Tutorial - Week 8 Content - Muscle Flashcards
Which of the following statements about muscle is FALSE?
a) skeletal muscle constitutes about 40% of total body weight
b) one of the functions of muscle is heat production
c) smooth muscle is responsible for the movement of food through the digestive tract
d) cardiac muscle is found in the walls of hollow structures such as blood vessels
e) smooth muscle is found in the walls of the organs of the reproductive systems
d)
Which of the following statements about motor neurones is true?
a) their somata are located in the anterior horns of the spinal cord
b) they have unmyelinated axons
c) they usually form a contact with one muscle fibre
d) they have axon terminals in terminal ganglia
e) they have synaptic vesicles that contain high concentrations of acetylcholinesterases
e)
Which of the following proteins is NOT found in the thin filaments of myofibrils?
a) tropomyosin
b) myosin
c) actin
d) troponin complex
e) all of the above proteins are found in thin filaments
b)
Which of the following statements about the sliding filament mechanism of muscle contraction is TRUE?
a) shortening of the myofibril is passive
b) one cross bridge cycle only decreases the sarcomere length by approximately 1 mm.
c) a single action potential causes of around 40% of the length of the sarcomere
d) a single action potential results in a single cross-bridge cycle
e) ADP binding is required for cross bridge detachment
c)
Which of the following statements about skeletal muscle contraction is FALSE?
a) during an isotonic contraction the length of the muscle decreases
b) during an isotonic contraction the tension remains the same
c) during an isometric contraction the muscle produces tension
d) during an isometric contraction the length of the muscle does not change
e) the force generated during muscle contraction is not affected by the number of motor units recruited
e)
Working in groups, write a question to establish whether someone understands why the length of a skeletal muscle when it contracts affects the maximal force of contraction that the muscle is capable of.
Then prepare a rough marking scheme for this question to help you calculate the number of marks you would allocate to this question.
Explain why the most difficult phase of a pull-up from a dead hang is the initial 2-3cm of movement and the final stage where you have to get your chin over the bar
Explain the difference between slow-twitch and fast-twitch skeletal muscle fibres and for each name a sport where someone with only that fibre type might be expected to excel.
