Bio 002 Exam 2 Questions
give one example of a hormone we discussed whose release is controlled by hypothalamus signals. Give one example of a hormone we discussed whose release is NOT controlled by hypothalamus signals
!! first: cortisol second: could it be insulin but I don't think so adenosine (close to caffeine?)
Many spicy foods cause people to experience a burning sensation. Propose a hypothesis to explain this observation.
!!! Because the chemicals that spicy foods compose of these chemicals when they interact with specific chemoreceptors they may inflame them and therefore send the corresponding burning sensation to receptor proteins and therefore be perceived by interneurons as burning.
Humans lack sensors capable of detecting the amount of vitamin D in the body. Based on that information, can the levels of vitamin D be regulated in your body? Why or why not?
!!! no if the body is unable to sense the vitamin signal and messages cannot be sent to parts of body?!!!
Gonadotrophin-releasing hormone (GnRH) produced by the hypothalamus promotes the release of luteinizing hormone (LH) from the anterior pituitary. In males, LH stimulates target cells to release testosterone. Draw a diagram to illustrate how testosterone release could be regulated by negative feedback. Wha would happen to the levels of GnRH and LH if you injected a male with testosterone? To the levels of GNRH and testosterone if you ejected a a male with LH?
!!! when testosterone levels are too low it could sent a signal to the hypothalamus/nervous system that they're too low which would the receptors would then transmit GnRH to be produced and sent to the anterior pituitary which would release LH and then the target cells would release testosterone bringing it back up. If you injected a male with testosterone the levels to GnRh and LH wouldn't be needed as much so they would decrease. To the levels of GNRH and testosterone if LH was injected the levels of testosterone would increase which would then tell the brain that they are normal and would eventually decrease the amount of GnRH but initially the anterior pituitary would produce enough for too much GnRH if necessary
Describe how/why regulation of insulin by blood glucose levels is an example of negative feedback. Do the same thing for glucagon.
As blood glucose levels increase insulin is realized which decreases the levels. As blood glucose decreases glucagon is released which increase the blood glucose. Causing an opposite effect in response to the condition.
Describe the difference between voltage-gated ion channels and chemically gated ion channels. Which type is important during an action potential?
Chemically gated: open and close in response to interaction of molecules Voltage gated: open and close in response to changes in relative charge inside vs. outside neurons
How are chemoreceptors similar to photoreceptor cells? How are they different?
Chemoreceptors also have receptors where they have receptor proteins and alter membrane potential photoreceptors are eventually translated to action potential signals and they interact with different lights and different signals unlike chemoreceptors
If the alpha cells of your pancreas could no longer produce glucagon, how would that affect the ability of your body to regulate blood glucose levels? What if target cells lost the ability to respond to glucagon signals? Now answer the same questions for beta cells and insulin.
It would inhibit the body to increase blood glucose levels because the targets cells wouldn't receive the signals sent from glucagon as it can't be produced. If target cells lost the ability to respond to them the same would happen the glucose levels would stay low however there would be a big increase in glucagon to increase blood glucose levels If beta cells couldn't produce insulin than blood glucose levels would stay high as target cells wouldn't receive insulin signals. If the target cells couldn't receive signals glucose levels would stay high and high amounts of insulin would be released to attempt to decrease blood glucose levels
make a table to start keeping track of similarities and differences between your nervous and endocrine signals
Similarities: long distance communication increase signals, maintain homeostasis, target cells receptors Nervous system: electrical signals neurotransmitters, synaptic cleft, fast communication lasting effect Endocrine System: travel through blood stream in animals, hormones, response dependent on sum of all hormones...
In the taste experiment, participants rinsed their mouths with distilled water and the researchers waited one minute between each solution application. Every 10 trials, they also gave the participants a five break. Why were these breaks between trials important? Hint - Think about what might happen if a taste receptor cell was repeatedly stimulated over a long period of time.
These breaks were given to ensure that the taste was fully processes and had left the perception and the mouth of the person. If the same conditon is given over time one cross contamination of tastes might have been given or a consistent taste may not be able to be perceived any longer
list as many properties/features of hormones as you can remember without looking at your notes. Then review your notes to check yourself.
