muscular system Flashcards
WHAT IS THE FUNCTION OF THE MUSCULAR SYSTEM
RESPONSIBLE FOR ALL TYPES OF BODY MOVEMENT – THEY CONTRACT OR SHORTEN AND ARE THE MACHINE OF THE BODY
WHAT ARE THE FOUR MAIN FUNCTIONS OF THE MUSCULAR SYSTEM?
- PRODUCE MOVEMENT
- MAINTAIN POSTURE
- STABILIZE JOINTS
- GENERATE HEAT
WHAT ARE THE THREE BASIC MUSCLE TYPES?
- SKELETAL MUSCLE
- CARDIAC MUSCLE
- SMOOTH MUSCLE
PREFIX: MYO
MUSCLES
PREFIX: MYS
MUSCLE
PREFIX: SACRO
FLESH
CONTRACTION IS DUE TO…
THE MOVEMENT OF MICROFILAMENTS
STRIATED
VISIBLE BONDING
VOLUNTARY
SUBJECT TO CONSCIOUS CONTROL
CONNECTIVE TISSUE AROUND A FASCICLE (BUNDLE) OF FIBERS
PERIMYSIUM
CONNECTIVE TISSUE AROUND SINGLE MUSCLE FIBER
ENDOMYSIUM
CONNECTIVE TISSUE THAT COVERS THE ENTIRE SKELETAL MUSCLE
EPIMYSIUM
CONNECTIVE TISSUE OUTSIDE OF THE EPIMYSIUM
FASCIA
A CORD-LIKE STRUCTURE IN EPIMYSIUM
TENDON
A SHEET-LIKE STRUCTURE IN EPIMYSIUM
APONEUROSES
BLENDS INTO A CONNECTIVE TISSUE ATTACHMENT
EPIMYSIUM
SITES OF MUSCLE ATTACHMENTS
BONES, CARTILAGES, AND CONNECTIVE TISSUE COVERINGS
WHAT ARE THE CHARACTERISTICS OF SMOOTH MUSCLES?
NO STRIATIONS
SPINDLE SHAPED CELLS
SINGLE NUCLEUS
INVOLUNTARILY – NO CONSCIOUS CONTROL
FOUND IN THE WALLS OF HOLLOW ORGANS
SLOW, SUSTAINED AND TIRELES
WHAT ARE THE CHARACTERISTICS OF CARDIAC MUSCLE?
HAS STRIATIONS, SINGLE NUCLEUS, JOINED TO ANOTHER MUSCLE AT AN INTERCALATED DISC
INVOLUNTARY, FOUND ONLY IN THE HEART, STEADY PACE
CELLS ARE MULTINUCLEATE
NUCLEI ARE BENEATH SACROLEMMA
SEGMENT OF MUSCLE FIBERS
A SPECIALIZED PLASMA MEMBRANE IS CALLED?
SACROLEMMA
A SPECIALIZED SMOOTH ER IS CALLED?
SACROPLASMIC RETICULUM
IT IS THE BINDLES OF MYOFILAMENTS ALIGNED TO GIVE DISTANT BANDS
MYOFIBRIL
WHAT TYPE OF BAND IS I BAND?
LIGHT BAND
WHAT TYPE OF BAND IS A BAND?
DARK BAND
ITS THE CONTRACTILE UNIT OF MUSCLE FIBERS
SACROMERE
IN THE ORGANIZATION OF SACROMERE, WHAT KIND OF FILAMENT IS THE MYOSIN FILAMENTS (COMPOSED OF PROTEIN MYOSIN AND HAS ATPase ENZYMES) BELONG TO?
THICK FILAMENTS
IT HAS THE ABILITY TO SHORTEN WHEN AN ADEQUATE STIMULUS IS RECEIVED
CONTRACTILITY
WHEN THE MYOSIN AND ACTIVE OVERLAP, ITS CALLED?
MYOSIN FILAMENTS
IN THE ORGANIZATION OF SACROMERE, WHAT KIND OF FILAMENT IS THE ACTIN FILAMENTS (COMPOSED OF THE PROTEIN ACTIN) BELONG TO?
THIN FILAMENTS
A NERVE STIMULUS THAT MUST BE STIMULATED BY A NERVE
MOTOR UNIT: ONE NEURON
MUSCLE CELLS STIMULATED BY THAT NEURON
SKELETAL MUSCLES
ITS THE ABILITY TO RECEIVE AND RESPOND TO A STIMULUS
IRRITABILITY
ITS THE ASSOCIATION SITE OF NERVE AND MUSCLE
NEUROMUSCULAR JUNCTIONS
THE GAP BETWEEN THE NERVE AND THE MUSCLE IS CALLED?
