Muscular System Flashcards
Describe smooth muscle
Smooth muscle = muscle found lining the tubes such as blood vessels and the gut. It is involuntary muscle.
What is the function of smooth muscle?
Controls the blood flow through vessels
Transport of materials through the digestive tract
What is the function of cardiac muscle ?
Exertion of pressure on the blood in the heart so that it acts as a pump
Describe skeletal muscle
Muscle connected to tendons and bones and is under voluntary control.
( doesn’t have to be attached to tendons and bone - can be attached to Aponeurosis )
What is the function of the skeletal muscle ?
Generates heat
Enables body to move
Stabilises bones and muscle
What microscopic structure is only found in the cardiac muscle?
Intercalated discs
Describe the tendon and its function
Connective tissue that is continuous with the Epimysium .
F: Anchors muscle to bone
What is found inside the myofiber that is essential for effective contraction?
Within each muscle cell there is an organised arrangement of protein molecules that is essential for effective contraction
What surrounds the Myofibril and what is its function?
Surrounded by a network of tubes = Sarcoplasmic reticulum that stores calcium
Why do muscle cells contain many mitochondria?
Mitochondria convert stored energy into a form that can be used for movement.
How are proteins arranged within the myofibril ?
Within each myofibril protein molecules are arranged into thick and thin filaments
Describe a sarcomere
Smallest contractile unit of muscle containing thick ( myosin protein) and thin ( actin protein) filaments
What is the function of a titin
The borders of the sarcomeres are joined by the structural protein titin
How does contraction occur?
Nerve impulses from the brain are sent to a muscle. This causes the release of calcium from the sarcoplasmic reticulum. The calcium then triggers a chemical reaction btw the heads of the myosin and the actin forming chemical bonds between them. Energy released by the mitochondria is used to power the movement of the heads of the myosin. Myosin heads swivel towards the centre of the sarcomere pulling the actin proteins and the attached z-discs together , shortening the sarcomere , hence the muscle.
