Io 223 Eaxm 3 Other Flashcards
What could change dramatically the potential across the plasma membrane?
action potential
what would increase the
permeability of sodium ions?
diffusion, k+ concentration and Na+ concentration
What would happen if you had increased potassium concentration
outside the plasma membrane?
depolarization
If the resting
membrane potential becomes more negative, what has happened?
hyper polarization
What causes depolarization?
Na channels opening and Na+ entering the cell
What results if
acetylcholine binds to a membrane bound receptor?
Hyperpolarization, depolarization, etc?
it opens the ligand gated Na+ channels, resulting in depolarization
What would happen if you have lack of acetylcholinesteras e in synaptic cleft?
the acetylcholine could not be broken down, resulting in the muscle not being able to relax
If you use a drug that blocks acetylcholine receptors, what would that result in?
no contractions
If someone has tetanic muscle contractions (tetanus), what happened on the post-synaptic region? Is it more acetylcholine caused the
contractions?
yes, excessive release of acetylcholine
What is the T-tubule?
invagination of the sar colemma
What is the
passageway for calcium from the sarcolemma?
terminal cisternae
What is the role of calcium in muscle contraction?
calcium binds to troponin
Which fibers slide on which fiber during muscle contraction?
myosin on actin
What should happen to the active sites in order for muscle relaxation to occur?
myosin heads need to release from actin active sites
If you use a drug that interferes with the active transport of calcium ions from
the sarcoplasm back into the sarcoplasmic reticulum, what would this result in?
contraction with no relaxation
What is an ATP molecule required for?
to release myosin heads from actin active site, to pump calcium back into SR
Where does calcium go after muscle contraction
has occurred?
back into the SR
What would happen if sodium ions could not enter a muscle fiber in response to a stimulus?
there would be no contraction
What happens during the contraction phase of a muscle twitch?
cross bridge cycles generate tension
What is the latent phase of a muscle twitch?
the time it takes the action potential to propagate across the sarcolemma
What happens during the relaxation phase of a muscle twitch?
calcium ions are reduced in the cytosol by SR pump and tension diminishes
When do cross-bridges form?
when the myosin head attaches to the actin active site
What chases tetanus?
action potentials being sent down a motor neuron with such high frequency that there is no relaxation
Depolarize
inside is not completely negative, not in resting membrane potential
Repolarize
return of the membrane potential to its resting state after the nerve impulse
Hyperpolarize
make the membrane more negative
What is troponin and what is its binding site for?
Holds tropomyosin, turns contractions on and off
what is troponin’s binding site for?
Calcium
I-band
thin filaments only
M-line
middle of sarcomere
h-zone
thick filaments only
A-band
has both thick and thin filaments
z-disc
separates sarcomeres
What do we find in the pre-synaptic terminal?
vesicles with ACh
What do we find in the post-synaptic terminal?
ligand-gated Na+ channel
What results from the electric signals that are called action potentials?
muscle contration
What is
contractility?
ability to shorten forcibly when stimulated
what is excitability?
ability to respond to a stimulus
what is elasticity?
ability to recoil to resting length
what is
extensibility?
ability to be stretched without rupture
What is the similarity between cardiac and smooth muscle?
they are both involuntary
what is fascia?
the fibrous tissue enclosing a muscle
what is an
endomysium?
tissue that surrounds individual muscle fibers
what is perimysium?
connective tissue that surrounds fascicles.
what is epimysium?
surrounds entire muscle
What happens during the resting membrane potential?
there will be equal positive (outside) and negative charges (inside) on the cell membrane.
What are ligand gated channels?
channels that respond to chemical messengers/ i ligands
What are voltage gated channels?
channels that open and close in response to changest i in membrane potential of plasma membrane
When we have depolarization of a cell membrane, which ion has rapid influx?
Na+
What are non-gated channels?
channels that are always open, leak channels
What do synaptic vesicles contain?
acetylcholine
What happens when an action potential reaches the pre-synaptic terminal?
acetylcholine is released into the synaptic cleft
What would happen if you had too much acetylcholinesteras e?
no contraction
What would happen if you used a drug that blocked acetylcholine receptors at the motor-end plate?
the ligand-gated channels wouldn’t open, there would be no contraction
What is Treppe?
when a muscle receives successive stimuli, the strength of the contraction increases slightly with each stimulus
What is complete tetanus?
no relaxation between contractions
What is incomplete tetanus?
muscle fibers partially relax between contraction
What is muscle tone?
constant tension by muscles for long periods of time
When a muscle performs concentric contractions, what happens to the tension it produces as it shortens?
it remains constant
What is
psychological fatigue?
decreased capacity to work and reduced efficiency of performance due to the emotional state of an individual
What is rigor mortis?
stiffness after death, cross bridges form but can’t release
What is lactic acid a byproduct of?
anaerobic glycolysis
What does oxygen debt represent?
