Chapter 3 Flashcards
Which 2 parts of the neuron are most involved in delivery and reception of an electrical transmission?
Dendrite and Axon terminal
What would a result in demyelination of the axon be?
A slow down in electrical transmission as myelin sheath speeds up transmission
What is the purpose of the Nodes of Ranvier?
Momentarily slows down the transmission of an electrical impulse
What type of cells form the myelin sheath?
Glial cells
What other important roles do glial cells play in our nervous system?
They guide new neurons into place, nourish the neurons, detoxify them, and modulate communication between them
What is the purpose of the blood brain barrier and what forms it?
Glial cells form the BBB and its purpose is to prevent the entrance of foreign substances from the blood into the brain
If a graded potential occurs on a neuron, what does this mean?
It means that the neuron does not fire as it does not meet the threshold voltage of -55mV
What “state” is the neuron in when it is at rest?
Polarized state
During depolarization, what occurs?
Sodium flows into the neuron until +40mV is attained
What is it called when potassium ions flow out of the neuron to restore the resting potential of the membrane?
Repolarization
What implications can be drawn from the absolute refractory period?
It implies that there is a limit in the number of action potentials that occur for a neuron
Why is the resting potential of a neuron -70mV?
Due to the uneven distribution of ions as there are more positive sodium ions out than there are positive potassium ions in
Even if a single graded potential is not enough to cause an action potential, why is it possible for graded potentials to cause a neuron to fire?
Since neurons are connected, various graded potentials can be summed so the threshold is met to allow the neuron to fire.
What is the all or none law?
States that the minimum threshold of -55mV must be met in order for the neuron to fire
In chemical transmission, the axon terminal and dendrite of two separate neurons are related by?
Synaptic cleft
What are the two primary categories of neurotransmitters?
Inhibitory and excitatory
If an action potential is less likely to occur due to a neurotransmitter (in other words promotes the flow of potassium ions out of the neuron), what kind of NT is it?
Inhibitory
What do excitatory neurotransmitters do to a neuron?
Makes them more likely to fire as they promote the entrance of sodium ions into the neuron
Is it possible for any neurotransmitter to bind to any receptors? If so/not, explain why.
Due to the lock and key analogy, there is a degree of specifity between NT’s and receptors that prevents just any NT’s to bind to just any receptor
What are the two methods of neurotransmitter deactivation?
Reuptake and breakdown
Explain the process of neurotransmitter reuptake.
After detaching from the receptors, NT’s are reabsorbed into the pre-synaptic axon terminal
Explain the process of neurotransmitter breakdown.
After detaching from the receptors, NT’s are degraded by enzymes in the synaptic cleft
If a person is experiencing a seizure, what inferences can be made regarding the type of neurotransmitter that is predominantly acting?
That the NT’s are likely excitatory in nature
If a person stops breathing, what inferences can be made regarding the type of neurotransmitter that is predominantly acting?
That the NT’s are likely inhibitory in nature
What is cross talk and how is it prevented?
It is when a neuron is receiving inhibitory and excitatory signals but this is prevented as certain neurons contain either inhibitory or excitatory NT receptors (VERY BIG SIMPLIFCATION)
What is the difference between neuromodulators and neurotransmitters?
While neurotransmitters have very specific effects, neuromodulators have more generalized effects
If a drug is agonistic, what kind of effect does it have?
It promotes neurotransmitter activity
If a drug decreases neurotransmitter activity, what kind of drug is it?
Antagonistic
If we determine that a NT is involved with learning, can we (for certain) identify which neurotransmitter it is?
Likely not as almost all of the NT’s we will be dealing with are involved in learning
Which NT is most closely associated with Huntington’s disease? What kind of NT is it?
GABA, inhibitory
Other than learning, what else is glutamate involved in? What type of NT is it?
Memory, excitatory
Acetylcholine is a _________ type of NT and is most associated with __________.
excitatory, motor control
Botulistic bacteria can cause paralysis. Which NT do they most likely inhibit?
Acetylcholine
If there are increases in depression, and an increase in stress and panic disorders, which NT is most likely being reduced?
Norepinephrine
Which NT is most involved in reward, motivation, pleasurable feelings, and voluntary motor control?
Dopamine
What are SSRI’s and what are they thought to help with?
These are serotonin reuptake inhibitors that are thought to help with depression by increasing the time of mechanism by preventing reuptake into the pre-synaptic axon terminal
Decreases in this NT are associated with Parkinson’s while increases in it are associated with scizophrenia. Which NT is it?
Dopamine
If you have an imbalance in this NT, you are often likely to develop depression, anxiety, insomnia, and eating disorders.
Serotonin
This NT is often described to be our “biologically manufactured opiate” and is involved in pain management (dulling).
Endorphins
What 2 branches make up the nervous system?
Central and peripheral
What are spinal reflexes?
These are innate survival reflexes that our spinal chord has developed without the need for input from the brain.
What 2 branches are there in the peripheral nervous system? Which of these branches is involved with voluntary and which is involved with involuntary movement?
Somatic = voluntary and autonomic = involuntary
How does the somatic system cause muscle movement?
