Chapter 8 : Structure and Anatomy Flashcards
Muscles are composed of which tissue types
All 4 main tissue types and are bundled by layers of connective tissue to increase their strength
Endomysium
Surrounds individual muscle fibers (cells)
Perimysium
Wraps around 10-100 muscle fibers bundling them into a structure called a fascicle
Epimysium
Surrounds the entire muscle and connects with the fascia
Fascia
Encases the entire muscle and serves as the connection to the periosteum of the bone via the tendon oor aponeurosis
Tendon
Cord like structure that connects the muscle to the periosteum of the bone
Aponerosis
Sheet like structure that connects the muscle to the periosteum of the bone
Muscle cell
each muscle cell is called a muscle fiber
Sarcolemma
Cell membrane and a thin coating of polysaccharides with collagen fibers
Sarcoplasmic Reticulum
Specialized endoplasmic reticulum that stores and releases Ca+ for filament binding
Transverse or T-tubules
Extension of the sarcolemma that attach and carry impulses to the sarcoplasmic reticulum
Sarcoplasm
Specialize cytoplasm that contains large amounts of gycogen for energy
Mitochondria
Muscle fiber has hundreds of mitochondria to provide the energy needed for contraction
Myofibrils
Specialized cylindrical organelles that fill in most of the space in the muscle fiber
Myofibrils contain
Contractile proteins
Actin filament
also known as thin filaments
Myosin filament
also known as thick filaments
Sarcomere
the functional or contractile units of a muscle fiber that extending between actin attachments
Motor Nerve
Nerve that sends “movement” message from the brain to the muscles
Motor end plate
region of the muscle fiber that meets with the motor nerve fiber (one per muscle fiber)
Nerve Fibers
Projections (axons) of the nerve cell that meet with the muscle fiber and release neurotransmitters (many branches per cell)
Neurotransmitter
Chemical translator released by the nerve fiber to communicate the “movement” message to the muscle fiber
Acetylcholine (ACh)
ALWAYS the neurotransmitter released for muscle contraction to occur; absorb the motor end plate
Neuromuscular junction
Point where the nerve fiber meets up with the motor end plate (don’t actually touch - gap)
Synaptic cleft
Gap between the neuron and the muscle fiber