Resistance Training 1

Question 1

what surround a muscle fibre

what surround fascicles in a muscle fibre

what surround individual muscle fibres

what are myofibrils(what zones do we need to know)

what are myofilaments

Answer 1

epimysium

perimysium

endomysium and sarcolemma

units for muscle contraction- Zline to Zline and A band where myosin is, doesn’t change width

make up myofibrils

Question 2

what is line of pull

what is angle of pull

when is the most torque produced
T=FxD

Answer 2

line of pull is the long axis of the muscle and the direction the muscle will pull things tgth

angle of pull is angle between long axis of the bone and muscle line of pull

when angle is perpendicular

Question 3

muscle architecture
parallel fibres
fusiform
oblique fibres

Answer 3

Muscle fibres can be arranged in a variety of orientations relative to its long axis

• Parallel fibred muscles have fibres orientated along the long axis
• Fusiform muscles narrow to insert at a tendon on each end
• Pennate muscles have fibres that run oblique to the long axis of the muscle
  oblique fibres

Question 4

what are the consequences of a fibre inserting obliquely
what does it mean to muscle force

Answer 4

muscle force is proportional to the # of fibres

By inserting obliquely, pennation allows a
greater number of parallel fibres to be
arranged.

So greater number of muscle fibres, produce greater force

Question 5

how are messages sent to the muscle from the brain

Answer 5

Corticospinal pathway, collection of axonal nerves bundles, white matter, terminating in lower motor neurons
upper motor neurons bring to interneurons(efferents)
lower(alpha) neurons bring it to fibres

Question 6

what does it mean the greater Ca2+ concentration in the cytoplasm

what does activation measure

how is force controlled at whole muscle level

Answer 6

Greater Ca2+ concentration means that MU fire more often

there is greater cross-bridge binding sites

more force produced

activation refers to the amount of Ca2+ released in a muscle fibre
therefore increasing the amount of stimulation

at the whole muscle level, we control force by increasing the firing frequency,
increasing the number of active motor units (MU recruitment)

Question 7

what does it mean to be a red or white muscle

Answer 7

red muscle is slow twitch and has more myoglobin

white muscle is fast twitch and has less myoglobin