A&P 3 Flashcards
Neurotransmitters stay in the synapse for only a very short time, leading to a transient response
in the post-synaptic cell
O
True
EPSPs are most commonly stimulated by the opening of a
O
non-specific cation channel
Most metabotropic neurotransmitter receptors are
O
G protein-coupled receptors
Opening a chloride channel in a cell that does not regulate chloride will
O
cause a resting neuron to stay at the same membrane potential
dampen an EPSP
dampen an IPSP
Define convergence in relation to the nervous system.
O
multiple neurons synapse onto a smaller number neurons
Define divergence in relation to the nervous system.
O
small number neurons synapse onto a larger number neurons
Define saltatory conduction
O
action potentials jump from node to node of Ranvier down length of axon
Describe spatial summation in the nervous system
when you set more than one postsynaptic potential from multiple synapses happening at the same time in a postsynaptic neuron so that the effects of all synapses add together to influence the membrane potential
Describe temporal summation in the nervous system
when you get one presynaptic neuron firing and releasing neurotransmitters more than once in a short period of time, so the effects on the membrane potential in post-synaptic cell from all the bouts of NT release adds together
Describe two ways of decreasing calcium entry in a presynaptic terminal to decrease
neurotransmitter release
O
axo-axonic synapse- activation of receptores on terminal by NT
autoreceptors- activated on presynaptic terminals by NT released by that neuron
These both lead to hyperpolarization of terminal
Then when the action potential reaches the terminal, it won’t depolarize as much leading to fewer voltage-gated Ca2+ channels opening thus less Ca2+ entering the cell and less NT release.
What are the four ways that neurotransmitter concentrations decrease in the synapse soon
after release?
O
reuptake into presynaptic cells terminals or uptake by glial cells (astrocytes)
diffusion out of synapse
enzymatic degradation in the synapse
receptor-mediated endocytosis in postsynaptic cell
What are the two general types of synapses and which is most common?
O
chemical: excitatory and inhibitory (common)
electrical
What are two ways of increasing the rate of propagation of an action potential? Which of these
is most effective?
O
myelination of the axon (effective)
increase axon diameter
What does EPSP stand for in neuroscience?
O
excitatory post-synaptic potential
What does IPSP stand for in neuroscience?
O
inhibitory post-synaptic potential
Draw a flow chart for the steps of neurotransmitter release starting with the action potential
reaching the axon terminal.
O
action potential reaches axon terminal
conf change in voltage-gated Ca2+ channel (VGCC)
VGCC opens
Ca2+ enters cytosol
Ca2+ binds to synaptotagmin
conf change in synaptotagmin
synaptotagmin binds to SNARE proteins
SNARE proteins pull vesicle into contact w/ the plasma membrane
vesicle membrane and plasma membrane fuse
exocytosis of NT
The thicker the axon diameter
O
the slower potassium leaks out of the cell during an action potential
Opening a chloride channel in a cell that does not regulate chloride would
O
dampen the depolarizing effect of opening a sodium channel
The highest concentration of voltage-gated sodium channels is in the plasma membrane of
O
the nodes of Ranvier of mylinated neurons
Action potentials during the relative refractory period
have a lower amplitude than action potentials fired from the resting membrane potential
What protein does calcium bind to in the presynaptic terminal that leads to exocytosis of neurotransmitter?
synaptotagmin
EPSPs and IPSPs are graded potentials.
O
True
Receptor number in the post-synaptic density is variable.
True
Internodal regions of a myelinated neuron are
less leaky for potassium
The absolute refractory period is primarily due to the
voltage-gated sodium channel
The relative refractory period is primarily due to the
voltage-gated potassium channel
Which type of synapses have more influence on whether or not a post-synaptic cell fires an action potential?
axosomatic
Opening of a non-specific cation channel in a resting cell causes
more sodium to enter the cell than potassium to leave the cell
Neurons carrying pain information to the central nervous system (nociceptor neurons) have a
thin axon and are unmyelinated
Decreasing potassium permeability will cause the cell to
depolarize
A solution containing 200 mM permeable solute and 300 mM non-permeable solute would be
hyperosmotic
A solution containing 200 mM permeable solute and 300 mM non-permeable solute would be
isotonic
In the sympathetic nervous system, the _______________ neuron is longer.
O
post-ganglionic
Catecholamines
are taken back up by the presynaptic cell
Serotonin is
taken back up by the presynaptic cell
The largest class of neurotransmitters (the class that has the most different types) is
the neuropeptides
The metabotropic GABA receptor links with
O
Gi proteins
Which branch of the nervous system has pre-ganglionic neuronal cell bodies in the brainsteam
and sacral spinal cord?
