week 3: skeletal muscle architecture and function

Question 1

parallel muscles fibre

Answer 1

fascicles are parallel to the long axis of muscles
typically attach to skeleton with little or no tendon
e.g sartorius muscle, biceps brachii muscle

Question 2

fascicles

Answer 2

muscle fibre bundles

Question 3

convergent muscles

Answer 3

fascicles converge on a common attachemnt point
fibres act at different angles to line of action of muscle and vary in length
e.g pectoralis, trapezius, latissimus dorsi

Question 4

pennate muscles

Answer 4

fascicles are shorter than the muscle and run at an angle to the principal axis of the muscle
typically attach to the skeleton via an external tendeon
uni or bi
e.g rectus femoris (bi), EDL (uni)

Question 5

circular muscles

Answer 5

fascicles are concentrically arranged around an opening
control the diameter of body openings or hollow organs
e.g orbicularis oris, orbicularis oculi

Question 6

unipennate vs parallel

Answer 6

pennate muscle can generate more force as it has a higher cross-sectional area than parallel

parallel can undergo longer length changes and can shorten more quickly

Question 7

msucles as motors

Answer 7

muscle actively shortens- concentric contraction
generates positive work and positive power

Question 8

human example of muscles as motors

Answer 8

biceps brachii performing bicep curl

Question 9

muscles as breaks

Answer 9

muscle actively lengthens- eccentric contraction
absorbs energy and generates negative power

Question 10

human example of muscles as brakes

Answer 10

biceps brachii lowering weight held in hand

Question 11

muscle as struts

Answer 11

isometric contraction
muscles generates force without changing length