Trying to replenish the cells that have used up their oxygen after exercise.
What is the affect of anaerobic activity?
increased oxidative enzymes, increased number of mitochondria, increased number of blood vessels
What would anaerobic activity do to your muscular strength?
increase it
do slow twitch fibers rely on aerobic or anaerobic respiration?
aerobic respiration
do fast twitch fibers rely on aerobic or anaerobic respiration?
anaerobic respiration
What affects does aerobic exercise have on slow-twitch fibers?
long distance, increases endurance and cardiovascular fitness
What affects does aerobic exercise have on fast-twitch fibers?
sprinting, ideal for quick contraction
What is muscle atrophy?
loss of muscle size and strength
What are cramps?
painful, involuntary twitches
What is muscular dystrophy?
a group of genetic diseases that cause progressive weakness and loss of muscle mass
What is the origin of a muscle?
anchoring point on a bone, where skeletal muscle “originates from”; typically not involved directly with movement of joint
What is the insertion of a muscle?
moving end of muscle whose tendon attaches to a bone or other structures, usually on far side of joint
what is agonist?
provide most force for a given muscle action
What is synergist?
aid agonists by supplying supplemental force, minimizing unwanted movement, and by helping to stabilize joints, all of which provide for more efficient movement
what is an antagonist?
usually on opposite side of bones and joint where they meet, have opposite action of agonist; allows for modulation and control of agonist movement
what is a fixator
provide stabilizing force that anchors a bone; provides movement efficiency and protection from injury due to unnecessary movements
What do we call muscles that have their fasciculi
arranged like barbs of a feather along a common tendon?
pennate
What kind of muscles act as a sphincter?
circular fascicle
The muscle extensor digitorum longus is named on what basis?
size, location and action
What is the muscle trapezius named for? Shape?
Length? Function?
Shape
When you say
quadracep femoris, what is the name based on?
four-headed muscle and location
If you hyperextend your head, which class lever system does it represent?
first class lever
If you flex your elbow, which class lever system does it represent?
third class lever
If you contract your left
sternocleidomastoid, what would happen to your head?
it would rotate right
Raising your eyebrows is the action of which muscle?
Frontalis
Puckering your lips?
orbicularis oris
which muscle is used for chewing gum?
Masseter
If you have hypertrophied mentalis muscle, what would you have?
Dimpled chin
What is the major movement of a muscle that is used during breathing?
diaphragm
What are the muscles of the rotator cuff?
supraspinatus, infraspinatus, teres minor, subscapularis
Function of the rotator cuff?
stabilize shoulder joint
What type of
contractions would your abdominal muscles do against your vertebral column (vomiting, childbirth, defecation, etc.)?
isometric contractions
Someone injures their shoulder hitting a ball high up, which muscle of the rotator cuff would be damaged?
supraspinatus
What muscle raises your arm to your shoulder level?
deltoid
Which muscle group in your forearm are flexors?
flexor carpi
Which muscle group in your forearm are extensors?
extensor carpi ulnaris
What muscle flexes the wrist?
flexor carpus radialis, flexor carpus ulnaris, and palmaris longus
Extensor policis radialis, what does this muscle move?
extends the thumb
you’re a sprinter and you hold your stance, which one of your muscles is contracted?
Gluteus minimus or maximus?
gluteus maximus
What is the largest buttock muscle?
gluteus maximus
What is the site for gluteal injection?
gluteus medius
If you give an injection on the interior aspect of your thigh, what muscle are you injecting?
rectus femoris
What muscle constitute the quadracep femoris?
rectus femoris, vastus lateralis, vastus medialis, vastus intermedialis
Biceps femoris make up which muscle group?
hamstrings
Which muscles
close the bulging of the calf?
gastrocnemius and soleus
What muscle is inserted on the calcaneus by the Achilles tendon?
gastrocnemius
What is the function of the tensor fascia
flexion latae?
hip joint flexion, abduction, medial rotation: assists in flexion of the thigh
absolute refractory period
the minimum length of time after an action potential during which another action potential cannot begin.
Refractory period
the time where the muscle does not respond to stimulus.
relative refractory period
a period after firing when a neuron is returning to its normal polarized state and will fire again only if the incoming message is much stronger than usual
Types of muscles
Smooth, cardiac, skeletal
What is triad?
Two terminal cisternae and a t tubule
