Muscles

Question 1

What are the three types of muscle and examples

Answer 1

Skeletal Muscle - bicep and tricep
Smooth Muscle - intestines
Cardiac Muscle - heart

Question 2

what are the two types of muscle fiber arrangements

Answer 2

Fast Twitch - contract quickly, providing short burst of power
Slow Twitch - contract gradually, little power but resistance to fatigue

Question 3

what is meant by contraction, extensibility and elasticity

Answer 3

contraction - muscles shorten when they contract
extensibility - muscles can be stretched
elasticity - muscles return to their original length after being stretched

Question 4

what are the levels of the structure of skeletal muscle

Answer 4

1. skeletal muscle
2. bundles of muscle fibres
3. myofibrils
4. myofilaments
5. actin and myosin

Question 5

Explain the first level of the structure

Answer 5

connective tissue encases bundles of muscle cells (allowing bundles to slide over each other in contraction) and joins at the end of muscles to form tendons (attaching to bone)

Question 6

Explain the second level of the structure

Answer 6

Muscle fibers are long cylinders with many nuclei lying parallel to each other (vary in length)

Question 7

Explain the third level of the structure

Answer 7

Myo fibrils which can be divided into sarcomere units (Z lines capacity) are surrounded by plasma membrane and contain cytoplasm, regulates calcium ions in muscle cells

Question 8

Explain the forth level of the structure

Answer 8

myofilaments are proteins slide past each other during muscle contraction (made up of two smaller structure)

Question 9

Explain the fifth level of the structure

Answer 9

thin myofilament - actin (straight line)
thick myofilament - myosin (squigly line)
overlap to shorten overall unit

Question 10

what happens when muscle relaxes

Answer 10

sarcomere lengthens ( Z and I lines further)

Question 11

what happens when muscle contracts

Answer 11

sarcomer shortens ( Z and I closer)

Question 12

explain the 5 types of movements

Answer 12

Flexion - decreases the angle between the bones of the joint bringing the bones closer together (butt kick)
extension - increase the angle between the bones of the joint (leg raise)
adduction - body part toward midline (leg side lift in)
abduction - body part away from midline (leg side lift out)
rotation - body part around its own axis (turn head)

Question 13

what is an antagonistic pair

Answer 13

pairs of muscles working together to move bones in opposite direction

Question 14

what is an agonist w example

Answer 14

the contraction of muscle that causes the desired action (moving elbow - bicep)

Question 15

what is an antagonist w example

Answer 15

the relaxing of muscle that moves the limb as the effect of the desired action (moving elbow - tricep)

Question 16

What is the origin

Answer 16

where the muscle is fixed to stationary bone

Question 17

what is the insertion

Answer 17

where the muscle is fixed to moveable bone

Question 18

what is the belly

Answer 18

the fleshy part of the muscle between origin and insertion

Question 19

what is the synergist

Answer 19

the muscle that helps the agonist

Question 20

what is the fixator

Answer 20

the type of synergist muscle that prevents unwanted movement

Question 21

what is muscle tone

Answer 21

partial contraction of skeletal muscle, no movement is produced but fibers contract and relax