Muscle Tissue Flashcards
4 functions of muscle tissue:
-excitability
-contractility
-extensibility
-elasticity
Skeletal muscle
-striated
-multinucleated
-voluntary control
-Cannot regenerate
Smooth Muscle
-not striated
-mononucleated
-autonomic control
-can regenerate
Cardiac muscle
-striated
-mononucleated
-automatic control
-cannot regenerate
-only found in the heart
-intercalated disk
2 regulatory proteins
-tropomyosin (covers active actin sites)
-troponin (draws tropomyosin away from active actin sites)
2 Myofilaments
Actin
myosin
Actin
-thin filament
-active sites
Myosin
-thick filament
-wants to snap onto active sites
Perimysium CT Layer
-loose CT
-surrounds muscle fascicle
Endomysium CT layer
-around each muscle fiber (superficial to sarcolemma)
-areolar CT
Epimysium
-around entire skeletal muscle
-dense irregular CT, fuse into tendons that connect bone
z lines
middle of actin
M lines
middle of myosin
H band
Myosin only
A band
actin and myosin
I band
Actin only
T-tubule
Transmits impulses to deeper regions of fiber
Sarcoplasmic reticulum
-stores Ca, surround myofibril
structure during contraction
-A band stays the same, z lines move closer together, H and I bands get smaller
5 functions of skeletal muscle tissue
-skeletal movement
-support soft tissue
-maintain body position/posture
-control entry and exit of materials
-maintain body temp
