Lecture 6: Muscle Introduction Flashcards
What are the characteristics of muscle cells
IRRITABILITY (“Electrical Excitability”)
• CONTRACTILITY
• EXTENSIBILITY
• ELASTICITY
what are the 3 types of msucle cells
skeletal
smooth
cariac
what are the chracteritics of skeletal muscle
striated
voluntary
what are the chracteristics of smooth msucle
non striated, non voluntary, visceral
what are the chracteritics of cardiac muscles
striated
non voluntary
specialized
what is fascia
Dense irregular connective tissue • Completely surrounds the muscle • Surrounds groups of muscles • Skeletal muscle found deep to it • Extensions of the fascia = Epimysium
What is the whole muscle covered by?
EPIMYSIUM
what is the whole msucle a group of
FASICLES
What is each fasicle covered by
perimysium
what is each fasicle made up of?
made up of bundles of MUSCLE
FIBERS
what is each muscle fiber covered with
endomysium
what is another name for muscle fiber?
muscle cell
be able to label the msucle diagram
./
Deep to the endomysium, what is each msucle fiber covered with
sarcolemma
what is each individual myofibril covered with>?
SR
what is each msucle fiber made up of?
bundles of myofibrils
what is Each MYOFIBRIL made up of
MYOFILAMENTS
proteins
within each sarcomere, what does each myofibril contain
3000 ACTIN (thin) myofilaments* 1500 MYOSIN (thick) myofilaments*
What do the actin and mysosin filaments die
Glide between each other in the contraction/relaxation of
muscle (length of each does not change, but the amount of
overlap does)
what is the sarcomere
fucntional unit of a myofibril
be able to label the actin and myosin filamets
/
What are the cross striations of the sarcomere
alternating bands of light and dark
what are the dark bands made up of/ the light bands (in a darcomere)
Dark Bands (A Bands): Actin + Myosin • Light Bands (I Bands): Actin only
true or false: H zone is only myosin?
truw
What are the z lines and m lines
Z lines (disks): indicate boundaries of sarcomere
M line (protein bands): center of sarcomere
how many cross bridges are there?
50 pairs per filament
what is the purpose of the SR
stores calcium
what is the fucntion of the T tubules?
allow AP to move efficeintly through the muscle
be able to label all the elemetns of a sarcomeere
g
What does kuscle contraction need
• Motor Neuron
• Motor Unit = Gross Functional Unit of the muscle
Ø Motor neuron + Muscle fiber
- Motor unit is found at the Myoneural junction
- Skeletal muscle – “All or none” principle
- Smooth muscle – Peristalsys principle
Where is the motor unit found
at the myoneural junction
true or false: skeletal muscle is a all or non principle
true
what principle do smooth muscles have
peristalsis
understand tthe myoneural junction
.
What are the different muscle fiber shapes
LONGITUDINAL (Parallel) • FUSIFORM • UNIPENNATE • BIPENNATE • MULTIPENNATE • RADIATE (Triangular / Convergent) • CIRCULAR
explain parallel shape and where can you find it
Only one direction of movement
found in rectus abdominus
explain fusiform msucle and ex
skinny then bulge most muscles (biceps)
explain the pennate msucles and examples
Unipennate : one dircetion of fiber, flexor pollicis longus
Bipennate: 2 directions of fiber out of tenfon, tricep
tripennate: 3 directiosn of fiber, deltoid
explain circular amd ex
fibers go along a circular motion
eyeball
explain triagnular and ex
looks triangular
pec
what are the ways we name the muscle
- ACTION
- DIRECTION OF FIBERS
- LOCATION
- SIZE
- # OF ORIGINS
- SHAPE
- ORIGIN / INSERTION
What is origin mean
ORIGIN: Proximal end, less mobile bone
•
what does insertion mean
INSERTION: Distal end, more mobile bone
•
what does muscle belly mean
BELLY (Head): Fleshy or meaty part
•
what is an aponeurosis
APONEUROSIS: Broad, flat, tendon
explain agonist vs antagonist
- AGONIST (Prime mover): Main action muscle
* ANTAGONIST: Opposing muscle
explain synergist
- SYNERGIST: Helps in action of agonist
* SYNERGIST (Fixator): Stabilizes to help agonist
explain • Atrophy vs. Hypertrophy
atrophy: loss
hypertrohpy: growth
what are tendons
extrensions of the msuce belly
true or false Epimysium, Perimysium and Endomysium are tendons
TRUE
What type of tissue are tendons> and what are they made of
- Dense, regular connective tissue
- Parallel bundles of collagenous fibers
• May / may not have a synovial sheath
what is the fucntion of tendons
• Attaches muscle to bone (at the periosteum)
What is the function of a ligament
- Attach bone to bone
- Important for joint stability
- Joint (fibrous) capsules offer strength / stability
- Also offer certain level of flexibility for movement
- Attaches to the bone’s periosteum
what are ligs made up of
- Dense regular or irregular connective tissue
- Mostly parallel fibers
- Mainly collagenous fibers
- Some elastic fibers
what are the 3 types of exercise
isometric
isotonic
isokinetic
explain isometric exercise
tension is developed but no mechanical work is performed. Shortening or lengthening is prevented where there is no observable joint or functional movement
FIXED RANGE/STATIC
explain isotonic execise
equal tension on the muscle is maintained
while the length of the muscle is decreased during performance. The exercise is performed with a fixed resistance at variable speeds. This is called Progressive Resistive Exercise (PRE).
THOROUGH RANGE, DYNAMIC, DIFF SPEED
explain isokinetic exercise
Isokinetic means constant speed. Isokinetic training provides an accommodating resistance that allows to maximally load dynamically contracting muscles at each point of a joint’s ROM, thus enabling to do
more work than is possible with either constant of variable resistance.
(Kuland)
what are the two types of contraction
concerntration
eccentric
explain concentric contraction
Concentric is the most common type of muscle contraction. It occurs when the muscle shortens as it develops tension.
explain eccentric contraction
Eccentric is where the muscle is lengthening in a constant state of tension. While lowering a weight, the muscle gives in to the resistance of the weight by stretching. An eccentric contraction can bring about a braking action.
WHERE IS muscle spindle located and what is its fucntion
located in the belly
prevrents overstretching by reacting contracting immeditely
WHERE are golgi tendon organs located
located in tendonous junction
are able to sense that tension is prolongued and controlled so they instruct the muscle spindles to stop contraction
how long until golgi tendons are initiated
6-10 secs
