Muscle TissueMuscle TissueThere are 3 types of muscle tissue:There are 3 types of muscle tissue:

skeletalskeletal smoothsmooth cardiaccardiac

Classification of Muscle CellsClassification of Muscle Cells

Striated vs. Nonstriated Striated vs. Nonstriated

striated have a banded appearance (stripes)striated have a banded appearance (stripes)

Single nucleus or multinucleated cellsSingle nucleus or multinucleated cells

Muscle cells can be controlled Muscle cells can be controlled

voluntarily (consciously)voluntarily (consciously)

oror

involuntarilyinvoluntarily (automatically)(automatically)

Skeletal Muscle CellsSkeletal Muscle Cells

Striated, voluntary, and multinucleatedStriated, voluntary, and multinucleated are long, thin and cylindrical; they are are long, thin and cylindrical; they are

attached to bones and move our skeletonattached to bones and move our skeleton are usually called “are usually called “muscle fibersmuscle fibers”” do not divide to create new cellsdo not divide to create new cells new fibers are produced by stem cellsnew fibers are produced by stem cells Striations -- cross stripes (bands) run Striations -- cross stripes (bands) run

perpendicular to the cellsperpendicular to the cells

Skeletal Muscle TissueSkeletal Muscle Tissue

Cardiac Muscle CellsCardiac Muscle Cells

are called “are called “cardiocytescardiocytes” and found in ” and found in heart wallsheart walls

branching cells connect at branching cells connect at intercalated intercalated disks disks which allow contractions to occur which allow contractions to occur fasterfaster

are regulated by pacemaker cells which are regulated by pacemaker cells which control contraction of the heart musclescontrol contraction of the heart muscles

striated, involuntary, and single nucleusstriated, involuntary, and single nucleus

Cardiac Muscle TissueCardiac Muscle Tissue

Smooth Muscle CellsSmooth Muscle Cells are small and pointed at their endsare small and pointed at their ends can divide and regenerate new cellscan divide and regenerate new cells non-striated, involuntary, and single nucleusnon-striated, involuntary, and single nucleus found in hollow organs like the intestine, found in hollow organs like the intestine,

bladder, lungs, and blood vesselsbladder, lungs, and blood vessels move substances through hollow opening move substances through hollow opening

by contracting slowly; they squeeze things by contracting slowly; they squeeze things through like a tube of toothpastethrough like a tube of toothpaste

Smooth Muscle TissueSmooth Muscle Tissue

Review What You’ve Learned…Review What You’ve Learned…

Muscle TypeMuscle Type Striated?Striated? # of nuclei# of nuclei Voluntary orVoluntary or InvoluntaryInvoluntary

SkeletalSkeletal

CardiacCardiac

SmoothSmooth

Yes

Yes

No

Single Nucleus

Single Nucleus

Multi-nucleated Voluntary

Involuntary

Involuntary