Term
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Definition
Massive Change in membrane voltage resulting from a strong stimulus;
All have the same peak
Always looks exactly the same |
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Term
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Definition
| All voltage-gated channels are shut and there is relatively more negative charge on the inside than the outside |
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Term
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Definition
A stimulus causes some gates to open.
The proteins change shape to allow the gates to open. The greater the stimulus, the more gated channels that open. |
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Term
As more gates open, the inside of the cell becomes ________ ____________, and more channels continue opening in response to the ___________
charge in the cell or greater intensity of stimulus more solutions, more sodium enters the cell |
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Definition
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Term
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Definition
| When threshold is reached, charge quickly goes from -70mv to +45/50 mv |
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Term
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Definition
| Time at which potassium is flowing out at a faster rate than what is needed to reach resting potential undergoing hyperpolarization relative to resting potential, making it harder to do an action potential preventing another action potential from forming and giving the neuron a chance to recharge and not continuously firing |
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Term
| Depolarizations that do not pass threshold return to _______ potential, keeping the charge below the threshold |
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Definition
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Term
| The signal is first received at the portion of the cell __________ to/from the body |
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Definition
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Term
| The signal travels from left to right because |
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Definition
| The sodium ions diffuse in both directions stimulating the other gated Na channels to open causing the signal to move down the axon |
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Term
| The signal cant go backwards because |
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Definition
| The sections on left are undergoing undershoot, preventing the signal from going backward |
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Term
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Definition
| The period in which another action potential cannot form as a result of undershoot |
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Term
| Steps of generating an action potential |
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Definition
1. Resting potential
2. Depolarization
3. Rising Phase of the action potential
4. Falling phase of the action potential
5. Undershoot
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Term
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Definition
| Causes some voltage-gated sodium channels to open making the cell less and less negative and more positive. This produced positive feedback. More sodium - more voltage gated channels, more positive leading to rising phase of action potential |
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Term
Rising phase of the action potential
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Definition
| all voltage gated sodium channels are open once it becomes too positive at the peak (action potential), the voltage gated sodium channels shut |
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Term
| Falling phase of the action potential |
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Definition
| the rising phase triggers the falling phase of the action potential in which more and more voltage gated sodium channels to close and allow the voltage gated potassium channels to open allowing the potassium to flow out down its concentration gradient in which the cell becomes more and more negative and it heads down toward resting potential |
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Term
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Definition
| The voltage gated potassium channels stay open for too long resulting in -75 mV undershoot. Then cell rebounds bck to resting potential. |
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Term
| Is the action potential system ever at equilibrium? |
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Definition
| No, because the sodium-potassium pump powered by ATP is continually working to maintain concentration gradients |
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Term
True or false?
Myelin sheaths allow for the transmission of the signal to travel at a much slower rate? |
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Definition
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Term
Nodes of Ranvier
(depolarized region)
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Definition
| The bare regions that sheaths do not cover |
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Term
| Where does depolarization only take place? |
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Definition
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Term
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Definition
| When the signal jumps from one node of Ranvier to another. This occurs because protein channels only occuer where there are exposed areas of axon |
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Term
True or false?
Myelin sheaths are companion cells made of nonpolar lipids that block movement of ions |
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Definition
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Term
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Definition
increased or total exposure of axons, muscle spasms, etc.
Attacks the myelin sheath |
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Term
| At the synapse, information is taken from the ____________ to the _____________. At this point the electrical signals are converted to chemical (neurotransmitter signals). |
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Definition
Presynaptic Cell; Postsynaptic Cell
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Term
| At the end of the axon, __________ are present. They are voltage gated and open in response to a positive action potential. |
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Definition
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Term
True or false?
