muscle tissue and muscles Flashcards
types of muscle activity (3)
motor actions (movement of skeletal sys) contractions of the heart and vessels actions in the intestines
Types of contraction (2)
isometric
isotonic
define isometric
length of muscle does not change
define isotonic
length of muscle does change
muscle gets shorter
concentric
muscle gets longer
eccentric
names of muscles: shape (2)
deltoid
trapezius
names of muscles: origin-insertion (2)
coracobrachialis
sternocleidomastoid
names of muscles: function (2)
pronator teres
extensor digitorum
names of muscles: relative size (2)
adductor magnus adductor brevis (thight)
names of muscles: fiber arrangement (2)
rectus abdominis
rectus cervicus
names of muscles: location (2)
pectoralis latissimus dorsi (wide back)
fiber arrangement: rectus abdominis
straight
fiber arrangement: biceps brachii
fusiform
fiber arrangement: palmar interosseous muscles
unipennate
fiber arrangement: dorsal interosseous muscles
bipennate
fiber arrangement: deltoid muscle
multipennate
agonist
muscle doing the desired action
antagonist
muscle that opposes the agonist
synergist
muscle that eliminates unwanted action by the agonist
fixator
muscle that stabilizes base of attachment of agonist
unijoint
muscle that crosses only one joint
multi-joint
muscle that crosses more than one joint
insufficiency
inability of a multi-joint muscle to contract maximally over all joints crossed simultaneously
agonist muscles are classified as
prime movers and assistant movers
when a muscle acts as a stabilizer, it usually contracts…
isometrically
a pure NEUTRALIZER…
will cause the opposite motion of the prime mover without assisting in the movement
MULTI-JOINT muscles do not allow…
complete range of motion in all joints at one time
muscles that pass anterior to the axis of a joint are flexors like (2)
deltoid
biceps
muscles that pass posterior to the axis of a joint are extensors like (2)
deltoid
triceps
muscles that pass lateral to a joint are abductors like (1)
deltoid
active insufficiency apples to
agonist
passive insufficiency applies to
antagonist/multi-joint muscles
Appearance of muscle tissue can be (2)
smooth
striated
Arrangement of muscle tissue nucleus//nuclei can be
multinucleated (syncytium)
mononucleated
Fcn of muscle tissue can be
voluntary
involuntary
3 types of muscle tissue
skeletal (striated)
smooth
cardiac
skeletal muscle aka (2)
characteristics (3)
striated
voluntary
peripheral nuclei
multinucleated
conducts action potential
smooth muscle aka (2)
visceral
involuntary
aponeuroses
flat, fan-shaped tendons typically giving rise to other tendons
tendons characteristics (5)
attach btwn muscle fibers and bone dense collagenous connective tissue surrounded by peritendineum bundles of collagen fibers poorly vascularized
myofilament: types (2) and oranized into…
myosin and actin. Organized into sarcomeres
myofibril
chain of sarcomeres
myofiber
bundle of myofibrils aka muscle cell
fascicle
bundle of myofibers
muscle
composed of varying numbers of fascicles
endomysium (2)
surrounds each muscle fiber
lies outside sarcolemma (cell membrane)
perimysium
surrounds each fascicle
epimysium (3)
surrounds each muscle
becomes continuous with tendons
attached to periosteum
actin associated molecules (2)
tropomyosin
troponin
actin characteristic (2)
thin filamentous protein polymer (f-actin)
made up of 2 helically wound polymers of G actin
myosin characteristics (3)
bundles of long molecules
heads attach to binding sites on actin filaments
attach-swivel-release cycles = contraction
separate adjacent sarcomeres in a fibril
composed of z-actin
z-line
make up ends of each sarcomere
located on either side of z-line
composed entirely of actin
i-band
located in middle of sarcomere
composed of both actin and myosin
does not change width during contraction
a-band
the mass of a myofiber and a muscle may be…
increased
structure of a sarcomere
sarcoplasmic reticulum
t-tubules
cisternae
conduct action potential from cell membrane surface to interior
t-tubule
release calcium ions in response to action potential
cisternae
during a contraction (2)
I band and H band shorten
A band remains the same length
Sliding occurs when…
ATPase heads of myosin attach to actin via troponin and swivel
Calcium ions trigger…
these ions trigger sliding of myosin and actin filaments resulting in contraction
in middle of each a-band
composed entirely of myosin
band width changes during contraction
h-band
units for fine control have…
fewer fibers
units for gross control have…
many fibers
myofiber type is determined by…
innervating neuron
red fibers
dark, slow fibers
white fibers
light, fast fibers
muscles predominantly composed of dark fibers
soleus
muscles predominantly composed of light fibers
gastrocnemius
dark, slow fibers (6)
fatigue resistant contract slowly (slow twitch) rely on oxidative phosphorylation large number of mitochondria high conc of myoglobin (red) low conc of ATPase
light, fast fibers (6)
fatigue easily contact rapidly (fast twitch) rely of glycolysis small number of mitochondria low conc of myoglobin (white) high conc of ATPase
