Ch38 Flashcards
What are the two main types of cells in the nervous system?
Neuron
Glial
What are the neuronal functions?
receive
process
transmit information
to control movements of the body
What are glial functions?
provide nutrients
regulate interstitial fluid that bathes neurons
modulating communication between neurons
speed up movement of electrical signals of neurons
What are the four main parts of a neuron?
- Dendrites
- Cell Body
- Axon
- Synaptic Terminals
What are Dendrites and their function?
branches protruding from the cell body
“receive information”
Name places where Dendrites can be found and their specific function.
Sensory Neurons-
produce electrical signals in response to stimuli from odor, pressure, light, temp, blood pH
Brain & Spinal Neurons-
respond to chemicals (neurotransmitters)
What are neurotransmitters?
chemicals released from neurons in the brain and spinal cord
What is a cell body and its function?
the part of the neuron that contains organelles
“process information” coordinates neurons and metabolic activity
How does a cell body complete its function?
adds up the signals produced by dentries. Negative or Positive
If large amount of positive cell produces action potential
What is action potential?
a large rapid electrical signal transmitted from a cell body
What is a Axon and its function?
a long thin strand extended away from the cell body
conducts action potential
What are the longest cells in the human body?
Axon neurons -
they can stretch from your spinal cord to your toes
What are bundled axons called?
Nerves
What is synapse?
when one neuron communicates with another cell
innervates
What does synapse consist of?
- synaptic terminal- swollen end of axon “sending” neuron
- “receiving” neuron
- small gap separating the two ^
Information carried ____ a neuron by electrical signals
within
Information is transmitted _____neurons by neurotransmitters
between
What is resting potential?
the constant electrical charge an inactive neuron still retains
-always negative -40 to -90 millivolts
What is the fundamental unit of the nervous system?
The Neuron
What are the neutrons functions?
- Receive info
- Process info
- Conduct electrical signals
- Transmit info
What are the steps of the action potential, as recorded in an oscilloscope? What causes each?
- Resting potential - voltage inside the cell is -40 to -90mV
- Stimulation - cell becomes less ( ^) or more negative
- Threshold - significant less negativity triggers action potential (-30)
- Action potential - Na+ enters the cell K+ exits the cells
- Resting potential
What are EPSP? Where are they added to produce an Action Potential?
Excitatory postsynaptic potential
to the axon helix ( between the cell body and axon)
What is an IPSP?
inhibitory postsynaptic potential
What is a neurotransmitter? Give some examples.
Acetylcholine Dopamine Norepinephrin Serotonin Glutamate Glycine GABA Endorphins Nitric Oxide
Acetylcholine
motor neuron- activates skeletal muscles
Dopamine
midbrain- emotions movement
Norepinephrin
sympathetic nervous system - activates target organs
Serotonin
Midbrain, pons, medulla- influences mood and sleep
Glutamate
many areas of the brain and spinal cord- excitatory neurotrans. in CNS
Glycine
spinal cord- inhibitory neurotrans. in spinal cord
GABA
many areas in brain and spinal cord- inhibitory in brain
Endorphins
many areas in brain and spinal cord- mood, reduce pain sensations
Nitric Oxide
many areas in the brain- forming memories
What neurotransmitter uptake is blocked by the use of most antidepressants?
Serotonin
Does the action potential decrease as it moves along the axon?
Action potential remains the same (it hops from node to node)
Why does repeated use of drugs results in a decrease in the response to the drug?
because the receptors internalize creating a type of “resistance”
What is a synapse?
site in which a cell communicates with another cell
What is a threshold?
When the neuron is stimulated past -30 mV “all or nothing” depolarization necessary to activate action potential
What is the function(s) of myelin in an axon?
Speed up action potential (conduction of the axon) with glial cell insulation
How is the intensity of a stimulus encoded by the nervous system?
- frequency- the neuron produces action potential
2. recruitment- more neurons excited by action p.
What are the parts of the Central Nervous System?
Spinal Cord
Brain
What is the function of the cerebellum?
to coordinate movements - compares information from both centers in the forebrain
What brain system is responsible for primitive emotions?
Limbic System - includes hypothalamus, amygdala, hippocampus, and nearby regions in the cerebral cortex
What area of the brain is involved in higher functions?
Frontal Lobe- cerebral cortex
What are the main lobes of the brain and what functions are assigned to them?
