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38 Cards in this Set
- Front
- Back
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Sarcomere |
A functional unit of myofibril. Region between z-disks. |
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Fascicle |
A bundle of muscle fibers. |
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Muscle Fiver |
A muscle cell. Made up of many small myofibrils. |
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Tendon |
Connects muscle to bone. |
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Myofibril |
Contains 2 types of protein filaments. |
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Strain |
An injury to a muscle or tendon
Is often caused by overuse, force, or stretching. |
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During a sprain, injured areas experience: |
-Pain and soreness. -Swelling. -Warmth, bruising, or redness. -Difficulty using or moving the injured area in a normal manner. |
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Steroid |
Supports such functions as fighting stress and promoting growth and development. |
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Contraction |
Muscle is short, firm, tight, and thicker around. |
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Flexion (Flexor) |
When the muscle bends the joint when contracted. |
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Extension (Extensor) |
When the muscle straightens the joint when contracted. |
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Neurotransmitter |
A chemical message that transmits signals from one place to another. |
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Motor Neuron |
A nerve cell that forms the pathway which impulses pass from brain or spinal chord to muscle. |
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Neuromuscular Junction |
The space/where the neuron meets the muscle. |
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Involuntary |
Happens no matter what (cardiac muscles) |
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Voluntary |
Able to control when you move a muscle (most skeletal muscles) |
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Spasm |
When a muscle (or even a few fibers of a muscle) involunarily contract. |
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Cramp |
Involuntarily and forcible contracted muscle that does not relax. Nick-named charley horse.
A forceful and sustained spasm. Muscle feels tied up in knots. Can last anywhere from a few seconds to a quarter of an hour. Caused by strain, injury, or fatigue. |
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Myasthenia Gravis |
A chronic autoimmune neuromuscular disease. Symptoms: -Muscles repeatedly start to weaken, hard to chew, talk, swallow, sometimes hard to breathe, etc. Muscle fatigue. Eyelids that droop as the day goes on. -Symptoms usually start in the face and spread out to other parts of the body as the disease progresses. Cause: A defect in the transmission of nerve impulses at the neuromuscular junction. |
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Cerebral Palsy |
-Cerebral palsy is a group of disorders that affect a person's ability to move and to maintain balance and posture. -Usually appears early in life and usually doesn't worsen. -May have difficulty walking or have trouble with tasks such as writing or using scissors. -Some people have other medical conditions like seizure disorders or mental impairment. Cause: -Happens when the areas of the brain that control movement and posture do not develop correctly or get damaged. |
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Muscular Dystrophy |
-Most well-known of hereditary diseases. -A genetic condition that describes over 20 genetic and hereditary muscle diseases. -Characterized by progressive skeletal muscle weakness, defects in muscle proteins, and the death of muscle cells and tissue. -In some cases, cardiac and smooth muscles are affected. Symptoms: Progressive Muscular Wasting (weakness) Poor Balance and Frequent Falls Walking Difficulty + Waddling Gait Limited Range of Movement Scoliosis (curvature of the spine) Inability to Walk Muscle Atrophy and Drooping Eyelids |
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Polio |
-Poliomyelitis (Polio), A viral infectious disease which is spread from person-to-person via the fecal-oral route. -Infects and destroys motor neurons. Vaccination created by Jonas Salk in 1955 has eliminated the disease. |
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Anabolic Steroids |
-Produced naturally by the body to support such functions as fighting stress and promoting growth and development -People use steroid pills, gels, creams, or injections to improve their sports performance or the way they look. -Anabolic steroids cause many different types of problems. |
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Types of problems caused by anabolic steroids |
-premature balding or hair loss -dizziness -mood swings -problems sleeping -nausea and vomiting -high blood pressure -aching joints -urinary problems -shortening of final adult height -increased risk of heart disease |
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Tetaunus |
-Preventable through vaccination. -Caused by bacteria that enters the body through the skin. -Found in soil, dust, and manure. -The toxin bacteria produces interferes with nerve transmission to your muscles and causes them to seize up in painful spasms. Symptoms: -“Lockjaw” -Difficulty swallowing -Intestines often seize up -Bladder fails to empty -Asphyxiation -Cardiac arrest |
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Treatment for muscle disorders: |
R.I.C.E Rest: Stop all activities which cause pain. Ice: Helps reduce swelling. Never ice more than 10-15 minutes at a time (protect the skin.) Compression: Wrap the strained area to reduce swelling. Elevation: Keep the strained area as close to the level of the heart as is conveniently possible to keep blood from pooling in the injured area. |
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Muscle Tissue Functions |
1.Provides voluntary movement of body -Enables breathing, blinking, and smiling Allows you to hop, skip, jump, or do push-ups 2. Maintains posture 3. Produces heat 4. Causes heart beat 5. Directs circulation of blood -Regulates blood pressure -Sends blood to different areas of the body 6. Provides movement of internal organs Moves food through digestive tract Enables bladder control 7. Causes involuntary actions -Reflex actions -Adjusts opening of pupils Causes hair to stand on end (Goosebumps) with the arrector pilli muscle. |
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Three main types of muscle tissue |
-Skeletal (striated) -Cardiac (heart) -Smooth (visceral) |
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Z-line |
Point of anchor of actin |
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Steps of a muscle contraction |
1. Message from brain 2. Message (in the form of an electrical impulse called an action-potential) travels down the motor neuron. 3. Impulse reaches neuromuscular junction and neuron releases neurotransmitter (chemical message) 4. Neurotransmitter causes muscle to release calcium ions. 5. Calcium ions cause myosin crossbridges to form 6. Myosin head pivot to pull actin filaments closer together 7. Myosin head releases and reattaches to pull actin even closer. |
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Mechanics of a muscle contraction |
-When each sarcomere becomes shorter it causes each myofibril to become shorter. -When each myofibril becomes shorter it causes the muscle fibers to become shorter. -When each muscle fiber shortens the overall muscle contracts. |
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How strongly does a muscle fiber contract?
So what controls the strength of a contraction? |
-To it’s fullest extent. -All-or-none response
-Number of muscle cells recruited. -To get a stronger contraction, more cells are stimulated. -A single cell can’t contract harder. |
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Where does stimulation occur?
How do motor neurons communicate with muscle cells?
What happens when a muscle cell is stimulated? |
-Neuromuscular junction
-Neurotransmitters (chemicals) carry
-Calcium ions are released into the muscle cell |
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What do calcium ions do?
How do actin and myosin interact?
What model explains this? |
-Cause interaction between actin and myosin
-Actin filaments slide over the myosin filaments.
-Sliding Filament Model |
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What causes actin to slide over myosin?
What is this connection called?
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-The head of myosin connects to actin and pivots.
-Crossbridge
Some myosin heads are binding while other heads are releasing the actin filaments. |
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The flexor of the elbow? The extensor of the elbow? The flexors of the knee? The extensors of the knee? |
Biceps Brachii Triceps Brachii Hamstring Quadriceps |
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Explain what static stretching does to muscles |
Static stretching actually weakens the muscles. -It strains the muscle and the strained muscles become less responsive and stay weakened for about 30 minutes. -Can decrease muscle strength by around 30 percent. -Static stretching stretches your muscles out pulling the actin and the myosin farther apart so when you need them there is less overlap. |
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Explain what dynamic stretching does |
Dynamic helps activate all the joints and connective tissue that will be needed for the task ahead. -Increases body heat and blood flow. -Helps make tissues and tendons more compliant. |
