exam 1 study guide Flashcards
Wilhelm Wundt
Founded 1sy psychology lab in leipzig, Germany in 1879
Franciscus Donders
1868, timed the mind
Wilhhelm Wundt and structuralism
We understand the world through combinations of basic experiences (sensation)
“Periodic table of the mind”
Hermann Ebbinghaus and Forgetting
Learned lists of nonsense syllables and plotted memory savings
William James and Functionalism
Concerned with why we do things
Investigated attention, consciousness, imagination, reasoning, and more
1932 - Edward Tolman
Rats formed mental maps of mazes
1932 - Frederick Bartlett
Found that memory of a story depended on attitude about the event
The Cognitive Revolution
1956- a shift in psychology in the 1950s that focused on how the mind works and how it drives human behavior
Luigi Galvani
demonstrated that nerves functioned via electricity
Phineas Gage
showed loss of social judgment after brain injury. Became mean and angry. This led to people believing that the top of the brain is responsible for personality changes.
Paul Broca
showed that damage to the left frontal lobe caused loss of speech
Radial symmetry
have distributed “nerve nets”, no centralized brain
Bilateral symmetry
The left side and the right side are almost mirror images of each other.
Bilateral symmetry characteristics
Has the presence of local, centralized networks within each body segment.
Longitudinal transmission of information up and down the body axis.
central nervous system
consists of the brain and spinal cord
Peripheral nervous system
receptors and nerves that are found throughout the body and outside the brain and spinal cord
forebrain
Contains the cerebral hemisphere (cerebral cortex, subcortical white matter, basal ganglia, and basal forebrain nuclei).
Contains the Thalamus and Hypothalamus
Midbrain
most rostral part of the brainstem that connects the pons and cerebellum with the forebrain.
Hindbrain
Contains the pons, cerebellum, and medulla
Rostral
towards the mouth or the front end
Caudal
towards the tail end
Dorsal
towards the top or back
Ventral
towards the belly, or bottom end.
Anterior
towards the front
Posterior
towards the back
Superior
towards the top
Inferior
towards the bottom
Medial
towards the middle
Lateral
towards the side
Ipsilateral
“on the same side”
contralateral
means “on the opposite side”
Distal
towards the far (distant) end of the limb
Proximal
towards the point where the limb attaches to the body
Axial slice
divides the body along its long axis
Sagittal slice
divides the body into left and right
Mid-Sagittal slice
slice through the exact midline of the body
Frontal or coronal slice
divides body into anterior and posterior sections.
peripheral nervous system consists of
somatic nervous system and autonomic nervous system
The somatic nervous system
detects and processes information from external stimuli. Includes the sensory inputs and motor outputs for guiding voluntary body movements in the external world. Has somatic afferent (or somatosensory) neurons for input and somatic efferent (or motor) neurons for output. (are found in the skin, muscle, and joints)
The autonomic nervous system
sympathetic nervous system and parasympathetic nervous system
Sympathetic nervous system
Reacts to threats or opportunities in the external world: feeding, fighting, flighting, and fucking.
Parasympathetic nervous system
“Rest-and-regenerate”
visceral afferent (or visceral sensory) neurons
input
visceral efferent (or autonomic) neurons
output
visceral
Anything having to do with organ activity.
Somatic motor neurons
Extend from the spinal cord to the muscles of the body
Make contact at specialized structures called the neuromuscular junction
Electrical activity releases signaling chemicals called neurotransmitters.
Neurotransmitters stimulate the muscle on the body to contract.
Visceral efferent neurons
Send output signals to the body’s internal organs.
Regulates activities of the body’s internal world.
Each segment of the spinal cord
has its own set of peripheral nerve roots on the left and right
All sensory inputs enter the spinal cord through the
dorsal nerve root at the back
then all motor outputs exit the spinal cord through the
ventral nerve root at the front of the spinal cord
Dermatomes
A region of the skin that
Receives input from a single spinal nerve
Myotomes
A region of the muscle that receives output from a single spinal nerve.
describe the structure of the spinal cord
Small central canal, surrounded by a butterfly-shaped structure of gray matter, which is surrounded by white matter
Gray matter
nerve tissue consisting of the unmyelinated cell bodies of dendrites and neurons. Handles sensory and motor info
Dorsal layers have mostly
sensory neurons of the spinal cord
Ventral layers (or ventral horns) are mostly
motor neurons
White matter
tissue in the CNS, consists of myelinated axons of neurons, which carry info over long distances. Handles communication with distant neurons.
