Muscle Anatomy Flashcards
The most abundant muscle type
Skeletal
This function requires muscles to contract and pull on tendons, which will then move bones. Can be simple or highly coordinated.
Movement of the skeleton
This function has constant muscle contractions to keep you upright or else you would collapse.
Maintenance of posture and body position
This function can be observed in the abdominal and pelvic cavities…organs are safe and secure!
Support of soft tissue
This function can be observed in digestive and urinary systems…muscles encircle and provide control of swallowing, urination, and defecation…
Guard entrances and exits
This function involves energy and heat. Muscle contractions require energy and give off heat!
Maintain body temperature
Skeletal muscle has _____ layers of connective tissue.
3
This is a layer of collagen fibers that surround the entire muscle and separates them from other tissue and organs.
Epimysium
This is a layer of connective tissue fibers that divides muscles into bundles.
Perimysium
The bundles in the perimysium are called…
Fascicles
Along with collagen and elastin, perimysium also contain…
Blood vessels and nerves
This layer is within a fascicle. It surrounds each skeletal muscle fiber and ties muscle fibers together.
Endomysium
When the collagen fibers at the end of a muscle come together to form a bundle it is a _____.
Tendon
When the collagen fibers at the end of the muscle form a broad sheet it called a _______.
Aponeurosis
A tendon connects muscle to
bone
Blood vessels provide muscles with
nutrients and oxygen
Nerves will
stimulate muscle contractions
Skeletal muscles are ______, You control their action!
Voluntary
Muscle fibers are composed of…
Myofibrils
Inside a myofibril are…
Thin and thick filaments
Repeating functional units of a myofibril are called
Sarcomeres
The thin filaments inside the sarcomere that attach at the z-line…they have the active site for contraction.
Actin
The thick filaments that will “walk” during contraction. They have heads and tails.
Myosin
This is an active force applied to muscles
Tension
Muscle fiber stimulation is known as a…
twitch
This period/phase begins at stimulation, lasts about 2msec, and during this time Calcium is released.
Latent
This period/phase is when tension rises to a peak and hits maximum tension after about 15msec.
Contraction
This period/phase is when tension falls. Lasts about 25 msec.
Relaxation
The proper sequence of events in a twitch
single stimulus –> Contraction –> relaxation
This is when a second stimulus arrives before relaxation is complete.
Summation
This is when the stimulation rate is so fast, relaxation is eliminated completely.
Complete tetanus
This is when muscles keep some tension, so they are firm…not flaccid.
Tone
This is when muscles become small and weak due to lack of stimulation.
Atrophy
The primary method muscles use to gain energy.
Aerobic Respiration (Cellular respiration)
Aerobic respiration requires this substance to work properly.
Oxygen
If muscle demand increases rapidly, muscles will switch to this form of energy gain.
Lactic Acid Fermentation.
The down side of lactic acid is
muscle fatigue…requires recovery. (it’s also painful!)
This type of fiber can contract in 0.01sec or less following stimulation.
Fast
This type of fiber takes 3 times longer than their counterparts to contract, but can contract for extended periods.
Slow
This type of fiber is associated with endurance…mainly because they need lots of oxygen.
Slow
This type of muscle is dominated by fast twitch fibers.
White
This type of muscle is dominated by slow fibers…it also contains lots of blood vessels.
Red
