Chapter 2 Flashcards
phrenology
studying bumps on the skull) was a popular tool for determining a person’s mental abilities and character traits
led to…
localization of function
the idea that various brain regions have particular functions
from phrenology
Neurons
neural cells specially designed to share information electrochemically with other neurons
○ Throughout life, new neurons are born and unused neurons wither away
Cell body
the cell’s nucleus and life-support center; AKA Soma (body)
Dendrites
fibers that receive and integrate information, conducting it toward the cell body (mouth)
Axon
the cell’s single lengthy fiber that passes messages through its branches to other neurons (pooper)
myelin (myelin sheath)
Much as home electrical wire is insulated, a segmented layer of fatty tissue called insulates the axons of some neurons and helps speed their impulses
i. As myelin is laid down up to about age 25, neural efficiency, judgment, and self-control increases
ii. If the myelin sheath degenerates, multiple sclerosis results - meaning communication to muscles slows, with eventual loss of muscle control
multiple sclerosi
If the myelin sheath degenerates, meaning communication to muscles slows, with eventual loss of muscle control
glial cells
Supporting these billions of nerve cells are (like worker bees)
i. They provide structure, ‘insulating’ myelin, communication, and mop up neurotransmitters
Action Potential
neuron sends a message by firing an electrical impulse down its axon
excitatory
Most neural signals - they transmit the flow of information to make an action potential
inhibitory
some - regulate the activation of excitatory signals
threshold
○ If excitatory signals exceed inhibitory signals by a minimum intensity, the combined signals trigger an action potential
synapse
○ Info is sent from the axon terminal of one cell to the dendrite of another, but it must cross the (gap/junction between the two cells)
neurotransmitters
○ The messages are sent from the axons across the synapse through the release of (specialized biochemical messages stores in sacs in the axon terminal); NT’s
i. Excess “” are reabsorbed by the sending neuron, or drift away and are broken down by the body’s enzymes
Reuptake
a neurotransmitter’s reabsorption by the sending neuron
Acetylcholine
involved in control of muscles and memory (a-set-l-cole-lean)
i. Myasthenia gravis is a disorder in which the immune system make antibodies that block ACh receptor sites - with fewer receptor sites, the muscles receive fewer signals and become weak
Dopamine
involved in reward/pleasure/emotion, motor behavior, and attention
i. Not enough: Contributes to psychological disorders like Schizophrenia
ii. Too much: Tremors and decreased mobility role in Parkinson’s disease
Serotonin
Sleep, mood, and appetite
little - depression
Norepinephrine
Alertness and arousal; “Fight-or-Flight”
little - depression
Endorphins
Morphine-like effects on the mind and body for pain and pleasure
Substance P
Transmits pain signals
GABA
Inhibitory neurotransmitter; increases tranquility
little - seizures or insomnia
Glutamate
excitatory - involved in learning and memory
too much - migraines
Nervous system
the body’s electrochemical communication network consisting of the nerve cells of the central and peripheral nervous systems
Reflex arc
Three types of neurons carry information through the nervous system.
Sensory Neurons
Motor Neurons
Interneurons
Sensory Neurons
Carry incoming information (from the body’s tissues and sensory receptors) to the brain and spinal cord; aka Afferent neurons
Motor neurons
Carry outgoing information (instructions) from the brain and spinal cord to the body’s muscles and glands; aka Efferent neurons
Interneurons
Neurons located within the brain and spinal cord; they process information between the sensory input and motor input
Central Nervous System
○ CNS comprised of the neurons of the brain and spinal cord
○ The brain and spinal cord are bathed in a cerebrospinal fluid, which helps to cushion the areas, flush waste products, and even carry some chemical signals
-Brain
-Spinal Cord
The Brain
i. The brain’s neurons cluster into work groups called neural networks
The Spinal Cord
Reflex, Reflex arc
Reflex
a simple, automatic response to a sensory stimulus
Reflex arc
Our body set up so that neural activity (finger touching hot flame) travels via sensory neurons to the interneurons in the spinal cord. These interneurons respond by activating motor neurons leading to (in this case) the muscles in your arm
Peripheral Nervous System
Basically all the other nerves of the body
Somatic
Autonomic
Somatic
transmits sensory messages to CNS and allows voluntary movement (activated by touch, temp, pain, body positions, sight, etc.)
