Muscular System Flashcards
What are the three muscle types?
Skeletal, cardiac, and smooth
What type of muscle is considered the “common muscle”?
Skeletal muscle
What type of skeletal muscles cause the “skin twitch” and have little to no attachment to bone
cutaneous muscles
What is the origin of a muscle?
The fixed, proximal end of a muscle
What is the distal. moveable end of a muscle?
Insertion
An ________ is a muscle that directly produces a desired movement.
Agonist
What is an antagonist?
It directly opposes the movement of the agonist muscle.
A _________ is made up of __________, which are made up of protein filaments (__________ and _________)
Muscle fiber; muscle myofibrils; actin; myosin
Skeletal muscle cells are….
Striated
Make sure you drink water
Hold your horses ;)
What is the endomysium?
CT around individual muscle fibers
What type of connective tissue is found around a bundle of muscle fibers?
Perimysium
What are the functions of the epimysium?
- Dense CT sheet covering a whole muscle
- Delineates muscles from each other and adjacent tissues
(NOTE) This is the white “film” you think of on top of muscles
What is a fascicle?
A small bundle of skeletal muscle fibers within a specific muscle.
Skeletal muscle cells are/have:
A. multinucleated
B. Intercalated discs
C. single nucleated
A. Multinucleated
What is a sarcolemma?
A thin, translucent sheet of muscle cell membrane that surrounds each myofibril.
What are myofilaments made up of?
Actin and myosin
What is the sarcoplasmic reticulum?
Equivalent to the ER of other cells and stores Ca
What extends inwards from the sarcolemma to help carry nerve impulses into the cell?
T tubules
I don’t remember what memes I’ve put on here anymore
What is a gap junction?
A gap junction connects muscle cells while allowing electrical impulses to flow rapidly and ensure synchronized contraction.
Smooth muscle is __________ of fine movement.
not capable
What source of energy is used only if absolutely necessary?
Fatty acids
What principle is similar between muscle contraction and neuron action potentials?
The “All or nothing principle”
How can you differentiate between the contractile proteins actin and myosin?
Actin is thin and myosin is thick
Where do actin and myosin come into contact and pull z lines together?
Crossbridges
What is the sliding filament theory?
When skeletal muscles contract, the thin parts of the sarcomere (actin), move toward each other. This happens when calcium ions are released from a nerve impulse.
Explain muscle contraction.
Troponin units on actin bind to calcium ions, displacing the troponin and exposing the myosin binding sites. Myosin heads then release a phosphate and bind to the site. Then they glide past each other with the movement of the myosin heads, which lose their ADP. This gliding stops when ATP binds to the heads, severing actin from myosin, and breaking into ADP and a phosphate, ready to start again.
What is a type of abnormal contraction?
Tetanus
Not with this class :(
What are the different types of muscle contractions?
Concentric, eccentric, isometric, and isotonic
What type of muscle contraction is the shortening or flexion of a muscle?
Concentric
What are isometric muscle contractions?
the muscle stays the same length, and the tension changes.
What is it called when a muscles length changes, but not the tension?
Isotonic muscle contraction
Describe hypertrophy.
Enlargement by increase in cell size
What is the difference between hypertrophy and hyperplasia?
Hyperplasia is enlargement by increase in number of muscle fibers, hypertrophy is enlargement by increase in cell size
What is the term use when a muscle falls into disuse?
Atrophy
What are slow twitch fibers?
Type 1, aerobic
Type 2 fibers are _______ and _____ twitch fibers.
anaerobic; fast
Fast twitch fibers are useful for ____ while slow twitch are useful for_________.
Sprinting; long distance running
Where is the location of the nervous and muscular system joining?
Neuromuscular junction
What is a unique characteristic of cardiac muscle? (Think: Histology)
Intercalated discs
What is the connective tissue that connects muscle to bone and allows for movement of the skeletal system (locomotion)?
Tendons
What part of the sarcomere “disappears” once contraction has been achieved?
H band
Is muscle contraction an active or passive process?
Active
What type of synapse delivers acetylcholine to a skeletal muscle fiber?
Chemical
Fml