Calcium tends to have a lower concentration outside of cell so when cannels open, calcium moves into the cell |
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Definition
False,
Calcium tends to have a higher concentration outside of the cell |
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Term
| Synaptic vessels containing neurotransmitters migrate after being triggered by __________. They move to synapse, fuse with cell membrane, and release chemical across the synapse. |
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Definition
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Term
| The presynaptic neuron synthesizes and packages the _____________? |
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Definition
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Term
| Neurotransmitter diffuses across the ____________ and is received by the postsynaptic cell |
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Definition
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Term
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Definition
| Neurotransmitter causes these channels to open, which causes a bunch of sodium to rush in and K+ to leave resulting in the origination of depolarization |
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Term
| If enough ligand gated channels open in response to a strong enough signal, theshold is reached an an __________ ___________ is produced |
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Definition
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Term
| When the neurotransmitter is removed from the protein channel, does the signal transmissions begin or end? |
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Definition
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Term
| Characteristics of neurotransmitters |
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Definition
1. Fit specifically into the ligand gated channels
2. Vary in structure, location, and function
3. Receptors are specific for individuals chemical transmitters |
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Term
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Definition
| Chemically operated receptor with ion channel. Ion channel opens when ACH binds and closes when it is removed |
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Term
| Epinephrine and norepinephrine |
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Definition
Trigger fight or flight in PNS
(everything outside CNS) |
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Term
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Definition
| Affects mood, sleep, learning in CNS |
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Term
| Substance P and Endorphins |
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Definition
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Term
|
Definition
| Enzyme degradation of neurotransmitter, then reabsorption of neurotransmitter |
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Term
| Acetylcholinesterase AchE |
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Definition
| An enzyme that breaks down acetylcholine and recycles it to be rebuilt ending signal transmitting |
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Term
| Cholinesterase inhibitors |
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Definition
| Blocks breakdown of acetylcholine; can't stop the action potential |
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Term
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Definition
| Overloads system going into shock causing death |
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Term
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Definition
| Slow down this breakdown if acetylcholine allowing the brain and nervous system to function a little better |
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Term
| Ex of Reabsorption of Neurotransmitter |
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Definition
Seratonin re-up taken into the presynaptic neuron.
Prozac and seratonin block uptake of serotonin thus increase the activation of seratonin receptors. |
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Term
| Calcium flows into the cell because of a ____________ ___________. It flows using facilitated diffusion. |
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Definition
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Term
| Neurotransmitter diffues across synapse and binds to ___________ ________ causing sodium to flow in triggering an action potential in the post-synaptic neuron. |
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Definition
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Term
| Some neurons are inhibitory and some are excitatory. This can change depending on which __________ are present because they can be excitatory or inhibitory. |
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Definition
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Term
| Two categories of postsynaptic potentials |
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Definition
1. Excitatory postsynaptic potentials (EPSPs) - depolarizations that bring membrane potential toward threshold
2. Inhibitory postsynaptic potentials (IPSPs) - hyperpolarizations that move membrane potential farther from the threshold |
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Term
| Two different ways in which the brain and the spine work |
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Definition
1. Temporal summation - signals coming into nerve cell. If the depolarizations occur too far apart (timing is not appropriate) an action potential will not occur. If they are close enough together, this can lead to enough of a depolarization for an action potential to occur.
2. Spatial Summation - input from multiple neurons. Ex: two neurons must release neurotransmitter at exactly the same time for an action potential to be produced. |
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Term
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Definition
| Brain and spinal cord with interneurons |
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Term
| Peripheral nervous system |
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Definition
| All other nerves outside nervous system: spinal nerves, ganglia outside CNS, cranial nerves |
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Term
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Definition
| bunches of neurons feeding into one location. Refers to the group of cell bodies |
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Term
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Definition
| interior regions of grey matter (mostly cell bodies or neurons without myelin sheath) and outside white matter (has axons coated with myelin sheaths) |
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Term
Where is the grey matter located in the brain?
White matter?
