Exam #5 Flashcards
Insertion
Generally the part that the muscle moves
Origin
Muscle attachment that doesn’t move
Agonist
The muscle that produces most of the force during a particular joint action
Antagonist
A muscle that opposes the prime mover
Perimysium
thicker connective tissue sheath
Wraps muscle fibers together in bundles called fascicles
Endomysium
thin sleeve of loose connective tissue that surrounds each muscle fiber
Epimysium
A fibrous sheath that surrounds the entire muscle
Neuromuscular junction
Motor end plate
The point where a nerve fiber meets any target cell is a synapse when the target cell is a muscle fiber the synapse is also called NMJ
Myoglobin
O2 binding protein stores O2
Regulatory proteins
Tropomyosin and Troponin
I band
The region of a striated muscle sarcomere that contains only thin filaments
Z line/disc
A protein band that defines the boundaries of a muscle sarcomere
A band
A dark region within a sarcomere that contains thick myosin filaments
Elastic filaments
Protein filaments in a sarcomere that stretch from the M-line to the Z-line
Thin filament
Made of actin along with the two other regulatory proteins-troponin and tropomyosin
Thick filament
Organized bundles of myosin
Sarcomere
The basic contractile unit of a muscle fiber
Tropomyosin
Blocks muscle contraction
Troponin
Promotes muscle contraction
Actin
A protein that is found in all eukaryotic cells
Globular heads
Key to muscle contraction
The globular head of myosin is a well conserved protein that extends from myosin filaments and binds actin
Flexed hinge region
A flexible amino acid stretch that connects two domains in a protein
Cross-bridge cycling
A series of events that occurs during muscle contraction
It describes the interaction of actin and myosin within muscle cells.
Myosin Binding sites
ATP binding site is when myosin binds to ATP at this site which causes myosin to release actin
Actin binding site is when myosin binds to actin at a binding site on the globular actin protein
What happens with ACh and Na+ during depolarization of a muscle fiber
Na+ channels are open
K+ channels are closed
The differences between isometric and isotonic contractions
Isometric contractions
no movement occurs tension builds
Isotonic Contractions
movement occurs tension builds and muscle length changes
The 3 energy producing pathways, how much ATP they produce, what activities are associated with each pathway
- Direct phosphorylation
1 ATP 15 seconds
hitting a ball diving kicking a ball - Anaerobic pathway
2 ATP 30 to 60 seconds
sprinting and running - Aerobic pathway
32 ATP and hours
marathon runners and activities longer than 30 mins
What events occur during a skeletal muscle contraction What channels are open and closed
What ions are transporting in and out of the cell
The action potential is conducted through the T-tubules
Calcium ions are released from the sarcoplasmic reticulum
Calcium ions bind to troponin
Myosin head (cross bridge) binds to the actin
The myosin head pivots and pulls on the actin filament
A new ATP attaches to the myosin head detaches from the actin
How is lactic acid produced in the body
When cells break down carbohydrates for energy
When oxygen levels are low it is mainly produced in muscle cells and red blood cells
But it can come from any tissue in your body.
Why does rigor mortis happens after death
Dying muscle cells take on calcium from the extracellular fluid this promotes the formation of myosin cross bridges
Actin myosin binding lack of ATP makes detachment impossible
Results in stiffness of the muscles
Disappears as muscle proteins breakdown 15-25 hours later
How is calcium transported during the relaxation and muscle contraction phases
During muscle relaxation calcium is pumped back into the SR using ATP
What is botox, where it comes from and how it affects the motor end plate
A neurotoxin produced by the bacterium Clostridium botulinum
Produced from a culture of the hall strain of C botulinum
It blocks the release of acetylcholine
What is Myasthenia Gravis
An autoimmune disease
Antibodies block or destroy ACh receptors
Results in a shortage of ACh receptors
Disease is progressive
Drooping eyelids difficulty swallowing generalized muscle weakness
The 3 muscle fiber types and what activities they are responsible for
Slow Oxidative Fibers
running a marathon
Fast Oxidative Fibers
sprinting and walking
Fast Glycolytic Fibers
hitting a baseball
List events in order
The action potential is conducted through the T-tubules
Calcium ions are released from the sarcoplasmic reticulum
Calcium ions bind to troponin
Myosin head (cross bridge) binds to the actin
The myosin head pivots and pulls on the actin filament
A new ATP attaches to the myosin; head detaches from the actin.
Flexion
Bending movement decrease angle of joint
Extension
Bending movement increase angle of joint
Hyperextension
Extension of a limb or part beyond the normal limit
Dorsiflexion
Lifting the foot superior surface toward shin
Plantar flexion
Depressing the foot pointing the toes
Inversion
Sole of foot turns medially
Eversion
Sole of foot turns laterally
Supination
Rotate forearm laterally so palm faces anteriorly or superiorly
Pronation
Rotate forearm medially so palm faces posteriorly or inferiorly
Abduction
Move a limb away from the midline along frontal plane
Adduction
Move a limb toward the midline long frontal plane
Circumduction
Distal end of limb moves in circle
Rotation
Turn a bone around its own long axis toward or away from midline
Protraction
Anterior movement in transverse plane moves mandible forward
Retraction
Posterior movement in transverse plane
Elevation
Lift a body part superiorly
Depression
Move elevated body part inferiorly
Isometric
No movement occurs, tension builds
Isotonic
Movement occurs tension builds and muscle length changes
