Biology

star goldstar goldstar goldstar goldstar greyFemaleMale
33 Questions - Developed by: V - Developed on: - 344 taken

  • 1
    - An individual action potential of the muscle cell evokes short lasting contraction – “single muscle twitch“
  • 2
    - A temporal summation of the muscle contraction always results in its isotonic contraction
  • 3
    - A recruitment of additional motor units results in a strengthening of muscle contraction
  • 4
    - A lower frequency of the skeleton muscle stimulation results in a “wave“ tetanus, the higher frequency of stimulation results in a “smooth“ tetanus
  • 5
    - A superposition and summation of the skeleton muscle are produced by two stimuli, which follow each other
  • 6
    - Muscle cells respond to stimulation by action potentials
  • 7
    - Action potentials of the muscle cell activate biochemical processes leading to the muscle contraction
  • 8
    - A myofibril contains contractile proteins actin and troponin
  • 9
    - A depolarization (action potentials) of the muscle cell releases the Ca2+
  • 10
    - Ca2+ being required for the muscle contraction, is stored within the sarcoplasmic reticulum and T tubular system
  • 11
    - Ca2+ is actively transported back to the sarcoplasmatic reticulum and T tubular system by Ca2+ pump
  • 12
    - The sarcoplasmic reticulum and T tubular system release Ca2+ only after hyperpolarization of these structures
  • 13
    - ATP molecules are required for Actin and Troponin molecules to „wedge“ into each other (contraction)
  • 14
    - Generally Ca2+ are required for contraction of the muscle cell
  • 15
    - Ca2+ is an activator of the muscle contraction because its interaction with Troponin C.
  • 16
    - The termination of the muscle contraction is provided by a depletion of ATP
  • 17
    - The motor unit of the skeletal muscle is determined by a number of myofibrils being supplied by one motoneurone
  • 18
    - During the skeletal muscle contraction the „heads“ of the troponin molecules shift the actin filaments
  • 19
    - The heart muscle is not cross stripped
  • 20
    - A smooth muscle is not stripped, its contraction is not intentional, but it is slower and longer lasting, comparing with the skeletal muscle
  • 21
    - The cardiac muscle is not controlled voluntarily, but skeletal and smooth muscles are under the voluntary control
  • 22
    - Refractory periods of the skeletal and cardiac muscles are short
  • 23
    - The cells of cardiac muscle are jointed with intercalar discs, which enhance a synchronization and speed of the heart contraction
  • 24
    - The skeletal and smooth muscles are primarily controlled by the nerve system, but neural control does not participate on the function of the cardiac muscle
  • 25
    - The cardiac and skeletal muscles are similar each other because they content of Intercalar discs
  • 26
    - The cells of smooth muscles are jointed with the „gap junction“ type of interconnections, which allows spreading of the action potentials and spreading of contraction from one cell to another
  • 27
    - The contraction of the heart requires a rapid increase of Ca2+ concentration in the sarcoplasm
  • 28
    - So called “plateau“ of cardiac action potentials is caused mainly by Ca2+ influx
  • 29
    -(2015) Cardiac and Skeletal muscle are completely out of voluntary control
  • 30
    -(2015) Refractory period for skeletal muscle are short(compared to those for cardiac and smooth muscle)
  • 31
    -(2015) muscle cells respond to stimulation by contraction
  • 32
    -(2015) concentration of Ca2+ is on activator of muscle contraction by means of its interaction with actin(resulting in alteration of conformation of actinmyosin)
  • 33
    -(2015) cells of cardiac muscle are joined with intercalary discs, wich would slow down heart contraction

Comments (0)

autorenew