Travel through the bloodstream with animals have different effects in the different types and the same cell; reach all cells but only interact with specific receptor cells a small amount of the hormone can cause a BIG response. most processes are controlled by multiple types of hormones
Sketch a neuron. Label its parts and describe their function
Dendrites: highly branched extension that receive signals->cell body: receives and integrates signals -> axon hillock: point where cell body and axon meet (signal starts here) -> axon: transmit signals -> synaptic terminal: ends of axon branches where signals are transmitted to next cell
Explain the role of glial cells in the nervous system
Function as neuron support system ex. Schwann cells insulte PNS neurons (has myelin sheath covering the axon)
Identify all the hormones we discussed that play a role in controlling blood glucose levels. For each hormone, describe conditions that promote its release. What hormones would you predict to be elevated in the blood of a person who walks into class while polishing off a candy bar and discovers that there is a pop quiz (and they didn't do the reading for the class)? Describe the effects of target cell responses to each hormone on blood glucose levels (i.e. will the hormone promote responses in target cells that increase or decrease blood glucose levels?).
Insulin: a increase in blood glucose levels Glucagon: a low blood glucose levels epinephrine: increased short term stress released through medullae cortisol: released through adrenal cortex an increase in long term stress insulin would be elevated to decrease the blood glucose level while the cortisol would increase and increase the blood glucose levels due to stress. It will promote both one to increase first the blood glucose level then to clean up via insulin and levels would increase via cortisol increases
Describe the roles of insulin and glucagon in regulation blood glucose levels.
Insulin: beta cells detect increased blood glucose and promote the release of insulin into the blood stream which when hit the target cells removes glucose from the blood stream which is then detected by the beta cells and releases less insulin Glucagon: alpha cells detect low blood glucose levels which promotes the release of glucagon into the blood stream which when responded to by the target cells leads to a production and release of glucose from cells into bloodstream the increase in glucose decreases the amount of glucagon released
Regulation of blood sugar levels is an example of negative feedback. In general terms, describe what would happen if you miss lunch and your blood sugar falls too low. Now describe what would happen if you ate 10 candy bars and your blood sugar rose too high
Your body would sense the low blood sugar levels which would send a signal to the integrating center there it would interpret that there is low blood sugar and send a message to the effector to release/ increase the blood sugar levels somehow When you blood sugar is too high it would sense integrate and effect it in the sense that it would decrease your blood sugar levels to reach homeostasis
Draw and analogy between the different parts of the nervous systems and a computer that is connected to a printer
a computer senses and receives iforamton from the internal or external environments via the user where the body of the computer (CNS) integrates and coordinates a message and sends it to the printer (neurons sending messages) where the response is printed (sensory ->interneurons-> motor neurons)
What does it mean that hormone receptors are specific for a particular type of hormone? Write a sentence that explains why it is important that this happens
an individual cell often has multiple types of hormone receptors and many hormones have different types of receptors on different types of cells; the interaction of one hormone molecule with a receptor protein can alter the activities of many molecules in side of a cell!!
Your liver and muscle cells respond differently to the hormone glucagon. Propose at least one hypothesis to explain how glucagon could cause different responses in your muscle vs. your liver cells.
because hormones cause different effects in the same cell due to altering the activities of many molecules inside of the cell the cell found in your muscle vs the cell may have different receptors/types of cells or the same type of cell but due to the many molecules they may cause different responses
explain why hormones released by cells in your adrenal medullae function in your short term stress response and hormones released by cells in your adrenal corticies are important for your long term stress response.
because neurosecretory cells recieve nervous system signals and respond which is where signals are sent first (it is faster) this is why medulla is shorter in adrenal corticies deals with endocrine cells and hormones take a longer time to travel through the blood stream these effects are longer lasting but are more time!!
you leave a brightly lit hallway and enter a dark room. Explain why you can't see very well right away, but over time you are able to see more clearly.
because the sudden change in light wavelengths causes the signals to a few cones in bright light to decrease and signals are sent to MANY rods which are sent to one bipolar cell which then first appears fuzzy but then it amplifies the dim light signal and your receptors adjust !!!
Why are the signals that reach you r brain from photoreceptors said to be partially integrated? explain the benefits of particle integration of photoreceptor signals.
because they travel through multiple cells and allow partial integration and processing of light signal before they reach the brain; the benefits are that it sharpens the images and improves the cells ability to detect low levels of light
explain why all rods respond to the same wavelengths of light. Explain why rod signals are all interpreted as shades of gray.
because they use all wavelengths of light as signals and because they do not interpret color higher and shorter wavelengths of light are translated to shades of gray
explain how the data obtained by loewi's experiment provided support for the hypothesis that chemicals were involved in signal transmission at synapses. explain why the data did NOT refute the hypothesis that electrical signals were involved in signal transmission at synapses.
because when the first heart was stimulated it altered the function of the unstimulated heart two which means that the stimulated heart and its neurons could have released chemicals which could have altered the function of the second heart. You can't rebut the hypothesis that electrical signals were involved in signal transmission because signals could have been transmitted by electrical signals at other synapses
Explain why blue cones, red cones, and green cones respond to different wavelengths of light, What determines that blue cone signals are interpreted as blue, red cone signals as red and green cone signals as green?
