Muscular Tissue Flashcards
What are muscular tissue ?
Elongated cells called muscle fibers or myocytes that use ATP to generate a force.
They are contractile, can shorten and generate a pulling force.
Can be voluntary or involuntary.
Function of muscular tissue
- Produce body movements
- Maintain posture
- Generate heat
- Provide protection
Three types of muscular tissue
- Skeletal
- Cardia
- Smooth
Are muscle cells excitable ?
Yes, they respond to stimulus
Describe the histology or structure of skeletal muscle
Long, cylindrical fiber, striated (light and dark bands) and many peripherally located nuclei.
In bundles, surrounded by connective tissue.
What causes the striation?
The regular alternation of the contractile proteins actin and myosin. Along with structural proteins that couple the contractile proteins to connective tissues.
Function of skeletal muscle tissue ?
- Voluntary movement (motion and posture)
-Produces heat (a by product of contractions) - Protects organs
Where are skeletal muscle tissues attached ?
Attaches bones to tendons.
Around entrance points to body - mouth and anus.
Description (histology) of cardiac muscle tissue.
Short, branched, striated and single central nucleus.
How do cardiac muscle tissue cells attach ?
End to end by traverse thickening of plasma membrane - called intercalated disks
Intercalated disks also contain desmosomes (strengthe) and gap junctions.
Purpose of gap junctions in cardiac muscle cells ?
Provide route for quick conduction of electrical signals (muscle action potentials) throughout the heart.
Are cardiac muscle cells involuntary or voluntary ?
Involuntary
Function of cardiac muscle tissue
Pumps blood to all parts of the body.
Location of cardiac muscle tissue
Heart - heart wall
What are the cells of the cardiac muscle known as?
Cardiomyocytes
What is a syncytium ?
A single cell or cytoplasmic mass containing several nuclei, formed by fusion of cells or by division of nuclei.
What type of syncytium does attached cells form ?
Mechanical and electrochemical.
Describe histology of smooth muscle cells
Short, spindle shaped, no evident striation, single nucleus in each fiber
What connects many fibers smooth muscle cells ?
Gap junctions
What happens when gap junctions are absent in smooth muscle tissue ?
And where does this occur.
Contractile individually,
Iris of eye.
Function of smooth muscle tissue
- Involuntary movement
- Moves food
- Control of respiration
- Moves secretion
- Regulates flow of blood in arteries by contraction.
Where are smooth muscle cells found ?
Walls of major organs and passageways .
