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Flashcards in Muscle Deck (25)
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1
Q

sliding-filament model

A

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
Q

evidence of sliding filament model of muscle contraction

A

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

  • light bands become narrower
  • dark bands no change
3
Q

types of muscle

A

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

4
Q

cardiac muscle

A

type of muscle

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

5
Q

smooth muscle

A

type of muscle

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

6
Q

skeletal muscle

A

type of muscle

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

7
Q

level of muscle organization

A

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

8
Q

adenosine triophosphate (ATP)

A

causes conformational change by releasing head from actin in thin filament

9
Q

adenosine diphosphate (ADP)

A

causes myosin neck to straight & head to pivot

- mysosin head bonds to new actin subunit

10
Q

sacromere

A

smallest component of muscle

  • contractile unit
  • Z disc to Z disc
11
Q

myosin

A

binding sites on thin filament

12
Q

tissue

A

group of cells that function as a unit

13
Q

types of tissue

A

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

14
Q

epithelial tissue

A

tissues that cover or line

15
Q

connective tissue

A

if not other 3 tissue then it is connective tissue

(ie) bone tissue & blood cells

16
Q

thick filament

A

purely myosin

MC

17
Q

thin filament

A

actin
location of myosin binding
regulated by: troponin & tropomyosin

AN

18
Q

Z disc

A

where sacromere attaches

- protein

19
Q

crossbridge cycle

A

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

20
Q

rigor mortis

A

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

“stiffness of death”

21
Q

motor neuron

A

neuron that make up muscle

  • action potential firing
  • acetylcholine
22
Q

acetylcholine

A

not a protein, lipid, sugar or nucleic acid

“other” category

23
Q

action potential

A

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

24
Q

muscle relaxed

A

ATP cannot attach

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

25
Q

muscle contraction

A

ATP attached

tropomyosin accessible