PSIO 305 Block 1 Quizzes and Clicker Questions
Apoptosis has few checks and balances, with primary apoptotic signals functioning in an "all or none" fashion. True or false?
False
Hepatocyte Growth Factor (HGF) has which of the following functions? -Promotes muscle cell differentiation -Liver cell proliferation -Activates satellite cells to undergo mitosis -Increases neurotransmitter release in motor neurons
HGF is responsible for liver cell proliferation and activates satellite cells to undergo mitosis
The Speeman organizer arises from the ______________ and is essential in the formation of ____________ -Ectoderm; skin sensory organs -Ectoderm; epidermal precursor cells -Mesoderm; neural precursor cells -Endoderm; synapses
Mesoderm; neural precursor cells Speeman organizer releases neural inducers to prevent binding of BMP which enables the transcription of genes required for neural cells
Dopamine release in the basal ganglia influences: -temperature regulation -thirst -movement planning and initiation -hunger
Movement and planning
The somatosensory cortex is part of which lobe(s) of the brain?
Parietal
An increase in ALL of the following would suggest trophic communication or support EXCEPT -# of dendrites & synaptic terminals -Size of primary sensory cortex area receiving input from finger -Rate of respiration with exercise -Density of glial cells in memory areas
Rate of respiration with exercise (
Differential effects of epinephrine and norepinepherine among cells types and across cell types is dependent on: -Receptor subtype expression -Nuclear receptors -Type of G-protein expressed -Capillary density
Receptor subtype expression & type of G-protein expressed
What phase of the cell cycle corresponds to DNA replication?
S
Which of the following is influenced by Nerve Growth Factor (NGF)? (check all that apply) -Synaptic efficacy -Growth and differentiation -Inhibition of apoptosis -Aggregation of acetylcholine receptors (AChRs) on the post-synaptic membrane in skeletal muscle.
Synaptic efficacy, growth and differentiation, and inhibition of apoptosis -NGF is necessary to enable growth and function of neurons -NGF is important in developing embryo and throughout adulthood for maintenance and repair of tissues
Nerve Growth Factor has specific targets for its impact. These include sympathetic and sensory neurons as well as the neurons in the frontal lobe and hippocampus. True or false?
True Effect is very specific for neuronal cell types
Myogenic regulatory factors are transcription factors that can activate a set of genes which specify cells to become muscle precursors and produce muscle specific proteins. True or false?
True Ex. MyoD
With necrosis, ATP ______________ while in apoptosis ATP ______________ -is depleted; is required -is required; is depleted -depletion leads to nuclear disassembly; depletion leads to activation of caspase cascade -enables release of enzymes; enables release of inflammatory cytokines
is depleted; is required In necrosis the cell membranes are ruptured or become permeable which results in a reduction in production/depletion of ATP
Referring to the Sargent's leg... Which of the following growth factors is/are most likely to be involved in the early stages of populating/filling the ECM scaffold with myoblasts? HGF FGF TGF VEGF 1 & 2 1,2 &3
1 and 2 -HGF would activate satellite cells to divide and increase number -FGF increases proliferation of satellite cells or myoblasts
There is a single specific myogenic regulatory factor regulating each stage of muscle development. True or false?
False
Neurotransmitters released into a synapse will bind to post synaptic receptors that could mediate their effects through: -catalytic receptors -nuclear receptors -GPCRs -ligand-gated ion channels
Ligand gated ion channels and GCPR's
What phase of the cell cycle corresponds to cell division or mitosis?
M
BMP/BMP Receptor interaction leads to SMAD1/SMAD4 complex migration into the nucleus, resulting in induction of transcription factors which up-regulate neural genes (resulting in neuronal cell development) and down-regulate epidermal genes (resulting in skin cell development). True or false?
False -Binding of BMP activates SMAD pathway which activates gene transcription for epidermal cells -Binding of BMP inhibits gene transcription of neural cells
If the neuromuscular junction is compromised by injury or denervation, the developmental process is reversed, leading to widespread distribution of acetylcholine receptors. This spread results from increased acetylcholine and agrin release. True or false?
