Muscle Structure: Skeletal Muscle
Largest to Smallest - this is the hierarchy of muscle structure.
What Are:
Muscle
Muscle-fibre bundle
Muscle fibre
Myofibrils
Myofiliments
The muscle fibres enclosed within a membrane are called __________________. The delicate sheath that surrounds muscle fibres.
What is SARCOLEMMA?
Myofibrils are made up of small sections called ____________. They are the actual things that contract. (Hmmm....the functional unit of the skeletal muscle?)
What are SARCOMERES?
Each whole skeletal muscle is composed of ________ bundles.
What are parallel bundles?
These run between the fibre bundles (hint: helps ensure they are supplied with energy and the ability to move).
What are BLOOD VESSELS (deliver nutrients) and NERVES (voluntarily impulse to move)?
When a contraction happens the THICK myosin does this to the THIN actin filaments. (Hint: a muscle can only _____ and not push).
What is PULL? (the THICK MYOSIN PULLS the THIN ACTIN).
Each BUNDLE is composed of parallel units called ______.
What is FIBRES?
Contained within the SARCOLEMMA are smaller units called ___________.
What are MYOFIBRILS?
Muscle contraction is based on the ______ _______ theory.
What is the SLIDING FILAMENT theory?
Each fibre is a functional single cell containing many _________.
What are NUCLEI?
Each MYOFIBRIL is made of _______________.
What are MICROFILAMENTS?
Muscle contractions are ___________ reactions. Bonds are constantly being made and broken.
What are CHEMICAL reactions?
Fun fact: some of the fibres are extremely long single muscle _______. In the leg they can be half a meter in length!
What are CELLS?
There are TWO types of MICROFILAMENTS that overlap each other. One is a THIN filament called ________, and the other is a THICK filament called _________. This is what creates STRIATIONS that are characteristic of Skeletal Muscle.
What is ACTIN (thin and light) and MYOSIN (thick and dark)?
This ion helps control muscle contractions....you get a good dose from drinking milk....which also helps muscle repair and growth.
What is Calcium?