Exam 1: Nervous/Muscle/Endocrine Flashcards by Insha Chhabra

Which of the following is kept at a homeostatic level in the body?
a. water
b. sodium
c. blood pressure
d. blood glucose
e. all of the above

all of the above

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True or false:
Action potentials can sun (you can add them together)

false

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potassium flows ___ the cell through leak channels, ___ its gradient

out of, down (with)

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the sodium potassium pump
a. uses ATP to power its activity
b. pumps sodium and potassium down their gradients
c. pumps 3 K’s out for every 2 Na’s in
d. more than one of the choices are correct
e. all are correcr

a. uses ATP to power its activity

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when sodium enter the cell during an action potential, it is
a. going through ligand gated channels
b. moving against its gradient
c. repolarizing the cell’s potential
d. going through voltage gated channels
e. more than one is correct

d. going through voltage-gated channels

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this ion is high in concentration outside cells and has very few leak channels present on nerve cell membranes

sodium

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the resting membrane potential of a typical neuron is

-70 mV

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insulin released following a meal to decrease blood sugar. this is an example of

negative feedback

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which of the following ends a positive feedback loop?

when the initial stimulus ends

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potassium is high in which fluid compartment(s)?

intracellular only

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of these scenarios, given normal K+ concentrations inside the cell, which solution would result in a highest K+ driving force?
a. extracellular k+: 0.5 mM
b. extracellular k+: 5 mM
c. extracellular k+: 50 mM

solution A

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opioids target the synapse by

inhibiting the modulatory interneuron

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metabotropic receptors
a. result in a decrease in transcriptional activity
b. are always excitatory
c. are not channels
d. activate cAMP

c. are not channels

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benzodiazepines help anxiety by

acting as a GABA agonist and promoting more post synaptic hyper polarization

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which of the following is true regarding the post synaptic cell in a chemical synapse?
a. its receptors can be metabotropic or ionotropic
b. binding of a nuerotransmitter will elicit an excitatory response in the presynaptic cell
c. binding of a neurotransmitter will reult in an excitatory response in the post synaptic cell
d. it is responsible for degrading excess nuerotransmitter

a. its receptors can be metabotropic or ionotropic

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why is it that changes in K affect resting potential while changes in Na don’t?

because there are way more K leak channels compared to Na

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in chemical synaptic transmission, the opening of what type of channel results in ion influx and eventual vesicle fusion with the presynaptic terminal membrane?

voltage gated calcium channels

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if a post-synaptic ionotropic receptor is permeable to potassium and assuming all normal ionic distributions, the response in the post synaptic cell will be

inhibitory

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increasing extracellular sodium will (in relation to AP spike height)

increase action potential spike height

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if you block calcium channels on an axon, which will not occur?

exocytosis of neurotransmitter

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The reason that Na leak channels do not significantly contribute to resting membrane potential is

because they are in far fewer concentrations compares to leak K channels

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a neurotransmitter binds to a metabotropic receptor on a neuron, which elicits an intracellular signaling cascade that opens a channel permeable to chloride. you do not know the distribution of chlorine in and outside of this cell. what can you conclude

if chloride is highly concentrated inside, this neurotransmitter will produce an excitatory response

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what could you say about the neurotransmitter released by the modulatory interneuron onto the presynaptic neuron in the synapse targeted by opiods?

its binding exerts an inhibitory response in the presynaptic neuron

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a ligand binds to a channel and opens it, resulting in the efflux of potassium out of a post-synaptic cell. the receptor and post synaptic response are

ionotropic and inhibitory

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the resting potential of a neuron that is submerged in a solution with zero extracellular potassium will ___ because ___

hyperpolarize; the driving force for potassium to exit the cell increases

during a typical action potential in a nerve, which of the following is happening? a. voltage gates K+ channels are allowing for influx of K+ b. Na/K pumps are pumping Na+ in and K+ out c. leak K+ current, with K+ exiting the nerve d. voltage gated Na+ channels are allowing for efflux of Na+ e. all of the above