False Agrin helps to bring ACh receptors together
Trophic support can inhibit the intrinsic pathway of apoptosis, thus promoting cell death. True or false?
False Apoptosis has an intrinsic and extrinsic method
Force production in muscle occurs at identical rates and velocities in all fiber and motor unit types. True or false?
False Force production depends on size of motor unit (number of fibers). Velocity of force depends on fiber type and to MHC isoform associated with each type.
The speed at which cross bridges form is largely dependent on Myosin ATPase activity which is largely homogeneous (i.e., the same) across muscle fiber types. True or false?
False - the rate is not the same across muscle fiber types
In cell culture, the observation that growth factors in conditioned medium could be depleted ("used up") by a second group of cultured cells suggested that growth factors were soluble substances produced and secreted by the specific cells used to "condition" the medium. True or false?
True
Mitosis is the time of the cell cycle where 2 daughter cells are created. True or false?
True
Myasthenia Gravis is an autoimmune disease in which antibodies attack acetylcholine receptors of the post-synaptic membrane of the neuromuscular junction. This results in the reduction in magnitude of the end plate potential, which could lead to an inability to initiate an action potential in the muscle fiber. True or false?
True
Proprioception is the awareness of the location of your body parts, provided by input from peripheral sensory receptors. True or false?
True
Quiescence and/or differentiation typically occur in the G0 phase of the cell cycle. True or false?
True
Removing the developing ectoderm intact and placing it in culture without other types of influence, it will form epidermal tissue. True or false?
True
Spatial summation refers to the fact that simultaneous stimuli arriving at different locations on the post-synaptic cell will increase ion flux, possibly bringing the post-synaptic cell closer to the threshold needed to generate an action potential. True or False?
True
Synapses are involved with converting electrical and chemical signals. True or False?
True
The balance of osteoblast and osteoclast activity is essential to maintaining proper bone mineral density. True or false?
True
The pattern and quantity of muscle activation impacts the fiber type of the muscle fibers innervated by that motor neuron. True or false?
True
The sliding filament theory refers to the shortening of sarcomeres to produce force, with the actin filaments being pulled and thus sliding past (or in between) the myosin filaments. True or false?
True
Extracellular fluid flow is essential to bone sensation of compression. True or false?
True Extracellular fluid will flow away from bone compression
A majority of growth factors typically bind to one type of receptors on the cell. This type of receptor is the: -Receptor tyrosine kinases or Trks -Ligand-gated ion channels -Guanalyl cyclase receptors -Transcription factors -GPCRs
Receptor tyrosine kinases or Trks
A naturally occurring myogenin gene defect has been discovered in mice. This defect is generally fatal due to which of the following? -Reduction in # of myoblasts -Excess # of fibroblasts -Reduction in # of myotubes and eventually muscle fibers -Excess production of myosin and actin
Reduction in # of myotubes and eventually muscle fibers Myogenin is a member of the MyoD family of transcription factors and is required for myoblasts to start producing muscle specific proteins and the fusion of myoblasts to form myotube
Compared to the 'classic' ionotropic synapse, the effects at a synapse mediated through GPCR (G-protein coupled receptors) are: -faster -result primarily from ion flux and voltage change -longer-lasting -slower
Slower & longer lasting
The organic component of bone is: Question options: -Known to form a lattice required for bone mineralization -Essential to providing tensile strength to bone -A calcium "bank" -Known to offer high compression strength -Deposited within the lattice -Primarily collagen
-Known to form a lattice required for bone mineralization -Essential to providing tensile strength to bone -Primarily collagen
The size of a motor unit (i.e., the # of muscle fibers innervated) can directly influence which of the following? -Ability to finely increase or decrease force produced during a movement -Ability to produce force for long duration -The arrangement of actin and myosin within the sarcomere -Speed (velocity) of a movement
-Ability to finely increase or decrease force produced during a movement Number of fibers (size of motor unit) affects the magnitude of force
Imagine a population of cells that have arisen from the ectoderm. If BMPs were applied to this population of cells, what events would occur? (check all that apply) -SMAD1 dephosphorylation -Epidermal and neural gene expression modulation -SMAD1/SMAD4 complex migration to the nucleus -BMP-R protein kinase activity -Neuronal differentiation -Epidermal differentiation