different wavelengths of light are translated to their corresponding color each color is determined by the specific wavelength of light which each wavelength is determined by the specific opsin protein which each cone has corresponding opsin protein which filters the wavelengths out
What is selective permeability (of membranes)? What does it mean that membrane proteins are specific? Explain the importance of selective permeability and specificity of membrane proteins in the context of nervous system signaling.
elective permeability membranes: proteins in membranes tightly control movement of molecules in and out of neuron Membrane protein are specific - Only allow certain molecules and out The importance of selective permeability and specificity in context of nervous system signaling allow concentration and singaling to be maintiained and ordered appropriately in oredre to start and complete action potentials...!!
Come up with a list of observation that would allow you to determine whether a chemical should be classified as a hormone or neurotransmitter. What observation s would NOT be helpful (i.e. what would you expect to observe that would be the same for both types of chemical signals)?
hormone: travel through blood stream, reach all cells neurotransmitter: released into synaptic cleft, act as communication links between cells
Describe the relationship between your hypothalamus, anterior pituitary and posterior pituitary (i.e. how and in what directions is information communicated between them.)
hypothalamus integrates and transmits nervous and endocrine system signals which it communicates via the pituitary gland to other endocrine organs which then releases hormones Posterior pituitary: extension of hypothalamus (neurosecretory) hormones released in response to nervous system signals anterior pituitary: endocrine cells (produce hormones), release of hormones is controlled by hypothalamus hormone signals anterior's cells are the only cells Abel to detect and respond to hypothalamus hormones pituitary hormones released in response to nervous system signals hypothalamus pituitary -> nervous system (posterior) hormones via hypothalamus (anterior)
calcitonin (a hormone) and parathyroid hormones (PTH) are both important for regulating levels of calcium in your blood. what observations would suggest that calcitonin and PTH should be classified as antagonistic hormones?
if when rates of calcium get too high the hormones would receive the signal and then send a response in cells to decrease the amount of calcium in the blood and like wise if there were too little then these could be considered as antagonistic hormones.
In your own words describe what happens when an action potential reaches the synaptic terminal of a neuron at a chemical synapse. now a electrical synapse
in chemical synapses the membranes are not connected and in electrical synapse the membranes are connected where ions pass through
Some demyelinating diseases only affect one particular type of neuron (sensory, motor, or interneuron). If a disease causes demyelination of sensory neurons what symptoms would you predict? Of motor neurons? of interneurons?
in sensory neurons the signals would take more time to run and there could be chance of cross wiring which would cause no tall the necessary signals to occur. In sensory less senses would be developed quicker. in motor the appropriate motor responses may be delayed or not occur at all or correctly. In interneurons not all internal and external conditions would be processed quick enough or correctly.
Explain why signals travel more rapidly along myelinated versus unmyelinated axons.
in unmyelinated axons more action potentials are generated whereas in a myelinated axon the action potentials are generated fewer only at the unexposed nodes.
Be able to describe the regulation of thyroid hormone levels by the hypothalamus and pituitary gland, and to predict the outcome of various disruptions to the normal mechanisms (eg. thyroid gland cells unable to respond to TSH).
inability of anterior pituairy cells to TRH means no TSH released TSh is required to stimulate thyroid homrone release from thyroid gland. if this thyroid hormone is at a low level in the blood than the hypothalamus neurosecretory cells release LOTs of TRH, think such as drugs can inhibit this and cause changes
You walk into your apartment and notice that it smells like the toast you burned in the morning. Propose an explanation for why, after a few minutes, you do not notice a burn toast smell.
it as undergone sensory adaptation which means that the CNS has filtered out signals and has decreases responses to continuous stimulus
Explain what allows the hypothalamus to act as the communication link between your nervous and endocrine systems.
it communicates via hormones to other endocrine organs and target cells and largely beaus of its location after the signals are processed in the interneurons the endocrine cells help facilitate the further resposne
Although it is frequently used, explain why the statement "An action potential moves down an axon" is NOT the best way to describe how a signal gets from the cell body to the synaptic terminals of a neuron.
it doesn't move down it is generated at many places down the axon just as many channels open and close down the axon.
Without looking at your notes sketch. graph of an action potential. In detail describe what happens as yo move along the curve from start to end
it is first at resting potential then Na+voltage gated ion channels open which cause the inside to become more positive reaching threshold it spikes up where the signal is sent and then drops down when voltage gated K+ ions move out of the membrane which makes the outside more positive, it dips below threshold where the channels close !!!
