Psychology Midterm (1) - Chapter 3 Flashcards
The Nervous System consists:
2 main divisions
CNS: Brain and spinal cord
PNS: All the other nerves in the body
The 2 divisions:
constantly work as a joined unit, to produce the simplest behaviours
Nervous System
a communication network
Receives: from the external world and from the body
Analyzes: organizing and joining existing info
Uses this information to: send out messages to muscles
Cells of the NS
Neurons: basic unit of communication in the network
Neurons: In a nutshell
an electrochemical process
the neuron fires and produces an electrical impulse when it communicates
Neurons Communicate
Electrochemically
Neurons ultimately lead to
release of neuro transitions
Neurons communicate in:
Action potential/neural impulse/electrical impulse
Neurotransmitters:
send messages to other neurons
Neurons shapes
they all have the same basic structure, but vary in shapes and sizes,
Basic structure of Neurons:
Cell body -> soma:
Contains the nucleus of cell and DNA,
manufacturer everything it needs to survive, grow, and function
Basic structure of Neurons: Dendrites
Tree branches coming out of cell body
Recieve info and messages from other neurons
Basic structure of Neurons: Axon
Carry the potential all the way to the terminal buttons
Basic structure of Neurons: Axon branches/ Axon terminals
end of axon where signal branches off
Basic structure of Neurons: Terminal buttons
Releases neurotransmitter
Basic structure of Neurons: Myelin sheath
made out of proteins and lipids, they cover some of the axon.
Basic structure of Neurons: Synapse
neurons meet in order to communicate and exchange information
Basic Sturcture of Neurons: Synaptic cleft/gap
A tiny gap between two neurons at the synapse
Basic Structure of Neurons: Presynaptic neuron
is the neuron that sends out messages.
Basic Structure of Neurons:
Postsynaptic neuron
is the neuron that receives messages.
Cells of the Nervous System: Glial Cells (Glia)
There are billions of them
Nannies of the neurons because They help neurons:
develop
nutrition
insulation
protection
clean after them
remove dead neurons
They help with higher mental function such as: learning, memory, intelligence and creativity.
Different types of glial cells: Oligodendrocytes and Schwann
Oligodendrocytes: do so in central nerovus system
Schwann cells: do so in the nerves outside of the brain and spinal cord
The cells are involved in the production, laying down, and repair of the myelin sheath, they speed up the communication in the central nervous system
Microglia
help form the Immune function
Play a role in learning and memory: degeneration linked with Alzheimer’s disease.
Astrocytes and Microglia Cells
Other types of glial cells share in the immune duties of the microglia.
what type of diseases are linked to the astrocytes and microgilia cells:
neurodegenerative disease
Communication within a neuron:
80% water dissolves chemicals in them
Intracellular Fluid
Inside neuron: Aprox 40% of total human body weight, contain electrolytes and proteins cells
Extracellular Fluid
Outside Neuron: Other 40%, body fluid which does not contain cells
Chemicals Dissolved
Na+ (Sodium Ion) Pos Charge
Cl- (Chloride Ion) Neg Charge
K+ (Pottasium Ion) Pos Charge
Neuron at rest
Does not communicate
High concentrations of neg ions are inside the neuron
High concentrations of pos ions are outside
Ions at rest
Electric charge is at -70mV
Membrane is polarized
“Receive messages even at rest
2 Major Types of Messages
Inhibitory and Excitatory
Inhibitory
Tells neuron not to fire and produce action potentials
Messeages change the concentration of ions
Membrane is Hyperpolarized: More neg inside neuron due to concentration change
Ex: -70mv to -76mv
Excitatory
Messages change the concentration of ions
The membrane is Depolarized; become less neg on inside
Ex: -70mv to -63mv
This occurs when it reaches about -50mv
Nodes of Ranvier
Gaps in the axon which are not covered by the myelin sheath
Nodes of Ranvier: Purpouse
Nodes are the “walls and windows of the axons
By using this channel, Ions can get in and out of the neuron
Ions do not move in and out randomly, there are rules which control their movemnts
Rules - Inhibatory Messages: What happens when Cl Channels open?