What are ventricles in the brain? |
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Definition
1. Outisde
2. Inside
3. Spaces inside the brain |
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Term
| Two main functions of the spinal cord |
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Definition
1. Conveys information between brain and PNS
2. Produces reflexes independently of brain (automatic response to a stimulus) |
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Term
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Definition
| Stimulus triggers action potential from neuron in quadriceps which travels through body and enter the spine at the doral root ganglia. It then enters the spinal cord and interacts with an interneuron in the gray matter. Information leaving the spine goes out through the ventral root ganglia. Muscles kick out. This represent a part of the Somatic Nervous system - we have voluntary control over this except for reflexes. |
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Term
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Definition
| growth, reproduction (rest and digest) ex. Constricts pupil of eye, slows heart, stops digestive functions. Ganglia of this system are found at the base of brain at brain stem. Some found near bladder |
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Term
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Definition
| emergency, excercise (fight or flight) ex. Accelerates heart, dilates pupils, sotp digestive functions. Ganglia of these neurons originate in the middle of the spine. |
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Term
| What is the most important in the somatic nervous system? |
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Definition
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Term
| What is most important in sympathetic division? |
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Definition
| Norepinephrine and Epinephrine |
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Term
| The sympathetic division can produce affects through homone production through glands instead of directly to organs. Is this a faster or slower response? |
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Definition
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Term
|
Definition
Neurons that send information to skeletal muscle, muscular system. Acetylcholine is the primary neurotransmitter.
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Term
| Nervous system and endocrine system work together how? |
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Definition
| Action potential stimulates glands to release hormones that cause organs to work in certain ways |
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Term
|
Definition
1. Mechanoreceptors - stretch, motion, touch, sound. These sensory cells allow organisms to respond to their environment
2. Pain Receptors
3. Thermoreceptors - Detect heat signals. Ex: some snakes can find prey through heat signatures
4. Chemoreceptor - detects presence of chemicals Ex: tase, smell, osmotic concentration, pH, Specific chemicals (glucose, oxygen etc.)
5. Electromagnetic receptors - light, electric, mag. fields
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Term
| Sensory receptors in human skin |
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Definition
| Largest organ in the body, protects internal body from outside bacteria, etc. Has sensory organs under skin to detect signals. Right under skin, nerve endings exist to detect pain. |
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Term
|
Definition
| coats the interior of the nasal cavity.It also traps odor particles in the air. Some particles attach to chemoreceptors in cells This attachment triggers a response and change in ion channels. |
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Term
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Definition
| Trigger smell. They are the particles in the air trapped by mucus. |
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Term
| Smokers or people in highly polluted areas destroy what types of cells, which reduce their sense of smell? |
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Definition
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Term
| Mechanoreception by a hair cell |
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Definition
| Number of action potentials (frequency)/ per second "code"information from receptor (sensory) cell |
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Term
|
Definition
| Extensions of cell membrane in the ear |
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Term
| When hairs are straight up and no movement occurs, action potentials are regular and no sound occurs and less _________ is produced |
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Definition
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Term
| If hairs are pushed one direction, by a sound, the potentials are more or less frequent? Is more or less transmitter produced? |
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Definition
| More frequent and more neurotransmitter is produced, resulting in sound being heard. |
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Term
| Animals use a diverse set of organs for vision, but the underlying mechanism for capturing light is the same... this leads us to agree with __________? |
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Definition
| Common Evolutionary Origin |
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Term
| Light detectors all contain photoreceptors. Define photoreceptors. |
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Definition
| Cells that contain light-absorbing pigment molecules |
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Term
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Definition
| One of the simplest light-detecting organs in planarians. These have pigment molecules that light bounces off of and then is abosrbed by the visual pigment triggering an action potentinal. Planarians only see light and darkness |
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Term
|
Definition
| Insects and crustaceans. They are composed of a series of lenses like ocelli. They have thousands on each eye,called Ommatidium. They are good at detecting motion. This is why flies can easily detect motion and can see some pictures. |
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Term
|
Definition
| Light enters through the pupil to the lens and bouces off of the retina and hits specialized photoreceptor cells called rods and cones |
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Term
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Definition
| More sensitive than cones. They are sensitive because they don't rely on threshold to send a signal. They allow for night vision. |
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Term
|
Definition
| Allows us to see colors. They only respond to bright light |
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Term
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Definition
| Work together to tell the brain what is being seen by the eye. They are stimulated to transfer action potentials to neurons and then to the optic nerve fibers which transfer them to the brain |
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Term
| Example of a Signal transduction pathway |
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Definition
| When hyperpolarization from a cell being closed triggers action potentials to tell the brain that light is present. |
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Term
| Chemical Signals in Animals |
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Definition
| Responses triggered by the presence or absence of chemical |
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Term
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Definition
| Communication between two neurons |
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Term
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Definition