c. leak K+ current, with K+ exiting the nerve

which is most directly responsible for the falling (repolarizing) phase of the action potential

the permeability to K+ increases while the permeability to Na+ decreases

the mechanism of action of opioids involves silencing the __ and results in more __

modulatory interneuron; post synaptic excitation

sodium levels in and out of cell

intraceullar - 15 (low) extracellular - 145 (high)

potassium levels in and out of cell

intracellular - 150 (high) extracellular - 5 (low)

calcium levels in and out of cell

intracellular - 7 (low) extracellular- 100 (high)

sodium flows (into/out) of cell - passively

into

potassium flows (into/out of) cell - passively

out of cell

calcium flows (into/out of) cell - passively

into

na+ VG channels

many, open at threshold, close at the peak of the action potential

Na+ leak channel

very few, always open, no effect on resting membrane potential

Na/K pump

many, always working, active (uses ATP)

K+ VG channel

many, open at peak of the action potential

K+ leak channels

many, always open, changes RMP

is sodium flux in the post-synpatic cell excitatory or inhibitory?

excitatory

is potassium flux in the post-synaptic cell excitatory or inhibitory?

inhibitory

sodium effect on RMP

no effect

sodium and AP spike height

driving force (concentration) changes height

potassium and AP spike height

no effect on spike height

Na/K pump flow

3 Na+ out, 2 K+ in

sodium's role in AP

depolarizes

potassium's role in AP

repolarizes

which ion is found in high concentrations inside normal nerve cells?

suppose a cell is no longer just permeable to potassium but is now more permeable to sodium. what would happen to RMP?

it would depolarize (get more positive)

which of the following is true regarding rods in the dark? a. guanylyl cyclase in inactive b. transducin is active c. non selective cation channels are closed d. cGMP levels are high inside rods and cones

d. cGMP levels are high inside rods and cones

in the light.. a. transducin is inactive b. the resting membrane potential is hyperpolarized compared to the dark c. cGMP levels in the rod/cone are high d. rod/cone action potentials are less frequent than in the dark

the resting membrane potential is hyperpolarized compared to the dark

which of the following would you not find in the synaptic cleft between an alpha motor neuron and a muscle cell? a. sodium b. acetylcholine c. troponin d. calcium

c. troponin

ATP binds to.. a. actin b. troponin c. myosin d. DHP receptor

myosin

endolymph, the extracellular fluid surrounding the hair cells, has high concentrations of which ion?

K+

these taste sensations employ ionotropic receptors

sour and salty

troponin interacts with

actin and tropomyosin

which of the following is/are true regarding nicotonic receptors? a. they permit the flow of Na+ b. they are a type of metabotropic receptor c. one ACh needs to bind in order to open them on the muscle and plate d. two of these options are correct e. all of these options are correct

a. they permit the flow of Na+

hair cells are analagous to which cell type in the retina of the eye?

rods and cones

these two channels types are present in the signal transduction cascade for hearing

mechanically gates K+ channels and voltage gated Ca2+ channels

Lo can be described as

the length at which a muscle produces maximum force or tension

T or F: relaxation of a muscle is a passive process (does not require ATP)

False Calcium ATPase pump uses ATP to pump Ca back into the SR against its gradient

T or F: all other things being equal, if the concentration of calcium increases, the force will increase also in a linear fashion

false

why does an unfused tetanus appear like a squiggly up and down line?

