Muscular System

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Muscular System
http//www.youtube.com/watch?vRy9IcQMFiz8feature
fvw
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How many muscles do we have?
Over 650!

• Our over 650 muscles fall into three categories
  
• 1. skeletal,
• 2. cardiac
• 3. smooth.

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Fun Facts

• There are 50 muscles in your face alone.
• It takes 17 muscles to smile and 40 muscles to
  frown.
• Your heart muscle NEVER gets any rest neither do
  the muscles of your intestines!
• The most active muscles are those in your eyes.
  They move more than 100,000 times a day!

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Biggest, Strongest, and Hardest Working

• The gluteus maximus is the largest muscle in the
  human body.
• The strongest muscle in your body is the
  masseter, located on each side of your mouth.
  These muscles help you bite down with 150 pounds
  of force!
• The hardest working muscle is the heart. Every
  day the heart pumps at least 2,500 gallons of
  blood.

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In one day, your blood travels nearly 12,000
miles.
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Three Types of Muscle Cells

• Skeletal
• Cardiac
• Smooth

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Skeletal Muscle a.k.a. striated muscle
Nuclei are on the periphery of the cells
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2. Smooth Muscle
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3. Cardiac Muscle
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Do Now!
3. What kind of muscle?
1. What kind of muscle?
(C, Sm, Sk?)
(C, Sm, Sk?)
4. Lines hollow organs (C, Sm, Sk?) 5. Makes up
the heart walls (C, Sm, Sk?) 6. Connected to bone
(C, Sm, Sk?) 7. Involuntary (C, Sm, Sk?) 8. Used
to push substances along internal passageways.
(C, Sm, Sk?) 9. Voluntary (C, Sm, Sk?) 10. Moves
bones (C, Sm, Sk?)
2. What kind of muscle?
(C, Sm, Sk?)
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Practice Practical Muscle Quiz

•                                                   
                      
• 1. Identify the type of tissue.
• A) Dense regular connective tissue
• B) Smooth muscle
• C) Cardiac muscle
• D) Skeletal muscle
• 2. In question 1, above, what was the most
  distinctive identifying feature?
• Striations
• Branched fibers
• Peripheral nuclei
• A and C
• A, B, and C
•  

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                      3. Identify this tissue A)
Dense regular connective tissue B) Smooth
muscle C) Cardiac muscle D) Skeletal muscle 4.
In question 3, above, what was the most
distinctive identifying feature? A) Striations B)
Branched fibers C) Central nuclei D) A and C E)
A, B, and C
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           5. This specialized junction separates
cells in A) Cardiac muscle B) Skeletal muscle C)
Smooth muscle D) Tendons
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• 6. Identify this tissue.
• A) Dense regular connective tissue
• B) Smooth muscle
• C) Cardiac muscle
• D) Skeletal muscle
• E) Dense irregular connective tissue

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•  
• 7. Identify this tissue.
• A) Dense regular connective tissue
• B) Smooth muscle
• C) Cardiac muscle
• D) Skeletal muscle
• E) Dense irregular connective tissue

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                         8. Identify this
tissue A) Dense regular connective tissue B)
Smooth muscle C) Cardiac muscle D) Skeletal
muscle E) Dense irregular connective tissue 9.
In question 8, above, what was the most
distinctive identifying feature? A) Striations B)
Branched fibers C) Peripheral nuclei D) A and
C E) A, B, and C
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                            10. Identify the name
of the connective tissue around each fiber A)
epimysium B) endomysium C) perimysium D)
meromysium E) sarcomysium
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                         11. Identify the
structures noted by the arrows A) striations B)
sarcomeres C) Intercalated discs D) Sarcoplasmic
reticulum E) endomysium
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Skeletal Muscle Fibers

• Connect to bones
• Forms the smoother contours of the body
• Very long and cylindrical in shape
• Multinucleated
• Largest of the 3 muscle types
• A.K.A. Striated muscles
• Only muscle type under voluntary control
• Can also be activated by automatic reflexes

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How can they be so strong?

• Each fiber is wrapped in connective tissue called
  endomysium.
• Several fibers are then wrapped in a courser
  membrane called a perimysium to form a fascicle.
• The fascicle is bound together by an even tougher
  cover called an epimysium.