| uses endocrine signalas carried by bloodstream (only affects target cells). Hormonal (endocrine) signals only produce a response in target cells. |
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Term
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Definition
| Located in brain - makes melatonin - works in mood, sleep patterns, etc. |
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Term
| Hypothalamus and Pituitary gland |
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Definition
| Hang off bottom of brain. .Control and regulate all other glands except pineal gland |
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Term
| Thyroid and associated glands |
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Definition
| parathyroid is in it. Regulates the metabolic rate and homeostasis, especially metabolism |
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Term
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Definition
| Glucagon and insulin regulates sugar content in the body |
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Term
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Definition
| Located on top of the kidneys. Make adrenaline |
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Term
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Definition
| Regulate development and reproduction |
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Term
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Definition
| conveys high speed electrical signals along specialized cells (neurons) to regulate other cells |
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Term
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Definition
| Secretes hormons to coordinate slower, long-lasting term acting responses (reproduction, development, energy, metabolism, growth, behavior) |
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Term
| Hormones are usually regulated by negative feedback loops. |
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Definition
| Example: Pancreas - insulin |
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Term
| Two different types of chemical messenger |
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Definition
| Hydrophobic and Hydrophilic |
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Term
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Definition
| communication between two neurons. An electrical signal released by presynaptic neuron causes it to release neurotransmitters that diffuse across a synapse. Can be between a neuron and some other cell. It is an example of synaptic signaling. |
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Term
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Definition
| Endocrine signals carried by bloodstream only target cells are affected |
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Term
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Definition
| Chemical messenger transported through the body in bloodstream. Have a specific 3D shape. |
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Term
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Definition
| release and synthesize hormones into the bloodstream. Target cells have protein receptors for hormones. The binding triggers a response |
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Term
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Definition
| An example of long distance signaling. Links nervous and endocrine signaling. |
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Term
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Definition
axon doesnt end at neurons, it ends at blood vessel and releases neurotransmitter in bloodstream which is now a hormone
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Term
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Definition
| last much longer and are more permanent than nervous system. |
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Term
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Definition
| Not lipid soluble. Hormones that bind specific receptors on cell membrane. The response in nucleus is either gene regulation (turning on and off of genes) or in the cytoplasm (cytoplasmic response). They pass through blood and cant go through membrane. They are eventually received by a signal receptor on the surface of membrane. They are charged or polar molecules |
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Term
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Definition
| non-polar not charged molecules. They can easily pass through cell membrane (lipid soluble) bind to transport protein to prevent sticking together in blood. Locate cell with correct receptor. Pass through membrane and nuclear membrane where it attaches to signal receptor in nucleus almost always results in gene regulation resulting in a cytoplasmic response. |
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Term
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Definition
| propagation of the signal. Binding between signal molecule (ligand) and receptor (plasmamembrane protein) highly specific |
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Term
|
Definition
| Because the receptor is bound to signaling molecule, usually shape change triggers the signal transduction pathway |
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Term
| Shape change causes transduction |
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Definition
|
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Term
| Response. Signal T. Pathway |
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Definition
| series of steps by which signal in cell's surface is converted into a specific cellular response |
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Term
| G- Protein coupled receptor |
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Definition
| Most common type of receptor. found on the surface. Just under the surface is an inactive g-protein. |
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Term
| Binding of signaling molecule |
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Definition
| energy is consumed and g-protein migrates across to activate an enzyme that can affect cell |
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Term
|
Definition
| acts as on/off switch; if GDP is bound to G protein, it is inactive. Example of a hydrophilic messenger using intermediary molecules |
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Term
|
Definition
| act via second messenger inside cell. The most common secondary messenger in cells is cyclic AMP (cAMP) |
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Term
|
Definition
| directly regulate genetic machinery (whats going in nucleus). Hormone binds to receptor in cytoplasm creating an activated hormone-receptor complex |
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Term
| Final activated HRC may function as a transcription factor by turning genes on or off |
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Definition
| Transcription factors turn transcriptionon and produce mRNA binding with ribosomes making protein. Most hydrophobic hormones work by turning genes on or off. |
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Term
|
Definition
| Activate 2nd messenger cascade. Act quickly but often short term. Not as fast as nervous system, but makes the fastest hormones. Have receptors on external outside of cell. |
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Term
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Definition
| Activate Genetic Machinery. Move slowly-longer term. Have internal receptors. |
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Term
| Hydrophobic and Hydrophilic Messengers |
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Definition
Allow the endocrine system to respond in different ways:
Hydrophilic - peptide and protein hormones (insulin growth hormones) work in blood sugar and seal wounds. Also epinephrine (adrenaline) which works in the fight or flight, These hormones are needed in quick use for immediate action.