- Frontal - higher functions, speech, motor areas
- Temporal- auditory, memory, comprehension, language
- Parietal- sensory
- Occipital- visual
What are the parts that make the hindbrain and its functions?
- Medulla- controls automatic functions (breathing, HR, BP)
- Pons- influence transitions between sleep and awake ( rate + pattern of breathing)
- Cerebellum- coordinates movement
What parts make the midbrain and what are their functions?
- auditory relay center
- clusters of neurons that control eye movement
- Reticular formation- groups of neurons from medulla pons and midbrain
What are the functions of the spinal cord? What are the two regions of the spinal cord called and why?
transmit signals to and from the brain and control reflexes
Grey matter- contains cell bodies
White matter- contains myelin
What are the differences between sympathetic and parasympathetic divisions of the CNS?
Sympathetic- releases neurotransmitter Norepinephrin to prepare the body for stress “fight or flight”
Parasympathetic- releases neurotransmitter Acetylcholine for rest and digestion
What kind of neurons activates muscles? Where are their cell bodies located?
motor neurons in the spinal cord (grey matter and white matter)
What is the function of the reticular formation?
to receive and filter sensory information before it reaches the brain
How many types of memories are known?
2
short term
long term
What is the corpus callosum and its function?
large bands of axons that help both hemispheres of the brain communicate
What colors in a PET scan indicate more activity?
Red
What types of receptors are used for touch, vision, hearing, and taste, respectively?
Mechanoreceptor- touch, hearing
Photoreceptor - vision
Chemoreceptor- taste, smell
What causes near or far-sight vision?
The shape of your eyeball and cornea
Nearsighted- long eye + round cornea
Farsighted- Short eye + flat cornea
What are the photoreceptors responsible for color vision?
Cones containing photopigments
red, blue, green
What is the fovea? What is the blind spot? Which one has depth perception: prey or predator?
fovea- eyes focus point inside retina
bind spot- optic nerve combine (no photoreceptor)
Predator has depth perception
What causes perception of pain?
Pain receptors (nociceptors)- subjective feeling arising the brain
What is biotic potential?
maximum rate at which population increases
What is environmental resistance?
Curves in population growth due to living and non-living environment
What is the equation for calculating population growth?
G= (r)(N)
What happens in exponential growth and what type of curve describes it?
large number is added to the population
- J curve
What is the carrying capacity of a population?
the max population size an environment can sustain
- S curve
What factors determine the carrying capacity of a population?
logistic population- natural resources, area to live
What are examples of populations with boom bust cycles?
cynobacteria, insects, annual plants
What are the important density-independent factors limiting population size?
climate and weather
What are the important density-dependent factors limiting population size?
adaptations for seasonal change
What advantages can a non-native species have when introducing population size?
with no natural predators populations will explode
What is the difference between intraspecific and interspecific competition?
intraspecific- competition w/ individuals of same species
interspecific- competition w/ individuals of different species
What are the 3 main types of survivorship curves and what are come organisms representative of each?
- Early Loss- dandelion
- Constant Loss- Robin
- Late Loss- Human
When predators and prey both have population cycles, how does the predator cycle tend to be in relation with the prey cycle?
Dependent-
increase in prey = increase in predator
decrease in prey = decrease in predator
Why are population growth rates higher in developing countries than in developed?
- Higher birth rates
- Children aid in family income
- limited access to contraception
What can you infer from population’s age structure diagram if it looks like a pyramid?
that the population is increasing
How much energy does an American use compared to the world average?
four times as much
Why the U.S. population is still growing, compared to other developed countries?
increased birth rate and increased immigration
An ideal habitat with unlimited resources is associated with
- Both exponential growth and logistic growth. - Exponential growth. - Population crashes. - Neither exponential growth nor logistic growth. - Logistic growth.
Exponential growth-
Populations grow exponentially with unlimited resources.
The maximum population a habitat can support is its
- Logistic growth. - Exponential growth. - Death rate. - Carrying capacity. - Birth rate.
Carrying capacity.
Logistic growth involves
- Population growth slowing down as the population approaches carrying capacity. - A population crash. - Population growth reaching carrying capacity and then speeding up. - Population size decreasing to zero. - Population growth continuing forever.
-A population crash
In exponential growth
Population size grows faster and faster as the population gets bigger.