-BMP-R protein kinase activity - -SMAD1/SMAD4 complex migration to the nucleus -Epidermal and neural gene expression modulation -Epidermal differentiation BMP bind to SMAD which migrates to nucleus and activates transcription of epidermal cells
Calcium can serve as the chemical mediator for many different types of cell processes. Examples would include which of the following? -Can prevent onset of necrosis -Can activate different sets of genes depending on concentration or frequency of calcium bursts -Can modify availability of trophic factors -Can increase release of both ionotropic and metabotropic types of neurotransmitters
-Can activate different sets of genes depending on concentration or frequency of calcium bursts -Can modify availability of trophic factors -Can increase release of both ionotropic and metabotropic types of neurotransmitters
Imagine you are walking and encounter an unexpected change in ground elevation and you begin to stumble. In order to recover your balance, what components of the nervous systems would be most significantly involved? -Primary motor cortex and corticospinal tracts -Cerebrum and corticospinal tracts -Cerebellum and vestibulospinal tracts -Sensory cortex and somatosensory tracts
-Cerebellum and vestibulospinal tracts (involved in balance and coordination)
Which of the following structure:function pairs is correct for the central nervous system components involved in developing the movement plan ? -Cerebellum: balance and coordination -Association area of frontal lobe: involved in the initial formulation of movement plan. -Basal ganglia: enables proprioception -Primary Motor cortex: responsible for sending the movement plan to the relevant muscles
-Cerebellum: balance and coordination -Association area of frontal lobe: involved in the initial formulation of movement plan. -Primary Motor cortex: responsible for sending the movement plan to the relevant muscles The basal ganglia are responsible for initiating movement NOT proprioception
Degradation of which brain cells is thought to be the main cause of many of the motor defects seen in Parkinson's disease? -Acetylcholine producing neurons in the primary motor cortex -Dopamine producing neurons of the arbor vitae in the cerebellum -Dopamine producing neurons in the substantia nigra of the basal ganglia -Serotonin producing neurons of the substantia nigra in the basal ganglia
-Dopamine producing neurons in the substantia nigra of the basal ganglia This is responsible for movement and planning
The neural tube arises from the ________________ and is surrounded by ____________________ which are focused collections of the mesoderm which eventually form _______________ -Ectoderm; somites; myogenic precursor cells -Somites; ectoderm; myogenic precursor cells -Ectoderm; Speeman Organizer; Neural precursor cells -Mesoderm; desmin; ectoderm .
-Ectoderm; somites; myogenic precursor cells
If the acetylcholine receptors of the neuromuscular junction are blocked by curare, which of the following will occur? -Only segments of the pre-synaptic membrane will deteriorate -If curare inhibition is removed, the neuromuscular junction will completely deteriorate -If curare inhibition is removed the neuromuscular junction will eventually return to normal -The pre & post synaptic segments of the neuromuscular junction affected by this blockage will deteriorate
-If curare inhibition is removed the neuromuscular junction will eventually return to normal -The pre & post synaptic segments of the neuromuscular junction affected by this blockage will deteriorate
An increase in the cross sectional area of muscle is known as hypertrophy. Hypertrophy allows muscle to produce more force due primarily to: -Increased number of T-Tubules -Increased calcium release from the sarcoplasmic reticulum -Increased number of potential cross bridges that can be formed (i.e., actin-myosin interactions) -Increased ability to activate the muscle
-Increased number of potential cross bridges that can be formed (i.e., actin-myosin interactions) Number of fibers influence magnitude of force production
Which of the following are roles of glial cells? -Transmit action potentials to other glial cells -Insulative -Supportive -Help to maintain appropriate extracellular ion concentrations in the CNS -Regulate growth
-Insulative -Supportive -Help to maintain appropriate extracellular ion concentrations in the CNS -Regulate growth Glial cells do NOT transmit action potentials
Acetylcholine is typically associated with opening of ______________________ in the synapses of the motor cortex resulting in _______________. -Calcium channels; depolarization -Ligand-gated sodium channels: hyperpolarization -Calcium channels; hyperpolarization -Ligand-gated sodium channels; depolarization .