Explain why regulation of blood glucose (sugar) levels is essential for maintaining homeostasis
it is the only energy source for red blood cells and the main energy source for brain cells (fast_)
Describe how a signal is transmitted along the length of an anon. Explain why signals always travel from axon hillock to the synaptic terminals. Come up with an analysis other than a stadium wave to describe action potential transmission along an axon.
its is transmitted in one direction because after voltage gated Na+ close they are inactivated and cannot be reopened for a period of time. urine cannot reenter your urethra after it has left
Compare and contrast the function of your nervous system control center (brain and spinal cord) and control of hormone signaling by our hypothalamus and pituitary gland.
nervous system control center uses electrical signals and neurotransmitters which are sent through the synaptic cleft; communicates quickly and has a lasting effect control of hormone signaling by hypothalamus and pituitary gland links between nervous and endocrine system, receives signals and can sent signals directly tot he pituitary gland, goes from hypothalamus to the pituitary; response depends on the sum of all hormones they both integrate signals, maintain homeostasis, have receptors and target cells and deal with long distance communciation
Why do the nervous, sensory and endocrine systems play particularly important roles in maintaining homeostasis? Describe the main functions of and connections between the three systems.
nervous: main homeostatic system; it integrates and transmits information regarding internal and external conditions sensory: transmits information about the internal and external conditions to the nervous system Endocrine system: works with nervous system to coordinate whole body communication signals (hormone signals) They play important roles because the sense interpret and transmit information from outside sources to the entire body to maintain homestasis Sensory-> nervous (transmits info) -> controls endocrine to release hormones
Describe the differences between a neuron, a neurosecretory cell and an endocrine cell.
neuron: a special cell transmitting nerve impulses; a nerve cell neurosecretory cell: receive and send nervous system AND endocrine system signals endocrine cell: produce and release hormones in response to specific signals !!!
describe signal integration in your own words and explain why it is important. If a neuron receives multiple excitatory stimuli simultaneously, can you be sure that it will generate an action potential? Why or why not?
neurons receive many different signals where these neurons then integrate the signals, the signals received cause local changes in the membrane potential the change spreads and depending on the number of inhibitory and excitatory signals received a response is determined no you cannot be sure that it will generate an action potential because the it depends on how many inhibitory signals are sent and an excitory signal only encourages action potentials
The hormone insulin causes responses in target cells that help lower blood glucose levels. Calcitonin causes changes in hormone levels that decrease blood calcium levels. Could insulin and calcitonin be classified as synergistic hormones? Why or why not?
no because they are regulating different condiotns they would have To do the same thing to the same thing
if a neuron was treated with a drug that inhibited sodium potassium pumps, could the neuron still generate nerve signals. Explain your answers
no the charges wouldn't be regulated in the first place?
Find someone you know who hasn't learned about the human sensory system and explain them the cause of color blindness.
opsin protein was produced but couldn't function properly that was found in certain colored cones; lacked functional specific colored cones
Compare and contrast the signal involved and the changes that occur during you short-term and long term stress responses
short response: prepares body for immediate action, acts quickly, responses is short lived long term: causes changes that maintain homeostasis during continued stress, takes longer to initiate response is long lasting
make a table to summarize the similarities and differences between your nervous and endocrine systems
similarities: integrate signals, maintain homeostasis, have receptors, long distance communication, target cells chemical signals nervous system: electrical signals, neurotransmitters, synaptic cleft, faster, long lasting, brain and spinal cord, cannot reach all cells endocrine sytem, travel through blood dream, hormones, response dependent on sum of all hormones, can link to nervous system, hypothalamus and pituitary gland...!!, can reach all cells
How is the sodium potassium pump different from gated ion channels?
sodium potassium pumps use energy to move Na+ and Ki+ in specific directions and are always functioning whereas the channels are conditional and function in reaction to conditions such as large or molecules
Describe how stimuli can affect the membrane potential of a neuron. If a stimulus allowed negatively charged chloride ions (Cl-) to flow into a resting neuron, would that cause the membrane potential to be closer to the threshold or farther from the threshold? What about a stimulus that allowed positively charged calcium ions (Ca+) to flow into a resting neuron? Explain your answers
stimulus causes threshold change in membrane potential. If more Cl- flowed into the resting neuron would make it harder for an action potential to occur due to the inside becoming more negatively charged and the outside more positively charged. if a positively charged Ca+ ion moved into the resting neuron it would cause the inside to be more positively charged and outside less which would increase the change of a action potential (would reach threshold)
Draw and label your own diagram to describe how hormone signals are regulated by negative feedback (make one "one-hormone" sketch. and one "multi-signal" sketch).