-Population size stays constant.
-Population growth slows as the population gets close to its carrying capacity.
-Population size grows more and more slowly as the population gets bigger.
-None of these are correct.
Population size grows faster and faster as the population gets bigger.
Which of the following would NOT cause population size to decrease?
- Increased birth rate - An exponentially growing population outgrowing its food supply and crashing - Increased death rate - Increase in the number of predators - Poor weather, resulting in less food being available
Increased birth rate
The study of how organisms interact with one another and with their nonliving environment is
- genetics. - morphology. - anatomy. - ecosystems. - ecology.
ecology.
The different species within an ecosystem that interact in various ways make up a(n)
- community. - population. - aggregation. - ecotone.
community.
All members of a species that reside within an ecosystem make up a(n)
- aggregation. - community. - ecotone. - population.
population.
A neuron’s nucleus is located in its _____.
- cell body - axon - myelin sheath - dendrite - synaptic terminals
cell body
A nerve impulse moves toward a neuron’s cell body along _____.
- dendrites - synaptic terminals - oligodendrocytes - axons - nodes of Ranvier
dendrites -conduct an impulse from a synapse toward the cell body.
A nerve impulse moves away from a neuron’s cell body along _____.
- dendrites - Nissl bodies - synapses - axons - glia
Axons- conduct a nerve impulse away from the cell body.
An impulse relayed along a myelinated axon “jumps” from _____ to _____.
- oligodendrocyte ... Schwann cell - node of Ranvier /Schwann cell - node of Ranvier/ node of Ranvier - Schwann cell / Schwann cell - Schwann cell /node of Ranvier
-node of Ranvier/ node of Ranvier
Axons insulated by a(n) _____ are able to conduct impulses faster that those not so insulated.
- node of Ranvier - synaptic terminal - myelin sheath - layer of asbestos - astrocytes
myelin sheath-
formed when Schwann cells wrap around an axon, allow such neurons to conduct impulses more rapidly than unmyelinated axons.
What type of cell makes up the myelin sheath of a motor neuron?
- astrocytes - microglial cells - Ranvier cells - ependymal cells - Schwann cells
Schwann cells -
Myelin sheaths are formed when Schwann cells wrap around the axons of motor neurons.
What part of a neuron relays signals from one neuron to another neuron or to an effector?
- dendrite - axon hillock - synaptic terminal - axon - node of Ranvier
synaptic terminal-
contain neurotransmitter molecules that relay the nerve impulse across a synapse.
Which of these causes the release of neurotransmitter molecules?
- the receipt of a signal from the postsynaptic neuron - an action potential reaching the end of the cell body - an action potential reaching the end of the axon - an action potential reaching the end of the dendrite
an action potential reaching the end of the axon-
vessels then fuse with the plasma membrane and release neurotransmitter into the synaptic cleft
The space between an axon of one neuron and the dendrite of another neuron is called a(n) _____.
- synaptic cleft - node of Ranvier - internodes - synapse - synaptic terminal
synaptic cleft
Neurons store neurotransmitter molecules in vesicles located within _____.
- the cell body - myelin - the synaptic cleft - dendrites - synaptic terminals
synaptic terminals
An action potential moves along a(n) _____.
- myelin sheath - axon - dendrite - synapse - cell body
axon
At rest, which of these plays a role in establishing the charge differential across a neuron’s plasma membrane?
- the sodium-potassium pump moving sodium ions into the neuron and potassium ions out of the neuron - the sodium-potassium pump moving sodium ions out of the neuron and potassium ions into the neuron - the diffusion of sodium ions into the neuron
-the sodium-potassium pump moving sodium ions out of the neuron and potassium ions into the neuron
The transmission of a nerve impulse first triggers the _____.
- action of the sodium-potassium pump - opening of voltage-gated sodium channels and the diffusion of sodium ions into the neuron - opening of voltage-gated sodium channels and the diffusion of sodium ions out of the neuron - opening of voltage-gated potassium channels and the diffusion of potassium ions out of the neuron - opening of voltage-gated potassium channels and the diffusion of potassium ions into the neuron
opening of voltage-gated sodium channels and the diffusion of sodium ions into the neuron
What type of nervous system is exhibited by the flatworm?