periods of relaxation follow each stimulation before another stimulation comes

passive tension a. is due entirely to the protein titin b. is a combination of titin force and actin myosin force c. happens when the muscle is slacked below Lo d. more than one of the choices are correct

a. is due entirely to the protein titin

acetylcholinesterase a. is blocked by organophosphates b. works with calcium to permit vesicle fusion and neurotransmitter release c. degrades acetylcholine in the postsynaptic cell d. activity results in an inhibitory response on the post synaptic cell

a. is blocked by organophosphates

the DHP receptor a. is a calcium channel b. is bound to troponin c. is a charge sensitive protein d. is found on the sarcoplasmic reticulum membrane

c. is a charge sensitive protein

the rate limiting step of the cross bridge cycle

is hydrolysis of ATP

Rafael went on a strength training program that allowed him to build more muscle. the increased amount of muscle he built will a. increase both the force and velocity at which he can contract his muscles b. increase the peak force he can produce c. increase the velocity at which he can contract his muscles

b. increase the peak force he can produce

T or F: the calcium that permits neurotransmitter release from the alpha motor neuron is recycled and used as calcium that becomes available for the muscle contraction

false

where does the calcium for skeletal muscle contraction come from?

Ca2+ storage organelle, SR

where does the calcium for skeletal muscle excitation come from?

extracellular environment

which of the following would cause constant contraction and not allow for relaxation? a. poison that degrades ACh b. something that renders AChE ineffective c. Ca2+ ATPase pumps not being able to pump Ca2+ back into the SR d. ATP remaining bound to myosin e. B and C

e. B and C

in the dark... a. the photoreceptor cell is hyperpolarized b. the photoreceptor cell is firing action potentials c. transducin is active d. cGMP gated channels are closed e. cGMP is high

e. cGMP is high

You are studying a frog gastrocnemius. You set the muscle up with a force transducer (measures force) at Lo. Your lab partner messes with something while you are in the bathroom and you come back to find that the muscle is producing 10g of force without any stimulation. What is happening? a. your lab mate sprinkled calcium on the muscle b. you lab mate stimulated ATP hydrolysis by placing the muscle in a solution of glucose c. you lab mate slacked the muscle and it is now producing passive tension d. your lab mate stretched the muscle and it is producing passive tension

d. your lab mate is stretched the muscle and it is producing passive tension

which of the following correctly describes the end plate potential (EPP)? a. it is a local potential in the alpha motor neuron that allows the muscle cell to depolarize b. it is both a local potential in the end plate area of the muscle cell that allows the muscle cell to depolarize and it is primarily mediated by Na+ influx c. it is both a local potential in the alpha motor neuron that allows a cell to depolarize and it is primarily mediated by Na+ influx d. it is a local potential in the end plate area of the muscle cell that allows the muscle cell to depolarize e. it is primarily mediated by Na+ infux

b. it is both a local potential in the end plate area of the muscle cell that allows the muscle cell to depolarize and it is primarily mediated by Na+ influx

the popular drug viagra treats erectile dysfunction in males. viagra is a cGMP phosphodiesterase (PDE) inhibitor. while it specifically targets the isoform of cGMP PDE that is present in the male reproductive organs, if taken in high doses, it can affect vision. which type of vision would viagra be more likely to affect?

light/color vision

in the cross-bridge cycle, when ATP is present

actin and myosin dissociate from one another

in the transduction of sound, potassium plays an important role. how is it involved?

it flows from the endolymph into the hair cell, depolarizing it

the Ca2+ ATPase pumps on the sarcoplasmic reticulum membrane play an important role in muscle contraction. In patients with muscular dystrophy, there is some evidence that shows the expression of the Ca2+ ATPase pumps is diminished (there are fewer). Which of the following cellular effects may be a result of the diminished number of Ca2+ ATPase pumps?

reduced Ca2+ uptake into the SR

the protein titin is present on the sarcomere and is responsible for passive tension. titin produces the most force a. when the muscle cell is maximally slacked, or shortened b. when the muscle cell is cycling as fast as it can c. when the muscle cell is stretched as far as it can go without breaking d. when the muscle cell is producing the most active force e. none of these, titin doesn't produce force

c. when the muscle cell is stretched as far as it can go without breaking

what would happen if tropomyosin couldn't change confirmation in the presence of Ca2+ binding to troponin

myosin couldn't bind to actin

how does increased K+ outside (hyperkalemia) affect driving force, RMP, AP spike height, and AP duration?