stimulus is sent to the neuron which releases neurotransmitters to neurosecretory cell and then to endocrien cells where the hormone is then sent signal to another hormone after it has reached the next endocrine cell it then finally meet the target cell; in a one hormone the neuron I senses the stimulus ashore the endocrine cell pick It up and releases the hormone to the target cell
Compare and contrast your senses of taste and smell. Include similarities/differences between the chemoreceptors involved and how signals are transmitted to your brain.
taste are modified epithelial cells that are chemoreceptors which send neurotransmitters to sensory neurons which send action potentials to the brain smell are receptor cell neurons which send action potential signals which are sent to a specific location in the brain
A cell is able to respond to three different hormones (X, Y and Z). Based only on this information, what can you say about the cell and/or the hormones?
the cell may have different receptor proteins in it which allows the cell top be receptive to many different hormones
what determines which chemicals a chemoreceptor can detect?
the chemical that is detected is determined by the receptor protein in the membrane?
Propose a hypothesis to explain the difference in the overall sensitivity (average frequency of detection for all tastes) of papilla #1 (first graph) and papilla #15 (last graph) observed in the taste analysis.
the papilla may not have similar taste receptor proteins chemoreceptors and the like
Choose a papilla from the experiment carried out by Bealer and Smith that could only detect one taste. Propose a reasonable hypothesis to explain why the papilla could only detect one taste.
the papillae may have only had taste buds that could perceive say bitter however had many different receptor proteins for that taste
Why is it important that mechanisms exist to remove hormone signals from your blood stream?
the processes are through organs such as the liver or kidney, they are destroyed by molecules in the blood stream or they are removed through degradation and reuptake; these are important to stop and over sending of signals and maintain alive status with as much equilibrium as possible as some conditions may send several signals to hormones
at some chemical synapses, dopamine is considered an exitatory neurotransmitter. at other chemical synapses it is classified as inhibitory. describe dopamine effects on the receiving neuron in each situation, then propose one explanation for how dopamine can function Both as an excitory and inhibitory neurotransmitter
the receiving neuron in excitatory would be more likely to receive the outcome from an action potential which !!! dopamine as an excretory would be inhibit the neuron from receiving the outcome of an action potential which would be more neurotransmitters. !!! dopamine would be an excitatory neuron when it reaches synapses that relate to exicitement and energy and be inhibitory when it reaches synapses that calm the body??
In your own words, describe the role of the sensory system in maintianing homeostasis.
the sensory system senses, interprets and then causes directions sent to the effectors; it maintains homestasis where the membrane potential is altered by specific type of stimulus and the magnitude of the stimulus. Because the sensory system uses outside information to therefore interpret and send signals it helps monitor and regulate conditions and keep them in check.
explain why your perception of the world around you is determined by the types, locations and communication links between your sensory receptor cells and interneurons in your CNS. Use an example to illustrate your description.
the types locations and communication links therefore cause different amounts of signals and therefore different responses as every signal etc. is interpreted differently by your inter neurons in your CNS. As you have a bag of different shaped animal crackers the signal is the same however each animal cracker is interpreted differently based off the type, size shape and color of the animal cracker or you could use an Easter egg hunt??
A neuron is stimulated so that its membrane potential is just above threshold. Later the same neuron is stimulated so that its membrane potential is significantly above the threshold. Compare and contrast what will happen after the first and second stimulation events in terms of action potential generation.
there first one would generate say one action potential whereas the second would open Na+ channels frequently therefore more frequent action potential signals
Describe the role of hormones in maintaining homeostasis.
they are chemical messengers that have different effects on different cells; they are important to distributing coummications in response to specific stimuli
Heart muscle cells and skeletal muscle cells (the ones attached to your bones) both responses to thyroid hormones. Based only on that information, what (if anything) do you know about heart muscle and skeletal muscle cells and their responses to thyroid hormones.
they could both have different effects due to the hormone affecting different cells and the variation in receptor cells
Describe TWO ways in which a drug could decrease signaling at a chemical synapse. Describe TWO ways a drug could increase signaling at a chemical synapse.
