Flashcards in List #6 Deck (54)
-layers of dense connective tissue that holds individual skeletal muscle in position.
-thick protein filament (dark)
-thin protein filament (light)
- The striations form a repeating pattern of units along tac muscle fiber
- The light bands, composed of thin actin filaments held by direct attachments to structures called Z lines
-Found in the center of I-bands
- A slightly lighter central region consisting only of thick filaments found in the A-band
-The second part of the striation pattern, which composes thick myosin filaments overlapping thin actin filaments
- Consists of proteins that help hold the thick filaments in place, found in the A band in a thicker section.
-A myosin head can attach to an actin binding site forming a cross-bridge, and bend slightly, pulling on the actin filament
- An enzyme found in myosin heads
- it catalyzes the breakdown of ATP to ADP and a phosphate
-rod-shaped and occupy the longitudinal grooves of the actin helix
-three protein subunits and are attached to actin
- corresponds to the endoplasmic reticulum. Membranous channels in the sarcoplasm of a muscle fiber that surrounds each myofibril and runs parallel to it.
- A set of membranous channels that extends into the sarcoplasm as invaginations continuous with the sarcolemma and contains extracellular fluid
-Region where the actin and myosin filaments overlap
sliding filament theory
- When sarcomeres shorten, the thick and thin filaments do not change length
- The synapse where a motor neuron axon and a skeletal muscle fibers.
- Here the muscle fiber membrane is specialized to form a motor end plate, where nuclei and mitochondria are abundant and the sarcolemma is extensively folded.
lower motor neurons
-Neurons that control effectors, including skeletal muscle fibers.
-Normally a skeletal muscle fiber contracts only upon stimulation by its motor neuron
motor end plates
- Where nuclei and mitochondria are abundant and the sarcolemma is extensively folded.
- Together a motor neuron and a muscle fiber control it
- A small gap that separates the membrane of the neuron and the membrane of the muscle fiber
- Biological messenger molecules that convey neural information
-tiny vesicles that stores neurotransmitters
- The neurotransmitter that motor neurons use to control skeletal muscle contraction.
- An enzyme that rapidly decomposes acetylcholine remaining in the synapse.
-grave muscular weakness
- The body produces antibodies that target receptors for the neurotransmitter acetylcholine on skeletal muscle cells at neuromuscular junctions
-Alternare contractions and relaxations of the longitudinal and circular muscles.
-In the intestines it pushes food down the digestive tract
- Small cellular processes that receive input