muscular system Flashcards
what are the 3 muscle type?
Smooth muscle cell
skeletal muscle
cardiac muscle
What is another name for skeletal muscle?
Strated (stripes) muscles or voluntary muscles
What is the structure of the skeletal muscle attachment?
Attached to bones by tendons (ligaments attach bone to bone
Why do muscle bone come in pair?
To move in opposite directions
one contracts and the other relaxes.
what does the skeletal muscle require to contract?
It requires nervous impulse to contract
if it’s from the spinal cord it’s a reflex.
what is the name of the muscle fiber cells?
muscle fibers (cells) Multi-nucleated.
what fibers bundle are muscle made up of? why?
Muscles are a bundle of parallel fibers to increase strength in one direction-unlike the branching fibers of the heart.
What is each cell of the skeletal muscle covered in?
Fascia aka connective tissue
what are muscle fibers (myofibrils) made up of?
myofibrils are made up of a series of small sections called sarcomeres.
what makes up each sarcomere?
Each sarcomere is made up of thin myofilaments(actin) and thick myofilaments (myosin)
What surrounds myofibrils (muscle cells)?
nuclei from stem cells
what happens as a result of the thin(actin) myofilaments extension?
thin extend beyond thick it creates a lighter area.
What happens as a result of the thick( myosin) myofilaments extension?
thick and thin together they create darker areas.
What forms as an alteration of the light and dark areas?
creates visible lines perpendicular to the muscle and are the striations.
what is the all or none theory for the muscular system?
they come together or don’t come at all
What happens when the actin and myosin slide together? what happens to the sarcomere?
this is a contracdation- sarcomere gets shorter.
What happens when the actin and myosin slide away from each other? what happens to the sarcomere?
this is relaxation- sarcomere gets longer
What is actin attached to?
actin is attached t the Z-line to the sarcomeres on either side
What is the lighter area of sarcomere called?
I band
What is the name of the dark area between the I bands?
A band
What is the H zone?
when the sarcomere is relaxed is called the H zone.
What are the characteristics of the skeletal muscle cell?
- ) Voluntary
- ) must have nervous innervation to contract
- )contraction controlled by cerebral motor cortex
- )Nerve connects to muscle at the motor endplate
What are the characteristics of the cardiac muscle cell?
- ) Heart muscle branching
- )Striated
- )Will contract without nervous innervation
- )Pacemaker SA node
- )Multinuclinated
- ) Intercalated discs
- )Pumps blood
- )Involuntary
Where are smooth muscles found?
- )Aorta
- )veins
- )the urinary bladder
- )respiratory tract
- )arrector pili of skin
- )the ciliary muscle distance
- )iris of the eye
- )glomeruli of the kidneys
What are characteristic of the smooth muscle cell?
- ) Nonstriated
- )Single nucleus
- )Spindle-shaped
- )Involuntary
- )Must have nervous innervation o contract
- ) from the brain stem.
What are the steps for muscle contraction?
1.)Motor Nerve
Impulse: Action potentials arrive at the synaptic end bulb the axon terminal, ole structure= neuromuscular junction
2.) Calcium ions diffuse into synaptic bulbs through voltage-gated calcium channels.
3.) Acetylcholine released by vesicles through exocytosis into the synaptic cleft.
4.)Then it binds to ACh receptors on the motor endplate (cell membrane of muscle across from the axon terminal)
5.) Na+ ion enters through these ion channels (and K+ leaves, just like in neuron, repolarization)
6.) Na+ entrance sets up an action potential on the sarcolemma. The sarcolemma is depolarized.
Where does muscle contraction occur?
Happens on multiple muscle fibers from one neuron with multiple terminal button.
How is ACh destroyed? What happens to the stimulus?
ACh is destroyed by AchEsterase or diffuses throughout the synaptic cleft. ACh also diffuses away.Stimulus stops when ACh is destroyed.
What covers up actin?
Actin is covered by a strip of tropomyosin with troponin molecules attached.
What covers up myosin?
movable myosin heads to move the actin.
What is the sliding filament theory?
Myosin slides the actin causing the shortening (contraction).
Shortening of the sarcomere in an “all or none” pattern
Only the sarcomere shortens not the protein fibers, Actin and Myosin.
What is the step for muscle fiber getting excited?
1.) The action potential travels to the T-tubules
2.)Where the Sarcoplasmic reticulum releases Ca+ into the sarcoplasm (cytoplasm)
3.) Ca+ binds to the troponin, causing a shift of the tropomyosin(cover strip over the myosin-binding sites)
4.)The myosin-binding sites(on the actin) are exposed.
5-8 power stroke follows
5.)ATP molecules which are bonds to the myosin head is hydrolyzed to ADP+ P1- Transfering the energy to the myosin head and causing the myosin head to straighten out. ADP + P remains attached o the myosin head.
6.) Activated myosin head will now bind to the actin, forming a cross-bridge. This foundation does not require energy.
