Chapter 10: Muscle Tissue Flashcards
Three types of muscle
Cardiac
Smooth
Skeletal
What are some muscle similarities?
Excitability
Contractility
Elasticity
Muscle contraction depends on what two kinds of myofilaments
Actin and myosin
Microscopic appearance of skeletal muscle
Elongated
Multinucleate
Striated
Nervous system control of skeletal muscle
Voluntary nervous system
Somatic motor neurons
What are the functions of the skeletal muscles?
Moves the bones, maintains posture and body position, supports soft tissues, guards body entrances, and exits, maintains body temperature, and stores nutrients
Cardiac Muscle Microscopic appearance
Branching cells, single central nucleus , straited and joined to another muscle cell at the intercalated disc.
Nervous system control of cardiac muscle
Involuntary autonomic nervous system
Function of cardia muscle
pumps oxygen, nutrients throughout the body
Microscopic appearance of smooth muscle
Spindle-shaped, single central nucleus, no striations
Location of smooth muscles
Around hollow organs including blood vessels.
Origin
Attach to bone and does not move.
Insertion
Crosses a joint and attaches to bone. Insertion will move towards the origin.
When a muscle contracts, the _____ is pulled toward the _________.
Insertion
Origin
Levels of organization of Skeletal Muscle
Skeletal muscles, fascicles, muscle fiber, myofibrils, sarcomere.
Skeletal Muscle
organ
bundle of fascicles
contains epimysium
Fascicles
Bundle of fibers
contains perimysium
Muscle fiber
cell
Bundles of myofibrils.
Contains endomysium
Myofibrils
Repeating contractile units that are called sarcomeres
Sarcomeres
Organized unit of myofilaments.
Myosin and actin
A bands are ____
I bands are ______
dark
light
M line
Anchor for myofilaments, it is the horizontal line in the middle of the sarcomeres.
H band
The area where there is only myosin
A band or Zone of Overlap
Where both myosin and actin are
Z lines
Separates the sarcomeres and marks the beginning of the end of a sarcomere
Titin
Stretchy protein that helps it pop back to its original position
I band
This is where it is only acting
Endomysium
surrounds the skeletal muscle
Perimysium
surrounds the fascicle
Epimysium
surrounds muscle fiber
Blends into connective tissue attachments like tendon (cord-like) or aponeuroses (sheet-like)
Sites of muscle attachments
Bones
Cartilage
and connective tissue coverings
Thick Filaments
Myosin
Each myosin molecule has a rod-like tail and two globular heads.
Thin Filaments
Actin
Actin subunits contain an active site (which myosin heads attach to)
What two regulatory subunits does actin contain
Tropomyosin and troponin
Tropomyosin
covers the active site of actin, prevents myosin from attaching
Tropinin
Can bind to calcium, and when calcium attaches to troponin, it causes tropomyosin to shift away from the active sites on the actin.