-Ligand-gated sodium channels; depolarization ACh is associated with muscle contraction so you need depolarization (Na+ channel opens first with active zones)
What events are essential to muscle fiber hypertrophy in an adult? (check all that apply) -Increased synthesis of actin and myosin contractile proteins -Donation of daughter cell nucleus resulting from satellite cell division -Progression of satellite cells through the S-phase of the cell cycle -Activation and division of myonuclei -Reduction of MyoD synthesis
-Progression of satellite cells through the S-phase of the cell cycle -Donation of daughter cell nucleus resulting from satellite cell division -Increased synthesis of actin and myosin contractile proteins
Which of the following might be considered examples of trophic interactions between cells and/or tissues? -Reduced frequency of neuronal action potentials results in reduction of muscle mass. -Consumption of high carbohydrate meal results in increased secretion of insulin. -Exposure to novel environments or mental stimulation leads to more dense receptive areas in the active neurons -Contractile force of muscle increases bone density in the areas of tendon attachments of muscle. -High intensity exercise results in increased heart rate.
-Reduced frequency of neuronal action potentials results in reduction of muscle mass. -Exposure to novel environments or mental stimulation leads to more dense receptive areas in the active neurons -Contractile force of muscle increases bone density in the areas of tendon attachments of muscle. Trophic factors promote cellular growth, differentiation, or survival
The wrinkle-reduction activity of Botox results from its ability to inhibit muscle contraction. Which of the following result from Botox application to the neuromuscular junction? -Reduction of vesicular fusion to the pre-synaptic membrane -Cleavage of SNARE proteins -Prevention of acetylcholine release from the pre-synaptic terminal -Prevention of vesicular fusion to the post-synaptic membrane -Degradation of acetylcholine receptors
-Reduction of vesicular fusion to the pre-synaptic membrane -Cleavage of SNARE proteins -Prevention of acetylcholine release from the pre-synaptic terminal
Which of the following can be affected by neural activity? -Type of ionotropic neurotransmitter released at the NMJ -Shape of the neuromuscular junction -Magnitude of Trophic support -Efficacy (effectiveness) of the neuromuscular junction
-Shape of the neuromuscular junction (Long term effect) -Magnitude of Trophic support (Long term effect -Efficacy (effectiveness) of the neuromuscular junction (Short term effect - increases ACh release & phosphorylates the exocytosis of proteins like synapsin of synaptotagmin)
An increase in the H-reflex with strength training is believed to represent an increase -The ability to create a motor program involving the motor centers of the brain -The excitability of the motor neurons innervating a target muscle -Ca++release from the sarcoplasmic reticulum allowing for greater force generation
-The excitability of the motor neurons innervating a target muscle At a given stimulus intensity, the magnitude of the H-reflex will indicate the excitability of the α-motor neurons
Imagine a "fast" muscle and a "slow" muscle and their associated nerves. If their nerves are exchanged, which of the following events could occur? -The slow muscle may begin to synthesize fast myosin isoforms. -Agrin release will increase and acetylcholine receptors will disperse -No change will occur -Motor neurons will begin to release dopamine -The fast muscle will begin to exhibit the slow force-production properties typical of slow muscle
-The slow muscle may begin to synthesize fast myosin isoforms. -The fast muscle will begin to exhibit the slow force-production properties typical of slow muscle
Temporal summation in Neuron A refers to the... -additive effect of simultaneous inputs from multiple neurons on to Neuron A -ability of sequential inputs from one neuron to increase ion flux and voltage change in Neuron A -increased likelihood of Neuron A reaching threshold and firing an action potential -process of coordinating the timing of a movement