driving force change: decreases RMP: increased, depolarizes spike height: n/a AP duration: increases

how does decreased K+ outside (hypokalemia) affect driving force, RMP, AP spike height, and AP duration?

driving force change: increases RMP: decreases, hyperpolarized spike height: n/a duration: decreases

how does increased K+ inside affect driving force, RMP, AP spike height, and AP duration?

driving force change: increases RMP: decreases, hyper polarized spike height: n/a duration: decreases

how does decreased K+ inside affect driving force, RMP, AP spike height, and AP duration?

driving force change: decreases RMP: increases, hyper polarized spike height: n/a duration: increases

how does increased Na+ outside (hypernatremia) affect driving force, RMP, AP spike height, and AP duration?

driving force change: increases RMP: n/a spike height: increases duration: n/a

how does increased Na+ inside affect driving force, RMP, AP spike height, and AP duration?

driving force change: decreases RMP: n/a spike height: decreases duration: n/a

how does decreased Na+ outside (hyponatremia) affect driving force, RMP, AP spike height, and AP duration?

driving force change: decreases RMP: n/a spike height: decreases duration: n/a

how does decreased Na+ inside affect driving force, RMP, AP spike height, and AP duration?

driving force change: increases RMP: n/a spike height: increases duration: n/a

More or less excitable? Cell is in a situation like hyperkalemia

more excitable

More or less excitable? Cell has more K+ leak channels than normal

less excitable

More or less excitable? Threshold to fire an action potential is -60 mV instead of -55 mV

more excitable

More or less excitable? Opioids are present - the presynaptic cell is

more excitable

Excitatory/inhibitory/not enough info Neurotransmitter binds to an ionotropic receptor and permits sodium flux

excitatory

Excitatory/inhibitory/not enough info Neurotransmitter binds to a metabotropic receptor, starts and second messenger cascade that closes a calcium channel

inhibitory

Excitatory/inhibitory/not enough info Neurotransmitter binds to a ionotropic receptor and permits chloride flux. chloride in this synapse is higher outside the cell compared to inside

inhibitory

Excitatory/inhibitory/not enough info neurotransmitter binds and an unknown ion flows into the post-synaptic cell

not enough info

Excitatory/inhibitory/not enough info neurotransmitter binds to a metabotropic receptor, starts a second messenger cascade that closes a potassium channel (which is normally open)

excitatory

a mutation in the guanylyl cyclase enzyme renders it non-functional. what would be disrupted?

dark vision

light or dark pathway? active rhodopsin

light retinal subunit receives light, opsin activates transducin

light or dark pathway? active cGMP phosphodiesterase

light

light or dark pathway? open non-selective cation channels

dark Na+, Ca2+ influx

light or dark pathway? depolarized RMP (-35 mV)

dark

light or dark pathway? no ganglion cell stimulation in the on-center pathway

dark

light or dark pathway? off-center pathway firing action potentials, ganglion cell stimulation

dark

light or dark pathway? on-center pathway firing action potentials, ganglion cell stimuation

light

light or dark pathway? no ganglion cell stimulation in off-center pathway

light

VG channel kinetics of Na+

fast

VG channel kinetics of K+

slow

role of Na+ in neuromuscular junction

depolarizes alpha motor neuron endplate potential in muscle cell AP in muscle cell

role of K+ in neuromuscular junction

repolarizes alpha motor neuron and muscle cell

role of Ca2+ in neuromuscular junction

promotes vesicle fusion in alpha motor neuron and ACh release

role of Na+ in sensory processing

influx in dark rods, salty taste

role of K+ in sensory processing

mechanically gated entry in hair cells

role of Ca2+ in sensory processing

influx in dark rods, influx in hair cells (nt release)

T/F on center bipolar cells employ ionotropic receptors

false (metabotropic receptors)

