10/09 Flashcards
what percent of body mass is contributed to skeletal muscle mass?
40%
What is skeletal muscle important for?
defend itself
provide for itself
communication
what does the skeletal muscle store to use as energy?
glycogen
what is stored in the muscle?
ions
glycogen
fluids
proteins
what are effectors?
something that receives instructions from the CNS
what is a glycogen?
a bunch of glucose molecules stuck together. a large starch compound.
Where is glycogen stored besides the muscles?
Liver
glycogen is broken down into
glucose
what does a ligament connect?
bone to bone
what does a tendon connect?
usually muscle to bone
however
sometimes it is muscle to muscle via an intermediary tendon (tendon bridge)
individual muscle cells are called
muscle fibers
more than one group of muscle cells are called a
fasciculous. These function as a unit
many fasciculous together are called
muscle
what are the internal cylinders called that are in a muscle fiber?
myofibril
what do myofibrils contain?
actin and myosin
how many myofibrils are in a muscle per skeletal muscle cell?
> 200 in smaller muscles
thousands in a larger cell in a larger muscle
what are skeletal muscle cells with little moyfibrils good for?
fine motor control
(don’t want to squeeze a glass with a ton of strength because it will crush it)
what is the basic contractile unit of a myofibril?
a sarcomere
what are the thick contractile units of a sarcomere called?
Myosin filament
what are the thinner contractile units of a sarcomere called?
actin filament
what is the area of overlap between a myosin and actin called?
A band
what does the overlap of actin and myosin allow for?
force
what is a motor unit?
one or more skeletal muscle fibers that are controlled by a single motor neuron
how many skeletal muscles cells can a motor neuron control?
one or many
what is a small motor unit?
a motor neuron controlling a small number of muscles
good for fine motor
what is a large motor unit?
a motor neuron controlling a large amount of muscles
good for strength
which is easier to excite, small or large motor units?
small motor units
it takes more and more action potentials in the ventral horn to elicit a large motor unit
how are skeletal muscles classified?
Type 1:
slow and sustained
red d/t iron
lots of myoglobin
lots of mitochondria
type 2
fast twitch- can’t sustain
white
very little myoglobin
fewer mitochondria
What is myoglobin?
a big protein similar to hemoglobin. A big iron containing protein that helps oxygen unload from the blood into the muscle.
higher affinity for O2 than hemoglobin. Oxygen is used by the mitochondria to create ATP efficiently.
duck or goose meat can be grouped into which type of skeletal muscle classification?
Type 1
chicken breast meat can be grouped into which type of skeletal muscle classification?
Type 2
how high can a goose fly?
30,000 feet. Can see them in a passenger airline
what is the soleus muscle?
the weight bearing calf muscle on the back of the leg. Is designed to produce and sustain a lot of force.
starts off kind of slow but can sustain for a while.
what is the gastrocnemius?
the muscle next to the soleus muscle in the back of the leg
an ocular muscle can be categorized into which skeletal muscle classification?
type 2
the soleus muscle can be categorized into which skeletal muscle classification?
Type 1
the gastrocnemius muscle can be categorized into which skeletal muscle classification?
Both type 1 and type 2, kind of falls in the middle
vast majority of our muscles can be classified in which skeletal muscle classification?
most muscles have characteristics of both Type 1 and 2