-ability of sequential inputs from one neuron to increase ion flux and voltage change in Neuron A -increased likelihood of Neuron A reaching threshold and firing an action potential
Order the remodeling process of bone ____ Activation of pre-osteoclasts to osteoclasts ____ Invasion of osteoblasts ____ Resorption of bone ____ Osteoblast conversion to osteocytes ____ Deposition of new extracellular bone matrix
1. Activation of pre-osteoclasts to osteoclasts 2. Resportion of bone (Osteoclasts release hydrogen ion) 3. Invasion of osteoblasts (from surrounding bone lining layer) 4. Deposition of new extracellular bone matrix 5. Osteoblast conversion to osteocytes (Osteoblasts become trapped and reduce their mitotic activity)
Order the progression of synaptic transmission from beginning to end at the neuromuscular junction ____ Arrival of the action potential at the pre-synaptic terminal ____ Action potential propagation along the length of the muscle fiber ____ Membrane depolarization and activation of voltage-gated calcium channels ____ Local membrane depolarization, leading to opening of voltage-gated sodium channels adjacent to the end plate. ____ Acetylcholine release into the synaptic cleft ____ Acetylcholine receptor activation and opening of non-selective cation channels ____ Vesicle fusion with the pre-synaptic membrane
1. Arrival of action potential at the pre-synaptic terminal 2. Membrane depolarization and activation of voltage gated calcium channels 3. Vesicle fusion with pre-synaptic membrane 4. ACh released into synaptic cleft 5. ACh receptor activation and opening of non-selective cation channels 6. Local membrane depolarization leading to opening of voltage gated sodium channels adjacent to end plate (active zones) 7. AP propagation along muscle fiber
Order the steps that myogenic precursor cells go through to becoming muscle cells during development. ____Mature ____Fuse ____Proliferate ____Differentiate ____Migrate
1. Migrate 2. Proliferate 3. Differentiate 4. Fuse 5. Mature
Order the general scheme of muscle development from beginning to end ____Myogenic precursor cells ____Myoblasts ____Muscle fiber ____Myotubes
1. Myogenic precursor cells 2. Myoblasts 3. Myotubes 4. Muscle fibers
What is the enzyme responsible for terminating the action of the neurotransmitter in the synaptic cleft of the neuromuscular junction? -Monoamine Oxidase -Caspase -Myosin ATPase -Glutamatase -Acetylcholinesterase
Acetylcholinesterase Acetylcholine Esterase cleaves Ach into acetyl and choline components which are taken back into motor neuron for re-synthesis and reuse
Initially ___________________ receptors are widespread in the developing muscle fiber. The approaching axon terminal releases ______________ and __________________ causing aggregation of these receptors at the newly forming neuromuscular junction. -Acetylcholine; acetylcholine; HGF -Dopamine; GABA; Agrin -Acetylcholine; dopamine; NGF -Acetylcholine; acetylcholine; agrin
Acetylcholine; acetylcholine; agrin
Realizing that this process varies at different synapses and ranges in effectiveness, synaptic transmission can be terminated in which of the following way(s)? -Endocytosis of ligand-receptor complexes by the post-synaptic cell -Neurotransmitter reuptake into the presynaptic terminal -Enzymatic degradation of the neurotransmitter -Diffusion of the neurotransmitter away from the synapse
All of them Diffusion of NT away from synapse is very slow and not exact
Which of the following are properties or structures of the sarcomere? -Actin as thin filaments -Contractile repeating unit -Myosin as thick filaments -Bounded by Z disc or line
All of them are properties of the sarcomere
Skeletal muscle fiber type variation in cat medial gastrocnemius muscle is based on which of the following parameters: Metabolic Preferences Fatigability Fiber Diameter Speed (velocity) of force production
All of them influence muscle fiber type
While studying the feasibility of donating a portion of liver for transplant, a large segment of liver was removed from a rat. Phenobarbital was given post-op to stimulate regrowth & the liver grew to 1.5 X original size & functioned normally. When the drug was stopped, the liver shrank to close to its original pre-surgery size, still functioning normally. This subsequent reduction in size is due to which type of cell death?