T/F in the light, off center bipolar cells release less glutamate onto the ganglion cell

true

T/F ionotropic receptors only produce excitatory responses

false

T/F in sensory transduction of taste, both sour and salty employ ionotropic receptors

true

T/F in sensory transduction of sound, voltage gated K+ channels play a role in depolarizing the hair cells

false, mechanically gated

T/F rods and cones fire action potentials

false

which of the following is an example of post-synaptic inhibitory response mediated by an ionotropic receptor? a. anti-anxiety meds acting as GABA agonists b. ACh binding to a nicotinic receptor at the neuromuscular junction c. a SSRI modulating serotonin levels in the brain d. salty chips being sensed by the tastebuds e. the effect of an opioid on a dopaminergic presynaptic cell

a. anti-anxiety meds acting as GABA agonists

the mechanism of action opioids involves silencing the __ and results in more post-synaptic ___

modulatory interneuron, excitation

the prolonged electrical depolarization of cardiac muscle cells that occurs during contraction is primarily due to the persistent influx of what?

calcium

high intensity fatigue involves a. buildup of H+ which accelerates the activity of the myosin ATPase b. impaired action potential firing from the alpha motor neuron c. Pi precipitating Ca2+, making it unavailable for troponin d. two choices are correct e. all choices are correct

c. Pi precipitating Ca2+, making it unavailable for troponin

which of the proteins involved in the contraction of smooth muscle is incorrectly paired with its function? a. myosin - changes shape upon phosphorylation b. myosin light chain phosphatase - removes the phosphate from actin c. calmodulin - binds calcium d. myosin light chain kinase - adds a phosphate to myosin e. actin - binds to myosin to generate force

b. myosin light chain phosphatase - removes the phosphate from actin removes phosphate from myosin

which of these is a major difference between smooth and skeletal muscle? a. myosin is the main protein that is regulated in skeletal muscle b. only skeletal muscle requires increased calcium ion concentration in the cytosol for contraction c. skeletal muscle usually exhibits spontaneous activity while smooth muscle cannot contract spontaneously d. only skeletal muscle has both actin and myosin e. myosin is the main protein that is regulated in smooth muscle

e. myosin is the main protein that is regulated in smooth muscle

the L-type calcium channel opens by

initial sodium influx during cardiomyocyte depolarization

If you could look at the cellular environment in and around a muscle at the end of an ironman (hours-long endurance race), what might you observe a. calcium in abnormally high concentrations in the extracellular environment b. more type II fibers being synthesized c. muscle damage due to activation of proteases d. all of these

c. muscle damage due to activation of proteases

a slow-twitch muscle fiber a. will cycle through the cross bridge cycle faster than a fast twitch muscle fiber b. will have more mitochondria than a fast twitch muscle fiber c. will fatigue faster than a fast twitch fiber d. all of the answers are correct

b. will have more mitochondria than a fast twitch muscle fiber

which of the following statements is false? a. smooth muscle cells usually have one nucleus b. contractile activity of smooth muscle cells does not normally require Ca2+ c. Ca2+ that activates contraction of smooth muscles can come from either the ECF or from the SR d. synaptic input onto skeletal muscle cells is always excitatory, whereas inputs to smooth muscle cells may be excitatory or inhibitory e. in the absence of any neural input, skeletal muscle cannot generate active tension

b. contractile activity of smooth muscle cells does not normally require Ca2+

An alpha motor neuron innervating type IIx fibers has about 30 muscle fibers in an individual motor unit. How many fibers would you predict there to be in a type I motor unit? a. 1 b. 15 c. 30 d. 40

b. 15

which type of muscle fiber is always recruited first?

Type I

is a DHP receptor a channel?

where is the DHP receptor located?

muscle cell membrane

what activates a DHP receptor?

voltage change from AP on muscle membrane

how does a mutation in the DHP receptor affect EC coupling?

no muscle contraction

is a ryanodine receptor a channel?

yes

where is RyR located?

sarcoplasmic reticulum (SR) membrane

what activates RyR?