7.) The myosin head reflexes (to a bent, lower energy position), pulling the thin filament along the myosin, Makes the sarcomere shorter. This is the start of a contraction. The ADP+P, is released.
8.)Myosin head remains bound to the actin until a new ATP molecule binds to it.
9.) The new ATP causes the myosin head to be released from the actin, thus allowing the head to repositioned (straighten) for another power stroke.
Repeated multiple times to shorten the muscle (contraction).
10.) Ca+ 2 transported( active, ATP used) back into the sarcoplasmic reticulum.
11.) Low (Ca+) in sarcoplasm causes Ca+ to leave the troponin
12.) The tropomyosin shifts around to cover the myosin-binding sites. The sarcomere will lengthen as the filaments slid back to the original position.
Contraction is over.
What are the steps of muscle movement?
- ) The sarcomere shortens( contraction) causing the entire muscle shortens.
- ) The muscle s attached to bone at the tendons.
- ) The insertion bone moves towards the muscle because the other end of the muscle is attached to the origin bone as an anchor.
- )Flexors-bends and biceps brachil
- )Extensor- straingten and triceps brachil
what is the fibers strength principle of the muscle?
more muscle fibers contract=more muscle strength
What is an example of the muscle fiber strength principle?
to pick up a penny fewer muscle fibers required to contract than picking up your backpack.
What is needed for glucose to enter the muscle?
Insulin
Insulin allows cells to bring in glucose.
What is needed for the muscle to make ATP?
enough oxygen.
What are the two types of muscular hypertrophy?
Sarcoplasmic and myofibrillar
What happens during sarcoplasmic hypertrophy?
During sarcoplasmic hypertrophy, the volume of sarcoplasmic fluid in the muscle cell increases with no accompanying increases in muscular strength.
What happens during myofibrillar hypertrophy?
the number of myofibrils in a muscle increases, which in turn increases the muscle fiber strength
What is Microtrauma? and what happens as a result?
Tiny damage to the fibers
may cause signficant hypertrophy
What happens when microtrauma occurs?
When microtrauma occurs(from weight training or other strenuous activities), the body responds by overcompensating, replacing the damaged tissue and adding more, so that the risk of repeat damage is reduced. The body is ding stop.
What has damaged to these fibers been theorized as? DOMS
Why is progressive overload essential?
the possible cause for the symptoms of delayed onset muscle soreness(DOMS) and is why progressive overload is essential to continued improvements, as the body adapts and becomes more resistant to stress.
What is “delayed onset muscle soreness?
Pain or discomfort that may be felt one to three days after exercising and subsides generally within two or three days later.
What does lactic acid buildup causes?
immediate cramping and the slowing of activity until oxygen levels can be restored and thus ATP levels.
How is lactic acid produced?
Lactic acid is produced when the muscles need more ATP and more oxygen to produce the ATP than what is available.
what does repeated lactic acid production cause?
cause angiogenesis( growth of new blood vessels to the muscle).
What are the benefits of lactic acid build-up?
more active myosin
What happens to muscles when they are not used?
Use your muscles or you’ll lose them. … In contrast, when you don’t use your muscles, you send a message that they are not important. In response, your body quits supporting your muscles with energy, which causes them to atrophy (shrink).
What is needed for proper action potential to occur?
Both sodium (Na+) and potassium(K+) are necessary for a proper action potential depolarization.
Is Sodium a problem when it comes to obtaining through a diet?
Sodium is not a problem to obtain through diet(salt.
What is difficult and what is suggested?
Potassium is often more difficult, often bananas are suggested.
What is the result of the releases of potassium?
involved in the rapid vasolidation of blood vessels near the muscle.
What are humans genetically predisposed with?
a larger percentage of one type of muscle group over another.
What are the characteristics of individuals with Type 1 muscle fibers?
An individual born with a greater percentage of Type 1 muscle fibers, would theoretically be more suited to endurance events, such as triathlons, distance running, and long cycling events.
What are the characteristics of individuals with Type 2 muscle fibers?
A human born with a greater percentage of Type 2 muscle fibers would be more likely to excel at anaerobic events such as a 200-meter dash, or weightlifting.
Where did the protein in your body muscles come from?
food
Does protein enter the bloodstream?
No
What are the building blocks of protein?
amino acids
what comes in?
amino acids
How many different amino acids are there?
20
what are good sources of those amino acids?
meet and eggs
what is the difference between essential and non-essential amino acids?
Nonessential amino acids can be made by the body, while essential amino acids cannot be made by the body so you must get them from your diet.
what are some potein rich foods?
human milk, eggs and chicken.
What is abduction?
move a limb away from the body
what is pronation?
palms of hand down
what is dorsiflexion?
extracting the foot up at the ankle
what is circumduction?
movement in a circle
what is flexion?
bending
what is the opposition?
moving thumb to touch other fingers
what is adduction?
move limb towards the body
what is plantar flexion?
pointing foot down
what is an inversion?
turning the foot medially
what is an extension?
straightening
what is rotation?
a moment from side to side
what is eversion?
turning the foot laterally
what is supination?
palms of hands up