Apoptosis -Cells are still functioning normally
Botox has become popular for reducing wrinkles. It is a dilute solution of a toxin which inhibits muscle contraction by working at the presynaptic portion of the NMJ. Which of the following could be a possible mechanism for Botox wrinkle-reducing action? Decrease synthesis of nSec1 Cleave (degrade) syntaxin Increase sensitivity of synaptotagmin to Ca Increase Calcium influx
Cleave (degrade) syntaxin The SNARE proteins are required to pull vesicles towards the pre-synaptic membrane for release of Neurotransmitter. If any one of them (syntaxin, SNAP 25 or Synaptobrevin) are missing or non-functional, the vesicles will not be moved to the membrane, thus no release of their ACh contents & no contraction
When calcium binds to calmodulin it induces a ______________________ which allows it to bind proteins to __________________ activity of enzymes and transport proteins. -Conformational change; alter -Phosphorylation; increase -Conformational change; inhibit -Calcium release; increase
Conformational change; alter
Which of the following could lead to a decrease in volume of neural tissue in the developing animal? -Decrease BMP release -Increase Noggin release -Decrease Cerebrus release -Decrease chocolate intake
Decrease Cerebrus release Cerebrus is a neural inducer that is released by the Speeman organizer to activate transcription of neural genes
Necrosis is typically known as "orderly" cell death. True or false?
False
The __________________ pathway of apoptosis is typically associated with ___________________ interaction subsequently activating caspases, while the __________________ pathway is associated with ____________ and subsequent caspase activation. -Extrinsic; Apaf-1 and IAP; intrinsic; fas (protein) receptor- inactive procaspase; -Extrinsic; fas (protein) receptor- fas ligand; intrinsic; cytochrome c and Apaf-1 -Extrinsic; cytochrome c and Apaf-1; intrinsic; fas (protein) receptor-fas ligand -Intrinsic; Apaf-1 and cytokines; extrinsic; loss of ATP
Extrinsic; fas (protein) receptor- fas ligand Intrinsic; cytochrome c and Apaf-1
Calmodulin is only found in a few specific, unique cell types. True or false?
False
Results of this experiment suggests that pyramidal tract output codes for A.Displacement B.Force C.Velocity D.None of the above
Force Absence of neuronal activity with an extensor load indicates that the neuronal output is encoding for force rather than direction or displacement. The neuron increased its activity when greater force was required for the same movement
What phase of the cell cycle corresponds to resting phase/quiescence?
G0
What phase of the cell cycle corresponds to cell growth and checkpoint control gap to ensure that DNA is ready for synthesis?
G1
What phase of the cell cycle corresponds to the checkpoint control gap to ensure that cells are ready to divide?