The cell bodies of the PNS live right outside. . . where
in the dorsal root ganglion
Dorsal root ganglion
collection of cell bodies of the sensory neurons of the PNS
Types of reflexes
monosynaptic and polysynaptic
Monosynaptic
the entire circuit involves only one synapse, or connection, between neurons
Polysynaptic
involved more than one synapse, because an interneuron (connects 2 other neurons) lies between the incoming sensory neuron and the outgoing motor neuron in the circuit.
Central pattern generator
a collection of neurons within the CNS that can spontaneously generate and maintain rhythmic movements like walking or swallowing.
The brainstem
most posterior region of the brain, point of communication between the spinal cord and the most anterior of structure of the nervous system
part of the brain stem
midbrain, pons, medulla
Midbrain
Involved in visual and auditory reflexes, arousal level, homeostasis functions, and motor control.
Superior colliculus: involved in locating visual stimuli in space and uses that info to direct complex movement (turning eyes to look). Eye movement
Inferior colliculus: parallel functions using auditory inputs. Sound location
Command generators: can start, stop, or modulate the activity of central pattern generators in the brainstem/ spinal cord. Can take input from visual and auditory sensors..
Periaqueductal gray matter: neurons organized into nuclei, each nucleus handles a different basic class of behavior, like defense, aggression, and reproduction. Central pattern generator that coordinates other pattern generators themselves.
Reticular formation (network of neurons)
regulates states of consciousness
Locus coeruleus (nucleus)
sends alert signals to the rest of the brain via a neurotransmitter called norepinephrine (regulates levels of arousal, alertness, and attention)
Substantia nigra (collection of cells)
main source of neurotransmitter dopamine. Helps with movement, cognition, motivation, and reward.
Midbrain raphe nuclei
main source of the neurotransmitter serotonin. Serotonin helps with mood, sleep, and social behavior.
Brainstem nuclei (collection of neuron cell bodies within the CNS):
handle new sensory, motor, somatic, and visceral functional requirements. These are due to the many important sensory receptors, such as pain, vibration, position, and touch receptors. And motor functions, such as the tongue, mouth, neck, and head.
Pons:
delays signals between the cerebellum and the cerebrum (anterior most structure of the CNS).
Involved in arousal, sleep, breathing, swallowing, bladder control, eye movement, facial expressions, hearing, equilibrium, and posture.
Medulla
Regulates involuntary functions that are essential to life, including breathing, heart rate, and blood pressure. (central pattern generators).
The cerebellum:
Coordinating movements across the midline
Contains more neurons than the cortex
Organized into leaflike structures called folia, lobules, and lobes
Predictions about expected outcomes of motor action, the refine plans
Also important in language, memory, attention, and emotion
Purkinje cells: beautiful, intricate branch work of input connections that gather information from the molecular layer above them. They send their output back to specialized output nuclei in the brainstem, which pass the info back to the spinal cord and ahead to the cerebral cortex and the brain.
Hypothalamus
Regulation of homeostatic and motivating behaviors - hormones
“Basic drives”; includes hunger, thirst, sexual arousal, temperature regulation, and sleep.
Neurons cluster into distinct groups: the hypothalamic nuclei. Each hypothalamic nucleus has a distant function.
Visceral inputs via the spinal cord, hormonal inputs from other body organs, and even direct measurements of the chemistry of the bloodstream.
Thalamus
Sensory relay station to the cerebral cortex.
Relays motor signals to the cerebral cortex from other motor control structures like the cerebellum and basal ganglia.
Thalamic neurons cluster into a larger # if separate thalamic nuclei.
Lateral geniculate nucleus - relays information from the light-sensitive neurons to the primary visual cortex
Reticular nucleus consists of a thin sheet of neurons that wraps around the entire surface of the thalamus. Organizes communication activity f=of the nuclei themselves.
