Week 3 - Skeletal Consideration for Movement (muscles)

Question 1

what are the 4 properties of skeletal muscle ?

Answer 1

• excitability
• extensibility
• elasticity
• contractability

Question 2

define excitability

Answer 2

ability to respond to stimulations

Question 3

define extensibility

Answer 3

ability to stretch beyond the resisting length

Question 4

define elasticity

Answer 4

ability to return to its resting length

Question 5

define contractibility

Answer 5

ability to contract and generate tension at the ends

Question 6

what is the hierarchical structure of skeletal muscle ?

Answer 6

• muscle
• fibre bundle
• fascicle
• fibre (cells)
• myofibril
• filament
• sarcomere

Question 7

define myofibrils

Answer 7

• made up of many sarcomeres
• thin filaments: strands of actin and tropomyosin coiled together
• thick filaments: strands of myosin

Question 8

define sarcomeres

Answer 8

bundles of filaments arranged parallel to one another

Question 9

define A bands

Answer 9

• constant length during contraction
• high content of thick filaments
• H Zone

Question 10

define I bands

Answer 10

• thin filaments containing actin

- Z zone

Question 11

define M line

Answer 11

in the middle of the Z lines - contain myomesin

Question 12

what are the 3 muscle contraction types ?

Answer 12

• isometric
• concentric
• eccentric

Question 13

define isometric contraction

Answer 13

static = no change in length

Question 14

define concentric contraction

Answer 14

• muscle shortens

- contraction velocity = positive

Question 15

define eccentric contraction

Answer 15

• muscle lengthens

- contraction velocity = negative