Endomysium
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• The epimysium (outer layer) can blend into strong
  cordlike tendons or
• Into sheet-like aponeuroses (fascia) which attach
  muscle indirectly to bone, cartilages, or other
  connective tissue coverings.

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Label this skeletal muscle using the diagram on
the next slide
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What do you remember?
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Origin vs. Insertion

• The muscles origin is attached to the immovable
  bone.
• At its other end, the insertion is attached to
  the movable bone.

Youll need this for lab!
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The endomysium can be further divided.
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The myofilaments of a myofibril are arranged in a
regular fashion so that their ends are all lined
up. This is what gives the muscle its striated
appearance. The contractile units of the cells
are called sarcomeres.
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Sarcomere
The myofibrils have distinct, repeating
microanatomical units, termed sarcomeres.
The sarcomere is composed of thick and thin
filaments myosin and actin, respectively. Chemic
al and physical interactions between the actin
and myosin cause the sarcomere length to shorten
(contract). The interactions between actin and
myosin serve as the basis for the sliding
filament theory of muscle contraction.
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Sliding Filament Theory

• The sliding filament theory is the basic summary
  of the process of skeletal muscle contraction.
• Myosin moves along the filament by repeating a
  binding and releasing sequence that causes the
  thick filament to move over the thinner filament.
  
• This progresses in sequential stages. By
  progressing through this sequence the filaments
  slide and the skeletal muscles contract and
  release.

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Naming Skeletal Muscles

• Named based on structural or functional
  characteristics.
• 1. Direction of fibers Rectus (straight or
  parallel to an imaginary line) or oblique (at a
  slant)

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Naming Skeletal Muscles

• 2. Size of muscle
• Maximus (largest),
• Minimus (smallest) and
• Longus (long)

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Naming Skeletal Muscles

• 3. Location of the Muscle
• Some are named for the bone they attach are
  associated with.

Ex. The temporalis muscle lays over the temporal
bones of the skull.
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Naming Skeletal Muscles

• 4. Number of Origins
• Ex. Bicep muscle has two heads, triceps have
  three and quadriceps have four.

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Naming Skeletal Muscles

• 5. Location of Muscles origin and insertion.
• Ex. Sternocleidomastoid has its origin on the
  sternum (sterno), and clavicle (cleido) and
  inserts on the mastoid process of the temporal
  bone.

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Naming Skeletal Muscles

• 6. Shape of the Muscle
• If a muscle has a definitive shape, it is used to
  help identify them.
• Ex. Deltoid (triangular)

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Naming Skeletal Muscles
Adductor A motion that pulls a structure or
part towards the midline of the body, or towards
the midline of a limb
7. Action of the Muscle

• Flexor Closes a joint
• Bending movement that decreases the angle
  between two parts. For ex. bending the elbow, or
  clenching a hand into a fist

Extensor opens a joint a straightening movement
that increases the angle between body parts
Abductor moves away from midline
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Four functions of skeletal muscles.

• Maintain posture
• Stabilize joints
• Generate heat
• Produce movement

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Aging and Muscles

• After 30, your muscle mass dwindles some 3-8
  percent each decade. Once you hit 60, these
  losses accelerate even more quickly.
• Decreased muscle mass means you'll burn far fewer
  calories.
• Muscles require a lot of calories to maintain.
  (Think of them as a bunch of high-strung, active
  family members visiting your home. They're always
  up, moving around. As a result, they're hungry
  and require a lot of food.)
• The strength of your muscles is related to the
  strength of your bones. When your muscles are
  weak, your bones are more likely to be weak.
  (This is esp. important for women who have higher
  risk of osteoporosis.)

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Muscle Pairs

• Muscles are usually in (Antagonistic) pairs. When
  one muscle contracts, the other extends.
• Adrenaline allows your muscles to use 4 to 6
  times more oxygen than usual thus creating a huge
  amount of energy.
• Extreme strength http//www.youtube.com/watch?vQ
  9wRTIZIBykNR1
• Two man strength performance http//www.youtube.c
  om/watch?vJWK5mfRGkiEfeaturerelated

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Disorders of the Muscular System

• Muscular Dystrophy Occurs when a particular gene
  on the X chromosome a. fails to make the
  protein dystrophin.
• b. makes low amounts of dystrophin.
• the membranes around muscle cells become weak
  and tear easily, eventually leading to the death
  of muscle fibers.
• More common in males.

