9.4 The Muscles Flashcards
What are the three different types of muscles?
The three different types of muscles include:
1. Smooth: Lines the esophagus, stomach, uterus, and arteries. It does not fatigue easily. And contraction is voluntary.
2. Cardiac: Acts as a pump that pushes blood through the vessels. Contraction is involuntary.
3. Skeletal: The contraction is voluntary. They are used for locomotion and it helps return blood to the heart. They shorten when they contract and lengthen when they relax. They are arranged in antagonistic pairs (when one contracts, the other relaxes).
What are the muscles that bend a joint called?
The muscles that bend a joint are called flexors.
What are the muscles that straighten a joint called?
The muscles that straighten a joint are called extensors.
What is the skeletal muscle structures made of?
The skeletal muscle structures are made of bundles of muscle fibres. Muscle fibres are made of protein structures called myofilaments. Myofilaments are responsible for muscle contraction. There are two types of myofilaments, actin and myosin.
What is the sliding filament theory?
The sliding filament theory states that actin filaments slides over the myosin filaments. The steps include:
1. The head of myosin moves.
2. The actin filament gets pulled along with myosin.
3. The actin filament then slides past the myosin myofilament in the direction of the flex.
4. Each time ATP is needed to reposition myosin head before a new flex.
What is muscle fatigue?
Creatine phosphate ensures that ATP supplies remain high. It supplies a phosphate to adenosine diphosphate (ADP).
What are muscle contractions?
They are caused by a nerve impulse. The strength of a contraction depends on the frequency of the stimulus. The steps include:
1. A nerve cell stimulates a muscle cell.
2. There is a pause called the latent period.
3. The muscle contracts/shortens, and the actin slides over the myosin.
4. Actin and myosin disengage.
5. The muscle begins to relax and then returns to its original size.
What’s the difference between fast and slow twitch muscle fibres?
There are three different types of myosin. They include:
1. Type l: Causes slow muscle twitches, breaks down ATP slowly, and are found greater abundance in long distance runners.
2. Type lla and llx: Causes a faster twitch, breaks down ATP faster, rely on anaerobic respiration, and are found in greater abundance in sprinters.
What are motor system injuries?
Examples of injuries include:
- Torn muscles/sprains
- Tendonitis: inflammation of tendons
- Torn ligaments
- Joint dislocation: movement of the joint out of it’s socket.
What is arthroscopic surgery?
Where the needle is inserted into the knee, and the lens provides a picture of the damage within.