O
the parasympathetic nervous system
Which branch of the nervous system has pre-ganglionic neuronal cell bodies in the thoracic and
lumbar spinal cord?
O
the sympathetic nervous system
The primary neurotransmitter(s) of the central nervous system
are the amino acids
According to lecture, long-term potentiation, which is important in learning and memory, often
involves
NMDA receptors
Which of the following are effects of endogenous opiods?
induce feeling of well-being and euphoria
slow down digestion
reduce awareness of painful stimuli
slow heart rate
The enteric nervous system controls which organ system?
O
digestive system
The parasympathetic nervous system primarily controls which organ system?
O
digestive system
The sympathetic nervous system primarily controls which organ system?
O
cardiovascular system
What type of ion channel is the AMPA?
non-specific cation channel
What type of ion channel is the glycine receptor?
choride channel
What kind of ion channel is the ionotropic GABA receptor?
choride channel
AMPA is a receptor for which neurotransmitter?
glutamate
The most common drugs used to treat depression, such as Prozac (fluoxetine), act through
which neurotransmitter?
serotonin
What is the primary inhibitory neurotransmitter in the brain?
GABA
What is the primary excitatory neurotransmitter in the central nervous system?
glutamate
What is the primary inhibitory neurotransmitter in the spinal cord?
glycine
What amino acid is the precursor for serotonin?
trypotophan
What is name of the enzyme in the synapse that breaks down acetylcholine?
acetylcholinesterase
What is the abbreviation for acetylcholine?
ACh
What is the abbreviation for serotonin that is used in the name for the serotonergic receptors?
5-HT
What type of receptor is the nicotinic receptor? Be specific.
ionotropic
non-specific cation channel
Dopamine is mainly involved in which two pathways/circuits in the brain?
reward and movement/motor
What are the two general types of cholinergic receptors?
nicotinic
muscarinic
What are the three divisions of the autonomic nervous system?
O
sympathetic
enteric
parasympathetic
What are the three types of endogenous opiods?
beta-endorphins
dynorphins
enkephalins
The term somatic refers to what four structures in the body?
skin, muscles, bones, joints
Which cranial nerves contain autonomic pre-ganglionic neuronal axons?
oculomotor III
facial VII
glossopharyngeal IX
vagus X
List the five adrenergic receptors and state what type of receptor each is.
O
alpha 1 - Gq protein-coupled receptor
alpha 2 - Gi protein-coupled receptor
beta 1-3 - Gs protein-coupled receptor
List the five muscarinic receptors and state what type of receptor each is.
O
M1,3,5 - Gq protein-coupled receptor
M2,4 - Gi protein-coupled receptor
Draw a flow chart for the production of the three catecholamines including all the intermediates
and the rate-limiting enzyme.
tyrosine —(tyrosine hydroxylase)–> L-Dopa –> dopamine –> norepinephrine –> epinephrine
Draw a flow chart for the mechanisms of long term potentiation at glutamatergic synapses.
high frequency of action potentials in presynaptic cell
high amount of glutamate released
glutamate binds to AMPA and NMDA receptors
enough AMPA receptors open and stay open long enough to depolarize the membrane by 20-30mV
depolarization drives Mg2+ ions out of the pore in the NMDA receptor
Ca2+ entry through the NMDA receptor activates second messenger systems in the postsynaptic cell
SPLITS INTO 2 PATHS
SPLITS ONE PATH: post-synaptic cell increases receptor expression and sensitivity of glutamate receptors
SPLITS 2ND PATH: post-synaptic cell release retrograde messenger
presynaptic cell increases glutamate synthesis and release synthesis
Most of the serotonin is the body is found in
the digestive tract
Muscarinic receptors are
metabotropic receptors
The autonomic nervous system uses ____________ neurons to get from the central nervous system to the target organ.
O
2
The NMDA receptor is
a calcium channel
Monoamine oxidase is involved in the degradation of
norepinephrine
epinephrine
A single neuron often releases more than one type of catecholamine
False
A single neuron only releases one type of neurotransmitter.
False
Adrenergic refers to both epinephrine and norepinephrine.
True
All efferent neurons from the central nervous system release acetylcholine that then binds to nicotinic receptors.
True
Neuropeptides are usually not released until the presynaptic neuron fires several action potentials in quick succession.
True
Substance P enhances painful stimuli.
True
Endogenous opiods are
inhibitory
In the parasympathetic nervous system, the _______________ neuron is longer.
O
preganglionic
Autonomic post-ganglionic neurons have ________________ on their cell body and dendrites.
