Smooth Brain
A scissor would represent what type of lever system?
First Class
Additionally, what is a first-class lever joint example in our body?
A motor unit can be defined as?
A neuron and all the muscle it innervates
Faitgue occurs due to?
*Lack of ATP
*Ionic Imbalance
Which of the following down below does not play a role in muscle relaxation?
Calsequestrin
SERCA
Acetylcholinesterase
None, they ALL play a role in relaxation.
The muscles of the hand in comparison to the muscles of the leg have different innervation ratios, why?
High innervation ratio in the hand allows for fine motor control in the hand, whereas the leg has low innervation ratio for powerful movements.
What is the role of MLCP in smooth muscle contraction?
Dephosphorylates the light chains in myosin heads for relaxation
In upper cross syndrome, the muscles that are weak/inhibited are:
Lower Trapezius
Serratus Anterior
Rhomboid Major
Longus Capitis
Factors that limit exercise include?
Type of training-Weights or Endurance (Weights/Cardio)
Oxygen availability,ATP, and substrate availability
CV health/Temp Regulation
In your own words, describe the sequence of the Excitation-Contraction Cycle
Vince's Version
AP causes ACH to be released at the motor endplate
Ach binds to NA+ gated channels for AP to depolarize the cell
AP travels down T-Tubule to release CA from SR
Contraction cycle
All steps above ends once ACH is removed from synaptic cleft, or AP no longer exist.
Maximal Stimulus can defined as?
No more motor neurons being recruited (No more tension/force being generated)-Think maxing out
Titin, MyoMesin, Nebulin, Dystrophin
Acronym- TELL ME NOW DAMMIT
For doing powerful contractions, like lifting a table, you are using? (hint:motor units and innervation ratios)
Fewer large motor units, low innervation ratio
In order to break the cross bridge between the actin and myosin, what must bind to the myosin?
ATP
What are the factors that determine the amount of force produced in skeletal muscle contraction?
The myofiber type
The degree of muscle stretch
Frequency of stimulation by motor neurons
The number of muscle fibers stimulated.
"tree trunk" legs are commonly made up of which type of muscle fibers?
TYPE 2B: Fast Twitch GLYGOLYTIC
What do TYPE 2 fibers lack that make them anaerobically adapted?
List the factors that determine whether or not the contraction cycle can continue to occur.
ATP availability
Calcium Concentration is high (near the filaments).
(Ability to contract also depends on INITIAL resting length)
In upper cross syndrome, the muscles that are tight (FACILITATED), are?
Pec Minor
Upper Trap
SCM
Levator Scap
If MLCP increases in the MLCK/MLCP ratio, what will occur?
The smooth muscle will be less sensitive to calcium.
What are factors that effects WHOLE MUSCLE contractions?
Number of Motor Units recruited
Muscle Stretch (length/tension)
Frequency of Stimulation
Type of muscle fiber
In lower Cross Syndrome, the muscles that are FACILITATED (tight) are?
Iliopsoas
Rectus Femoris
Lumbar Extensors
TFL
Piriformis
QL
Thigh Adductors
Power stroke refers to the droppage of which molecule?
ADP
State the steps of smooth muscle contraction in order.
I.Myosin cross bridges are formed to create muscle tension.
II. Calcium binds to calmodulin
III. Intracellular calcium levels increase.
IV. MLCK phosphorylates light chains in myosin heads and increases myosin ATPase activity.
Calcium ions are released from the sarcoplasmic reticulum to initiate muscle contraction and are removed upon muscle relaxation. What will follow in terms of contraction if calcium ions are not completely removed?
The next muscle contraction will be greater than the previous muscle contraction
Determine and come up with an explanation of whether the statement is true or false.
ATP is required only for contraction of muscle as it causes the myosin head to drop away from the Myosin binding site provides energy to move the myosin head back in position to bond with the actin.
False: ATP is needed for not just contraction but also relaxation through SERCA for the removal of calcium
Calcium levels can increase in smooth muscle through:
1. IP3 receptor channels
2. Calcium release channels
3. Voltage-gated, ligand-gated, mechanically-gated channels