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DMD

• Types of MD
• A. When one of these proteins, dystrophin, is
  absent, the result is Duchenes muscular
  dystrophy.
• B. Poor or inadequate dystrophin results in
  Beckers muscular dystrophy.

Animation http//www.youtube.com/watch?v6wLnR7GJ
akY A familys story http//www.youtube.com/watch
?vdSEc5zvGTbc
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Disorders of the Muscular System

• 2. ALS Amyotrophic lateral sclerosis disease of
  the nerve cells in the brain and spinal cord that
  control voluntary muscle movement.
• AKA Lou Gehrig's disease.
• The symptoms usually do not develop until after
  age fifty.
• Persons with this disease have a loss of muscle
  strength and coordination that eventually gets
  worse.
• Breathing or swallowing muscles may be the first
  muscles affected. As the disease gets worse, more
  muscle groups develop problems.
• Life expectancy of an ALS patient averages about
  two to five years from the time of diagnosis.

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• Amyotrophic lateral sclerosis (ALS) is caused by
  the degeneration and death of motor neurons in
  the spinal cord and brain. These neurons convey
  electrical messages from the brain to the muscles
  to stimulate movement in the arms, legs, trunk,
  neck, and head. As motor neurons degenerate, the
  muscles are weakened and cannot move as
  effectively, leading to muscle wasting.

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http//www.youtube.com/watch?vtKRWUZr4gBg
Fans, for the past two weeks you have been
reading about the bad break. Today I consider
myself the luckiest man on the face of this
earth. That I might have been given a bad break,
but I have an awful lot to live for. Thank you.
His record for most career grand slam home runs
(23) still stands today (Alex Rodriguez has 22,
Manny Ramirez has 21)
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Disorders of the Muscular System

• 3. Myasthenia gravis is caused by a defect in
  the transmission of nerve impulses to muscles.
• Its a disease in which the immune system attacks
  the body's own tissues ("autoimmune" disease)
• Causes a weakness of voluntary muscles without
  pain that gets worse with repeated or sustained
  use of the muscle (fatigued muscle weakness).
• In two thirds of patients with MG, the first
  muscles to be affected are those controlling eye
  movements (causing double vision) and those
  holding the eyelids up (causing drooping of the
  eyelids).
• There are medications to treat the disorder. It
  is not fatal.

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• 4. Chronic Fatigue Syndrome Symptoms of chronic
  fatigue syndrome include loss of memory,
  difficulty concentrating, fatigue, random muscle
  pain, headaches, unrefreshing sleep and sore
  throats.
• 5. Fibromyalgia results in widespread pain
  throughout every muscle in a person's body.
  Approximately 2 of the entire US population is
  affected by fibromyalgia. Symptoms of
  fibromyalgia include joint tenderness, fatigue
  problems, and sleep disturbances. No cure.

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• 6. Cerebral Palsy
• Cerebral palsy is condition that can involve
  brain and nervous system functions such as
  movement, learning, hearing, seeing, and
  thinking.
• There are several different types of cerebral
  palsy.
• Cerebral palsy is caused by injuries or
  abnormalities of the brain.
• Most of these problems occur as the baby grows in
  the womb, but they can happen at any time during
  the first 2 years of life, while the baby's brain
  is still developing.

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Botulism Botox

• Difficulty swallowing or speaking
• Facial weakness on both sides of the face
• Blurred vision
• Drooping eyelids
• Trouble breathing
• Nausea, vomiting and abdominal cramps (only in
  food-borne botulism)
• Paralysis

• Botulism is a rare but serious condition caused
  by toxins from bacteria called Clostridium
  botulinum.
• can be fatal
• A weakened botulinum toxin (BOTOX) has been used
  to reduce facial wrinkles by paralyzing muscles
  beneath the skin, and for medical conditions,
  such as eyelid spasms and severe underarm
  sweating.

