Muscle System

What surround the whole muscle?

Epimysium

Surround fascicles within a muscle

Perimysium

Surround muscle fibers (cells) within a fascicle

Endomysium

The Neuromuscular Junction os a type of

synaphase

The Neuromuscular Junction is also called

Myoneural junction

the neuromuscular junction site where

an axon of motor neuror and skeletal muscle fiber interact

Skeletal muscles fibers contract only when stimulated by a motor neuron in the

Neuromuscular Junction

Parts of a NMJ

Motor neuron

Motor and plate

Synaptic cleft

Synaptic vesicles

Neurotransmitters

Where is the ATP only produced little?

Anaerobic Phase

Glycolysis is part of

Anaerobic Phase

What occurs in the cytoplasm?

Anaerobic Phase

What phase does myoglobin stores extra oxygen in muscles?

Aerobic Phase

What occurs in the mitochondria?

Aerobic Phase

Aerobic phase

Citric acid cycle and electron transport system

Where is the most ATP produced?

Aerobic Phase

Summation is the

Process by which the force of individual muscle fiber twitches combine

What can lead to partial or complete tetanic contractions?

Summation

Produces sustained contractions

Summation

Slow-twitch fibers (Type I):

• Always oxidative

• Resistant to fatigue

• Red fibers

• Abundant myoglobin

• Good blood supply

• Many mitochondria

• Slow ATPase activity; slow to contract

Fast-twitch glycolytic fibers (Type IIb):

• Anaerobic respiration (glycolysis)

• White fibers (less myoglobin)

• Poorer blood supply

• Fewer mitochondria than fast-twitch

• More SR than fast-twitch

• Susceptible to fatigue

• Fast ATPase activity; contract rapidly

Fast-twitch fatigue-resistant fibers (Type IIa):

• Intermediate twitch fibers

• Intermediate oxidative capacity

• Intermediate amount of myoglobin

• White fibers

• Resistant to fatigue

• Rapid ATPase activity

How is the skeletal muscle contraction resemble?

• Interaction between actin and myosin

• Both use calcium and ATP

• Both are triggered by membrane impulses

How is the smooth muscle contraction different from the skeletal muscle?

• Smooth muscle lacks troponin; uses calmodulin instead

• Two neurotransmitters affect smooth muscle: Acetylcholine (Ach) and norepinephrine (NE)

• Hormones can stimulate or inhibit smooth muscle

• Stretching can trigger smooth muscle contraction

• Smooth muscle slower to contract and relax

• Smooth muscle more resistant to fatigue

• Smooth muscle can change length without changing tautness 38