Week 5 Ch. 3 Lecture Flashcards
How are NT released to synaptic cleft?
The shift in positivity from the Na+ AP runninging down the axon causes vesicles in the terminal buttons containing neurotransmitter to move to end of terminal branch and the membrane of vesicle will fuse with the terminal membrane and release the neurotransmitters into the synatic cleft.
Where is the motor cortex found
frontal lobe
Role of astrocytes
- Has extensions that support the neurone and help hold it in place.
- axon guidance and synapse support
- Plays a role in providing nutrients and supports blood brain barrier.
- Helps surround capillaries and further protecting the brain from other substances getting in.
- May also play a role in mediating communication in the nervous system.
What is Prosopagnosia
face blindness - unable to recognize faces due to dysfunction of fusiform face area
What is an action potential?
brief shift in electrical charge that travels along the axon
What might damage to one side of parietal lobe cause?
hemineglect
Name the parts of the neuron
Where is lymbic system found
Medial temporal lobe’s
Why is it important for NT to be deactivated?
When NT have done there job after binding to receptor they are released to synaptic cleft but they could bind again which could overstimulate the post synaptic neuron and decreases performance of synaptic cleft, so need to clear up the NT thar have been released to the cleft.
what primary message carrier between the brain and body?
spinal chord
what are the three major parts of the brain?
- Forebrain
- Midbrain
- Hindbrain
Describe the receptors on the post synaptic membrane
ion channel proteins embedded in the post synaptic membrane have receptor sites that allows specific neurotransmitters the bind to their site which alters the flow of ions in and out of the post synaptic membrane
What are the four sections of the cerebral cortex?
- frontal lobe
- occipital lobe
- parietal lobe
- temporal lobe
What is the resting potential of nerve conduction?
-70mV
Gluteus
Gabby
Aced the
End
Service
Nore
Doped it
Glutamate (glutamic acid)
GABA (gamma-aminobutyric acid)
Acetylcholine (ACh)
Norepinephrine
Serotonin
Dopamine
Endorphin
What happens when sodium passively enters the neuron through its channels?
increases the positive voltage inside the neuron
pseudo unipolar neuron function?
They are sensory neurons. The ones found in the dorsal root ganglia, and majority of those in cranial nerve sensory ganglia carry information about touch, vibration, proprioception, pain and temperature to spinal chord for immediate reaction and also carry up to brain for processing.
What are some disorders associated with malfunctioning endorphin?
- oversupply: insensitivity to pain
- undersupply: pain hypersensitivity; immune problems
How does have myelin make nerve conduction faster?
This is faster because Na+ dissipates under myelin sheath to the nodes of ranvier must faster than what it would take for the channels to open if there was no myelin.
which neurotransmitters are inhibitory?
- GABA
- serotonin
- endorphin
What are the key ions in nerve conduction?
- Na+
- K+
- somewhat A-
what are disorders associated with malfunctioning serotonin?
Sir Rotten
depression & sleeping and eating disorders
Describe the sodium-potassium pump
embedded in the membrane and require energy to pump out 3 Na+ and bring in 2 K+ - brings neuron back to resting potential
Role of microglial cells
- They remove damaged neurons and infections and are important for maintaining the health of the CNS.
- Gets rid of waste materials by engulfing them.
Describe the sympathetic nervous system
- Generally activates
- Fight or flight response
- Asked to prepare the body for stressful situation Engaging all the systems organisms resources to respond to the threat
What is the major function of dopamine?
- inhibitory and excitatory
- invovled in voluntary movement, emotional arousal, learning, motivation, experiencing pleasure
Describe saltatory conduction
The propagation of action potentials along myelinated axons from one node of Ranvier to the next node, increasing the conduction velocity of action potentials.
Describe the terminal buttons
The small knobs at the end of an axon that release chemicals called neurotransmitters. The terminal buttons form the Presynaptic Neuron of the synapse
How does Cl- moving into the post synaptic neuron alter its voltage?
Cl- moving into internal space of the post synaptic neuron will cause further decrease in the internal voltage and as it dissipates to the beginning of the axon it will decrease the likelihood the threshold to be acheived for an AP to occur due to depolarization.
Temporel lobe function
- hearing
- processing speech and comrehending language
- recognizing faces
- memory
- emotion
Myelin sheath function
- This myelin sheath allows electrical impulses to transmit quickly and efficiently along the nerve cells
What is the major function of glutamate?
Good Mate
- Excitatory
- found throughout all the brain
- Involved in the control of all behaviours, especially important in learning and memory
When does the voltage change from -70mV to +40mV?
At the site where sodium ions rush in to the interior of the cell passivelt through their channels and cause a significant increase in the positiviely interiorly
Why is the inside of a neuron more negative?
