Shared Flashcard Set

Details

April 10
Pages 248-255
9
Anatomy
Undergraduate 1
04/09/2013

Additional Anatomy Flashcards

 


 

Cards

Term
Twitch
Definition
  • weak, transient muscle contracton
  • results from a single action potention in a muscle fiber
Term
Tetanus
Definition
  • incomplete= progressively greater force in which the muscle fiber only relaxes slightly between subsequent contractions
  • complete= only in maximal contractions, such as lifting the heaviest weight possible for a single reetition in which action potentials arrive so frequently that the fiber does not relax at all between contractions
Term
Recruitment
Definition
the process of adding additional motor units to produce a graded icrease of force
Term
Isometric contractions
Definition
  • "same length" contractions
  • contractions that do not alter muscle length
  • force is generated and the muscle tenses; however, the myofibrils do not slide and the muscle does not change length
  • maintain our upright body posture
Term
Isotonic contractions
Definition
  • "same tone" or "same force"
  • everyday movement
  • constant foce is maintained over the course of a contraction, but the length changes
Term
Concentric contractions
Definition
  • shorten the muscle, bring the muscle attachment closer to the origin
  • bicep curls
  • myofilaments slide; sarcomeres, fibers, and muscles shorten
  • movement occurs
Term
Eccentric contractions
Definition
  • generate a restraining force as the muscle lenthens
  • enable weight to be smoothly and controllably lowered following a biceps curl
  • myosin heads grab onto the actin filaments and slow the rate of movement
Term
Muscle Tone
Definition
  • state of subconscious isometric contraction that occurs even in voluntarily relaxed muscle.
  • maintains muscle in a healthy state
  • if nerve supply is interrupted, muscle loses this and become flaccid. 
Term

Activators of smooth muscle

 

Definition
  1. mechanical signals- prevents overstretching
  2. autonomic nerves- 
  3. chemical signals- 
  4. pacemaker activity- self stimulating action potentials, move food
Supporting users have an ad free experience!