DHR receptor

best predictor of force? a. myosin ATPase activity b. # of actin myosin cross bridges c. amount of Ca2+

b. # of actin myosin cross bridges

best predictor of velocity? a. myosin ATPase activity b. # of actin myosin cross bridges c. amount of Ca2+

a. myosin ATPase activity

blood is a part of which fluid compartment? a. intracellular fluid b. interstitial fluid c. plasma

c. plasma

T/F: interstitial fluid and plasma are both considered extracellular fluid and thus have similar ionic components

True

intracellular fluid

within cells (cytoplasm)

extracellular fluid

outside cells (interstitial fluid + plasma/blood)

if the amount of sodium in the blood decreases, what would a negative feedback control be expected to do? a. increase the amount of sodium in the blood b. decrease the amount of sodium in the blood c. leave the amount of sodium unchanged d. change the set point for sodium e. inhibit the ingestion of more sodium

a. increase the amount of sodium in the blood

negative feedback

increase or decrease in variable --> response moves the variable in opposite direction ex. blood sugar meal, blood sugar increases --> pancreas receives signal about increase in sugar, beta cells of pancreas release more insulin --> insulin tells fat + muscle cells to store sugar (out of blood, into cells) --> decrease in blood sugar

positive feedback

accelerated process, explosive system that ends when stimulus is gone ex. labor & delivery baby's head pushes on mom's cervix, stimulates release of oxytocin from posterior pituitary --> oxytocin binds to receptors on smooth muscle cells of uterine walls, uterus contracts --> baby's head pushes more enhancement of original stimulus

feedforward system

body anticipates changes

which of the following is an example of homeostasis? a. you take a hot shower and your body temp increases b. you go swimming in a cold lake and your body temp decreases c. you overheat for a week and you gain weight d. you run a marathon and you get thirsty e. none of the above

d. you run a marathon and you get thirsty you have an event (the marathon, which dehydrates you) and then you have the body's attempt to return to homeostasis by activating thirst mechanisms

T/F: extracellular fluid, including intracellular and interstitial fluid, is high in potassium

false

nerve cells are most permeable to a. sodium b. calcium c. potassium d. chloride e. potassium and chloride equally

c. potassium

a neuron at rest has a resting potential of -70 mV. you put this neuron in a solution where the concentration of potassium in the extracellular environment is much higher. What happens to the RMP?

gets more positive (depolarized)

hormones a. activity depends on the amount secreted compared to the amount secreted b. travel freely in the blood for long periods of time c. only act in the brain d. all can cross cell membranes

a. activity depends on the amount secreted compared to the amount secreted

T/F: Thyroid hormones increases basal metabolic rate by promoting insulin release

false

which of the following statements is not true of the endocrine system? a. it is composed of glands that secrete chemical messengers into the blood b. most of its components are anatomically connected, like most other systems of the body c. it is one of two major regulatory systems of the body d. it influences and is influenced by the nervous system e. it is an important regulator of homeostatic mechanisms

b. most of its components are anatomically connected, like most other systems of the body

which of the following is not an anterior pituitary hormone? a. vasopressin b. LH c. ACTH d. growth hormone e. FSH

a. vasopressin

which of the following statements about oxytocin is true? a. oxytocin is synthesized by the hypothalamus b. oxytocin keeps uterine smooth muscle from contracting, so it prolongs pregnancy c. oxytocin is secreted by the anterior pituitary d. oxytocin's main function is to increase the rate of respiration e. target cells of oxytocin have receptors for the hormone in their nucleus

a. oxytocin is synthesized by the hypothalamus

lab work showing consistently higher levels than normal of TSH would indicate

the individual may have hypothyroidism

you have discovered a novel steroid hormone. you'd like to isolate its receptor as a part of your next project. where should you look first? a. on the cell surface b. in the cytoplasm c. in the blood stream d. within a membrane protein e. any of these might be places where the receptor could be found

b. in the cytoplasm

thyroid hormone is able to negatively feedback and inhibit the release of __, a hormone that is synthesized and secreted by __

