Chapter 3 - Biology & Behavior Flashcards
Three Kinds of Neurons
Sensory (take info and send to brain), Motor (direct muscle movement), interneuron (integrate neural activity in given area, don’t send signals to CNS)
Structure of Neurons (Describe each part)
Dendrites (branch-like areas), cell body (gathers info here), axon (sends out signals across this outgrowth), terminal buttons (nodules at end of axon that release chemical signals into synapse)
Synaptic Gap (what is it?)
Where chemical signals travel between neurons over the synaptic cleft
Action Potential (definition)
aka neural firing, it’s an electrical signal that passes along the axon and causes a chemical release that transmit signals to other neurons
How is action potential produced?
two types of signals arrive at the dendrites (excitatory (+) - depolarize cell memb & inc chance of firing, or inhibitory (-) - hyperpolarize cell, dec chance of firing), if enough excitatory, then the cell can fire, meaning that sodium (+) then potassium (-) channels open as it depolarizes, so the cell reaches its action potential and fires (cell overall slightly negative)
How is action potential propagated?
Propagation is when the depolarization of the cell membrane as it travels along the axon from the cell body to the terminal buttons - Na and K channels open like dominoes, sped up by myelin sheath
All or none principle
idea that neuron will fire at same strength (potency) every time - it either fires or doesn’t there is no inbetween
Neurotransmitter (definition, importance)
chemical substances that carry signals from one neuron to another and are contained by vesicles in the terminal buttons, important because they carry signals across the synaptic cleft and bind to receptors on the other neuron, causing either an excitatory or inhibitory signal
Three major events that terminate a neurotransmitter’s influence in the synaptic cleft
Reuptake (consumed by the presynaptic terminal button), enzyme deactivation (when enzyme destroys neurotrans in the synaptic cleft), autoreception (autoreceptors monitor how much of a neurotrans has been released into the synaptic cleft and if it detects and excess, will stop its release)
How do drugs alter activity at the synapse? (major categories)
2 ways - agonists (drugs that enhance the actions of neurotransmitters), or antagonists (drugs that inhibit the actions of neurotransmitters)
How do agonist drugs work?
3 ways - inc how much of the NT is made in the terminal button so there are more in each vesicle, block reuptake, or mimic NT and bond to its postsynaptic receptor
How do antagonist drugs work?
3 ways - dec amount of NT made so less in each vesicle, destroy NT in synapse, or bind to its receptor and block it
Acetylcholine (major func?)
(NT) - major function - motor control over muscles, involved in botox!
Epinephrine (major func?)
(NT) - energy, used to be called adrenaline (fight-flight response)
Norepinephrine (major func?)
(NT) - arousal (alertness) and vigilance
Serotonin (major func?)
(NT) - emotional states and impusliveness, used in Prozac to treat depression
Dopamine (major func?)
(NT) - reward and motivation, depletion of dopa is part of Parkinson’s Disease
GABA (major func?)
(NT) - gamma-aminobutyric acid, inhibition of action potentials
Glutamate (major func?)
(NT) - Enhancement of action potentials
Endorphins (major func?)
(NT) - pain reduction, opiates like heroin and morphine do this too
substance P (major func?)
pain perception, capsaicin activates this in the brain
Broca’s area
small portion in the left frontal part of the brain crucial for the production of language
Brain stem
an extension of the spinal cord, it houses the structures that control functions associated with survival, such as breathing, swallowing, vomiting, urination, and orgasm
Cerebellum
a large, convoluted protuberance at the back of the brain stem - it is essential for coordinated movement and balance
Hypothalamus
a brain structure that is involved in the regulation of bodily functions, including body temperature, blood pressure, and blood glucose levels - it also influences our basic motivated behaviors
CNS
(central nervous system) the brain and spinal cord
PNS
(peripheral nervous system) all nerve cells in the body that are not part of the central nervous system. PNS includes the somatic and autonomic nervous systems
Thalamus
the gateway to the brain, it receives almost all of the incoming sensory information before that info reaches the cortex
Hippocampus
brain structure associated with the formation of memories
Amydala
brain structure that serves a vital role in our learning to associate things with emotional responses and in processes emotional info
Basal Ganglia
a system of subcortical structures that are important for the production of planned movement
Cerebral Cortex
the outer layer of the brain tissue, which forms the convoluted surface of the brain
Occipital Lobes
regions of the cerebral cortex at the back of the brain, important for vision
Corpus Callosum
The fibrous structure that connects the two hemispheres of the cerebral cortex
Parietal Lobes
regions of the cerebral cortex in-between the occipital and frontal lobes, important for the sense of touch and for conceptualizing the spatial layout of an environment
Temporal lobes