O
nicotinic receptors
Endogenous opiods are released in
axoaxonic synapses
The ganglia for the parasympathetic nervous system are
O
Near or in the wall of the target organ
The ganglia for the sympathetic nervous system are
O
Near the spinal cord
Convergence leads to _______________________ acuity.
Lower
Smaller receptive fields lead to ________________________ acuity.
Greater
The more overlap in receptive fields, the ________________________ acuity.
Greater
The receptor for sensation may be
Either a neuron or a receptor cell
Craniosacral refers to the
O
Parasympathetic nervous system
Thoracolumbar refers to the
O
Sympathetic nervous system
Which branch of the nervous system is called the rest and digest system?
O
Parasympathetic nervous system
Which branch of the nervous system is activated by stressful stimuli?
O
Sympathetic nervous system
The information for each sensory receptor follows a specific pathway and activates a specific
neuron in the cerebral cortex. This is important for the coding of
Location
Target organs for the parasympathetic nervous system have
O
Muscarinic receptors
Target organs for the sympathetic nervous system have
O
Adrenergic receptors
What receptor do you find on adrenal medullary cells?
Nicotinic receptors
Converting a stimulus into a signal that the central nervous system can understand is called
coding
If a constant stimulus is applied, over time the frequency of action potentials decreases. This
decrease in action potential frequency is known as
adaptation
We are not consciously aware of a stimulus until a cell in the _______(area of the brain) is activated.
cerebral cortex
Activation of the sympathetic nervous system prepares the body for what?
O
physical activity
What two hormones are released by the adrenal medulla, and which is released in larger
amounts?
epinephrine 80%
norepinephrine 20%
List the two primary receptors found on target organs for the parasympathetic nervous system
and the effect of each.
O
M2 - decrease heart rate, smooth muscle relaxation, decrease secretions
M3 - smooth muscle contraction, stimulate secretions
List the adrenergic receptors and the effect of each.
O
alpha 1 - smooth muscle contraction
alpha 2 - autoinhibitory-> decrease release of epi and norepi
beta 1 - increase heart rate and force of contraction
beta 2 - smooth muscle relaxation
beta 3 - lipolysis, glycogenolysis, thermogenesis
What are the three components of a sensory system?
receptor
neural pathway
parts of the CNS that process the sensory information
Describe adequate stimulus in relation to sensory systems and state why it is important.
type of stimulus (modality) that normally activates a receptor
how we code modality
Describe how a higher stimulus strength can lead to a higher frequency of action potentials.
the stronger the stimulus, the earlier in the relative refractory period an action potential will fire. The sooner the neuron fires, the more action potentials you can have in a second
What does modality refer to in sensation? Give an example of two different modalities.
type of stimulus
senses: touch, taste, smell, temp
Greater sensory neuron density leads to ____________________ sensory acuity.
greater
Intensity in the sensory system is coded by
action potential frequency
Which adrenergic receptor causes smooth muscle contraction?
O
alpha 1
Most post-ganglionic sympathetic neurons release
O
norepinephrine
The primary hormone released by the adrenal medulla is
epinephrine
β2 adrenergic receptors can be found outside of synapses
O
True
Some places in the brain do not have a blood-brain-barrier.
True
Only first order neurons have a receptive field
False
Both the sympathetic and parasympathetic nervous systems always have some level of activity.
O
True
The blood-brain-barrier controls the entry of ___________________ into the brain.
water-soluble substances
Pre-ganglionic neurons _______________________ post-ganglionic neurons in the autonomic nervous system.
O
stimulate
The blood-brain-barrier is found
In the blood vessels throughout the brain
Which diencephalic region helps control the autonomic nervous system?
O
hypothalamus
Which adrenergic receptor has a low affinity for norepinephrine?
O
β2
Which branch of the nervous system tends to have finer control over individual organ systems?
O
parasympathetic nervous system
Nociceptors from visceral organs and somatic organs can synapse onto the same second order
neuron.