Chloride ions move inside the neuron (Influx)
They increase number of negative ions inside the neuron
Neuron becomes more negatively charged
Membrane is hyperpolarized and the neuron is less likely to fire
Rules-Exicatory Message, When sodium channels open:
Sodium ions move inside the neuron (Influx)
Increases number of positive ions inside neuron
Inside nuron becomes less negativly charged and is depolarized (neuron is likely to fire)
If electrical charge inside the neuron to reach -50mv, neuron will fire
Once neuron has fired, it needs to go back to resting potential before it can fire again
Once sodium ions have entered cell, k+ channels open
Exicatory Message: When K+ Channels open:
Potassium ions start leaving the neuron (Efflux)
less positive ions in neuron which makes the cell less positive
When Electrical charge reaches -70mv and the neuron is polarized again.
The neuron is at resting potential.
Refactory period
Before the neuron reaches its resting potential,
neuron will not fire when stimulated
Membrane is hyperpolarized (more negative than -70mv) due high number of potassium ions out of the cell.
Sodium ions will be pumped out and potassium ions will be pumped back in.
Communication between neurons:
Presynaptic neuron sends out messages and produces:
Action potential travels/propagates
Terminal buttons
neurotransmitteres exits
Synaptic Vesicles
Little bags which contain neurotransmitters, (they attach to the terminal button which attach to the membrane of the neurons)
Neurotransmitters
goes to the postsynaptic neuron, and attaches to the receptor site (it’s own parking site)
They must attch to the receptor site, if it does not attach it can not deliver messages
Each neurotransmitter has its own receptor site
Reuptake
reabsorbption by neuron after delivering the message, it gets reobserved and recycled
Degradation
Once neuron has delivered message, enzyme comes and breaks it down
Why?
If neurotransmitter is deactivated, It delivers the message over and over again and it over inhibits the nervous system
Bind to receptor sites : Neurotransmitters:
Deliver messages between neurons
to be healthy mentally and physically, healthy levels of neurotransmitters are a must,
Some deliver excitatory messages only:
Acetylcholine:
Acetylcholine:
Learning muscle action
Associated Drug: Botox
Botox stops the release of neurotransmitter acetylcholine, which prevents muscle contractions (ex: wrinkles)
Glutamate
Leaning and movement
Associated Drug: PCP causes hallucinations, ketamine (anesthetic)
Some deliver inhibitory messages only: GABA
Leanirning, anxiety regulation through inhibition of neurons, says to not fire/communicate
Some deliver inhibitory messages only: Dopamine
Learning, Reward/ Pleasure
Healthy levels of dopamine: Positive mood, more motivated. Healthy motor functions
Low levels of dopamine: Depressed, not motivated
It is implicated in behaviours and circuits
Some deliver inhibitory messages only: Serotonin
Elevation/Depression of mood
Drug: Cocaine (prevents reuptake of dopamine and replectates euphoria)
Cocaine creates pleasurable feelings, they extend the duration of dopamine in the synapse
Norepinephrine:
Elevation/ depression of mood
Drug: doxepin (used for treating anxiety and depression)
Enkephalins/ Endorphins:
Pain responses drug: Opiates (Morphine Heroin)
When they are abnormal: it is linked to schizophrenia
Synapse
Small fluid-filled gap between neurons into which transmitters are released
Types of Drugs: Agonist
Drug which increases neurotransmitter activity
They mimic and deliver the same messages neurotransmitter
Types of Drugs: Antagonists
Drugs which decrease, reduce and weaken activity of the neurotransmitter.