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• Botulism What is this toxin? http//video.google.
  com/videosearch?qbotulinumtoxinwww_google_domai
  nwww.google.comhlenemb0aq3oqbotu
• Botulism Cerebral Palsy treatment and Botox
• http//www.youtube.com/watch?vRI7FVOBKTXM

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Poisons vs. Venom

• Terms are often used interchangeably, but they
  actually have very different meanings.
• It is the delivery method that distinguishes one
  from the other.
• Poison is absorbed or ingested Ex. Toxin in skin
  or organs. (frogs, puffer fish, poison ivy)
• Venom is always injected. Ex. Stab with tails.
  Slash with spines. Pierce with fangs. Spike with
  spurs. Shoot with harpoons. Chew with teeth.
  (snakes, spiders, bees)

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Poisons (venom)
Stiletto Snake bite Part 1 Envenomation Part
2 http//dsc.discovery.com/videos/i-was-bitten-st
iletto-snakebite-symptoms.html Part 3 surgery
Part 3 automatically plays first so select Part 1

• Effects of snake venom
• Part 3 Rattlesnake Compartment Syndrome
  http//dsc.discovery.com/videos/discovery-channel-
  snakebite-stories/
• Part 2Symptoms of the Bite
• http//dsc.discovery.com/videos/discovery-channel-
  snakebite-stories/
• Part 1 Bitten By a Rattler
• http//dsc.discovery.com/videos/discovery-channel-
  snakebite-stories/

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Two Types of Venom and What They Do To The Body

• 1. Neurotoxin acts on the victim's nervous
  system, causing excitation (cramps, vomiting,
  convulsions) or depression (paralysis,
  respiratory or cardiac depression or arrest).
• Black Widow Spider
• Cobra
• Coral Snakes
• Gila monster
• Puffer fish
• Short-tailed shrew
• Kraits

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Two Types of Venom and What They Do To The Body

• 2. Hemotoxin ("blood poison") breaks down the
  victim's tissues, usually by an acid or a toxin
  that prevents or causes blood clotting, or
  destroys red or white blood cells. Venom usually
  contains both types, but one dominates.
• scorpion
• Copperhead
• Rattlesnakes
• Water Moccasin/Cottonmouth

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You are 9X more likely to die by lightening
strike than getting bit by a venomous snake.
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Hey You! Label my muscles!
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Steroids anyone?

• http//www.youtube.com/watch?vgp11d7qDQSg

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Steroid use 15minutes (some bad lang.) Part 3
http//www.youtube.com/watch?vITG-IbHEYEEfeature
related Part 4 http//www.youtube.com/watch?vU0
dmXRAKieQNR1 Tyra Greg Today
http//www.youtube.com/watch?vvwcL6mOcPF4
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Muscle System Test

• 3 types of muscles chara. of each one, and ID a
  picture.(matching description with muscle type)
• Four functions of skeletal muscles.
• Produce movement
• Maintain posture
• Stabilize joints
• Generate heat
• Basic Microscopic Anatomy/sliding filament
  theory. Label muscle cell.
• 7 ways to name muscles ex of each.
• Name the main anterior and posterior muscles.
• Disorders/diseases (M.D., cerebral palsy, ALS,
  myasthenia gravis, botulism, snake venom)
  treatment Botox

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The anatomy of a sarcomere

• The entire array of thick and thin filaments
  between the Z disks is called a sarcomere.
• The thick filaments produce the dark A band.
• The thin filaments extend in each direction from
  the Z disk. Where they do not overlap the thick
  filaments, they create the light I band.
• The H zone is that portion of the A band where
  the thick and thin filaments do not overlap.
• The M line runs through the exact center of the
  sarcomere. Molecules of the giant protein, titin,
  extend from the M line to the Z disk. One of its
  functions is to provide a scaffold for the
  assembly of a precise number of myosin molecules
  in the thick filament (294 in one case). It may
  also dictate the number of actin molecules in the
  thin filaments.
• Shortening of the sarcomeres in a myofibril
  produces the shortening of the myofibril and, in
  turn, of the muscle fiber of which it is a part.

• This electron micrograph of a single sarcomere
  was kindly provided by Dr. H. E. Huxley.

