A&P Test Muscles
Look over PP Ch 10 Pt 1 Sl 16
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Look over PP Ch 11 Pt 1 Sl 9-11
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Look over entire PP Ch 10 Pt 2
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Look over entire PP Ch 11 Pt 2
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Neuromuscular activation steps
1. Action potential arrives at the somatic motor neuron axon 2. Calcium enters and stimulates acetylcholine to be released 3. Acetylcholine bind to motor end plate, opening sodium ion channels 4. Sodium ions cause muscle action potential 5. Action potential goes through T tubules, stimulating SR to release calcium 6. Contraction cycle
Beginning of muscle contraction steps
1. Action potential triggers release of calcium from sarcoplasmic reticulum 2. Calcium binds to troponin on actin > tropomyosin moves off actin's binding sites 3. Contraction cycle
Contraction cycle steps
1. Myosin hydrolyzes ATP, gaining its energy > myosin cocks its head 2. Myosin forms cross bridges with actin 3. Power stroke pulls actin toward M-line > ATP goes away 4. Myosin binds another ATP > resets
Contraction process will continue as long as...
ATP and calcium is present
Rigor Mortis
Begins 3-4 hrs after death Calcium leaks out of SR Muscle contraction begins ATP production stops
Third class lever example
Bicep curl Fulcrum: Elbow joint Effort: Biceps brachii Load: Anything held in hand
Second class lever example
Calf raise Effort: Gastrocnemius Load: Weight of body Fulcrum: Ball of the foot
3 ways skeletal muscle produces ATP for muscle metabolism
Creatinine phosphate Anaerobic glycolysis Aerobic cellular respiration
How long are muscle fibers
Depends on the muscle They run the entire length of the muscle
Criteria for naming muscles
Direction Size Shape Action Number of origins Location Origin - Insertion
Muscle insertion
Distal attachment Mobile
4 groups of head muscles
Facial movement Eye movement Mouth movement Tongue
First class lever example
Head and neck during neck extension Effort: Neck extensor muscles Fulcrum: Head-neck joint Load: Front of skull
Myofibrils
Increases in size from exercise The "bulk" of the muscle
Cardiac tissue characteristics
Involuntary control Location: heart Striated Intercalated discs
Smooth tissue characteristics
Involuntary control Location: hollow organs No striations
Mechanical advantage
Load is closer to fulcrum Effort further from fulcrum Easier to move load
Mechanical disadvantage
Load is further from the fulcrum Effort is closer to the fulcrum
Myosin extends across ____________ Actin extends across ______________
M line Z line
Embryonic development of muscle tissue
Mesoderm > Myoblasts > Muscle Fibers
Functions of muscle tissue
Movement Stabilizing body position Storing/moving substances Generating heat
Muscle origin
Proximal attachment Fixed
Muscle names based on direction
Rectus Transverse Oblique
Role of calcium in contraction process
Relaxation Action potential stimulation Following action potential
Synergist types and what the do
True: neutralize unwanted movement by fixing a bone in place Helping: prevents unwanted movement but also assists the prime mover with the movement
Skeletal tissue characteristics
Voluntary control Location: bones Striated
Contractibility
ability of muscle tissue to contract
Elasticity
ability of muscle to return to its original shape after contracting
Extensibility
ability of muscle to stretch without being damaged
Types of contractile proteins
actin and myosin
Ligaments
connect bone to bone
Tendons
connect muscle to bone
Aponeurosis
connect muscle to muscle
Types of muscle proteins
contractile, regulatory, structural
Oblique
diagonal to midline external oblique
Muscles move more ______ sections
distal
What determines if there is a mechanical advantage or disadvantage
distance between the load and the fulcrum
Forces acting on levers
effort (causes movement) load/resistance (opposes movement)
First class lever
effort, fulcrum, load mechanical advantage or disadvantage
Second class lever
effort, load, fulcrum mechanical advantage
3 connective tissue layers of skeletal muscle tissues (outer to inner)
epimysium perimysium endomysium
Properties of muscle tissue
excitability, contractility, extensibility, elasticity
Fastest moving muscles
eye movement muscles
3 types of levers
first class, second class, third class
Muscle belly
fleshy main portion of the muscle
Third class lever
fulcrum, effort, load mechanical disadvantage most common
Contractile proteins
generate force of contraction
Sarcoplasm contains large amounts of ________
glycogen
Vastus
huge
What is needed for muscle metabolism
huge amounts of ATP
Longissimus
large
Magnus
large
Major
larger
Maximum
largest
To produce movement: Bones act as _________ Joints act as _________
levers fulcrums
Longus
long
M line
middle of sarcomere
Muscle cell = ____________
muscle fiber
Excitability
muscle responds to action potentials form neurons
Contractile units
myofibrils
Regulatory proteins
on-off switch
Types of muscle fascicle arrangement
parallel fusiform circular convergent unipennate bipennate multipennate
Rectus
parallel to midline rectus abdominis
Transverse
perpendicular to midline transverse abdominis
Agonist
prime mover contracts to cause of movement
Transverse (T) tubules
rapidly transmit info into the muscle cell
Myoglobin
red-colored sarcoplasm that binds/stores oxygen
Antagonist
relaxes/yields to the effects of the prime mover muscle
Plasma membrane of muscle fiber
sarcolemma
Basic functional unit of the of the myofibril
sarcomere
Cytoplasm of muscle fiber
sarcoplasm
Endoplasmic reticulum of muscle fiber
sarcoplasmic reticulum
Muscle stem cell
satellite cell
Z line
separates one sarcomere from the next
Brevis
short
Types of muscle tissue
skeletal, cardiac, smooth
Minor
smaller
Minimum
smallest
Exception to regular origin and insertion characteristics
sternocleidomastoid
What triggers muscle contraction
the release of calcium
When does motion occur
when the effort at the insertion exceeds the load
Latissimus
widest
Sliding filament theory
Actin and myosin don't change size during contraction Myosin heads walk along actin Myosin pulls thin filament toward the M line
Fascia
Body stocking Outermost connective tissue Dense sheet of irregular connective tissue Holds muscles together