Cerebral cortex
Covered in convolutions (gyri/gyrus, sulci/sulcus) which triples the surface area
Gyri, rounded convolutions of the cerebral cortex
Sulci, grooves between gyri.
Outer layers make up the cortex where higher processing happens
Gray matter = cell bodies
White matter = axons
Mid Sagittal sulcus, divided the two hemispheres.
Corpus callosum: bridge of white matter that connects the two hemispheres.
Frontal
personality, motor control, planning, decision-making, goal selection
Parietal
processing sensory information, spatial cognition, and body movement
Occipital
Visual processing
Temporal
sound processing, what something is, social cue perception
The Cerebral Ventricles
Duct system of the brain
4 chambers
Filled with cerebrospinal fluid (CSF)
Meninges
Three layer of membranes
Dura mater (tough mother).
Arachnoid membrane (spiderweb): Subarachnoid space.
Pia mater (pious mother) - adheres to the brain.
Order starting from brain goes from pia mater, to arachnoid, to dura mater
Dehydration helps with cerebrospinal fluid.
cerebrospinal fluid: is a clear, colorless fluid that protects and nourishes the brain and spinal cord.
Blood is in subarachnoid space
The Limbic System
hypothalamus, amygdala, hippocampus, fornix
Hypothalamus
(feeding, fighting, flighting, fucking) and limbic nuclei of thalamus project to the limbic system.
Amygdala
emotional evaluation and learning
Hippocampus
learning and memory
Episodic memory: memory gained from emotional experiences, good and bad.
Fornix
white matter that connects the hippocampus and hypothalamus
Mammillary bodies (pair of nuclei): links current needs to memories of past events
cell body (soma)
Contains the nucleus and organelles; responsible for metabolic processes and integration of signals.
Dendrites
Branch-like structures that receive incoming signals from other neurons. They contain receptors for neurotransmitters.
Axon
A long, slender projection that conducts electrical impulses (action potentials) away from the cell body
Axon Hillock
The junction between the cell body and axon, where action potentials are initiated.
Myelin Sheath
Fatty insulation that surrounds segments of the axon, produced by oligodendrocytes in the CNS and Schwann cells in the PNS.
Nodes of Ranvier
Gaps in the myelin sheath where action potentials are regenerated.
Axon Terminals (Synaptic Boutons)
Small branches at the end of the axon that release neurotransmitters into the synaptic cleft.
Function of Neurons
Neurons transmit information via electrical impulses and chemical signals, allowing communication within the nervous system.
Sensory Neurons (Afferent Neurons)
Function: Transmit sensory information from receptors (e.g., skin, eyes) to the CNS.
Structure: Usually have a long dendritic tree to gather signals from sensory receptors.
Motor Neurons (Efferent Neurons)
Function: Convey signals from the CNS to muscles and glands, facilitating movement and response.
Structure: Typically have long axons that extend to muscles.
Interneurons
Function: Connect neurons within the CNS, facilitating communication between sensory and motor pathways. Involved in reflexes and higher cognitive functions.
Structure: Shorter axons; can be local or long-range.
Glial Cells
Support cells in the nervous system, involved in various functions including homeostasis, forming myelin, and providing support and protection for neurons.
Astrocytes
Star-shaped cells that maintain the blood-brain barrier, provide nutrients to neurons, and regulate ion balance.
Oligodendrocytes
Form myelin sheaths around axons in the CNS, increasing the speed of conduction.
Schwann Cells
Myelinate axons in the PNS.
Microglia
Act as immune cells in the CNS, clearing debris and responding to injury.
Ependymal Cells
Line the ventricles of the brain and produce cerebrospinal fluid (CSF).
Action Potential Arrival
When an action potential reaches the axon terminal, it depolarizes the membrane.
Voltage-Gated Calcium Channels:
The depolarization opens these channels, allowing Ca²⁺ ions to flow into the presynaptic neuron.
Neurotransmitter Release
The influx of calcium triggers synaptic vesicles to fuse with the presynaptic membrane, releasing neurotransmitters into the synaptic cleft.
Presynaptic Membrane
Contains vesicles filled with neurotransmitters.
