Quiz 6 Flashcards
How do contractions and vibrations work with muscles?
Skeletal, Cardiac have contractions; Visceral, Smooth have peristalsis motions (vibrations or wave-like motions)
Salts help in muscle contractions; spasms occur when the body is lacking in a salt
Define functional unit.
Agonist: primary or first mover
Antagonist: opposite action to agonist
Synergistic: help muscle; helps antagonist
Specialist: one action only
*antagonistic movements (agonist-antagonist pairs) are superficial or visible
What are the characteristics of skeletal muscle?
attached to skeleton or bone with a process, tuberosity, or trochanter; only muscle with a tendon; voluntary and striated with protein bands; CNS innervation
What is origin and insertion? Fast twitch and slow twitch?
SKELETAL MUSCLE
Origin: closer or proximal to head; fixed or stationary
Insertion: farther or distal; moveable
Fast Twitch: quick contractions and fatigues; burst of energy or speed; developed first in the human body as barbies; “white meat” because of low amount of myoglobin
Slow Twitch: slow contractions and fatigue; endurance; “dark meat” because of high amount of myoglobin
*twitch ratio is genetically influenced
What are the characteristics of smooth muscle?
involuntary, unstriated; ANS innervation; moves through peristalsis; found in internal organs and blood vessels
What are the characteristics of cardiac muscle?
involuntary, striated; ANS innervation; has syncytium gaps formed by crossing over matrix; has autorhythmicity (each cell has its own beat)
What are the muscles of mastication?
Buccinator: agonist
Masseter: antagonist
Pterogoids: synergist
What are the types of innervation?
Innervation: origin of an electrical impulse involuntary
muscles innervate from the ANS (autonomic nervous system); voluntary muscles innervate from the CNS (central nervous system)
What are the steps of muscle contraction?
- ANS/CNS innervation of 70+ mV occurs
- Mitochondria react to stimulus
- ATP is released
- Presynaptic Vesicles react to ATP
- ACH (acetylcholine) is released
- ACH moves across the synaptic gap (synapse)
- Polarity change from rest (positive in, negative out) to contraction (positive out, negative in)
What is the sodium potassium pump?
SPM keeps positive sodium ions out, negative potassium ions in; electrical impulse allows SPM to “open” and polarity change occurs
ACH-esterase repolarizes everything to equilibrium and requires protein
What is the sliding filament theory?
takes place at myoneural junction; filaments become depolarizers and slide across one another to come together; change of polarity causes shortening of muscle
Define summation, fatigue, and the all or none law. What is the difference between a natural and unnatural twitch?
Summation: natural, continuous flow of ACH
Fatigue: lack of protein that causes a lack of ACH-esterase
All or None Law: fibers contract all the way or not at all
Natural Twitch: involuntary muscle contraction Unnatural
Twitch: aka tetanus; twitching caused by external stimulation
Define myology, myoglobin, and dual function. What is the basic unit and fiber content of muscle?
Myology: study of muscle
Myoglobin: blood-colored liquid protein
Dual Function: of muscles; allows for movement and heat
Basic Unit: fibers
Fiber Content: 75% interstitial fluid; 20% protein; 3-6% basic salts (KNaCa)
ANTERIOR
- Pectoralis major: draws arm forward and toward the body
- Serratus anterior: helps raise arm; contributes to pushes; draws shoulder blades forward
- Biceps brachii: bends forearm at the elbow
- Rectus abdominus: compresses abdomen; compresses backbone; compresses chest cavity
- External oblique: lateral roation of trunk; compresses abdomen
- Abductor longus: flexes thigh; rotates thigh laterally; draws thigh toward body
- Satorius: bends thigh at hip; bends lower leg at knee; rotates thigh outward
- Quadriceps group: flexes thigh at hips; extends leg at knee
- Tibialis anterior: flexes foot toward knee
POSTERIOR
- Deltoid: raises arm
- Trapezius: lifts shoulder blade; braces shoulder; draws head back
- Triceps brachii: straightens forearm at elbow
- Latissimus dorsi: rotates and draws arm backward and toward body
- Gluteus maximus: extends thigh; rotates thigh laterally
- Hamstring group: draws thigh backward; bends knee
- Gastrocnemius: bends lower leg at knee; bends foot away from knee
- Achilles tendon: connects gastrocnemius muscle to heel
MUSCLE ULTRASTRUCTUE
- Process
- Tendon
- Fundus (body)
- Bundle
- Sarcolemma
- Fiber
- Myofibril
- Filament
MYOFIBRIL ULTRASTRUCTURE
- Dark Bands: aka A-bands; thick filament of myosin
- Light Bands: aka J-bands; thin filament made of actin
- Sarcomere: aka Z-bands; location of contraction
- H-zone: takes in impulses via end knob
How are muscles named? (Types 1 to 4)
- By Geometric Shape or Form: Trapezius; Rhombus; Deltoid; Teres; Quadratus; Splenius
- Size and General Configuration: Latissimus (broad); Longus; Brevis (short); Vastus (thick); Maximus; Minimus
- Fiber Direction: Rectus (up, down); Transversus (superior, anterior); Oblique (cleft through the body)
- Origin and Insertion (attachements): sternocleidomastoid (sternum, clavicle, mastoid); brachioradialis (arm, radius); caracobrachialis (carcoid of scapula, arm)
How are muscles named? (Types 5 to 7)
- General Location: intercostal (ribs); brachialis (arms); pectoralis; tibialis; Iliacus (hips); Femoris; Subscapularis (scapula)
- Action or Function: Flexor; Extensor; Abductor (opens); Adductor (closes); Pronator (faces posteriorly or inward); Supinator (faces anterioirly or outwards); Levator (brings up); Depressor (brings down)
- Number of Heads or Origins: Biceps (two); Triceps (three); Quadriceps (four)
8.
Derive these muscles.
- Biceps brachii
- Pronator teres
- Levator scapulae
- Extensor carpi radaialis longus
- 7, 5
- 6, 1
- 6, 5
- 6, 5, 2
ACTION POTENTIAL; ignore 5
impulse determined by action; action determines potential
resting potential of -70 mV; threshold requires 70 mV to contract; subthreshold is any stimulus that is less than 70 mV
- resting potential
- depolarization; sodium in
- action potential
- polarization; potassium in
NUEROMUSCULAR JUNCTION
- Dendrite
- Cell Body; Soma
- Axon
- Myelin Sheath
- Telodendrils
- End Knob
- Mitochondria
- Pre-Synaptic Vesicles (release ACH)
- Conductive Gel (for transmitting electrical impulses)
- Synapse
- Receptors
