Topic 7-Run For Your Life

What is a Skeletal Muscle?

Muscles that are attached to bones by Tendons.

What do Ligaments do?

Attach bones to other bones.

What do Skeletal Muscles do?

Contract and Relax to move bones at a joint.

What are Antagonistic Pairs?

Muscles that work together to move a bone.

What are the bones of the lower arms attached to and with what?

• Biceps

• Triceps

• By Tendons

What happens when the bicep contracts?

• Tricep relaxes

• This pulls the bone so your arm bends.

What is a Flexer?

• A muscle that bends a joint when it contracts.

• Eg.Bicep

What happens when the Tricep contracts?

• Bicep Relaxes.

• This pulls the bone so the arm straightens (extends).

What is an Extensor?

• A muscle that straightens a joint when it contracts.

• Eg.Tricep.

What is Skeletal Muscle made from?

Muscle Fibres.

What is the Cell Membrane of Muscle Fibres cells called?

Sarcolemma

What is made when parts of the Sarcolemma folds inwards and sticks to the sarcoplasm?

• Forms Transverse(T) Tubules.

What do T Tubules do?

Help spread electrical impulses throughout the sarcoplasm, so they reach all parts of the muscle fibre.

What does the Sarcoplasmic Reticulum do?

• Stores and releases calcium ions that are needed for muscle contraction.

Why do Muscle Fibres have many Mitochondria?

To provide ATP for muscle contraction.

What are Muscle Fibres made of?

• Myofibrils

What 2 kinds of Myofilaments do Myofibrils contain?

• Thick Myofilaments-Protein Myosin

• Thin Myofilaments-Protein Actin.

What are Darks bands on electron mircoscops