Week 2-Muscle Tissue Flashcards
Muscle tissue
-contractile, conductive, elastic, and excitable
-contraction=movement
-well vascularized
3 types
1) Skeletal
2) Cardiac
3) Smooth
Skeletal
-primarily responsible for movement of skeleton
-functions in thermoregulation (when contract they produce heat)
-composed of skeletal muscle fibers
-multinucleated
-striated
-voluntary= doesn’t contract unless stimulated by somatic nervous system
Cardiac
-confined to myocardium (thick middle layer of heart wall)
-responsible for pumping action of heart to move blood through cardiovascular system
-composed of short cells that are bifurcated (branched)
-cells contain one or 2 centrally located nuclei
-cells are connected by intercalated discs (intercellular junctions between cells composed of desmosomes and gap junctions)
Cardiac
-confined to myocardium (thick middle layer of heart wall)
-responsible for pumping action of heart to move blood through cardiovascular system
-composed of short cells that are bifurcated (branched)
-cells contain one or 2 centrally located nuclei
-cells are connected by intercalated discs (intercellular junctions between cells
composed of desmosomes and gap junctions)
-strengthen connection between cells and promote rapid conduction of electrical
activity through many cells at once, allowing cells of heart chamber to contract
as a unit
-striated and involuntary
Smooth
-lacks striation
-are fusiform (spindle shaped) which means they are thick in middle and tapered at their ends
-cells are short and contain one central nucleus
-found in walls of most viscera (internal organs) like intestines, stomach, airways, urinary bladder, uterus, and blood vessels
-also located in specialized structures where involuntary muscle contraction is required like iris of eye which adjusts size of pupil
-contractions help propel material through these organs or controls size of lumen
-involuntary
-engage in cells division to provide growth and healing of tissue