regions of the cerebral cortex, around ears, important for processing auditory info, memory, and object and face perception
Frontal lobes
regions of the cerebral cortex, important for movement and higher-level psychological processes associated with the prefrontal cortex
prefrontal cortex (definition, famous case study patient, procedure that focuses on this region)
frontmost portion of frontal lobes, esp prominent in humans, important for attention, working memory, decision making, appropriate social behavior, and personality, damaged in Phineas Gage, targeted in lobotomies because it makes mental patients easier to manage - no personality, passive (late 1940s, early 1950s)
Somatosensory homunculus
a distorted man based on which areas of the primary somatosensory cortex are most devoted to each body part
Primary somatosensory cortex
strip at the front of the parietal lobe, grouping nearby sensations of the body
Regions of the cerebral cortex
parietal, frontal, temporal, occipital
primary components of the PNS
somatic and automatic nervous systems
Somatic nervous system
component of PNS, it transmits sensory signals and motor signals between the central nervous system and the skin, muscles, and joints
automatic nervous system (ANS)
component of the PNS, transmits sensory signals and motor signals between the CNS and the body’s glands and internal organs
sympathetic division
division in the ANS, type of signal, prepares the body for action (fire alarm analogy)
parasympathetic division
division of the ANS, type of signal, returns the body to its resting state
Types of signals in ANS
sympathetic and parasympathetic divisions
endocrine system
communication system that uses hormones (not electrochemical signals like in nervous sys) to influence thoughts, behaviors, and actions, works in conjunction with nervous system
Hormones
chemical substances , released from endocrine glands, that travel through the bloodstream to targeted tissues - the tissues are subsequently influenced by hormones
pituitary gland
a gland located at the base of the hypothalamus - it sends hormonal signals to other endocrine glands, controlling their release of hormones
chromosomes
structures within the cell body that are made up of DNA, and DNA consists of genes
genes
the units of heredity that help determine the characteristics of an organism, particular molecules on a DNA strand which give instructions to make distinct polypeptide
dominant gene
gnee that is expressed in the offspring whenever it is present
recessive gene
gene that is expressed only when it is matched with a similar gene from the other parent
genotype
the genetic constitution of an organism, determined at the moment of conception
phenotype
observable physical characteristics, which results from both genetic and environmental influences
Behavioral genetics
the study of how genes and the environment interact to influence psychological activity
monozygotic twins
identical twins, result of one zygote splitting in two and they share the same genes
dizygotic twins
fraternal twins, two separate fertilized eggs so no more related than any 2 sibilings
Why twin studies?
These allow us to look at the different between nature and nurture, since they have the same genes but can be raised in different environments
heritability
a statistical estimate of the extent to which variation in a trait within a population due to genetic factors
Misconceptions about heritability
refers to populations, not individuals, if height has .60 heritability, then 60% of height variation is genetic, not 60% due to genes, 40% from environ
How do genes and the environment interact? How do genes influence behavior indirectly? (use Caspi study as example)
Nature and nurture are inextricably linked. In the study, they looked at 1000 kids, and if they displayed violent behavior. 2 metrics were used - MAO gene (low or high), and mistreatment by parents, and they found that if they were mistreated and had the low MAO gene, they were much more likely to be convicted of violent crimes
plasticity
property of the brain that allows it to change as a result of experience, drugs, or injury - helps link nature and nurture
synesthesia
cross-sensory experience (ex: image has a taste), like due to cross-wired neurons?, often associated with creative people
phantom limb syndrome
in amputees, an intense sensations that the amputated body part still exists, and it seems that the cortex associated with that area then is used for the next closest area, and are activated by that nearby spot (face touch activates hand)
Difference between phantom limb syndrome and synesthesia
Phantom limb is caused primarily by the environment (limb loss), whereas synesthesia is caused primarily by genetics
Differences in male and female brains
Male brains are larger, different hormones, females may have language in both hemispheres (female stroke patients have better language skills)
Name that NT! Motor control over muscles
Acetylcholine
Name that NT! Energy
Epinephrine
Name that NT! Alertness
Norepinephrine
Name that NT! Emotional states and impulsiveness
Serotonin
Name that NT! Reward and motivation
Dopamine
Name that NT! Inhibition of action potentials
Yo GABA GABA
Name that NT! Enhancement of action potentials
Glutamate
Name that NT! Pain reduction
Endorphins
Name that NT! Pain perception
Substance P