to decrease signaling at a chemical synapse a drug could increase the reuptake of the neurotransmitter or cause the signal at the chemical synapse to be determined as an inhibitory. to increase signaling the drug could hinder reuptake or cause the synapse to interpret the signals as excitatory OR increase or decrease the amount of neurotransmitter released OR mimic the effects of a neurotransmitter OR block the neurotransmitter interaction OrR increase/inihibit of neurotransmitter from the synaptic cleft
Find someone who is not in the class and explain to them why virtually all type 1 diabetics are treated with insulin injections while insulin injections are much less effective at treating type 2 diabetics and therefore not frequently prescribed
type 1 is the inability to produce insulin which therefore requires expternal productions of insulin to be in the body because in type 2 the target cells do not respond properly to insulin signals more insulin will not improve the target cells ability to respond to the cell
You put a piece of lemon in your mouth. In general terms, explain why your reaction is "sour!" rather than "sweet!"
with each taste bud that composes the papillae the sensory neuron contained receptor proteins in the receptor cells that respond to chemical associated with taste where it is then interpreted by the interneurons as one of five basic tastes and then integrated
A drug prevents cells in your hypothalamus from responding to cortisol. How would the levels of releasing hormone, ACTH, and cortisol during long term stress be different in the presence of the drug vs without the drug? What if cells in your anterior pituitary could no longer respond to cortisol? What if cells in your anterior pituitary could no longer respond to CRH?
with the drug the levels of ACTH, cortisol, and releasing hormone would all be increased in efforts to have the hypothalamus respond to cortisol without the drug it would be normal. If cells in anterior pituitary could no longer respond then more ACTH would be produced as they hypothalamus believes that the cortisol isn't reaching if the cells couldn't decree CRH in the anterior pituitary then less ACTH would be made
Formation of a blood clot when you cut yourself is an example of positive feed back. In general terms describe the process of blood clotting.
your body senses the excess release of blood which sends a. Signal to the integrating center which interprets it as a loss of blood and sends a message to the effector which acts and releases enough blood and hardens to act a barrier for extra release of blood
The statement "negative feedback promotes homeostasis while positive feedback disrupts homeostasis" is NOT true. Explain why?
Both methods of feedback are done in order to have the body push towards homes stasis and return the body to its normal state
Choose THREE ways animals (humans) are different from plants. For each difference try to explain how/why this difference would contribute to the differences in there homeostatic (equilibrium) systems
1. mobile vs. inmobile: able to obtain homeostasis by moving areas and obtaining resources rather than being limited the resources that surround it 2. obtain energy from foods: plants obtain energy from the sun which they don't necessarily have to seek animals have to seek and obtain food 3. determinate growth/growth occurs throughout organism: plants have indeterminate growth which means their body continues to drastically change to meet equilibrium throughout their entire life rather then reaching a set point and minimizing change/battling outside sources
observation: the same amount of pressure is applied to two different sensory receptor neurons that detect touch in your skin. One generates action potentials and one does not. Propose a hypothesis to explain this observation. Hint - Think about what determines whether or not a sensory receptor cell that is a neuron generates action potentials.
??? the two different sensory receptor neurons contain synapses that interpret the signals as excitatory or inhibitory neurons? OR each neuron interprets the same stimuli differently because interpretation is dependent on the condition and type? OR the neuron has undergone specification and sensory adaptaiton
humans can detect MANY different bitter-tasting chemicals but cannot distinguish between them. Use what you know about chemoreceptors, receptor proteins and perception to propose a reasonable hypothesis to explain why.
Because bitter tasting chemicals may be chemically similar they may be processed and received into the same receptor proteins and ver similarly therefore because all other tastes are absent except bitter, bitter tastes may be perceived as very similar!!!
Why can humans detect a much wider range of smells than tastes?
Because each individual olfactory receptor cells have one of 1000 different types of chemicals
Look back at the results from the analysis performed by Bealer and Smith. Which taste(s) was/were detached by the greatest number of papilla? The fewest number? Based on what you know about taste receptor cells, taste buds and papilla, propose a hypothesis to explain why the sensitivities of papilla to particular tastes could be different.
Because each papilla consists of many and different taste buds each of them has different taste receptor cells which can detect different tastes. Sour and sweet by the greatest number and bitter and salty by the least?
Propose a reasonable hypothesis to explain why liver, muscle, and adipose (fat) cells respond to insulin, but only liver cells respond to glucagon
Because external conditions usually cause the body to increase in blood glucose levels more frequently and rapidly than low blood glucose levels more areas of the body are needed to respond faster to high blood glucose effects and because high blood glucose levels have a more severe effect?
If hormones released by the pituitary gland only communicated to a few types of target cells and didn't carry messages to other endocrine cells, do you think that the hypothalamus would still be considered the main control center of the endocrine system. Explain your answer.
Because the pituitary gland is like the middle man if the pituitary gland is less likely to transmit information to other endocrine cells than since the hypothalamus doesn't use other glands to communicate it wouldn't be considered therein control center
You drop your textbook on the floor and it makes a loud noise. A minute later you drop your pen on the floor and it makes a much softer sound. Explain how the messages sent by the sensory receptor cells your ear are different when you textbook versus your pen and how their messages are interpreted as noise rather than say the color orange.
