What is the functional unit of a muscle contraction? ✔️✔️sarcomere (sections of a muscle cell); made
up of alternating bands of actin and myosin protein filaments
Difference between a tendon and a ligament ✔️✔️tendon: connects bone to muscle
ligament: connects bone to bone
Define rigor mortis
Cause? ✔️✔️temporary death stiffness
contraction that has not released due to lack of ATP
What causes Muscle Fatigue? (SAOLSA) ✔️✔️--lack of sugar
--lack of ATP to restore Ca 2+ gradient
--low Oxygen
--lactic acid drops pH which interferes with protein function
--synaptic fatigue (failure of nerve impulse)
--loss of acetylcholine
What causes Muscle cramps? ✔️✔️--buildup of lactic acid
--ATP depletion
--ion imbalance
--massage or stretching increases circulation
Define Livor Mortis ✔️✔️Lividity (purple color)
As a body decomposes, bloods seeps down through the tissues and settles into the lower parts of the
body; RBC's spill contents
, Describe Fast Twitch Fibers ✔️✔️few mitochondria
rich in glycogen
depends on creatine phosphate and glycolysis for ATP
fatigue easily with production of lactic acid
low in myoglobin, hence whitish in color
activated by large diameter, thus fast conducting motor neurons
dominant in muscles used for rapid movement, eyeballs
contract quickly but get tired rapidly
store more glycogen for anaerobic respiration
sprinter
white meat
Slow Twitch Fibers ✔️✔️loaded with mitochondria
depends on cellular respiration for ATP
fatty acid is the major energy source
resistant to fatigue
rich in myoglobin, dark meat
activated by small-diameter, thus slow conducting motor neurons
dominant in muscles used for endurance and those that depend on tonus, posture
contract slowly but keep going for a long time
more mitochondria for aerobic respiration
less SR--->Ca 2+ remains in cytosol longer
long distance runner
dark meat means more blood vessels
Do muscles ever rest? ✔️✔️Tonus: skeletal muscles are in a state of partial contraction