Muscle

Question 0

Motor unit definition

Answer 0

Somatic motor neuron together with all of the muscle fibers that it innervates

Question 1

What surrounds muscle fibers

Answer 1

Sarcolemma

Question 2

Muscle fibers going from big to small starting at muscle itself

Answer 2

Muscle to fascicle to fiber to myofibrils to filaments

Question 3

Thin filaments

Answer 3

Actin

Question 4

Thick filaments

Answer 4

Myosin

Question 5

What makes up the Iband. what is in the middle of the Iband.

Answer 5

Myosin.

Z disc

Question 6

What makes up the a band. What is in the middle of the A band. Why does the middle look the way it does

Answer 6

Thick filaments. h band. The H band is only myosin where as the rest of the a band has Actin also

Question 7

Summarize excitation contraction coupling

Answer 7

release of ACH from nerve fiber, ACH binds to receptors on sarcolemma, opens ligand gated channels, Sodium defuses in producing depolarization, action potential produced. AP conducted a long transverse tubules, voltage gated CA channels open, CA released channels in SR open, CA diffuses into sarcoplasm, CA binds to troponin, stimulating contraction.

Question 8

What is treppe

Answer 8

Ability to evoke stronger contractions after subsequent contractions. Staircase effect

Question 9

Iso tonic contraction

Answer 9

Muscle is contracting during shortening. Iso means same tonic means strength

Question 10

Isometric contraction

Answer 10

Contraction without muscle shortening. Holding a dumbbell with partially flexed arm

Question 11

Concentric contraction

Answer 11

Iso tonic contraction where muscle shortens

Question 12

Eccentric contraction

Answer 12

I so tonic contraction where muscle length and

Question 13

What two things are different in cardiac muscle from skeletal muscle

Answer 13

Cardiac muscle does not require neural stimulation to contract – cardiac cells have own pacemaker. Action potentials are conducted from one of cardiac cell to another via intercalated disks

Question 14

What six things are different between smooth and skeletal muscle

Answer 14

Not striated, no transverse tubules, calmodulin calcium binding instead of troponin, calcium enters from extracellular fluid and sarcoplasmic reticulum, nerve stimulation not required, gap junctions in most

Question 15

Describe calcium reception and smooth muscle cells

Answer 15

Calcium binds to calmodulin which activates myosin light chain kinase. MLCK phosphoralyses myosin heads and allows for cross bridge attachment

Question 16

Single unit smooth muscle cells

Answer 16

Connected by gap junctions

Question 17

Multiunit smooth muscle cells

Answer 17

Not connected by gap junctions

Question 18

Synapses en passant

Answer 18

Autonomic neurons have varicosities that release neurotransmitters along the length of the smooth muscle cell

Question 19

Myosin head mechanism of function in skeletal muscle

Answer 19

ATPase enzyme splits ATP into ADP and phosphate activating crossed bridge. Phosphate is released to undergo a power stroke. ADP is then released and cross bridge is detached.

Question 20

H I and a bands – which shorten during contraction

Answer 20

H and I bands decrease a bands stay same length

Question 21

What surrounds the muscle

Answer 21

Epimysium

Question 22

What surrounds the fascicles

Answer 22

Perimysium

Question 23

What surrounds the muscle cells

Answer 23

Endomysium

Question 24

What does troponin I do

Answer 24

Inhibits crossbridge binding

Question 25

What does troponin T do

Answer 25

Binds to tropomyosin

Question 26

What does troponin C do

Answer 26

Binds to calcium

Question 27

Dihydropyridine and ryanodine receptors

Answer 27

Dihyrdro voltage gated ca receptors
Ryanodine ca release channels

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