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What is responsible for all types of movement?
Muscles
What do muscles do?
Contract and shorten and are the machine of the body
What are the three basic types of muscle found in the body?
Skeletal Muscle
Cardiac Muscle
Smooth Muscle
What are the functions of the muscles?
Support the body
Allow for movement by making bones and other body parts move
Maintain constant body temperature
Assist in movement of cardiovascular veins and lymph
Protect internal organs and stabilize joints
What is the organization of Skeletal Muscle?
Muscle
Fascicle
Muscle Fiber
Sarcomere
Myofibrils
Myofilament
Myosin and Actin
What is the fascicle?
A bundle of muscle fibers
What is a muscle fiber?
A muscle cell
What is a sarcomere?
Contractile units of a myofibril responsible for the striated appearance
What is a myofibril?
Structures that make up a muscle fiber
What is a myofilament?
Protein filaments that make up a sarcomere
What is myosin?
Thick filaments
What is actin?
Thin filaments
What are skeletal muscles?
Organs
What does skeletal muscle contain?
Muscle fibers, nerves, and blood vessels
What separates muscle structure?
Connective tissue membranes
What is fascia?
Layer of fibrous tissue that separates muscles from each other and from the skin
What are the coverings of the muscle?
Epimysium
Perimysium
Endomysium
What is the epimysium?
Covers the entire skeletal muscle
What is the perimysium?
Surrounds a bundle of muscle fibers (fascicle)
What is the endomysium?
Surrounds a single muscle fiber
What does the epimysium blend into?
A connective tissue to form the tendon
What is a tendon?
Cord-like structure
What are the sites of muscle attachment?
Bones, cartilage, and connective tissue coverings
Where are the nuclei located in the muscle cell?
Beneath the membrane sarcolemma
What is the membrane sarcolemma?
Specialized plasma membrane
What is the sarcoplasmic reticulum?
Specialized smooth endoplasmic reticulum involved with muscle contraction
What is the light band known as?
I Band
What is the dark band known as?
A Band
What are thick filaments made of?
Myosin protein
What are thin filaments made of?
Actin protein
Where do myosin and actin overlap somewhat?
In the sarcomere
What is a cross bridge?
Where the myosin filament extensions (heads) 'grab' onto actin
How are skeletal muscles stimulated to contract?
By a nerve (motor neuron)
What are the steps of muscle stimulation by a nerve impulse?
Nerve releases a neurotransmitter (acetylcholine)
Neurotransmitter causes the muscle cell membrane gates to open
Ions (Na+ and K+) exchange places causing the sarcoplasmic reticulum to release Ca 2+
This release of Ca+ starts the muscle contraction as the actin filaments slide past the myosin filaments
What is the sliding filament model?
A muscle contractions when the thin filament in the muscle fiber slides over the thick filament
How is the sliding filament model activated?
With ATP and Calcium (Ca 2+) ions
What are the steps of the sliding filament model?
An influx of Ca 2+ causes thick myosin filaments to form cross bridges with the thin actin filament by exposing the binding site on actin.
The cross bridges change shape as it pulls on filaments which slides towards the center of the sarcomere in the power stroke.
The cross bridges detach from the actin filament when ATP bond to myosin head
The myosin gets ready to bond to actin again using ATP energy
What method does muscle fiber contraction follow?
"All or none"
Can all fibers, within a skeletal muscle, be stimulated during the same interval?
Not all of them
What do different combinations muscle fiber contractions do?
Differing responses
What are graded responses?
Different degrees of skeletal muscle shortening
What is rapid stimulus?
Constant contraction or tetanus
What does muscle force depend upon?
The number of fibers stimulated
How does one get greater muscle tension?
More fibers contract
What causes muscle fibers to stop contracting?
ATP or CA 2+
How much energy does one ATP molecule provide?
Enough energy for one actin and one myosin cross bridge
What do muscles use stored ATP for?
Energy
How is energy released?
Bonds of ATP are broken
What are the three ways muscles make energy (ATP)?
Creatine Phosphate
Cellular Respiration
Anaerobic Respiration/Fermentation
What is creatine phosphate?
A high-energy compound that is the fastest way to make ATP available for muscles
What kind of activities is creatine phosphate used for?
Activities lasting <15 seconds
What is the reaction for creatine phosphate?
Creatine Phosphate + ADP => Creatine + ATP
When is creatine phosphate made?
When a muscle is at rest
What is cellular respiration?
Mitochondria uses glucose molecules to make ATP in the presence of oxygen
Does cellular respiration require oxygen?
Yes
What kinds of activities is cellular respiration used for?
Activities lasting hours
What is the reaction for cellular respiration?
C6H12O6 + 6O2 => 6CO2 + 6H2O + Energy
How much ATP does 1 glucose molecule make?
36 ATP
What is anaerobic respiration/fermentation?
Reaction that breakdowns glucose without using oxygen
Does anaerobic respiration/fermentation require oxygen?
No
What kinds of activities is anaerobic respiration/fermentation use for?
Activities lasting 30-60 seconds
What is the reaction for anaerobic respiration/fermentation?
Glucose => pyruvic acid + 2 ATP => Lactic Acid
What does Lactic Acid do?
Causes pain in the muscle
What is a sign of oxygen deficiency?
Heavy breathing after exercise
What is Tetanus?
Tetanus is a deposited in a wound and the neurotoxin interferes with the nerves that control muscle movement.
Where is the Clostridium tetani bacterium located in the environment?
Dirt
What type of environment does Clostridium tetani thrive in?
Any environment. It thrives in either cold or warm environments.
How does the toxin released by Clostridium tetani affect the body?
It infects the nervous system.
What is an incubation period? What is the incubation period for tetanus?
7-10 days after the initial infection
What are the symptoms of tetanus? What is the mortality rate?
Difficulty breathing, stiffness, fever, headache
Why is the incidence rate of tetanus so low in the US? Is there a cure?
People receive shots and it is preventable.
How is movement attained?
Muscle moving an attached bone
How many points do muscles attach to?
Two
What are the points that muscles attach to called?
Insertion
Origin
What is an insertion point?
Attachment to a moveable bone
What is an origin point?
Attachment to an immovable joint
What are the types of ordinary body movements?
Flexion