The concentration of Na+ is greater on the outside than that of the K+ concentration on the inside.
Describe the synaptic cleft
microscopic gap between pre-and-postsynaptic neurons; terminal button and dendrites respectively.
What are the three primary types of neurons?
- motor neurons
- sensory neurons
- inter-neurons
Which neurtransmitters are excitatory?
- glutamate
- Acetylcholine
What parts make up the hindbrain?
- medulla
- pons
- cerebellum
Name given to neuron recieving NT
postsynaptic neuron
Which ions cause excitatory post synaptic potential?
Na+ causing depolarization
Where is the prefrontal cortex found
frontal lobe
What is the major function of GABA?
- Inhibitory
- found throughout the brain
- involved in controlling all behaviours; especially important in anxiety and motor control
What is the action potential of nerve conduction called?
depolarization
What are some disorders associated with malfunctioning GABA?
ABBA
Destruction of GABA producing neurons in hungtingtons disease produces tremors and loss of motor control as well as personality changes
Which ions cause inhibitory post synaptic potential?
K+ & Cl- causing hyperpolarization
What disorders are associated with malfunctioning ACh?
A
- undersupply: memory loss in Alzheimers disease
- oversupply: muscle contractions; convulsions
In the nerve conduction when is the neuron in hyperpolarization?
absolute refractory period
Describe the peripheral system
- Made up of neurons with long axons and dendrites
- Branches out from the spinal cord and the brain to reach the extremities of the body
What pump is used in nerve conduction?
sodium-potassium pump
Describe the myelin sheath
- Insulating layer, or sheath that forms around nerves, including those in the brain and spinal cord.
- It is made up of protein and fatty substances.
Describe summation
is the process that determines whether or not an action potential will be generated by the combined effects of excitatory and inhibitory signals, both from multiple simultaneous inputs, and from repeated inputs
The 2 parts of the nervous system
- central nervous system
- peripheral nervous system
What are the steps in nerve conduction?
What is the permability of an neuron membrane?
selectively permeable
How are NT deactivated?
- Chemical breakdown from enzymes present in synaptic cleft
- recycles due to reuptake into presynaptic terminal membrane where it is once again stored in vesicle to be released when AP comes.
What type of model is the NT and receptor sites?
lock & key model
describe the absolute refractory period
A period where it is completely impossible for another action potential to be activated, regardless of the size of the trigger (stimulus). This is because the sodium channels are inactivated and remain that way until hyperpolarisation occurs to allow Na+ to dissipate down the axon and let the sodium-patassium pump serve its purpose.
Describe the parasympathetic nervous system
- Generally inhibits
- Maintaining normal functions
- Asked to call nobody after emergency a stressful situation has ended
What are some disorders associated with malfunctioning dopamine?
- undersupply: parkinsons disease and depression
- oversupply: schizophrenia
What is the function of the autonomic nervous system?
- Controls smooth muscles cardiac muscles and glands
- Basically involuntary muscle movements
What are the 4 types of glial cells?
- astrocyte
- microglial cell
- oligodendrocytes
- ependymal cells
Role of Ependymal cells
- Found mostly in ventricles
- help filter blood
- manufacture and regulate cerebral spinal fluid (CSF) which provide nutrient to CNS and some cushioning.
- Bathes the brain and spinal chord in protective layer.
How does Na+ moving into the post synaptic neuron alter its voltage?
Depolarizes the post synaptic neuron by increasing the positivity of voltage inside and bringing some postivity with it as it dissipates towards the axon start making it more likely to achieve the neccessary threshold for an AP to occur at the start if the axon.
parietal function
- sensory touch info
- visual attention
- spatial reasoning
How does the AP move down the axon?
If -55mV threshold is met, a sodium channel at that threshold position will open and Na+ ions will rush in a dissipate down the axon increasing the positivity in the direction it moves so as to open sodium channels as it moves down the axon, and K+ channels, and process goes all the way to terminal buttons.
What messages to sensory neurons carry?
Messages to the CNS
describe temporal summation
occurs when voltage runs down one dendrite of post synaptic neuron many times over a period of time.
Describe a pseudo-unipolar neuron
Type of neuron which has one extension from its cell body. This type of neuron contains an axon that has split into two branches; one branch travels to the peripheral nervous system and the other to the central nervous system. Cell body exists in dorsal roots just outside of spinal chord.
motor cortex function
Control over goal directed movements
What is the shift of voltage during an AP?
from -70mV to +40mV
Occipital lobe function
- vision
- specialized for: colour, shape, movement
What is the disorder associated with a dysfunctioning basil ganglia?
parkinsons
What are the 2 forms of summation?
