Session 5 Flashcards
Central nervous system consists of
Brain and spinal cord
Peripheral nervous system
Neurons that link the central nervous system to our skin muscles and glands
What system is the nervous system connected to
Endocrine system
Nervous system consists of
Central nervous system and peripheral nervous system
What does the peripheral nervous system do
Connects the nervous system to organs skin and limbs
Allows the brain and spinal cord to receive and send information to other areas of the body
Carries away sensory and motor information to and from the central nervous system
Regulate involuntary body functions
I’ll nervous system composed of
100 billion neurons
Neuron
A cell in the nervous system whose function to receive and transmit information
Neurons composed of
3 different parts
1- cell body/soma
2-dendrite
3-axon
Cell body/soma
Part of neuron
Contains nucleus of cell and keeps the cell alive
Dendrite
Branching treelike fiber
Collects information from other cells and sends info to the soma
Axon
Segmented fibre
Transmits information away from the cell body toward other neurons or to the muscles and glands
Mylenation
Fatty tissue covering axons
Improve speed and keep electrical charges from shorting out
Myelin sheath
How do neurons communicate
Electrical and chemical systems
Electrical charge moves through the neuron itself
Chemicals are used to transmit information between neurons
Signal received by ____ then
Dendrites
Then transmitted to soma (electrical signal) and Then (if signal strong enough) maybe passed to axon and then terminal buttons
If signal reaches terminal buttons what happens
Signaled to emit chemicals (neurotransmitters) which communicate with other neurons across the spaces between the cells (synapses)
Resting potential
More negative than positive ions
Axon remains in resting potential
A state where interior of neuron has a greater number of negatively charged ions than the outside of the cell
Resting potential sodium
More sodium on the outside
Action potential :semipermeable
Semipermeable membrane lets the sodium in
When the axon is stimulated
Action potential more + than -
When the sodium gets let in, the segment temporarily becomes positively charged
Nodes of ranvier
Axon segmented by breaks between segments of myelin sheath
How do can neurons fire a little bit
No they always fire completely
Synapse
Small spaces between neurons
The area where the terminal buttons at the end of the axon of one neuron NEARLY but don’t quite touch the dendrites of another
Neurotransmitters
Neurons communicate with one another by the axons sending chemicals (neurotransmitters) into the space (synapse) that can bind with the dendrites
Complex communication in 2 ways
Lots of connections, but some a better fit than other
Transmitter specific receptors
Complex communications: lots of connections
Some are a better fit than other
Neuron may have synaptic connections with thousands of other neurons
Reason 2 of complexi communication: transmitter specific receptors
Different terminal buttons release different neurotransmitters.
Dendrites will admit the neurotransmitter only if the right shape to fit in the receptor sites on the receiving neuron
LIKE A LOCK AND KEY
Excitatory neurotransmitters
Make cell more likely to fire
Ex. Glutamine
Inhibitory neurotransmitters
Make cell less likely to fire
Ex. Serotonin
What happens white excitatory and inhibitory neurotransmitters are received same time
Influenced by both. Whichever has higher effects wins
What happens when neurotransmitters aren’t accepted
Neurotransmitters not accepted by the receptor sites must be removed from the synapse in order for the next potential stimulation of the neuron to happen
1- Get broken down by enzymes
2-reuptake
Reuptake
Neurotransmitters in the synapse are reabsorbed into the transmitting terminal buttons ready to be released after the neuron fires
Common neuro transmitter
-Acetylcholine
-dopamine
-endorphins
-GABA
-Glutamate
-serotonin
Acetylcholine (ACh)
-Used in spinal chord and motor neurons to stimulate muscle contractions
- used in brain to regulate memory, sleeping, and dreaming by
Nicotine is a ____ acts like _____
Agonist acts like acetylcholine
Dopamine
-involved in movement, motivation, and emotion
-produce feeling of pleasure when released by brain reward system
-involved in learning
Alzheimer’s disease bc of
Under supply of acetylcholine
Schizophrenia linked to
Increases in dopamine
Parkinson’s linked to
Reductions in dopamine
Endorphins
-released in response to exercise, orgasm
-natural pain relievers
-related to compounds found in opium,morphine,heroin
GABA
-gamma-aminobutyric acid
-major inhibitory transmitter in the brain
-lack of GABA leads to involuntary motor actions (seizures)
-alcohol stimulates release of GABA inhibits nervous system and make us feel drunk
Glutamate
-most common neurotransmitter
-realeased in 90% of brains synapses
-found in MSG
-excess can cause overstimulation/migraines/seizures
Serotonin
-involved in mood/appetite/sleep/aggression
-drugs designed to treat depression are to prevent their reuptake
Antidepressants
-make serotonin and norepinephrine more available
-make dopamine more available
-can block ACh to get side effects like dry mouth
Types of antidepressants
-SSRIs
-SNRI
-Atypical
-serotonin modulators
-TCAs
-MAOI
Anti anxiety meds example
SSRIs
Buspirone
Benzodiazepines
SSRIs often used for
Anxiety
Medication used to treat ADHD do what
Increase dopamine
Inhibition serotonin reuptake
Difference between concerta and vyvanse vs Ritalin and adderall
Concerts 12-14 hours
Addy- 4hr
