Muscle Unit Flashcards
Functions Of muscle Tissue
Movement, Thermogenesis, postural support, protects internal organs, pumps blood
Charactertitics of muscle tissue
Contractibility (able to shorten, Elasticity, Excitability ( able to respond to a stiumulus
What is cardiac muscle
Forms bulk of heart wall, striated, Involuntary, Centrally located nucleus, Sarcolemmas connected by intercalated discs
What is Smooth Muscle
Located in walls of hollow internal surfaces, Non-striated, involuntary, Can be stretched to great lengths, allows for tremendous size variability
What is skeletal muscle
Attached to bones, striated under a microscope, voluntary control, Multinucleated
What is Origin, insertion, and belly
O-Where the muscle begins, I- Where the muscle ends, B- The fleshy parts between the tendons
Roles of skeletal muscles
Agonist (Muscle responsible for the majority of force, Antagonist (Preforms the oppisite movement, Synergist (Muscle that assits the agonist, Fixator (Stabalized a body segement)
What are Muscle fiber, Endomysium, Perimysium, Epimysium
M-A muscle cell, En-Cell membrane, P-Membrane that surrounds a fascicle, Ep-Membrane that surrounds the whole muscle
What is the Sarcolemma, Sarcoplasm, and the Myofilaments
Sarc- Cell Membrane of a muscle, Sarco-Cytoplasm of a muscle, Myofilaments- actin and Myosin, protein filaments inside a cell
What are the Filaments and landmarks
F- Myosin is thick, actin is thin, Landmarks- z line, m line, h zone, a band, I band
Actin
Thin filament, receptor for calcium, anchored to the z line
What are the two additional proteins
Troponin- Sits on Tropomyosin, calcium recpetor, Tropomyosin- wraps around the actin, shifts when calcium binds to toponin
Myosin
Thick Filament, Globular heads- shaped like golf clubs also called cross bridges. Overlap actin, binds to actin to cause muscle contraction
what is the Sliding Filament Theory
1.Nervous impulse hits a muscle. 2. Myosin and actin slide past each other 3. Myosin and actin dont change size 4. H zone and I band narrow or disappear 5. A band remains the same length
Threshold stimulus
The weakest stiulus from a neuron that will initiate a muscular connection
All or none principle
Once a threshold stimulus is applied to a muscle the muscle fibers that are being stimulated will contract to their fullest potenital
Motor Unit
Your whole muscle rarelt contracts only certain motor units contract
Motor Neuron
Brain sends a signal throguh a motor neuron that we nned to move.
Axon
The signal propagated down the axon or the long projection off the cell body
Synaptic end bulb
The end of the axon
Neurmosucalr Junction
Where a motor neuron axon meets a muscle
Motor unit
A motor neuron and all the fibers it effects
Synaptic vesicles (ACH)
When the action potential hits the synaptic end bulb, vesicles release ach from the neuron
Synaptic cleft
The area between the synaptic end bulb and the motor end plate
