Module 2 Flashcards Preview

Physiology Module > Module 2 > Flashcards

Flashcards in Module 2 Deck (234)
Loading flashcards...
61

Fiber diameter: Intermediate
Oxidative Capacity: Very High
Glycolytic capacity: High
Activities: Uncommon in humans

Type IIA: Fast Oxidative (Red to Pink)

62

- found in heart; striated; single nucleus (centrally); involuntary
a. Atrial Muscle Fibers
b. Ventricular Muscle Fibers
c. Conductive Muscle Fibers

Cardiac Muscle

63

- found in colon, GIT, lungs; involuntary
a. Multi-Unit Smooth Muscle
b. Unitary Smooth Muscle

Smooth Muscle

64

- One nerve, multiple muscle fibers that may act on their own
- Controlled mainly by nerve signals (Ach, NE)
- (-) Gap junctions
- No True Action Potentials (Electrotonic Conduction)
- (-) Spontaneous contractions
- e.g. Ciliary Eye Muscle, Iris, Piloerector muscle, Vas Deferens

Multi-Unit Smooth Muscle

65

- One nerve, multiple muscle fibers that are act together as one
- Maybe controlled by nerve (Ach, NE), hormones, stretch, local factors
- (+) Gap junctions
- Slow/Pacemaker waves, Spike Potentials and Plateau Potentials
- May exhibit spontaneous contractions
- e.g. Intestines, Bile Ducts, Ureters, Uterus

Unitary Smooth Muscle (aka Syncitial Smooth Muscle, Visceral Smooth Muscle)

66

- Rhythmic, Intermittent
E.g. walls of the GI and urogenital tracts

Phasic Smooth Muscle

67

- Continuously active
E.g. Vascular smooth muscle, respiratory smooth muscles, sphincters

Tonic Smooth Muscle

68

Composition of Skeletal Muscle

Sarcomeres -> Myofibril -> Muscle Fiber -> Muscle Fascicle -> Skeletal Muscle

69

Surrounds Muscle Fiber

Endomysium

70

Surrounds Muscle Fascicle

Perimysium

71

Surrounds Skeletal Muscle

Epimysium

72

Plasma membrane surround muscle fiber

Sarcolemma

73

invaginations of the sarcolemma in close proximity to the terminal cisternae of the Sarcoplasmic Reticulum

Transverse Tubules

74

- Endoplasmic reticulum surrounding myofibril
- Contains Calcium

Sarcoplasmic Reticulum

75

- Functional unit of the muscle
- Area between two Z lines
- Exhibited by certain muscle types only
- Has thick filaments and thin filaments

Sarcomere

76

Myosin
- Two Heavy Chains: MYOSIN TAIL
- Free Ends of Heavy Chains + Light Chains: MYOSIN HEAD
- Tails bundled together: BODY
- Arms and Myosin Heads: CROSS-BRIDGES
- Arm-Body and Arm-Head: HINGES

Thick Filaments

77

o Actin
o Tropomyosin
o Troponin

Thin Filaments

78

attaches troponin complex to tropomyosin

Troponin T

79

inhibits actin-myosin binding

Troponin I

80

calcium binding protein

Troponin C

81

- contain myosin and actin
- contain the entire length of the thick filament

A Band

82

- contain the remaining thin filament

I Band

83

- Tethers Myosin to Z lines (scaffolding)
- Binds Z lines to M line

Titin

84

- Attaches to plasmalemma
- Stabilizes plasmalemma and prevents contraction-induced rupture

Dystrophin

85

Binds Actin to Z lines

Actinin and Capz Protein

86

Binds Z lines to plasma membrane

Desmin

87

- Involves motor neurons and extrafusal fibers
- Demonstrated by the Sliding Filament Model

Skeletal Muscle Contraction

88

- Thin filaments “slides” against the thick filaments towards the center of the sarcomere
- Z-discs meets the myosin filaments

Sliding Filament Model

89

if activated, this receptor would activate RYANODINE RECEPTOR (a calcium release channel)

Dihydropyridine Receptor

90

it would sequester the Calcium back once the action potential is gone

Calsequestrin