Chapter 4: The Muscular System Flashcards
What are the three types of muscles?
- Skeletal - attached to bone (only voluntary muscles)
- Cardiac - heart
- Smooth - hollow vessels and organs
What are the 5 main functions of skeletal muscles?
- Movement
- Stability
- Stabilizing joints
- Heat production
- Protection of underlying tissues and organs
What are the 3 layers of muscle connective tissue?
- Epimysium: connective tissue that separates the muscle from surrounding tissue and joins with tendons.
- Perimysium: connective tissue that separates skeletal muscles into bundles of muscle fibers.
- Endomysium: surround individual muscle fibers
How do muscles contract?
Each skeletal muscle fiber is stimulated to contract by a motor neuron AKA a nerve.For this to happen, contracting muscle fibers need a continuous blood supply to receive oxygen and fuel for the production of ATP.
What is ATP?
The energy source that allows muscle contractions.
What is a motor unit?
Made up of a motor nerve and the muscle fibers it stimulates. It is the size of the motor unit that determines the force.
What size of motor unit would be needed for a precise movement VS a large movement?
A precise movement like playing the piano will only need 3-4 muscle fibers in each motor unit. Whereas large movements that require large muscles need 100-2000 muscle fibers.
What are the two muscle attachment sites?
- The origin: the proximal attachment of the muscle to the bone.
- The insertion: the distal attachment of the muscle to the moving bone.
What are the 5 different types of skeletal muscle?
- Fusiform - bicep (bulging middle, tapered ends)
- Parallel - abs (more flat, weaker)
- Convergent - pecks (fan shaped w wide origin and narrow insertion)
- Penate - deltoid (feather shaped muscles, run at an oblique angle and insert into a tendon, strong)
- Circular - openings