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Actin Myosin
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Actin Myosin
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Sliding Filament Theory

• 1. http//msjensen.cehd.umn.edu/1135/Links/Animati
  ons/Flash/0008-swf_sarcomere_shor.swf
• 2. http//www.youtube.com/watch?vren_IQPOhJc

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7 stages of the Sliding Filament Theory

• First Stage The first stage is when the
  impulse gets to the unit. The impulse travels
  along the axon and enters the muscle through the
  neuromuscular junction. This causes full two to
  regulate and calcium channels in the axon
  membrane to then open. Calcium ions come from
  extra cellular fluid and move into the axon
  terminal causing synaptic vessels to fuse with
  pre synaptic membranes. This causes the release
  of acetylcholine (a substance that works as a
  transmitter) within the synaptic cleft. As
  acetylcholine is released it defuses across the
  gap and attaches itself to the receptors along
  the sarcolemma and spreads along the muscle
  fiber. Second Stage The second stage is for
  the impulse spreads along the sarcolemma. The
  action potential spreads quickly along the
  sarcolemma once it has been generated. This
  action continues to move deep inside the muscle
  fiber down to the T tubules and the action
  potential triggers the release of calcium ions
  from the sarcoplasmic reticulum. Third Stage
  During the third stage calcium is released from
  the sarcoplasmic reticulum and actin sites are
  activated. Calcium ions once released begin
  binding to Troponin. Tropomyosin blocking the
  binding of actin is what causes the chain of
  events that lead to muscle contraction. As
  calcium ions bind to the Troponin it changes
  shape which removes the blocking action of
  Tropomyosin (thin strands of protein that are
  wrapped around the actin filaments). Actin active
  sites are then exposed and allow myosin heads to
  attach to the site. Fourth Stage The fourth
  stage then begins in which myosin heads attach to
  actin and form cross bridges, ATP is also broken
  down during this stage. Myosin binds at this
  point to the exposed binding sites and through
  the sliding filament mechanism the muscles
  contract. Fifth Stage During the fifth stage
  the myosin head pulls the Actin filament and ADP
  and inorganic Phosphate are released. ATP binding
  allows the myosin to detach and ATP hydrolysis
  occurs during this time. This recharges the
  myosin head and then the series starts over
  again. Stage Six Cross bridges detach while
  new ATP molecules are attaching to the myosin
  head while the myosin head is in the low-energy
  configuration. Cross bridge detachment occurs
  while new ATP attaches itself to the myosin head.
  New ATP attaches itself to the myosin head during
  this process. Stage Seven During stage seven
  the ATP is broken down and used as energy for the
  other areas including new cross bridge formation.
  Then the final stage (stage 8) begins and a drop
  in stimulus causes the calcium concentrate and
  this decreases the muscle relaxation.
• Read more http//wiki.answers.com/Q/How_does_t
  he_sliding_filament_theory_workixzz1JDtbSisM

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Resting and Action Potential

• Neurons send messages electrochemically. This
  means that chemicals cause an electrical signal.
• The important ions in the nervous system are
  sodium and potassium (both have 1 positive
  charge, ), calcium (has 2 positive charges, )
  and chloride (has a negative charge, -).
• Resting Membrane Potential
• When a neuron is not sending a signal, it is "at
  rest.
• Action Potential
• An action potential occurs when a neuron sends
  information down an axon, away from the cell
  body. Neuroscientists use other words, such as a
  "spike" or an "impulse" for the action potential.
  
• The action potential is an explosion of
  electrical activity that is created by some event
  (a stimulus).
• There are no big or small action potentials in
  one nerve cell - all action potentials are the
  same size. Therefore, the neuron either does not
  reach the threshold or a full action potential is
  fired - this is the "ALL OR NONE" principle.
• This is in reference to an individual muscle cell
  not the whole muscle therefore there can be a
  graded response in the muscle contraction.

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Neuromuscular Junction

• A skeletal muscle cannot contact unless
  stimulated by a motor nerve.
• This junction between a nerve fiber (axon) and
  muscle cell is called a neuromuscular junction.
• http//video.google.com/videosearch?hlenrlz1T4H
  PND_enUS310US240resnum0qbotulismum1ieUTF-8
  saNtabwvqmotorneuronjunctionhlenemb0
• Watch it using flash player
• http//www.galaxygoo.org/biochem/neuro/nmj_flash.h
  tml

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Acetylcholine

• When acetylcholine is released from an axon
  terminal, it moves across the synaptic cleft to
  bind to a receptor on the other side of the
  synapse (on the post-synaptic membrane).
• In the peripheral nervous system, acetylcholine
  is located at the "neuromuscular junction" where
  it acts to control muscular contraction.

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Extra Credit

• 1. How does adrenaline make you stronger?
• 2. Muscles are usually in antagonistic pairs.
  What does that mean and give an example of a
  pair?