- Bilateral nervous system - Peripheral nervous system - Diffuse nervous system - No nervous system - Centralized nervous system
Centralized nervous system
The stronger the stimulus, the more powerful the action potential. True or False?
True
False
False
Addictive drugs that make people feel good, such as cocaine, ecstasy, and methamphetamine, affect the parts of the brain that use which neurotransmitter(s)?
- Nitric oxide - GABA - Serotonin and dopamine - Acetylcholine - Serotonin and GABA
Serotonin and dopamine
If I step on a shard of glass while playing volleyball barefoot, which path will the reflex to pull my foot up follow?
- Sensory nerve - motor nerve - spinal cord - brain - Motor nerve - spinal cord - brain - spinal cord - sensory nerve - effector - Sensory nerve - spinal cord - motor nerve - effector - Sensory nerve - spinal cord - brain - spinal cord - motor nerve - effector - Motor nerve - sensory nerve - spinal cord - brain
Sensory nerve - spinal cord - motor nerve - effector
Which of the following is part of the peripheral nervous system?
- Brain - Thalamus - Medulla - Autonomic nervous system - Spinal cord
Autonomic nervous system
The autonomic nervous system consists of two parts: the sympathetic and parasympathetic divisions. The sympathetic division is responsible for which type of response?
- Constriction of the air passages in the respiratory system - Slowing of the heart rate - "Rest and digest" responses - Involuntary responses to extreme danger or stress
Involuntary responses to extreme danger or stress
Most brain cells are
- saltatory neurons. - interneurons. - parasympathetic neurons. - motor neurons. - sensory neurons.
interneurons.
Which of these parts of the brain controls breathing and heart rate?
- Medulla - Thalamus - Cerebrum - Cerebellum - Hypothalamus
Medulla
Memory, sensory processing, motor responses, creativity, and higher intellectual functions are carried out by the
- hypothalamus. - cerebellum. - cerebrum. - amygdala. - medulla.
cerebrum.
The _____ is the region of the eye where photoreceptors are most highly concentrated.
- lens - fovea - optic nerve - pupil - sclera
fovea
What name is given to the tough layer that forms the “white” of the eye?
- blind spot - choroid - fovea - sclera - aqueous humor
sclera
The _____ changes shape to focus light on the retina.
- vitreous humor - blind spot - cornea - lens - optic nerve
lens
What name is given to the opening that allows light into the interior of the eye?
- sclera - pupil - ligament - optic nerve - retina
pupil
The ________ ear not only detects sound, but also detects gravity and movement.
inner
Mechanoreceptors include
- taste buds. - nociceptors. - rods. - cones. - Meissner's corpuscles.
Meissner’s corpuscles
Chemoreceptors include
- olfactory receptors. - muscle spindles. - Pacinian corpuscles. - rods. - hair cells.
olfactory receptors.
There are ________ distinctly different tastes that stimulate receptors on the human tongue.
five (sour, salty, sweet, bitter, and umami)
Receptor potentials are ________ the strength of the stimulus.
- unrelated to - the same regardless of - much greater than - directly proportional to - inversely proportional to
directly proportional to
Which type of receptor signals that your stomach is full after a big meal?
- Chemoreceptor - Mechanoreceptor - Pain receptor - Photoreceptor
Mechanoreceptor
When sound waves travel through the auditory canal they stimulate the ________ membrane, which then vibrates the hammer (malleus) in the middle ear.
- auditory - pinna - tympanic - vestibular - cochlea
tympanic
Prolonged exposure to very loud noises is most likely to damage
- the auditory nerve. - corpuscles. - the hammer and anvil. - hair cells. - the tympanic membrane
hair cells
Why do things appear mainly black or white to us in low light?
- Only white light is available at night. - The diffused light of night does not fall on the fovea. - Few action potentials are stimulated in low light. - Rods are more sensitive to light than are cones.
Rods are more sensitive to light than are cones.
In humans, depth perception is possible because
- the two eyes have overlapping visual fields. - each of the two eyes "sees" an entirely different image. - the two eyes see identical images. - the two eyes are necessary for any vision to occur.
the two eyes have overlapping visual fields.
The sense of taste relies on
- taste buds, olfactory receptors, and nociceptors. - taste buds only. - olfactory receptors only. - both taste buds and olfactory receptors. - taste buds, olfactory receptors, and mechanoreceptors.
both taste buds and olfactory receptors.
