The Muscular System Flashcards
How many muscles are there in the body?
650
What are the four characteristics of the muscles?
Excitability, contractility, extensibility and elasticity
What are the four roles of the muscles?
Produce movement, stabilise the body, store substance and generate heat
What is the fasical net?
The area where muscles are attached to bones and usually cross one or more joints
What is a cardiac muscle?
Involuntary muscle which forms the walls of the heart. Purpose is to pump blood around the Circulatory system
What is a skeletal muscle?
Its is attached to bone, and is a voluntray muscle tissue as it is consciousily controlled.
What is a smooth muscle?
Involuntary muscle that assists with the movement of blood and food through the relevant systems of the body. It contracts without us even knowing about it
What is a tendon?
Connective tissue that connects muscle to bone and is capable of withstanding tension. Elastic properties allow them to operate and store and release energy.
What is an agonist?
Prime mover - the muscle which contracts the most to bring about the desired movement
What is an antagonist?
The muscle which is on the opposite side of the body that allows for movement of the agonist by downgrading the amount of activity it provides.
What is a synergist?
Assists with the movement. They help the agonist to perform the desired movement
What is a fixator?
Contracts to make the moving joint stable. These muscles help to keep the other parts of the body stationary
What is the muscle belly?
The main body of the muscle
What is the epimysium?
The entire muscle is enclosed in an outer sheath of fibrous connective tissue
What is the fasciculi?
A bundle of fibres, usually muscle or nerve fibres
What is the perimysium?
A membrane that protects and supports groups of fibres within the skeletal muscle
What is the Levator ani?
Supports pelvic viscera and provides spincter-like action in the anal canal and vagina
What is the superficial transverses perinea?
Supports pelvic viscera
What is the bulbospongiosus?
For males it assists in emptying urethra. For females it contracts the vagina
What is the ischiocavernosus?
Assists with the function of bulbospongiosus
What is the sliding filament theory?
States how muscles contract. During muscle contraction, the cross bridges on the myosin filaments, attach to the actin filaments and pull the actin towards the centre of the sarcomere. As the actin moves, the cross bridge detach and reattach further along the actin to continue the process. This is called cross bridge cycling. During the contraction, the actual length of each actin and myosin filament does not change.
What is a slow twitch fibre Type I?
contain large amounts of myoglobin, many mitochondria and many blood capillaries. Type I fibres are red, split ATP at a slow rate, have a slow contraction velocity, very resistant to fatigue and have a high capacity to generate ATP by oxidative metabolic processes. Such fibres are found in large numbers in the postural muscles of the neck.
What is a Fast Twitch Fibres (Type II A or Fast Glycolytic Fibres)?
contain very large amounts of myoglobin, very many mitochondria and very many blood capillaries. Type II A fibres are red, have a very high capacity for generating ATP by oxidative metabolic processes, split ATP at a very rapid rate, have a fast contraction velocity and are resistant to fatigue. Such fibres are infrequently found in humans.
What is a Fast Twitch Fibres (Type II B or Fast Glycolytic Fibres)?
contain a low content of myoglobin, relatively few mitochondria, relatively few blood capillaries and large amounts glycogen. Type II B fibres are white, geared to generate ATP by anaerobic metabolic processes, not able to supply skeletal muscle fibres continuously with sufficient ATP, fatigue easily, split ATP at a fast rate and have a fast contraction velocity. Such fibres are found in large numbers in the muscles of the arms.