Agonist
Drug that has chemical properties similar to a particular neurotransmitter
What happens when an agonist ingested
Binds to receptor sites in the dendrites to excite neuron
Also blocks the real neurotransmitter
Acts like more of the neurotransmitter is present
Glial cells
Support cells of the CNS
What do glial cells do
Surround and link neurons (protecting them/giving nutrients/ absorbing unused neurotransmitters)
Part of the cause of nerve pain
Glial cells
3 different functions of neurons
Sensory
Motor
Interneuron
Sensory neuron
Carry information from the sensory receptors
Motor neuron
Transmit info to muscles and glands
Interneuron
Most common type
-located primarily within the CNS
-responsible for communicating among the neurons
Spinal cord
Long thin tubular bundle of nerves and supporting cells that extend down from the brain
Ascending tracts in spinal cord
Sensory neurons relay sensory info from the sense organs to the brain
Ascending tracts in spinal cord
Sensory neurons relay sensory info from the sense organs to the brain
Descending tracts spinal cord
Motor neurons relay motor commands back to the body
Reflexes
When a quicker than usual response is required
Spinal cord can do it own processing bypassing the brain altogether
Reflexes triggered when
Sensory info is powerful enough to reach a given threshold and interneurons in spinal cord act to send a message through the motor neurons without relaying info to the brain
Autonomic nervous system
ANS
division of the PNS that governs internal activities:
-heart rate
-breathing
-digestion
-salivation
-urination
-arousal
Can actions of the ANS be controlled
Breathing and sexual activity can
Heart rate and digestion can’t
Somatic nervous system
SNS
-division of PNS controls external aspects of the body:
-skeletal muscles
-skin
-sense organs
Consists mostly of motor nerves for sending brain signals for muscle contraction
ANS divided into
Sympathetic and parasympathetic systems
Sympathetic system
Involved in preparing body for
-behaviour (mostly response to stress)
-^activates organs and glands in endocrine system
-
Parasympathetic system
Calm the body by slowing down heartbeat and breathing
and allowing body to recover from activities the sympathetic system causes
Sympathetic and parasympathetic systems analogy
Sympathetic like the gas pedal
Parasympathetic like the brake
Old brain parts
Brain stem
Limbic system
Cerebellum
New brain parts
Cerebral cortex
Old brain functions
Regulates basic survivals functions such as :
-breathing
-moving
-resting
-feeding
Creates our experiences of emotion
New brain functions
Further brain layers
Provide more advanced functions
-better memory
-more sophisticated social interaction
-new emotions
-
Brain stem parts
Medulla
Pons
Reticular formation
Brain stem location
Begins where spinal cord enters the skull and forms the medulla
Oldest part of brain
Brain stem
Brain stem functions
Control breathing, attention and motor responses
Medulla function
Control heart rate. Blood pressure. Swallowing and breathing
Medulla alone can sustain life
Pons function and shape
Spherical shape above the medulla
Movement and balance and walking
Reticular formation
Long, narrow network of neurons
Running through medulla and pons
Filtering and arousal
-walking. Eating. Sexual activity. Sleeping
Thalamus location
Above brain stem
Thalamus function and shape
Egg shape
Filtering and relaying
Limbic system parts
Hypothalamus
Hippocampus
Amygdala
Limbic system
Social functions/Memory/emotions/rewards and punishment
Involved in Psychological struggles: anxiety. Depression. Autism
Amygdala functions
Perception of and reaction to fear and aggression
Social cognition
Fear-fight or flight/facial responses/processing smells
Amygdala shape and location
2 almond shaped clusters at the end of the hippocampus
Why do children with autism have more anxiety but focus better on special interests
Bigger amygdala’s
Hypothalamus
Monitoring our temperature, heart rate, hormones
Creates feelings of pleasure
Hypothalamus location and shape
Below thalamus
Look like 2 horns
Hippocampus function
Stores info for Long term memory
Cerebellum
“Little brain”
Voluntary movements
-emotional responses, learning (different sounds and textures/procedural memories)
Cerebral cortex
-80% of brains weight
-corticalization
-frontal cortex-reasoning
-parietal lobe- touch
-accipital lobe-vision
-temporal lobe-hearing
Corticalization
Wrinkled surface-more surface area and size
-increased capacity for learning/remembering/thinking
Frontal lobe function
Reasoning, judgement. Planning. Memory
Parietal lobe
Touch
Occipital lobe
Vision
Temporal lobe location and function
I’m front of occipital lobe
-responsible for hearing and language
Neuroplasticity
Brains ability to change its structure and function in response to experience or damage
Enable us to learn and remember new things and adjust to new experiences
Neuroplasticity as adult
Best as a kid. Continues as adults but less so
Can neurons repair themselves
No. But we can grow new ones
3 founders of Neuroplasticity
Paul bach-y-rita - (can blind adults learn to see. Ppl balance with tongues)
Marian Diamond- (use it or lose it. Brain development at any age: diet/exercise/challenge/ newness/ love)
Michael Merzenich-
Michael merzenich
-Naming Neuroplasticity
-competitive neurons
-neural efficiency
-Microelectrodes
-reorganize sensations of hand
Competitive neurons
If u don’t use neurons for one functions something else takes over
Neural efficiency
Learning a task uses more neurons. Then when u get better at it it uses less bc u become more efficient
