Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
80 Cards in this Set
- Front
- Back
|
Characteristics of Muscles
|
1. contractile
2. stretchable 3. elastic- spring back to resting position 4. they are irritable and respond to stimuli |
|
|
Smooth Muscles
|
1. elongated, tapered ends with one nucleus
2. NO striations 3. found in walls of hollow organs (digestive tract, blood vessels, ureters) 4. INvoluntary 5.2 types-visceral and smooth |
|
|
Visceral Smooth
|
contract slowly and found in the stomach, uterus, intestines and bladder.
|
|
|
Multiunit Smooth
|
contracts fast and found in the eye, blood vessels, and arrector pilli
|
|
|
Cardiac Muscle
|
1. cylindrical, elongated, central nucleus
2. striated 3. INvoluntary 4. separated by intercalated discs 5. muscle cells branch freely |
|
|
Intercalated Discs
|
where adjacent muscle cells connect together allowing efficient communication between cells
|
|
|
Skeletal Muscle
|
1. elongated, cylindrical, multi nuclei on surface on the cells
2. voluntary 3. striated 4. connect to bone cause movement of body |
|
|
Origin
|
the end (attachment) of a muscle that connects to a bone that remains stationary during a contraction or when movement at joint occurs.
|
|
|
Insertion
|
the end of the muscle that attaches to the bone that will move during the contraction
|
|
|
body
|
the main part of the muscle between the origin and insertion
|
|
|
tendon
|
band of connective tissue connecting a muscle to a bone.
|
|
|
bursae
|
small synovial-lined sacs containing a small amount of synovial fluid; located between some tendons and underlying bones
|
|
|
Microscopic structure of skeletal muscle
|
contractile cells-muscle fibers grouped into bundles and intricately arranged
fibers contain thick and thin myofilaments |
|
|
Basic Function of Muscles
|
contractile- contractions require calcium and energy rich ATP molecules
|
|
|
fascia
|
a fibrous (connective tissue) membrane covering, supporting and separating muscles
|
|
|
epimysium
|
the membrane that is located on the surface of one individual muscle; connective tissue
|
|
|
perimysium
|
the (connective tissue) membrane that covers a bundle of muscle fibers called a fascicle
|
|
|
endomysium
|
connective tissue layer that surround EACH muscle fiber (muscle cell)
|
|
|
histology of skeletal muscle
|
consists of many muscle fibers that run parallel to each other
|
|
|
sarcolemma
|
cell membrane that surrounds each muscle fiber
|
|
|
sarcoplasm
|
found inside each fiber that is this liquid cytoplasm
|
|
|
sarcoplasmic reticulum
|
enclosed tubules within each muscle fiber; stores, releases, reabsorbs CALCIUM IONS
|
|
|
transverse tubule
|
enclosed tubules within each muscle fiber; carries an electrical stimulus from the surface of the muscle fiber deep until it reaches the sarcoplasmic reticulum
|
|
|
muscle fascicle
|
group of muscle fibers bundled together
|
|
|
myofibrils
|
bundles of myofilaments within each muscle fiber
|
|
|
myofilaments
|
groups of thick and thin filaments within each myofibril;
|
|
|
thin myofilaments
|
filaments in myofibril made mostly of protein-actin; rope like structures that originate at the Z lines and reach toward the M line and are used in muscle contraction
|
|
|
thick myofilaments
|
filaments in myofibril made mostly of protein-myosin; thicker structures originating at the M line reaching out toward the Z lines. used in muscle contraction
|
|
|
sarcomeres
|
compartments that are separated by Z lines; functional unit of the muscle and location where the work is done causing muscle contraction
|
|
|
H zone
|
location of only thick myofilaments
|
|
|
I band
|
location of only thin myofilaments
|
|
|
A band
|
where thick and thin filaments overlap and includes the H zone, the full length of the thick myofilaments
|
|
|
Actin Molecule
|
THIN MYOFILAMENT; small molecules that link together forming a double chain with each molecule containing an active bonding site where they myosin head will bind during the muscle contraction
|
|
|
Tropomyosin
|
THIN MYOFILAMENT; another rope like structure that runs along each actin chain. covers the active bonding site on the actin molecules preventing myosin from binding and preventing muscle contraction
|
|
|
troponin
|
THIN MYOFILAMENT; smaller molecule attached to tropomyosin and is responsible for moving the tropomyosin on and off the active binding site when a muscle should contract. this happens when calcium bones with troponin causing it to change shape. when calcium is released the troponin will return back to its original shape. its this change in shape that causes the movement of tropomyosin on and off the actin binding sites
|
|
|
tail
|
THICK MYOFILAMENT; connects the molecule to the M line
|
|
|
hinge
|
THICK MYOFILAMENT; allows the specific movement of the molecule
|
|
|
head
|
