Section 6

Question 1

Fasciitis

Answer 1

inflammation of fascia

Question 2

Plantar fasciitis

Answer 2

inflammation of the fascia on the bottom of the foot

Question 3

How is plantar fasciitis often fasciosis?

Answer 3

Research says that plantar fasciitis is a degenerative fasciosis without inflammation, not a fasciitis

Question 4

What did studies using proteolytic enzymes teach us about the myosin molecule?

Answer 4

Myosin is a multiunit protein.
2 heavy chains: Light meromysin (LMM) (coiled) and Heavy meromyosin (HMM) (S1 and S2).
4 light chains: essential and regulatory (2 each).

Question 5

What are the general atomic (10), molecular (5), and cellular (3) components of muscle fibers?

Answer 5

Atomic: Oxygen, Hydrogen Carbon, N, Ca, P, S, K, Na, Cl

Molecular: Water, Protein, Glycogen, Minerals, Lipid

Cellular: Muscle cells, Extracellular fluid, Adipocytes

Question 6

The mosaic distribution of fibers serves what purposes in muscle? (3)

Answer 6

Smooth contraction
Delivery of nutrients
Removal of byproducts/waste products

Question 7

Slow Twitch (Type I) characterisitcs

Answer 7

• Slow contraction
• Oxidative (aerobic) exercise
• High capillary, mitochondria, and myoglobin content.
• Slow Vmax and myosin ATPase
• Low force/ Low velocity
• Size: smallest motor neuron
• Resistance to fatigue: High
• Lower recruitment of Type I fibers = low force output (Step graph)

Question 8

Fast twitch Type IIa characteristics (6)

Answer 8

• Moderately fast contraction
• Long-term anaerobic exercise
• Resistance to fatigue: fairly high
• Size: Medium motor neuron (bigger than I, smaller than IIx)
• Medium force/ Medium velocity
• Medium-high recruitment of Type II fibers = medium force output (Step graph)

Question 9

Fast twitch Type IIx characteristics (7)

Answer 9

• Fast contraction time
• Size: large
• Resistance to fatigue: medium
• Short-anaerobic exercise
• High force/ High velocity
• Size: biggest fiber
• High recruitment of Type II fibers = high force output (Step graph)

Question 10

Parallel muscle fibers (2)

Answer 10

Strap and Fusiform

-not much bulge

Question 11

Strap

Answer 11

fibers originate and insert across entire width of broad flat tendon; can shorten (contract) fibers 40-60% of resting length

Question 12

Fusiform

Answer 12

spindle shaped; fibers originate and insert in one focused location on the tendon

Question 13

Pennate muscle fibers (3)

Answer 13

Uni-, Bi-, Multi-pennate

• longer the fiber = more potential bulge
• whole pennate muscle = not as much bulge as parallel

Question 14

Uni-pennate muscle fibers

Answer 14

one angle; fibers run in one direction

Question 15

Bi-pennate muscle fibers

Answer 15

two angles; fibers run in two directions

Question 16

Multi-pennate muscle fibers

Answer 16

multiple angles of fibers run in multi directions

Question 17

Why is the aponeurosis vital to pennate fibers?

Answer 17

Aponeurosis: type of connective tissue that provides a point for muscle to attach to bone or cartilage.
-it acts like a spring to bear the extra pressure and tension

Question 18

What are the benefits of pennation?

Answer 18

Pennation: muscle fibers run in the direction AWAY from the force generating axis.
Produces more force and does not bulge as much.
-Greater # fibers in muscle = higher number of MU. So each MU can be smaller to allow for fine control movements.
Can recruit in different patterns/order and varying numbers at a time.

Question 19

Why isn’t human muscle optimal for force and velocity? (3)

Answer 19

Mass of muscle is away from insertion
Pennate fiber not parallel
Reduced ROM for multi-joint muscle

Question 20

How are electron dense feet intertwined in the topic of Electron Contraction Coupling (ECC) steps?

Answer 20

As action potential travels down t-tubules, an electron dense feet is attracted to the t-tubule (depolarization), allowing Ca2+ to leak out of the sarcoplasmic reticulum. Thus, continuing the process of ECC by CA2+ binding to troponin, moving tropomyosin, and exposing myosin binding sites on actin.

Question 21

How is ACh during ECC? (4)

Answer 21

ACh enters the synaptic cleft
Acetylcholinesterase (enzyme) breaks down ACh in Acetate and choline
Acetate goes to plasma, choline goes back into nerves and binds with acetyl (stored in synaptic vesicles)

Question 22

How is Calcium during ECC? (5)

Answer 22

Calcium in cytosol
Parvalbumin (“runner”) binds with Ca2+ out in the cell Transports Ca2+ to sarcoplasmic reticulum
Ca2+ is handed off to calsequestrin (“receiver”) Calsequestrin takes Ca2+ and gives its to “Ca2+ ATPase pump”

Question 23

What seems to be true about relative muscle force is we just focus on biopsied muscle (muscle taken away from nerve control)?

Answer 23

Whether the biopsied muscle is compared between a human, monkey, or squirrel, the relative muscle is the same (structurally).

Question 24

How is bioenergetics connected to thermogenic function of muscle?

Answer 24

Triglyceride is broken down though lipolysis which produces lycerol and free fatty acids.
The fatty acids go the beta oxidation.
B-oxidation = NADH and FADH which are donated to ETC.
We build up a gradient and the uncoupling protein allows them to rush thru a different channel so we don’t have to burn ATP but we still get warming effect.
-the uncoupling protein is trying to warm body up.

Question 25

How are green mamba snaked connected to lack of ACh clean up?

Answer 25

fasciculins (toxic snake venom) interferes with acetylcholinesterase
-if you break down the acetylcholinesterase, you can’t breakdown Ach so your muscle stays chronically active and the person freezes up and cant move.
Body eventually shuts down and you die.