SYNAPTIC CLEFT
- MUSCLE FIBER CONTRACTION IS “ALL OR NONE”
- WITHIN A SKELETAL MUSCLE, NOT ALL FIBERS MAY BE STIMULATED DURING THE SAME INTERVAL
- DIFFERENT COMBINATIONS OF MUSCLE FIBER CONTRACTIONS MAY GIVE DIFFERENT RESPONSES
- GRADED RESPONSES – DIFFERENT DEGREES OF SKELETAL MUSCLE SHORTENING;
RAPID STIMULUS = CONSTANT CONTACTION OR TETANUS
CONTRACTION OF A SKELETAL MUSCLE
- MUSCLES USED STORED ATP FOR ENERGY
*BONDS OF ATP ARE BROKEN TO RELEASE ENERGY
*ONLY 4-6 SECONDS WORTH OF ATP IS STORED BY MUSCLES - AFTER THIS, OTHER PATHWAYS MUST BE UTILIZED TO PRODUCE ATP
ENERGY FOR MUSCLE CONTRACTION
- ACTIVATION BY NERVE CAUSES MYOSIN HEADS (CROSSBRIDGES) TO ATTACH TO BINDING SITES ON THE THIN FILAMENT
- MYOSIN HEADS THEN BIND TO THE NEXT SITE OF THE THIN FILAMENT
- THIS CONTINUED ACTION CAUSES A SLIDING OF THE MYOSIN ALONG THE ACTIN
- THE RESULT IS THAT THE MUSCLE IS SHORTENED (CONTRACTED)
THE SLIDING FILAMENT THEORY OF MUSCLE CONTRACTION
- REACTION THAT BREAKSDOWN GLUCOSE WITH OXYGEN
- GLUCOSE IS BROKE DOWN TO PYRUVIC ACID TO PRODUCE SOME ATP
- PYRUVID ACID IS CONVERTED TO LACTIC ACID
- THIS REACTION IS NOT AS EFFICIENT, BUT IS FAST
- HUGE AMOUNTS OF GLUCOSE ARE NEEDED
- LACTIC ACID PRODUCES MUSCLE FATIGUE
ANAEROBIC GLYCOLYSIS
- MUSCLE FORCE DEPENDS UPON THE NUMBER OF FIBERS STIMULATED
- MORE FIBERS CONTRACTING RESULTS IN GREATER MUSCLE TENSION
- MUSCLES CAN CONTINUE TO CONTRACT UNLESS THEY RUN OUT OF ENERGY
MUSCLE RESPONSE TO STRONG STIMULI
- MUSCLE CELLS CONTAIN CREATINE PHOSPHATE (CP); CP IS A HIGH ENERGY MOLECULE
- AFTER ATP IS DEPLETED, ADP IS LEFT
- CP TRANSFERS ENERGY TO ADP, TO REGENERATE ATP
- CP SUPPLIES ARE EXHAUSTED IN ABOUT 20 SECONDS
DIRECT PHOSPHORYLATION
- SERIES OF METABOLIC PATHWAYS THAT OCCUR IN THE MITOCHONDRIA
- GLUCOSE IS BROKEN DOWN TO CARBON DIOXIDE AND WATER, RELEASING ENERGY
- THIS IS A SLOWER REACTION THAT REQUIRES CONTINUOUS OXYGEN
ANAEROBIC RESPIRATION
- WHEN A MUSCLE IS FATIGUED, IT IS UNABLE TO CONTRACT
- REASON: OXYGEN DEBT
- OXYGEN MUST BE REPAID TO TISSUE TO REMOVE OXYGEN DEBT
- OXYGEN IS REQUIRED TO GET RID OF ACCUMULATED LACTIC ACID
- INCREASING ACIDITY (FROM LACTIC ACID) AND LACK OF ATP CAUSES THE MUSCLE TO CONTRACT LESS
MUSCLE FATIGUE AND OXYGEN DEBT
A TYPE OF MUSCLE CONTRACTTIONS WHERE MYOFILAMENTS ARE ABLE TO SLIDE PAST EACH OTHER DURING CONTRACTIONS; THE MUSCLE SHORTENS
ISOTONIC CONTRACTIONS
A TYPE OF CONTRACTION WHERE THE TENSION IN THE MUSCLES INCREASES; THE MUSCLE IS UNABLE TO SHORTEN
ISOMETRIC CONTRACTIONS
