle

Answer 6

Muscles that produce oppositely directed movements at a joint

Question 7

Muscle Insertion

Answer 7

• Most distal attachment
• Most moveable part
• May be more than 1 for a muscle belly

Question 8

Type I Fibers

Answer 8

• Slow twitch (S)
• Endurance
• Low tension, longer duration

Question 10

Muscle Origin

Answer 10

• Most proximal attachment
• Usually no tendon (may have aponeurotic/small tendon)
• Least moveable part of muscle

Question 11

Agonist Muscle

Answer 11

Muscles that produce similarly directed movements at a joint

Question 12

Type II Fibers

Answer 12

• Fast twitch
  
  • Fast, fatigueable (FF)
    
    • high tension, short duration
  • Fast, resistive (FR)
    
    • intermediate tension, intermediate duration
• Speed (racehorses, greyhounds)

Question 13

Pennation of Muscles

Answer 13

• Range of shortening
  
  • unipennate > bipennate > multipennate
• Force developed
  
  • multipennate > bipennate > unipennate

Question 14

Fusiform Muscle

Answer 14

Spindle shaped