Muscular System Flashcards
2 prefixes that mean/refer to muscle
myo
sarco
What are the three series-elastic components of muscular tissue?
The stretchy:
- endomysium
- perimysium
- epimysium
Are the 3 series-elastic components of muscular tissue excitable?
NO but they do stretch and recoil
dont contract
In what type of pairs do voluntary muscle usually work?
Antagonistic
What happens to your muscles when you work out?
Do NOT make more fibers/muscle, you are making your fibers bigger
Do muscles expand?
NO they only contract
ex: muscle contracts to flex arm then an entirely diff. muscle contracts to bring arm back down
What is the name of the cell membrane in a muscle?
sarcolemma
Fascicle
a group of muscle fibers
Difference btwn perimysium, endomysium, and epimysium
Epimysium- surrounds whole muscle
Endomysium- wraps each individuals muscle fiber
Perimysium- surrounds each muscle fiber bundle, called fascicles
What do myofibril contain in a muscle cell?
Thin and thick filaments
What is the one neurotransmitter in skeletal muscle?
Acetylcholine
Acetylcholine
The ONLY one neurotransmitter in skeletal muscle
In which direction does a neuron nerve cell travel?
In the direction in which the axon is pointing; it’s a one way street they can’t go back the same way they came from
Where are neurotransmitters
In synaptic vesicles
How does a neuron move?
Electrical impulse forces calcium channels to come in and push synoptic vesicles to the end of the axon
From left to right, what is the anatomical structure of a neuron
dendrites, soma (body), axon (synaptic vesicles in membrane), gap/synapsis/junction, NEIGHBORING neuron
How does an electrical impulse get from one neuron to another?
Dendrites on the next cell/neuron have receptors for the neurotransmitter acetylcholine, once they receive the acetylcholine the electrical impulse starts all over again on the new neuron
Why can’t electrical impulses travel backwards?
There are no receptors on the front of the cell, only on the dendrites, and there is no acetylcholine in dendrites only receptors
Action potential
the change in electrical potential associated with the passage of an impulse along the membrane of a muscle cell or nerve cell
What are the only two types of cells that have action potential?
nerve cells and muscle cells
What happens when the acetylcholine goes to muscle fiber?
Goes to the synapse called neuromuscular junction and the muscle contracts
Neuromuscular junction
where neuron and muscle meet
What happens to acetylcholine after it does its job?
Acetylcholinesterase (enzyme) breaks it down then the neuron (it came from originally) picks up the broken down neurotransmitter and rebuilds it to use it again.
SSRI
Selective seratonin re-uptake inhibitor
ex: prozac, Zoloft, ect.
Sensory neurons
Going INTO the brain (Afferent)
Motor neurons
Going FROM brain to muscle (Efferent)
SAME
sensory—> afferent
motor—–> efferent
How many mitochondria do muscles have?
thousands
What does the sarcolemma consist of?
it has characteristic transverse (T) tubules which are continuous with the sarcolemma. The fibers are multi nucleic
What does the sarcoplasm contain?
Myofibrils made up of myofilaments
Abundant glycogen and myoglobin
Sarcoplasmic reticulum
Stores CALCIUM
2 terminal cisternae of the sarcoplasmic reticulum join with avT tubule to constitute a triad.
Triad
A T tubule with terminal cistern on each side
Myoglobin
attracts oxygen that will help metabolize the glucose in glycogen
What happens when electrical impulse goes into T tubule?
Causes the swollen part of the sarcoplasmic reticulum (cisternae that stores calcium) to RELEASE the calcium
Are T tubules apart of the cell membrane (sarcolemma) ?
YES
Sarcomere
basic unit of muscle contraction
Myofilaments
CENTRAL to muscle contraction; two kinds: thick and thin
Thick myofilaments
Made of MYOSIN shaped somewhat like a gold club
Thin myofilaments
Made up go fibrous (skinny protein) ACTIN with bead-like subunits of globular actin, each of which has an active site that can find with the head of a myosin molecule
Tropomyosin
Lies within the fibrous actin; protein that consists of smaller proteins troponin
Regulatory proteins
Helps to regulate/control when muscle will contract; tropomyosin and troponin
If troponin hides active sites on a actin, how does myosin grab onto the actin to cause it to contract?
The myosin (thick filaments) are already cocked back but troponin is hiding active sites on actin. However, once calcium is released form the cisternae of the sarcoplasmic reticulum, it combines with the troponin and moves it so that myosin can grab onto the actin, release its cocked position, and cause the actin to contract.
What do myofibrils contain?
Thick (myosin) and thin (actin) filaments
What is in between two z-lines in a muscle fiber?
A sarcomere (filaments)