They completely block the activity of the neurotransmitter
Partial agonists and partial antagonists
They do the same thing but less powerful
Competitive-direct
Drugs compete with the neurotransmitters for the same receptor site
Drugs: Agonist
take over parking spot and mimic the neurotransmitter
Drugs: Antagonist
Takes over parking spot, blocks it
By blocking it stops the transmitter from delivering messages (ex: coffee)
Non-competitive (indirect)
Drug does not compete for the same spot
It finds another receptore site and either enhances or reduces the activity of the neurotransmitter
CT Scan (Computerized Tomography)
Function: uses x-rays that pass through the body too generate “slices” images of the body
Advantages: Fast, Cheap and noninvasive
Disadvantages: Radiation exposure
Does not allow us to see the brain in action, only shows us the structure of the brain
Ex: it does not allow us to show us which area is more active in a math task
MRI (Magnetic Resonance Imaging)
Function: Uses magnetic field and hydrogen ions are used (different tissues have different amounts of water)
MRI Advantages and Disadvanatges
Advantages: Noninvasive, great precision, no radiation
Disadvantages: Really expensive, cannot have biomedical devices or metal in patients
Does not allow us to see the brain in action, we can only see the structure
Ex: Detect changes in structure due to disease
fMRI (functional MRI)
Function: Uses magnetic field to image alignments of hydrogen ions (different tissues have different amount of water)
fMRI (functional MRI) Advantages and Disadvanatges:
Advantages: Noninvasive, no radiation, no injections or ingestions
Disadvantages: Cardiovascular disease or compromised function can make measurements unreliable; delay between stimulus and output
Ex: Can mesure activation during a task or following stimulation
DTI (Diffusion Tensor Imaging)
Function: Tracks water movement along neutral pathways, and measures density of neural tracks (bundles of axons)
DTI (Diffusion Tensor Imaging) Advantages and Disadvanatages
Advantages: Noninvasive, no radiation, no injections or ingestions needed, It is a sophisticated MRI tech
Disadvantages: The interpretation can be difficult in tracts that have different kinds of fibers
Ex: Study white matter degeneration in disease
PET/SPECT
(Single Photon Emission Computed Tomography)
Function: Uses radioactive compound to track molecular changes
One of the radioactive are glucose substance, more active the more it consumes, it shows which part is more active
PET/SPECT (Single Photon Emission Computed Tomography) Advanatages and Disadvanatges
Advantages: You can see molecular changes in real time
Disadvantages: Radiation exposure
Examples: Visualize the activity of specific neurotransmitters and can measure binding
Lower Brain Structure
From spinal cord to the center of the brain
Brainstem
starts where the spinal cord ends
connects the brain to the spinal cord
Relay station: all info coming to the brain and leaving the brain will have to go through it
information coming from the left side of the body will cross over to the right side of the brain (and vise versa)
Life center of brain, contains structures that control vital functions that are essential for survival
Medulla:
where spinal cord ends, controls breath, heart beat, blood pressure, vomiting
Pons:
Information from the spinal cord enters the medulla and is then transferred to the pons and to higher-order brain functions
Reticular Activating System
a network of cells in the pons and medulla which help regulate the awareness and alertness in humans
Where is the Reticular Activating System located?
Located within Hypothalamus and Brainstem
Reticular Activating System: Main Functions
Helps regulate our level of excitement/energy
Helps focus our attention on tasks, people or objects
Reticular Activating System: Disorder
Autoimmune leukoproliferative disorder
Cerebellum
Little brain
Cerebellum controls
voluntary movement
Where is the Cerebellum located:
back of the head, below temporal and occipital lobes, above brainstem
Ex: typing and writing, maintain balance , muscle tone
What is the Cerebellum involved in:
In learning motor skills which become automatic
Ex: typing, writting
1/10th of the volume of brain
Half neurons are in cerebellum
20x more connection than any other are in the brain
What does recent reasearch say on Cerebellum
linked to learning, thinking, creativity and language
Autism: cerebellum is essential for proper cognitive development
Alcohol: cerebellum gets drunk when your drunk
Thalamus
Center of the brain and sits on top of the brain cells
Thalamus: Relay station
All senses (excluding senses) receives info from upper areas and transfers to lower areas
What does the thalamus highlight
analyzes info and highlights which is important
Studies show in Thalamus
Part of the system in the brain directs attention to the potentially important stimuli
Goosebumps
Form Thalamus
Limbic System
found at center of brain
What is the Limbic System linked to?
Learning, motivation and memory
Hippocampus
Helps in form new conscious memories and found in the temporal lobes
Important in Cognitive maps and maintenance
Vulnerable to chronic stress: Chronic stress kills neurons is hippocampus
In Alzheimer’s diseases, ome of the first areas to get damaged is the hippocampus
Amygdala
found at the center of brain, they are linked to: Aggression, Emotions, Experience, Memories
Hypothalamus
located under the thalamus, sits under the brain, Very tiny, Brain within a brain: very powerful
It controls thirst, hunger and sex
It maintains and controls homeostasis
Homeostasis
Internal balance of the body
keeping certain vital functions, within a narrow healthy range
Important role in the formation of social bonds
Produces a hormone called oxytocin
Social Bonds
Important role in the formation maintenance of social/emotional bonds by producing oxytocin
Cerebral Cortex
outer layer of brain, big grooves and rainbows
1/3 of your cortex is visible to the naked eye, rest hides in the grooves
The left hemisphere:
Receives information from the right side of the body. Controls the right side of the body
It controls language
The right hemisphere:
Receives information from the left side of the body. Controls the left side of the body.