THICK MYOFILAMENT; part of the myosin that attached to the active site on the actin molecule
|
|
|
ACTIN AND MYOSIN INTERACTION
|
1. calcium bonds with troponin causing it to change shape and pulling the tropomyosin off the active binding site of the actin molecules
|
|
|
ACTIN AND MYOSIN INTERACTION
|
2. the myosin head is energized with an ATP molecule. the head attaches to the active binding site of actin and pulls toward M line
|
|
|
ACTIN AND MYOSIN INTERACTION
|
3. a new ATP molecule attaches to the myosin molecule and allowing it to attach to the actin molecule at a different location and pull again
|
|
|
ACTIN AND MYOSIN INTERACTION
|
4. this continues until the electrical message from the nervous system ends or the muscle runs out of ATP
|
|
|
sliding filament theory (contraction of a muscle)
|
1. during contraction, thin myofilaments slide inward past the thick myofilaments toward the H zone
2. tgus occurs when the cross bridges of the thick filament "beat" on the surface of the thin myofilaments and pull them inward. |
|
|
neuromuscular junction
|
the area of contact between a neuron and a muscle cell
|
|
|
motor neuron
|
a nerve cell that carries the electrical message to a muscle causeng the contraction
|
|
|
motor unit
|
the motor neuron and muscle it connects with; stimulation of a muscle by a nerve impulse is required before a muscle can contract
|
|
|
all or none principle
|
individual muscle fibers will contract to their fullest extent or not contract at all as long as a certain level of electrical stimulus is generated
|
|
|
threshold stimulus
|
the weakest stimulus from a neuron that can cause the contraction of a muscle fiber
|
|
|
agonist
|
a muscle responsible for a specific movement
|
|
|
antagonist
|
a muscle that relaxes and yields to the agonist
|
|
|
synergist
|
muscles that help fix joints in a position and reduce undesired motion
|
|
|
tonic contraction
|
contraction of only SOME muscle fibers in a muscle that does not cause movement but does produce pressure required to maintain posture
|
|
|
muscle fatigue
|
1. muscles require oxygen, ATP, and periodic rest in order to resist fatigue
|
|
|
muscle fatigue
|
without oxygen, ATP and rest, the muscle will produce lactic acid- a waste product- that builds up in the muscle causing the burning muscle sensation
|
|
|
oxygen debt
|
results in that n ow excess oxygen is required to burn off the lactic acid and return the muscle to homeostasis; labored breathing to 'pay off the debt'
|
|
|
tetanic contractions
|
sustained and steady muscular contractions caused by a series of stimuli bombarding a muscle in raid succession
|
|
|
isotonic contractions
|
type of contraction that does cause movement and a change in the length of muscle
|
|
|
concentric contraction
|
type fo isotonic contraction; the muscle shortens
|
|
|
ecentric contraction
|
type of isotonic contraction; the muscle length increases
|
|
|
isometric contraction
|
the muscle contracts under resistance causing tension but no change in muscle length and no movement
|
|
|
atrophy
|
a muscle gets smaller because of the lack of use
|
|
|
hypertrophy
|
a muscle gets large because of regular exercise
|
|
|
strength training
|
contraction of muscles against resistance which causes an increase in the number of myofilaments in each muscle fiber but does not increase the number of muscle fibers.
|
|
|
endurance training (aerobic)
|
increases the muscles ability to contract over long periods of time by increasing the flow of oxygen and nutrients to the muscle and an increased efficiency in the use of oxygen in the muscle
|
|
|
flexion
|
movement that decreases the angle between two bones at their joint; bending
|
|
|
extension
|
movement that increases the angle between two bones at their joint; straightening
|
|
|
abduction
|
movement of a part away from the midline of the body
|
|
|
adduction
|
movement of a part toward the midline of the body
|
|
|
rotation
|
movement around a longitudinal axis, shaking your head no
|
|
|
supination
|
palm up
|
|
|
pronation
|
palm down
|
|
|
dorsiflexion
|
foot upward
|
|
|
plantar flexion
|
foot downward (pushing a pedal)
|
|
|
myopathies
|
muscle disorder; can range from mild to life threatening
|
|
|
strain
|
injury from overexertion or trauma; involves stretching or tearing of muscle fibers
|
|
|
cramps
|
painful muscle spasms
|
|
|
crush injuries
|
result from severe muscle trauma and may release cell contents that ultimately cause kidney failure
|
|
|
duchenne muscular hystrophy
|
most common type and is characterized by rapid progression of muscle weakness and atrophy, resulting in death by 21
|
|
|
myanthenia gravis
|
autoimmune muscle disease characterized by weakness and chronic fatigue
|
|
|
neurotransmitter
|
end of the neuron that contains chemical message which are released into the synaptic cleft
|