G2
Trophic interactions between cells and tissues can promote all of the following EXCEPT: -increased heart rate -increased cell proliferation -cell survival -increased cellular differentiation
Increased heart rate
Ligand binding to a Receptor Tyrosine Kinase can lead to which of the following? -Activation or suppression of gene transcription -Activation of MAPK3 to regulate downstream effects -Activation of the ras/Raf-1 pathway -Bring the membrane potential closer to threshold, making it more likely for an action potential to be generated -Increase or decrease ongoing cellular synthetic activities
Ligand binding leads to activation of RAF-1 and MAPK This pathway can phosphorylate many cellular proteins but can also affect trancription factors in the nucleus
Fibroblast Growth Factor (FGF) is essential for muscle development and growth. It actively promotes which of the following? -Myogenic cell proliferation -Inhibition of satellite cell proliferation -Satellite cell differentiation -Activation of Myogenin
Myogenic cell proliferation FGF is associated with proliferation
All of the following are true of the Myosin molecule EXCEPT:? -Power stroke occurs as head swivels, pulling actin filament towards center of sarcomere -attachment and detachment (i.e., cross-bridge formation) rates vary with myosin isoform (i.e., myosin heavy chain isoform) -binds to the Z line -contains an actin-binding site
Myosin does not bind to the Z line, titin binds myosin to the Z line
In the process of neural determination, ________________ such as ____________ are released to enable activation of ____________ -Transcription factors; SMAD1/SMAD4 complex; epidermal specfic genes -Neural inducers; NGF & HGF; neural specifc genes -Neural Inducing factors; cerebrus & noggin; neural specific genes -BMPs; follistatin & chordin; neural specific genes
Neural Inducing factors; cerebrus & noggin; neural specific genes
In sensory perception, is action potential frequency inversely proportional to stimulus intensity?
No AP frequency is PROPORTIONAL to stimulus intensity
_____________ are typically associated with ______________ while ______________ are typically involved with ______________ -Osteocytes; bone resorption; osteoclasts; bone formation -Osteoblasts; bone formation; osteoclasts; bone resorption -Osteoblasts; bone resorption; osteocytes; bone mainteance -Melanoblasts : bone formation; melanoclasts: bone resorption.
Osteoblasts; bone formation; osteoclasts; bone resorption Osteocytes-maintenance of bone
Retrograde signaling or transmission can have a variety of actions that impact the 'pre-synaptic' neuron. These actions could include which of the following? -Impact synaptic efficacy -Promote cell survival -Inhibit or reduce the amount of neurotransmitter released -Enhance synthesis of the neurotransmitter normally released by that neuron.
Retrograde signaling can impact all of them
Single neurons typically receive thousands of synaptic inputs which are resolved by what type of summation? -Spatial -Temporal -Spatial & temporal -Nodes of Ranvier -Temporal process
Spatial & temporal
All of the following structure: function pairs is correct for the neuron EXCEPT? -Post-synaptic ligand-gated channels: ion flux and post-synaptic local voltage changes -Synapse: typically enables an electrical signal to be transmitted directly to a subsequent neuron -Axon: conducts action potentials to other cells Dendrite and soma: receptive area for incoming signals
Synapse because it does NOT allows electrical signal to be transmitted directly to subsequent neuron. Synapse in responsible for converting the electrical signal to a chemical signal
The effect of Neuron A on Neuron B is determined by all of the following EXCEPT? -Type of Neurotransmitter released by Neuron A -Number of inputs coming in rapid sequence from Neuron A -Type of post-synaptic receptors on Neuron B -Length of Neuron A's axon
The length of the axon has no influence on the effect between neurons
A homunculus represents the somatotopic organization of the primary sensory cortex and shows the relative sensitivity of each area of the body. True or False?
True
A motor unit is the smallest voluntary functional unit of force production and consists of one motor neuron and all the muscle fibers that it innervates. True or False?
True
Calcium is essential for the fusion step of vesicle release of neurotransmitters at the pre-synaptic membrane of the neuromuscular junction. True or false?
True
Early in the development of a muscle fiber, there is typically more than one motor neuron innervating a single muscle fiber until one neuron "wins out". This motor neuron then goes on to innervate a number of muscle fibers to establish a motor unit. True or false?
True
Given what you now know about Myasthenia Gravis, patients with this disease would most often complain of which of the following symptoms? Tetanic (continued) contractions Excessive appetite Decreased sensory perception Weakness & fatigue
Weakness & fatigue -Antibodies against ACh receptors result in reduced #'s of AChR's at the NMJ, reducing the potential for ACh to bind to and activate its receptor. -Reduced binding results in smaller local depolarization (i.e. smaller EPP) -AP is not general for each neural signal -Muscle contraction does not occur as intended, resulting in weaker than desired forces (weakness) -requiring repeated neural signals to active muscle (fatigue)
