5b Responding To The Environment

Question 1

The sarcolemma

Answer 1

The cell membrane of the muscle fibre

Question 2

Transverse tubules

Answer 2

Bits of the sarcolemma fold inwards across the muscle fibre and stick into the sarcoplasm

They help to spread electrical impulses throughout the sarcoplasm so that they reach all parts of the muscle fibre.

Question 3

Sarcoplasmic reticulum

Answer 3

A network if internal membranes that run through the sarcoplasm.

The Sarcoplasmic reticulum stores and releases calcium ions that are needed for muscle contraction.

Question 4

Muscle fibres have a lot if mitochondria..

Answer 4

That provide ATP needed for muscle contraction (protein channels)

Question 5

Skeletal muscle

Answer 5

Is the type of muscle that you use to move

Skeletal muscle is made up if large bundles of long cells called muscle fibres