- temporal summation
- spatial summation
What ions are the protein channels specific to on the post synaptic membrane?
- Na+
- K+
- Cl-
multipolar neuron function
Constitute the majority of neurons in the central nervous system. They include motor neurons and interneurons/relaying neurons are most commonly found in the cortex of the brain and the spinal cord. Peripherally, multipolar neurons are found in autonomic ganglia.
Which neurotransmitters can be both excitatory and inhibitory?
Dopamine and Norepinephrin
What is the major function of endorphin?
inhibits transmission of pain impulses
Describe multipolar neurons
Possesses a single axon and many dendrites (and dendritic branches), allowing for the integration of a great deal of information from other neurons.
What are some disorders associated with malfunctioning norepinephrine?
- undersupply: depression
- oversupply: stress and panic disorders
prefrontal cortex function
- executive function
- complex mental abilities such as setting goals, judgements, tartegic planning, controlling impulses, adapting behaviour to novel scenarios
Where do neurons communicate?
functional connection at the synapse
What to systems make up the PNS?
- autonomic nervous system
- Somatic nervous system
Where is the somatic sensory cortex found
parietal lobe
Role of oligodendrocytes
- highly specialized neural cells whose function is to myelinate central nervous system axons.
What is the major function of Acetylcholine
Aces are fit
excitatory at synapses invovled in muscular movement and memory
What is the major function of norepinephrine?
pine trees are connected
- excitatory and inhibitory functions at certain sites
- invovled in neural circuits controlling learning, memory, wakefulness and eating
How does K+ moving out of the post synaptic neuron alter its voltage?
If a neurotransmitter opens a K+ channel then the voltage within will become even more negative, and K+ at start of axon will move to dendrites to equalize the conc. internally causing hyperpolarization therfore making the beginning of the axon more positive and decreasing the likelihood for the neccessary threshold to be met for an AP to occur.
bipolar neuron function
Specialized sensory neurons for the transmission of sense. As such, they are part of the sensory pathways for smell, sight, taste, hearing, touch, balance and proprioception.
How long is a Na+ channel open for?
less than a 1 ms
What is the major function of serotonin?
Sir Rotten
inhibitory at most sites; involved in mood, sleep, eating and arousal and may be an important transmitter underlying pleasure and pain
what messages do motor neurons carry?
Messages from the CNS to voluntary muscles
How does passive ion movement occur for the Na+ and K+ channels?
- concentration gradient
- electrostatic pressure
What part of the nerve conduction is polarized?
the resting stage and resting potential.
What are the key regions of the limbic system? What are their key functions?
- hippocampus - memory
- amygdala - emotional response
How do the Na+ and K+ channels open?
voltage gated - -55mV voltag must be met for Na+ channels to open which ions can then passively move through
Cerebellum function
- Timing and coordination of fine movement
- balance
frontal lobe function
- ability to plan and carry out sequences of action
- control our behaviour
Describe spatial summation
occurs when dendrites together release enough ions to summate to exceed the threshold of the postsynaptic neurone at the axon start
Describe glial cells
non-neuronal cells in the central nervous system (brain and spinal cord) and the peripheral nervous system that do not produce electrical impulses. They maintain homeostasis, form myelin, and provide support and protection for neurons.
What is the voltage threshold the neuron must meet in order for a AP to occur along the axon?
-55mV
How do neurotransmitters interact with the post synaptic neurons
through receptors
Purpose of neurons
to recieve, integrate and transmit information
What types of neurons make up the somatic peripheral nervous system?
- Sensory neurons
- Motor neurons
Describe a bipolar neuron
a type of neuron that has two extensions (one axon and one dendrite).
What are the 3 configurations of neurons?
- unipolar
- bipolar
- multipolar
What are the 7 major neurotransmitters?
- Glutamate (glutamic acid)
- GABA (gamma-aminobutyric acid)
- Acetylcholine (ACh)
- Norepinephrine
- Serotonin
- Dopamine
- Endorphin
What are the two parts of the autonomic nervous system?
- Sympathetic nervous system
- Parasympathetic nervous system
Name given to neuron sending neurotranmitters
presynaptic neuron
What is the CNS composed of?
brain and spinal chord
function of basil ganglia
- Helps to regulate voluntary movement initiated by motor cortex
- Involves the neurotransmitter dopamine
Describe graded potential movement
Changes in membrane potential that vary in size, as opposed to being all-or-none. The magnitude of a graded potential is determined by the strength of the stimulus.
How do K+ channels open?
After Na+ ions rush in tey increase the positivity of th inside beyond the -55vM threshold so as to increase the voltage moreso and this opens the k+ channels for them to passively move out of the cell to regions of lower conc. to help restore resting potential