Because the stimuli were specific types and location which was determined by the communication links the different sensory cells were therefore communicated to different CNS interneurons. The different sensory cells must be first interpreted as noise and then interpreted in the CNS by noise inter neurons? depends on what the sensory receptor cells can interpret and how they are wired
Why do objects appear sharper and more distinct in bright light, but fuzzier in dim light? Why does bright red apple appear more gray in dim light?
Because when signals from few cones are sent to one bipolar cell the image is sharper in brighter light and when signals from many rods are sent to one bipolar cell it amplifies the dim light signals but makes the images fuzzier.
In what direction(s) does information flow through the different parts of the nervous system - the CNS and the two divisions of the PNS
Goes from the PNS sensory division to the CNS where it is interpreted and motor division receives the responses
As we continue our discussion of homeostasis, continue to compare and contrast how humans and plants maintain homeostasis.
Humans use brain to interpret senses and signals Different part of the plan sense and therefore interpret signals (not a central area) Plants have some specialized areas however humans have more and more specific that deal with certain senses and interpretations Plants and humans both sense and interpret and respond to internal and external conditions They integrate messages
describe the roles/functions of each of the endocrine system organs we discusses (hypothalamus, pituitary gland, pancreas, and adrenal glands)
Hypothalamus: main control center of the endocrine system; communicates between the nervous and endocrine systems and integrates these signals; communicates to endocrine organs via pituitary gland involved in regulating some not all hormones Pituitary gland: link from hypothalamus to endocrine organs relies hormones as communication signals, has posterior pituitary (neurosecretoary extension of hypothalamus and releases hormones in response to nervous system signals anterior pituitary (endocrine cell release hormones controlled by hypothalamus hormone signals only one to detect hypothalamus signals pancreas: regulates insulin and glucagon hormones by alpha and beta cells releases to liver muscle and fat adrenal glands: riger changes in respons to stress has the medulla (short term neurotransmitter) and cortex (long term hormone signals)
When gated sodium ion channels in the membrane of a resting neuron open, in which direction will ions move? what if gated potassium ion channels open? Explain your answers.
If gated sodium ion channels open in a resting neuron the sodium ions would move inside which would cause the inside to become more positively charged and influence and action potential if gated potassium ion channels open K+ ions move out of the membrane cause the outside to become more positively charged and therefore influencing an action potential.
If two drugs are added simultaneously to a neuron, one that opens voltage gated Na+ channels and one that opens voltage gated K+ channels do you think that the neuron will generate an action potential? Explain your answer
If they are done at the same time then they would counteract each other and an action potential will not be generated.
Describe/explain how the different parts of your nervous system work together to allow you to catch a pen that rolls of your desk. Include the specific function categories of neurons your description
PNS (sensory neurons) sense pen rolling off the desk signal is sent to the CNS (interneuron) where it is interpreted and coordinates sensory data and motor commands a motor neuron is sent which causes you to pick up the pen.
What types of ions are important for nerve signals? Indicate their charges.
Potassium and sodium positively charged ions
Compare the structures and properties of rods and cones
Rods: are very sensitive and can detect low levels of light the signals are NOT interpreted as different colors Cones: are less sensitive to light than rods and interpret signals as colors green blue red
In one sentence, summarize the role of the nervous system in maintaining homeostasis:
Sense/collect information regarding the internal and external conditions/enviornments interpret and integrate proper messages to effectors which carry out appropriate responses
In you own words, describe the three main parts of animal homeostatic systems, their roles and their connections. Between which parts do messages NOT travel?
Sensors: detect internal and external conditions Specific/one sensor monitors certain conditions Send signal to integrating center One condition monitored by many different sensor Integrating Centers: receive and interpret messages regarding many different things from Many places Integrate information Communicate messages to effectors ONLY if response is necessary Effectors receive messages from integration centers (that interpret signals) ACT/ alter behavior to carry out responses Do not send signals to sensors or integrating centers Between the effectors and sensors messages do not travel
Compare your ability to detect light to the way plants detect light. Include similarities/differences in sensing, communicating and responding.
They both externally sense light however a plant senses light through several parts of it's body and light is sensed through photoreceptors found in the eye several synapses are used to communicate the light it responds differently the plant grows and humans respond differently by adjusting what it can see.!!!
Explain why action potentials are described as "all or nothing" event. Come up with an analogy other than flushing a toilet to describe action potentials.