True
Mechanoreceptor pathways travel in the
Dorsal column of the spinal cord
Nociceptor and thermoreceptor pathways travel in the
Anterolateral column of the spinal cord
The anterior compartment is filled with
Aqueous humor
The dilator pupillae muscle is controlled by
The sympathetic nervous system or circulating epinephrine
The sphincter pupillae muscle is controlled by
The parasympathetic nervous system
In lateral inhibition for touch, interneurons between first order neurons would release
GABA
A left-side hemisection of the spinal cord (the left half of the spinal cord is cut) in the neck would
lead to the loss of
Pain sensation on the right side of the body and touch sensation on the left side of the
body
State if each of the following somatic sensations are rapidly adapting or slowly adapting.
a. Light touch
b. Movement across the skin
c. Pressure
d. Vibration
rapid
rapid
slow
rapid
A reduction in the perception of pain is known as
analgesia
Capsaicin can activate ___________________ receptors.
heat
Changes in __________________________________________ open and close ion channels in
thermoreceptors.
membrane fluidity
Enhanced perception of pain is known as
hyperalgesia
Menthol can activate _____________________ receptors.
cold
Pain is detected by ________________________________________ afferents.
nociceptor
The sensation of our posture, where our limbs are in space, and the angle of our joints is called
proprioception
Where are the tarsal glands located?
in eyelids
What nerve innervates the lacrimal gland?
facial nerve CN VII
What do tarsal glands produce?
modified sebum
What does the lacrimal gland produce?
tears
What is the main purpose of the cornea?
refract light
What is the purpose of the pigmented retina?
absorb light that passes through the photoreceptor layer of the retina to give us a sharper image
Assuming a sensory pathway has only three neurons in series, where would you find the cell
body for the third order neuron, and where would that neuron project to?
found in the thalamus
projects to the cerebral cortex
The afferent end of some sensory neurons are wrapped in a connective tissue
capsule/corpuscle. How do these capsules/corpuscles work?
a certain type of tension in the capsule will cause the CT in the capsule to pull open nonspecific cation channels in the neuron leading to depolarization and increased firing in the afferent neuron
How does drinking ethanol make people feel warm?
ethanol inserts into the plasma membrane of cells, making them more fluid, which leads to the opening of nonspecific cation channels on heat thermoreceptors which causes them to fire more action potentials
List the stimuli that can activate nociceptive afferents.
excessive heat or cold
intense mechanical deformation
chemicals: bradykinin, prostaglandin, histamine, cytokines, neuropeptides
What are the three purposes of tears that were mentioned in the videos?
kill pathogens
wash away debris
prevent dehydration
List the three layer of the eye and what can be found in each layer.
fibrous: cornea, sclera
vascular: iris, ciliary body, choroid
nervous: retina
What are the two main purposes of the choroid?
absorb excess light to give us a clear image
nourish retina
Which receptor for acetylcholine is in the iris, on which muscle of the iris do you find this
receptor, and what is the effect of activation of this receptor on the diameter of the pupil?
M3 muscarinic - sphincter pupillae
pupil constriction (smaller)
Which receptor for catecholamines is in the iris, on which muscle of the iris do you find this
receptor, and what is the effect of activation of this receptor on the diameter of the pupil?
alpha 1 adrengeric - dillator pupillae
pupil dilation (larger)
Lateral inhibition __________________ sensory acuity.
increases
The duration of a stimulus can be coded by
slow-adapting neurons
Endogenous opiods are primarily released in
Descending sensory pathways
Sensory pathways that do not code for modality would be useless to the brain.
False
In somatic sensation pathways, ______________ order neurons cross to the contralateral side of the spinal cord or brain.
second
The somatosensory cortex is in the _________________ lobe.
parietal
The lacrimal gland is controlled by the
parasympatetic nervous system
Tears drain into the nose.
True
The conjunctiva is usually
clear
The anterior compartment of the eye between the
lens and the cornea
Lateral inhibition assists in
determining location
Some sensory pathways do not carry information about modality.
True
Skin receptors for pressure are
slow-adapting
Ethanol
increases membrane fluidity
Hyaluronic acid is found in
vitreous humor
There are no photoreceptors in the
optic disc
Humans can only detect a very small portion of the electromagnetic spectrum.
True
Wavelengths of light that are ___________ by an object can be detected by our photoreceptors when we look at the object.
reflected
The most refraction of light occurs when light passes through the
cornea
The image that focuses on our retina is upside-down and backwards.
True
Contraction of the ciliary muscles in the eye causes the suspensory ligaments to
pull less on the lens
The ciliary muscle of the eye is primarily innervated by which branch of the nervous system?
parasympathetic
The stress response leads to enhanced
far-vision
Which cells in the retina would light hit first?
20sec
the ganglion cells
The fovea centralis is a pit in the retina.
True
cones or rods are active in high light conditions.
cones
When light passes into a slower medium it is bend toward an angle ______________________ to the interface between the media.
perpendicular
For near vision
the ciliary muscles contract and the lens gets fatter
Photopigment is found in the ________________________________ of a photoreceptor.
outer segment
The phosphodiesterase in the photoreceptor that is involved in light signal transduction
converts cGMP into GMP