TSH, anterior pituitary gland

hypothyroidism a. is caused by an autoimmune disorder b. is caused by a lack of iodine in the diet c. produces symptoms of fatigue and cold intolerance d. all of the above

d. all of the above

what is true regarding the posterior pituitary? a. it synthesizes its own hormones b. it makes up 2/3 of the pituitary gland c. it secretes TSH d. none of these

d. none of these

a type IIx motor unit is isolated and has 30 fibers. what else can you conclude in that same muscle? a. a type I motor unit would have 40 fibers b. the type IIx motor unit would make as much force as 10 type I fibers c. a type IIx fiber would have a similar velocity as the type IIx motor unit d. the type IIx motor unit would be recruited before a type IIa motor unit

c. a type IIx fiber would have a similar velocity as the type IIx motor unit because velocity is not additive

if you were able to control fatigue in the muscle cell experimentally such that you only exposed the muscle to high levels of Pi and no other metabolites, what would you observe?

a decline in force without much change in velocity

a patient comes to the clinic with the main complaint of fatigue accompanied with moderate weight gain and always feeling cold. After running the appropriate labs, you would find TSH to be ___ and diagnose this patient with ____

higher than normal, hypothyroidism

which of the following is true regarding thyroid hormone? a. an anterior pituitary hormone stimulates the release of thyroid hormone b. excessive release of TH results in excessive release of epinephrine and norepinephrine c. thyroid hormone is released by the parathyroid d. thyroid hormone solely targets muscle cells e. excessive release of TH is easily targeted by synthetic thyroxine

a. an anterior pituitary hormone stimulates the release of thyroid hormone

slightly high levels of thyroid hormone would result in feedback that would ___ plasma concentration levels of TSH

decrease

which of the following does not correctly describe cardiac muscle cells? a. they can contract in the absence of external calcium b. they are arranged in layers surrounding hollow cavities in the heart c. they are much shorter than skeletal muscle fibers and generally have a single nucleus d. they depolarize prior to contraction e. their membranes are depolarized initially by the influx of sodium ions

a. they can contract in the absence of external calcium

Last weekend you went on a challenging 4-hour hike and got some great photos for your Instagram. You noticed that the day after the hike, your quads were really, really sore! What was likely the cause of this soreness?

muscle damage as a result of the action of calcium-activated proteases

the posterior pituitary gland has a __ connection to the hypothalamus

neural

Suppose you are studying a muscle fiber and experimentally raise the concentration of H+ to mimic fatigue-like levels. You can measure anything you want about this muscle fiber. What would you expect to see under the fatigue conditions described here?

depressed peak velocity, as shown by a smaller y intercept on the force-velocity curve

an anterior pituitary hormone like LH a. is stimulated by a hypothalamic hormone b. requires a binding protein to travel in the blood c. is a peptide hormone d. two of these are true e. three of these are true

d. two of these are true is stimulated by a hypothalamic hormone and is a peptide hormone

the primary signal for insulin release is

elevated blood glucose concentrations

you are designing an experiment to quantify the levels of stress experienced by different individuals. which of the following would reveal insight as to a patient's chronic stress a. testing plasma levels of cortisol b. testing plasma levels of growth hormone c. testing plasma levels of follicle stimulating hormone d. testing plasma levels of dopamine e. testing plasma levels of parathyroid hormone

a. testing plasma levels of cortisol

which hormone discussed in this unit it the 'love' hormone?

oxytocin

this hormone does not need a receptor on the cell membrane of its target cell a. oxytocin b. insulin c. TSH d. testosterone e. none of these

d. testosterone

growth hormone effects include a. protein synthesis b. fat breakdown c. increased gluconeogenesis d. increased IGF-1 secretion e. all of these

e. all of these

the negative effects of a pregnant mother being diabetic include

large body size in fetus

untreated diabetes results in increased levels of what? a. glucagon b. glycogenolysis & gluconeogenesis c. GLUT4 transport to muscle cell membranes d. fatty acid synthesis

b. glycogenolysis & gluconeogenesis

thyroid hormone has permissive effects on norepinephrine and epinephrine. this means...