Corpus Callosum:
way hemispheres communicate to each other
Each hemisphere:
Consists of 4 lobes: Frontal, Parietal,Temporal, Occipital
Each lobe:
Consists 2 areas: Primary and Association
Primary areas
linked with the processes of motor or sensory information.
The primary areas are P. visual cortex, P. auditory cortex, P. sensory cortex aka P. somatosensory cortex,
P. visual cortex
located in the occipital lobes (processes visual information)
P. auditory cortex
located in the temporal lobes (processes auditory information).
P. sensory cortex aka P. somatosensory cortex
located in the parietal lobes and arches from one ear to the next.
It receives information from the skin, muscles and joints.
Processes information pertaining to touch, pain, temperature
Right part of the parietal cortex
receives info from the left side of the body
Left part of the parietal cortex
receives information from the right side of the body.
Each body part
is represented in the parietal cortex
Body parts adjacent to each other (example, hand and arm) are serviced by areas in the brain that are adjacent to each other
Association areas:
Each Lobes has 2 areas
Found in each lobe, they are linked with complex mental functioning
These areas are involved in the processing of complex motor or sensory information
Frontal Lobes (Executive function):
Planning, Descision making, Personality, Language (Broca’s area-language production), Emotions
Temporal Lobes:
aspects of language (Wernicke’s area: understanding language), music, memory, recognizing faces, god spot
Parietal Lobes:
Nonverbal thinking (ex: math), sense of space
Occipital Lobes
Processing of complex visual information
What do the brain lobes do?
The brain’s lobes work in tandem to produce complex human behaviours & mental processes
Brain laterality:
Functional asymmetry: Carry out similar functions but have their own specialized functions
Ex: Left hemi is more associated with language than the right hemi
Ways of studying the brain:
Neuron imaging studies
Clinical observations
Split-brain patients:
They have Severe epilepsy, hemispheres do not communicate to each other?
Corpus callosum:
People with severe epilepsy get treatment by cutting the corpus call osum.
Personality stays the same but the levels do not change
What does Peripheral Nervous System consist?
all nerves in body, which are outside of the central nervous system
It connects you to the world
What is the main function:
Carry info between the body and the central nervous system (back and forth)
2 Types of Periphral Nervous System:
Somatic Nervous system and Autonomic Nervous system
Somatic Nervous System
Two Main Functions
Sensory Neurons: collect info from environment and send in to the central nervous system
Afferent axons
axons of the sensory neurons, they carry information from the body/the external world to the CNS
Ex: Motor skills
Efferent axons
axons of the motor neurons, they carry information from the CNS to the body
Autonomic NS:
It controls organs, glands, visceral muscles
Visceral muscles do not have voluntary control over, ex: heart muscles
2 Types of Autonomic NS:
Sympathetic NS: Energizes the body, mobilizes the resource of the body, to prepare us to take action
(Fight or flight)
Parasympathetic NS: Calms the body down, relaxes the body conserves the energy, helps body restore itself (Rest and digest)
Both systems: have distinct functions, constantly working together, to maintain the homeostasis of the body
The Endocrine system
A major communication network in the body
and consists all the glands in the body
Glands releases hormones directly into the bloodstream
Hormones carry messages to the endocrine system from rest of the body including the brain, directly into the bloodstream stream, they are super powerful
3 Types of Hormones
Homeostasis: Maintain a balance of the internal body
Reproductive:
Ex: testosterone, estrogen
Stress hormones:
Ex: cortisol, epinephrine
Pituitary gland:
Located at the center of brain, Under hypothalamus
Controls all the glands in the system
Hypothalamus controls system by controlling the pituitary gland
Nervous System and Endocrine system
Different functions, but they constantly interact with each other
“While it controls the endocrine system, hormones can stillaffect the NS including the brain”
Why study Hormones:
related to how we behave and think