They do not vary in size; the strength of stimuli is communicated by the frequency not size of action potentials to open. Strong -> more frequency etc. another analog could be turning on a car it doesn't matter how hard you turn the key it will turn out the same every time...
What does it mean that action potentials are local events?
They occur in a specific place in membrane; the inactivation of voltage gated Na+ channels prevents another action potential from occurring in the same place.
Why was it important for Bealer and Smith to assess whether droplets of solution applied to individual papilla spread on a person's tongue?
To find what set up would inhibit this as when solution spreads more than one papilla may be able to taste the solution which doesn't isolate.
without looking at your notes, draw a diagram to illustrate how cortisol release is controlled by the hypothalamus and regulated by a negative feedback loop. Then check your notes to correct it
When the body senses high amount of stress signals are sent to the nervous system which sends signals to the hypothalamus which releases more cortisol. How is this negative feed back?
Explain why glucagon and insulin are antagonistic hormones
cause responses in target cells that result in an opposite effect on the same condition when blood glucose increases insulin is released which decreases blood glucose when blood glucose is low glucagon is released which increases blood glucose levels (positive feedback)
Compare and contrast signal transmission at chemical and electrical synapses
chemical: neurotransmitters transmitted by chemicals, gap between sending and recieving cells electrical signals cross it occurs more slowly and can modify signals electrical; cannot modify signals and cannot cross; it occurs rapidly and directly ions flow from sending neuron to receiving cell
for each hormone we discussed describe condition under which it is released, how its release is controlled and its main effects on target cells
cortisol: high stress, through the hypothalamus and pituitary and increase in blood glucose levels epinephrine: high stress hypothalamus, higher heart rate more open airways insulin: high blood sugar, through hypothalamus and pancreas? decrease in blood glucose glucagon: opposite as above: adenosine; produced by neurons in the brain acts a caffeine and keeps sleeping receptors from working
describe the steps from when light enters your eyes to when signals from a photoreceptor reaches interneurons in your brain
light is absorbed though the optic nerve where they interact with photoreceptors the rods and cones opsin protein and bends the shape of the retinals this information is then processed (the membrane potential decreases and decreases inhibitory neurotransmitter release this decrease alters the membrane potential of bipolar cells which releases excitory neurotransmitters. the excitatory neurotransmitter reverses the membrane potential of ganglion cells and sends action potential to the brain IF the threshold is reached
Describe the roles of each of the systems we discussed - nervous system, sensory system, endocrine system in maintaining homeostasis. Explain why, although ALL body systems are important for maintain homeostasis these three systems play particularly important roles.
nervous and endocrine systems coordinate together to manage all activities of all cells in the body Nervous system receives many signals from many external conditions and send the signals further to the endocrine system or through body via neurotransmitters endocrine systems regulated functions via hormones the hypothalamus and the pituitary gland. the sensory system senses sight taste and smell through receptor cells and sends neurotransmitters to respond to functions. these three first immediately receive signals from internal and external conditions they are the most prominent on the body
Explain why each of the four criteria we discussed for identifying a new taste is important and why demonstrating all of them are necessary to establish the existence of the sixth sense
receptor proteins are needed to interact with chemicals associated with taste where then taste receptor cells respond to chemical associated with taste the signal are then transported to the taste processing region of the brain where the taste is perceived in the absence of other tastes to identitfy a taste the taste processes and recognized because other tastes do not exist
In general terms, describe how you could modify Loewi's experiment to obtain data that would allow you to support tor refute the hypothesis that chemicals were released by the sending neuron.
remove the heart muscle cells and evaluate the liquid and chemicals related at just the neuron aspect if possible
In your own words, define resting potential. Sketch a resting neurons. Indicate where the concentrations of sodium ions and potassium Ions are highest and the relative charges inside and outside of the cell. Explain why the conditions inside and outside a neuron are like this when it is at rest.
resting potential: membrane potential of neuron when NOT sending signals. DRAW!!! more Sodium Na+ ions on the outside; more positively charged on the outside inside more potassium K+ ions less positively charged than outside more negatively charged; they are like this beacause this condition is what does not trigger signals or potentials the pressure within the neuron needs to remain this way
you've probably heard someone say that eating carrots which contain a significant amount of vitamin A, improves your ability to see at night. Explain why a vitamin A deficiency affects your ability to see in the dark AND brighter light, and increasing your vitamin A consumption would improve your ability to see under all light conditions.
retinal is made from vitamin A which means that when higher intake of vitamin A occurs stronger or more retinal can be produced which would improve your ability to improve light which would then be interpreted when its deficient the retinal would less abundant or not as strong and less incapable of absorbing light