Neurotransmitters are released into the synaptic cleft when vesicles fuse with the membrane.
Postsynaptic Membrane:
Contains receptors specific to the neurotransmitters released.
Binding of neurotransmitters to these receptors causes changes in the postsynaptic neuron’s membrane potential.
Ionotropic Receptors
Ligand-gated ion channels that open in response to neurotransmitter binding, allowing specific ions to flow through (e.g., Na⁺, K⁺).
Metabotropic Receptors
G-protein coupled receptors that, when activated, initiate intracellular signaling cascades that can lead to changes in cell function over a longer duration.
Reuptake
Neurotransmitters are taken back into the presynaptic neuron via transporters, allowing them to be reused.
Enzymatic Degradation
Specific enzymes break down neurotransmitters in the synaptic cleft (e.g., acetylcholinesterase breaks down acetylcholine).
Diffusion
Some neurotransmitters simply diffuse away from the synaptic cleft.
Agonists
Molecules that enhance or mimic the action of neurotransmitters (e.g., morphine is an opioid agonist).
Antagonists
Molecules that block the action of neurotransmitters (e.g., naloxone blocks opioid receptors).
Resting Potential
The neuron at rest has a voltage of approximately -70 mV, maintained by:
Ion Distribution: Higher concentration of Na⁺ outside and K⁺ inside the cell.
Sodium-Potassium Pump: Actively transports 3 Na⁺ ions out and 2 K⁺ ions into the cell, contributing to negative internal charge.
Permeability: The membrane is more permeable to K⁺ than Na⁺, allowing K⁺ to leak out, further contributing to negativity.
Depolarization
Triggered when a stimulus causes the membrane potential to reach the threshold (~-55 mV).
Voltage-gated Na⁺ channels open, allowing Na⁺ to rush into the cell, rapidly depolarizing it.
Repolarization
After peak depolarization, Na⁺ channels close, and voltage-gated K⁺ channels open, allowing K⁺ to exit the cell, restoring the negative charge.
Hyperpolarization
K⁺ channels remain open slightly longer, causing the membrane potential to drop below the resting potential (around -80 mV).
Return to Resting Potential:
The sodium-potassium pump restores the original ion distribution, returning the neuron to resting potential.
Before Action Potential
Resting potential (-70 mV); Na⁺ outside, K⁺ inside.
During Action Potential
Phase 1 (Depolarization): Na⁺ influx (voltage increases to +30 mV).
Phase 2 (Repolarization): K⁺ efflux (voltage decreases back to -70 mV).
Phase 3 (Hyperpolarization): K⁺ continues to leave, voltage drops to -80 mV.
After Action Potential
Returns to resting potential via the sodium-potassium pump.
Saltatory Conduction
The process by which action potentials jump between Nodes of Ranvier along myelinated axons, greatly increasing conduction speed (up to 120 m/s).
Myelin Sheath
Insulates axons, preventing ion leakage and allowing for faster transmission of electrical impulses.
Graded Potentials
Changes in membrane potential that are not large enough to trigger an action potential. They are variable in magnitude and can be either depolarizing or hyperpolarizing.
Excitatory Postsynaptic Potentials (EPSPs):
Caused by the influx of Na⁺ through ionotropic receptors.
Result in depolarization, making the neuron more likely to fire an action potential.
Inhibitory Postsynaptic Potentials (IPSPs):
Caused by the influx of Cl⁻ or efflux of K⁺.
Result in hyperpolarization, making the neuron less likely to fire an action potential.
Spatial Summation
Occurs when multiple EPSPs or IPSPs from different locations on the neuron combine to influence the overall membrane potential.
Temporal Summation:
Occurs when multiple signals from the same presynaptic neuron arrive in quick succession, reinforcing each other.
Neural Coding
Refers to the way information is represented in the brain through patterns of neuronal firing.
Rate Coding
Information is represented by the frequency of action potentials; a stronger stimulus results in a higher firing rate.
Temporal Coding
Information is conveyed through the timing of spikes; specific patterns of neuronal firing may represent particular information.
Population Coding
Information is represented by the activity of a group of neurons rather than a single neuron.
