Muscle Characteristics
the three types of muscle tissue
skeletal, cardiac, smooth
group of muscle fibers
fasicle
skeletal muscle fibers
region between two successive Z discs
sarcomere (smallest contractile unit of skeletal muscle)
What are joints also known as?
articulations
What are the (2) places of muscle attachment (hint: one is immovable and one is moveable)?
origin and insertion
sheet-like tendons that are used to indirectly attach muscle to bone
aponeuroses
T/F there are multiple nuclei on skeletal muscle fibers
T
What are thick filaments and thin filaments also known as?
thick=myosin
thin=actin
What are the (3) functional classifications of joints?
synarthrotic
ampiarthrotic
diarthrotic
(4) special characteristics of muscle tissue
1. excitability
2. contractility
3. extensibility
4. elasticity
What is the purpose of the connective tissue sheaths of skeletal muscle?
wrap muscles, fascicles, and fibers; prevent muscles from bursting/falling apart when contracting
What is the purpose of glycosomes and myoglobin in the sarcoplasm of skeletal fibers?
-glycosomes: store glycogen (energy)
-myoglobin: store oxygen
line of protein myomesin that bisects H zone (found in middle of each sarcomere)
Why does it take a long time for ligaments to repair/can't repair at all?
not vascularized so cannot receive adequate nutrient supply to regenerate quickly
Describe each muscle type as striated/smooth and voluntary/involuntary.
cardiac: striated; involuntary
smooth: smooth; involuntary
skeletal: striated; voluntary
What are the (3) prefixes for muscle?
myo-
mys-
sarco-
Myofibrils make up _____% of skeletal cell volume and contain _______ which are the contractile units of skeletal muscle cells.
80%; sarcomeres
What is the difference between I bands and A bands? What types of filaments are found in each?
I band=light band; no overlapping of filaments, only has actin
A band=dark band; overlapping of filaments, has both actin and myosin
Define abduction and adduction.
abduction=away from midline
adduction=towards midline
Why are skeletal muscle fibers served by multiple veins but only one artery?
need more veins to get rid of metabolic wastes; arteries supply muscle with O2
What does epi- in epimysium mean, peri- in perimysium mean, and endo- in endomysium mean? Where do you find each of these connective tendon sheaths of skeletal muscle?
-epimysium (on muscle): DICT surrounding entire muscle
-perimysium (around muscle): fibrous connective tissue that surrounds fascicles
-endomysium (within muscle): fine areolar tissue that surrounds each muscle fiber
What are the (3) modified structures found in a skeletal muscle fiber?
1. myofibrils
2. sarcoplasmic reticulum (SR)
3. T tubules
How are A bands and I bands distributed throughout a single sarcomere?
A band is found in the middle; 1/2 I band found on each end
What are the (4) muscles that rotator cuff tendons extend from?