Postlab quiz 10 Flashcards
Skeletal muscle does this
works with the skeletal system (bone) to produce movement
Connective tissue surrounding muscle
epimysium
A bundle of muscle cells is called this, and is surrounded in this
fasical
perimysium
Muscle cell name, and what it is surrrounded by
muscle fiber
endomysium
T/F: connective tissue is continuous with the tendon
t
Striations in the skeletal muscle reflect this
the arangement of the microfilaments within the muscle
T/F: skeletal muscles are multinucliate
T
Single muscle cells fuse togeather to form this type of structure
syncytium
T/F: muscle fibers are usually short
F, they can be very long (up to feet long)
T/F: skeletal muscle is involuntary
F
This provides the stimulus for skeletal movement
motor neurons from motor areas of the brain
Name for the synapse between motor neurons and muscle fibers
neuromuscular junction
The termiinus of the axon attaches to this on the muscle fiber
motor end plate
Neurotransmitter present in vesicles at the axon terminus
acetycholine
All muscle fibers innervated by a single neuron are called this
motor unit
Small motor units have this
very precise contractions
weak strength
large motor units have this
imprecise contractions
greater strength of contraction
Functional unit of the muscle fiber
sarcomere
The ends of the sarcomere are know as this
z lines (discs)
Thin filaments are known as
actin
thick filaments are known as
myosin
This is where only actin is present
I band
This is where we have both action and myosin
a band
This is where there is only myosin
h zone
myosin attaches to eachother at this spot
m line
This is known as the sliding filament theory
when the muscle contracts the z disks come closer togeather as a result of the actin and myosin sliding past eachother
The name for the connection between actin and myosin
crossbridge
During the power stroke this occurs
myosin head bend towards the m line
This provides energy for myosin to move from a relaxed state to a contracted state
ATP
This occurs when a person dies for this reason
Rigor Mortis
loss of ATP
These overlap the G-actin
Tropomyosin
troponin complex
The G-actin has this
active sights for attactment to myosin
this moves the tropmyosin complex to allow access to the active sights on G-actin to the myosin head and results in this
Ca++
contraction
Pathway of a stimulus to a muscle cell
stimulus starts in sarcolema
enter through T-tubules
T-tubules trigger the sarcplasmic reticulum to release Ca++
Ca++ triggers the myosin to bind the new revealed active sites on the actin
Summation
closer the stimuli the greater the “piggy backing” effect
Incomplete tetanus
Stimuli are summed together to create a contration
complete tenanus
The fiber is said to be fuse and there is no relaxation between contractions
Eventually the muscle will fatigue causing relaxation
Review videos (pod casts for information over figures)
okay
Level of actin/myosin overlap with the strongest contraction capability (most contraction)
intermediate levels of overlap
What full is most used in the first 30 min of exercise (mild exercise)
free fatty acids
this occurs as exercise intensity is increased
more and more muscle glycogen is used, and less free fatty acids are used
If you want to use free fatty acids as a primary source of energy you need to exercise in this manor
mild intensity
Three types of muscle fibers
Slow (type 1)
Fast (type IIA)
Fast (type IIX)
Slow type 1 muscle fibers use this type of respiration
aerobic
Fast muscle fiber types are also known as this
white muscle fiber
Fast type muscle fibers use this type of respiration
anaerobic
Specific types of exercise can do this
create hypertrophy in the desired muscle type
What is myasthenia gravis
autoimmune disorder characterized by weakness and rapid fatigue of any of the muscles under voluntary control
Myasthenia gravis is caused by
breakdown in the transfer of nerve impulses to muscles
With myasthenia gravis this occurs if the muscle is used repeatedly
weakness worsens
Direct cause of myasthenia gravis (what causes the breakdown in the transfer of nerve impulses to muscles)
production of antibodies to acetylcholine receptors
production of antibobodies to a muscle specific receptor thyrosine kinase (MuSK)
MuSK is responsible for this
the recruitment of acetylcholine receptors to the neuromuscular junction
Myasthenia gravis is less commonly caused by this, and is known by this name when caused by the aforementioned problem
antibodies to lipoprotein-related protein 4
antibody negative myasthnia gravis
The rarest form of myasthenia gravis is caused by this, and is known by this name
heredity
congenital myasthetic syndrome
Signs and symptoms of myasthenia gravis (8)
drooping of one or both eyelids (ptosis) double vision (diplopia) which improves with one eye closed altered speech difficulty swallowing limited facial expression trouble holding up your head waddling while walking difficulty lifting or raising arms
Treatment for myasthenia gravis (5)
cholinesterase inhibitors (Mestinon) corticosteroids (prednisone) Immuno-suppressents plasmapheresis intravenous immunoglobulin
Prognosis for myasthenia gravis (3)
symptoms progress to highest severity within 3 years
after 3 years symptoms usually stabilize
can live a fairly normal life with regular medical treatment
What are the essentials of a reflex mechanism
receptor organ
effector organ
some type of communications network connecting the two
Reflex action is initiated by this and results in this
input response
output response
Reflex activity ranges from this to this
simple axon reflex
complex reflexes in which the cerebrum participates