Question

Compare the rates of muscle contraction and relaxation of skeletal, smooth, and cardiac muscles. How do they differ? (5 pts) What relationship best describes the differences? Draw a figure to illustrate this. (5 pts) What are the differences mostly due to? (5 pts)

Answer 1

SKELETAL MUSCLE	SMOOTH MUSCLE	CARDIAC MUSCLE
These are the muscles that attached to the bones and skin	Smooth muscle cell line walls of internal organs	These are the muscles found only in the heart
They produce voluntary muscular movements	They produce involuntary muscular movements	They produce involuntary muscular movements
For the movement of joints and helps in physical movement	For the movement of internal organs to perform their function	It is responsible for pumping the blood throughout the body
They contain long, cylindrical multinucleated cells	Consists of single, tapering and unicellular cells	Consists of branching chain of cells which are connected by the porous unicellular intercalated discs
Striated with orderly arranged myofibrils	Not striated and myofibrils are of varied length and more actins than myosin. There is no orderly arrangement of contractile proteins	Striated with orderly arranged myofibrils
self stimulating	self stimulating	self stimulating
Under regulation of nervous system	Under regulation of nervous system, endocrine system, and various chemicals	Under regulation of nervous system, endocrine system, and various chemicals
Calcium ions are released into sarcoplasmic reticulum	Calcium ions are released into sarcoplasmic reticulum and extracellular fluid	Calcium ions are released into sarcoplasmic reticulum and sometimes mitochondria

	Skeletal muscle	Cardiac muscle	Smooth muscle
Rate of contraction	Have intermediate speed of contraction. So, do not fatigue and require energy less energy	Have high speed of contraction. so, fatigue and require energy more	Have low speed of contraction So, do not fatigue and require less energy
Rhythmic contractions	Do not exhibit any rhythmic contractions	exhibit Rhythmic contractions	exhibit any rhythmic contractions
Stretching	exhibit stress releasing response	Strength increases with stretching	Strength increases with stretching

The whole differences of skeletal muscle, smooth muscle and cardiac muscle are due to the structure and arrangement of actin and myosin filaments arrangement.

CELL SHAPE FILANCN ACTIN A CT , VERT SLOUs SxeLETAL MUSCLE TIME CS