ability to respond to stimuli by producing action potential
ability to shorten/thicken generating force
ability to stretch without damaging tissue
ability to return to original size/shape after contraction/stretching
fibrous CT that surrounds the muscle tissue
separates muscle from skin -protects muscle from trauma -protects against shock (insulates) -stores fat -carries blood vessels/nerves
it groups muscles with similar functions together -it fills spaces b/w muscles -it carries nerves/blood vessels/lymphatic vessels
CT membrane that covers entire muscle
CT membrane covers individual fasicle
CT covers individual muscle fiber and fills space in between.
resembles ER. encircles each myofibril -stores/ release Ca++
to rapidly propagate nerve impulse along muscle fiber
resembles cytoplasm. -glycogen=ATP -myoglobin--reddish pigment. stores and releases 02 in aerobic reaction.
area between 2 Z discs. most important basic functional unit in muscle tissue
the thin filament protein
thick filament protein -a motor protein=spreads ATP
-H Zone: only myosin -A Band: both actin and myosin -I band: only actin -M line: marks center of the H-Zone -Z discs: mark center of I-Band -----anchors thin filaments -----connect myofibrils
-contractile, regulatory, and structural
for contraction -actin -myosin
to switch contraction on/off
holds tropomyosin in place
when is held in place, it blocks myosin from reaching actin
titin: responsible for elasticity Myomesine: form M-line Nebulin: ensures alignment of thin filaments Dystrohin: carries tension from sacromere to tendon.
1.) Ca++ is released from sarcoplasmic reticulum 2.) Ca++ binds to troponin and changes its shape 3.) Tropomyosin moves out of the way 4.) Myosin can now reach actin 5.) myosin heads use ATP and move actin (contraction)
area of communication b/w two neurons, or a neuron/target cell.
a protein released from neuron to switch a muscle contraction on.
a brief contraction of all muscle fibers in a motor unit in response to single action potential
A brief delay between the stimulus and muscular contraction
-Ca++ binds to troponin -Cross-bridges form
the increased strength of contraction resulting from the application of second stimulus before the muscle has completely relaxed after a previous stimulus. (fused/complete or unfused/imcomplete)
Skeletal fiber types
1.) Based on content of Myoglobin a. increased myoglobin = dark meat fibers b. decreased myoglobin = white meat fibers 2.) Based on structural function a. Aerobic--oxidative fiber (fast/slow) b. Anaerobic--Glycolytic fibers (fast)
-in the walls of the heart -fibers branch -fibers have intercalated discs (desmosomes & gap junction) -contractions are longer than skeletal -involuntary; striated
1.) visceral (single unit) -----in organs/large blood vessels -----all muscle fibers contract as a single unit 2.) Multi unit -----iris/arrector pili muscle ----- each muscle fiber contract singly -slowest, non-striated, involuntary