TH up-regulates the expression of receptors for epi and norepi, potentiating their effects

the disease that is chracterized by high levels of cortisol is

cushing's syndrome

which hormone is incorrectly paired with where it's released from in the adrenal gland?

a. norepi - adrenal medulla b. cortisol - adrenal cortex c. aldosterone - adrenal cortex d. ACTH - adrenal cortex e. epinephrine - adrenal medulla

which of the following is a posterior pituitary hormone? a. growth hormone b. dopamine c. norepi d. cortisol e. vasopressin

e. vasopressin

a hormone is isolated and requires a binding protein to travel in the blood. this hormone is a

steroid

T/F: Extracellular calcium is required for EC coupling and contraction in skeletal muscle

false - comes from SR

what initiates contraction in skeletal, smooth, cardiac muscles?

skeletal - alpha motor neuron smooth - lots of things - hormones, nerves, Ca cardiac - SA node depolarizes cardiomyocytes

source of calcium for muscle contraction skeletal, smooth, cardiac

skeletal - SR smooth - EC and/or SR cardiac - EC and SR

fiber types for skeletal, smooth, cardiac

skeletal - type I, IIa, IIx smooth - slower than type 1 cardiac - like type 1 but different

how does H+ affect fatigue

no change in force, lowers velocity by decreasing myosin ATPase activity, decreases calcium sensitivity - rightward shift of force/Ca curve

how does Pi affect fatigue

decrease in force, no change in velocity, decrease in calcium sensitivity - right ward shift

myosin light chain phosphatase a. is more active when calcium decreases in the muscle cell cytosol b. requires the activation of calmodulin c. phosphorylates myosin light chain d. results in calcium-induced calcium release e. is required in cardiac, but not smooth muscle contraction

a. is more active when calcium decreases in the muscle cell cytosol

during a complete cardiomyocyte contraction, which ion fluxes would you observe in the cardiomyocyte that aid in contractile/relaxation process?

Na+ influx, K+ efflux, Ca influx

amines

derivatives of tyrosine, receptors on plasma membrane of target cells, travels freely in blood, hydrophilic ex. epi, norepi, dopamine, TH (exception to some of these rules, intracellular receptor + binding protein required)

peptides

string of amino acids, wide range of sizes, receptors on plasma membrane of target cells, travel freely through blood, hydrophilic ex. insulin, glucagon, all pituitary PTH, calcitonin

steroids

derived from cholesterol, hydrophobic, intracellular receptors (can cross cell membrane), requires binding protein to travel in blood ex. testosterone, estrogen, aldosterone, cortisol

posterior pituitary

1/3 of pituitary, connected to hypothalamus by nerves, hormones synthesized in hypothalamus

anterior pituitary

2/3 of pituitary, connected to hypothalamus by portal system (blood vessels), hormones synthesized and stored by anterior pituitary

if calcium were distributed across cell membranes such that there was an equal amount of calcium in and outside of cells, which processes would no longer happen a. skeletal muscle contraction b. skeletal muscle excitation c. smooth muscle contraction d. chemical synaptic transmission e. action potentials f. light vision

b and d: skeletal muscle excitation and chemical synaptic transmission

T/F: An action potential is not required to initiate smooth muscle contraction

True

gluconeogenesis

synthesis of glucose

growth hormone

stimulated by GHRH, inhibited by somatostatin, bone growth (increase in cell division in epiphysical plate), liver --> IGF-1 promotes cells division (increase in cyclins) increased gluconeogenesis in liver (increase in blood sugar), breakdown of fats, synthesis of proteins, esp in muscle (increase aa uptake into muscles)