Hydrophobic - thyroid hormones, metabolic activity, melatonin- mood /sleep cycle, steroid hormones (cortisol, sex hormones) influence development. These work in gradual long-term efffects |
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Term
| One hormone may have different effects in different target tissues (parts of body) caused by: |
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Definition
1. Same receptors, but different intracellular proteins lead to different cellular response
2. Or two different receptors lead to different cell response
3. Different effects |
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Term
| Many endocrine glands have other functions such as the heart. Whereas the thymus is solely an endocrine gland |
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Definition
|
|
Term
| The endocrine system is better at coordinating and controlling slower but loner acting responses in comparison with the nervous system. |
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Definition
| ex: metamorphosis of a butterfly, energy metabolism. growth, etc. |
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Term
| Posterior pituitary - heurohormone pathway |
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Definition
| How hypothalamus and pituitary work together. The hypothalamus is a part of the brain composed of neurons called neurosecretary cells that produce action potentials and release hormones instead of neurotransmitter. The hypothalamus is triggered by direct connection to the brain. Directly below the hypothalamus are two small structures called pituitary glands: the posterior pituitary and anteior pituitary. They hang just below the brain and above the nasal cavity. The posterior pituitary is actually just an extension of the neurons in the hypothalamus. They end here. Hormons released by the posterior pit are ADH and oxytocin. The posterior pit is a neurostimulated pathway |
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Term
|
Definition
| Anti-diuretic hormone - has a target in the kidneys. Regulates the amount of urine production and water retention in the body |
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Term
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Definition
| Primarily important in females. Stimulates lactation in mammary glands and contraction in the uterus at birth. Males have it at very low levels and may affect mood/behavior but not sure |
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Term
|
Definition
FSH and LH - have receptors in testes/ovaries
TSH - thyroid
ACTH - adrenal complex
PROLACTIN - mammary glands
MSH - melanocytes in skin
GH - growth hormone, live, bones, other tissues
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Term
| The temperature-regulating center of vertebrate animals is located in the? |
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Definition
|
|
Term
| Thyroid hormones function in |
|
Definition
| Development. Maintain heart rate, epidermis, difgestion and reproduction. Bioenergetics (metabolic rate) |
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Term
|
Definition
| Elevated heart rate, blood pressure, and metabolism |
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Term
|
Definition
| Decreased metabolic rate, lethargy, hair loss, weight gain, fertility prolems |
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Term
| What happens when a resting neuron's membrane depolarizes? |
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Definition
| Its membrane voltage becomes more positive |
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Term
| The operation of the sodium potassium pump moves? |
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Definition
| sodium ions out of the cell and potassium ions into the cell |
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Term
| The activity of acetylcholine in a synapse is terminated by? |
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Definition
| its degradation by a hydrolytic enzyme on the postsynaptic membrane |
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Term
| Most of neurons in the human brain are |
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Definition
|
|
Term
| A resting motor neuron is expected to? |
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Definition
| Exhibit a resting potential that is more negative than the threshold potential |
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Term
| Where are the neurotransmitter receptors located? |
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Definition
| The postsynaptic membrane |
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|
Term
| Why are the action potentials usually conducted in one direction? |
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Definition
| The brief refractory period prevents reopening of voltage-gated Na+ channels |
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Term
| As body size increases in animals |
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Definition
| there is a decrease in the surface to volume ratio |
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Term
| An example of effectors roles in homeostatic responses is observable when? |
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Definition
| An increase in body temperature results from involuntary shivering |
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Term
| To prepare flight muscles for use on a cool morning, moths? |
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Definition
| Rapdily contract and relax these muscles to generate metabolic warmth |
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Term
| Humans can lose but not gain heat through the process of |
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Definition
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