Sensory neurons send sensory information to the brain that triggers the motor neurons to generate a response in the form of movement
What is the difference in the way that the parasympathetic and sympathetic nervous systems behave?
Sympathetic excites while the parasympathetic calms. The effects that the sympathetic has are more widespread while parasympathetic often has more localized effects.
What do neuropsychological tests allow us to infer?
The state of cognition, brain function, etc.
What is the process of using electrical impulses to examine and map out the brain called?
Destruction and stimulation
What are the 2 types of structural forms of neuroimaging?
CT and MRI (computerized topography and magnetic resonance imaging)
What is the difference between PET scans and fMRI scans?
While both track bloodflow to the brain during certain events, PET radioactively marks hemoglobin while fMRI tracks hemoglobin as it responds to magnetic impulses.
How do EEG’s (electroencephalograms) act as a functional form of neuroimaging?
It uses electrical impulses to track neural activity during events such as EVENT RELATED POTENTIALS
What are the 3 main parts of the hindbrain?
Cerebellum, pons, and medulla
What is the primary part of the midbrain that we will be discussing?
The reticular formation
What are the 4 parts of the forebrain that we will be discussing?
Thalamus, hypothalamus, basal ganglia, and pituitary gland
What are the 3 main parts of the limbic system that we will be discussing?
Hippocampus, nucleus accumbens, and the amygdala
What is the cerebellum responsible for?
Fine motor control and muscle memory
What are the 3 things that the pons responsible for?
Sleep regulation, dreams, and respiration
What 2 things is the medulla responsible for?
Heart rate and respiration
Why is the reticular formation called the “gatekeeper” or the brain’s “dam”?
Because it can dictate how much information gets transmitted to the cerebral cortex from the hindbrain.
What is the thalamus involved in?
Like a sensory springbroad, is responsible in relaying sensory information to the rest of the brain
What is the basal ganglia responsible for?
Also involved in motor control but is also involved in reward/motivation
What is the pituitary gland responsible for?
Secreting MANY hormones of the body
What is the hypothalamus responsible for?
Controls various biological drives such as eating, temperature regulation, etc.
What is the hippocampus responsible for?
Formation and recollection of memories and navigation
What is the amygdala responsible for?
Emotional response patterns, especially those in response to stress
What is the nucleus accumbens responsible for?
Very involved in dopaminergic responses as it dictates behavior related to pleasure and reward
If vision becomes impaired, which of the four lobes of the brain was most likely affected?
Occipital
If hearing becomes impaired, which of the four lobes was most likely affected?
Temporal
If motor control becomes impaired which of the four lobes was most likely affected?
Frontal
If you are having trouble physically feeling and sensing things around you, which of the four lobes was most likely affected?
Parietal
If self-awareness, speech, and emotional regulation are reduced, which of the four lobes was most likely affected?
Frontal
If you are having trouble with understanding what someone has to say, which of the four lobes was most likely affected?
Temporal
What is the association cortex?
These are neurons that are not directly involved with any specific function but are involved with generating neural activity that aid in the occurrence of these specific functions.
Where is the primary motor cortex located?
Hind frontal lobe
In which lobe is the somatosensory cortex located?
Parietal
If your left expenditures are starting to feel numb, which side of the brain is likely to have experienced an issue?
Right Hemisphere
True or false. If your right side of the brain has experienced any issues, the right side of your body will be experiencing issues as well.
False, it’s the Left Hemisphere
What would happen if you have a stroke in Wernicke’s area?
An issue in comprehending language would arise.
What would happen if you have a stroke in Broca’s area?
An issue in developing speech would arise.
In which lobe is Broca’s area located?
Frontal lobe
In which lobe is Wernicke’s area located?
Temporal lobe
Why is the primary motor cortex next to Broca’s area?
Because Broca’s area is involved in speech formulation, the primary motor cortex is important in enforcing voluntary muscle movement of the tongue to generate speech.
What is neural plasticity?
This is the neuron’s ability to change in structure and function over time.
True or false. Increased use and activity will cause neurons to increase in plasticity?
True. One analogy would be like working out. If you work out a certain muscle (neuron), they will go stronger (increased neural plasticity).
True or false. Plasticity is constant throughout one’s lifetime.
False. Plasticity is highest in young children and gradually decreases as one gets older.
What is evidence for children having higher plasticity?
- They have much more synapses
- They are able to learn languages easier than adults
What is pruning and what causes it?
Connections are lost and synpases are degraded due to decreased use/function.
What is neurogenesis?
This is the process of new neurons being created
Can neurogenesis be modulated?
Yes! Exercise can promote it while alcohol and drugs can suppress it.
What is lateralization?
This discusses how certain functions are localized to certain parts of the brain
Language, logic, and positive emotion are localized to which hemisphere?
Left
Negative emotion, creativity, spatial and melody processing, and imagery are localized to which hemisphere?
Right
Which part of the brain is cut to prevent communication between the two hemispheres of the brain?
Corpus callosum
Is it possible for the two hemispheres to behave independently of one another after the corpus callosum is severed?
Yes, through completely lateralizing certain functions in one of the two halves. For example, language in the left.
