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Flashcards in Muscle Deck (25):
1

sliding-filament model

hypothesis that thin filaments (actin) & thick filaments (myosin) slide past one another during contraction

- sliding shortens sacromere
- 1954 - proposed by Huxley & Hanson (individually @ same time)

2

evidence of sliding filament model of muscle contraction

light & dark bands in sacromere changed when muscles relaxed or contracted

- light bands become narrower
- dark bands no change

3

types of muscle

(1) cardiac muscle
(2) smooth muscle
(3) skeletal muscle

4

cardiac muscle

type of muscle

location: heart
function: move food & help regulate blood pressure
properties: involuntary
striated due to sacromeres

5

smooth muscle

type of muscle

location: intestines, arteries, digestive tract, lungs, etc.
function: pump blood
properties: involuntary

6

skeletal muscle

type of muscle

location: attached to skeleton
function: move skeleton
properties: voluntary
striated due to sacromeres

7

level of muscle organization

(1) muscle
(2) muscle fiber/cell
(3) myofibril
(4) sacromere

8

adenosine triophosphate (ATP)

causes conformational change by releasing head from actin in thin filament

9

adenosine diphosphate (ADP)

causes myosin neck to straight & head to pivot
- mysosin head bonds to new actin subunit

10

sacromere

smallest component of muscle
- contractile unit
- Z disc to Z disc

11

myosin

binding sites on thin filament

12

tissue

group of cells that function as a unit

13

types of tissue

(1) epithelial
(2) connective
(3) muscle
(4) nervous

14

epithelial tissue

tissues that cover or line

15

connective tissue

if not other 3 tissue then it is connective tissue

(ie) bone tissue & blood cells

16

thick filament

purely myosin

MC

17

thin filament

actin
location of myosin binding
regulated by: troponin & tropomyosin

AN

18

Z disc

where sacromere attaches
- protein

19

crossbridge cycle

(1) myosin/myosin
(2) myosin/actin
(3) myosin/ATP

20

rigor mortis

muscles are contracted
ATP hydrolizes
you're stiff because you're stuck

"stiffness of death"

21

motor neuron

neuron that make up muscle
- action potential firing
- acetylcholine

22

acetylcholine

not a protein, lipid, sugar or nucleic acid

"other" category

23

action potential

(1) receptor binds to channel (acetylcholine)
(2) channel signals through T-tubule
(3) releases Ca+ ions

24

muscle relaxed

ATP cannot attach

troponin binds Ca+, which causes shift in tropomyosin (allowing it to be accessible)

25

muscle contraction

ATP attached
tropomyosin accessible