nervous system
Autonomic
regulates vital, automatic functions of internal organs (heartbeat, breathing, blood pressure, digestion, etc.)
i. Sympathetic - arouses and expends energy; “fight or flight”; activated at times of stress
ii. Parasympathetic - conserves energy; returns body’s functions to names levels
nervous system
Homeostasis
a state of equilibrium/normalcy for the body
Endocrine system
○ The endocrine system is a communication system which secretes hormones (chemical messengers in the bloodstream), which influences our interest in food, aggression, etc.
○ While the nervous system sends messages lickety-split, endocrine messages take several seconds or more to reach their destinations
Melatonin
Adrenaline
Melatonin
produced by the brain and helps regulate sleep/maintain circadian rhythms
Adrenaline
released when we experience stress; linked to fight or flight response to aid breathing/blood circulations
Pituitary Gland
the most influential gland of ES - regulates growth hormones, cortisol, and oxytocin
endocrine system
oxytocin
important for contractions and trust
Regulated by Pituitary Gland
Lesion
tissue destruction or removal
EEG
Function
i. Electrodes measure overall brain activity
CAT/CT
Anatomy
i. Beefed up x-ray taken at different angles
PET
Function
i. Radioactive glucose… gobbled up during brain activity
fMRI
Function
i. Detectors transmit info abt areas of naturally occurring oxygen metabolism via blood in the brain
MRI
Anatomy
i. Magnetic fields from water molecules show 3-D soft tissue scan of brain (density and location of brain material)
brainstem
oldest part and central core of the brain
i. Responsible for autonomic survival functions
ii. Its base is the medulla, which controls heartbeat and breathing
○ Sitting at the top of the brainstem is the thalamus, which is the brain’s sensory control center
i. It receives info from all the senses (except smell), an routes the information to the appropriate higher brain regions
reticular activating system
Inside the brainstem (right between your ears)
i. It is a neural network extending from the spinal cord right up through the thalamus – controls sleep/wake transitions and arousal
cerebellum
Extending from the rear of the brainstem is the baseball-sized
i. Functions include coordinating movement and balance, enabling nonverbal learning and discriminating time
ii. Ties to well-rehearsed movements such as dancing/athletics or playing an instrument
iii. Under the influence of alcohol, coordination suffers
Limbic System
a neural system located below the cerebral hemispheres; it is associated with emotions and drives
contains the hypothalamus (which controls the nearby pituitary gland), the amygdala, and the hippocampus
hypothalamus
Just below the thalamus
i. It directs maintenance activities (The 5 Fs: Food/Fight/Flight/Fahrenheit/Sex), helps govern the endocrine system via the pituitary gland, and is linked to emotion and reward; runs your biological clock
amygdala
two lima-bean-sized/almond shaped neural clusters linked to the emotions, especially fear and aggression
hippocampus
helps process memories of facts and events, before being sent to other location sin the cerebral cortex
i. People who lose the hippocampus to surgery or injury show an inability to form new memories of facts and events
cerebrum
the wrinkly stuff we see/associate as ‘brain’
corpus callosum
The cerebral cortex is composed of two sides (hemispheres) connected by a group of nerve fibers
i. The corpus callosum acts as a communication bridge between the two hemispheres ii. The brain is contralateral - meaning: information received on one side of the body is transmitted to the opposite hemisphere of the brain
Frontal
Higher processing: such as speaking, thinking, judgement, personality, and emotion
Parietal
Receives sensory input for pain, warmth and cold. Functions also include perception
Occipital
Visual information interpreted
Temporal
Auditory/linguistic information interpreted
Sensory and motor cortexes
○ The Sensory (parietal) and Motor (frontal) cortexes are located in the very small strips, and they control the opposite side of the body
○ Damage to a lobe/area may affect sensory ability but may not totally eliminate it
Association areas
areas of the cerebral cortex involved in higher cognitive functions such as learning, remembering, thinking, and speaking (not sensory or controlling muscle movement)
○ Association areas are found in all four lobes - damage to any of them rarely affects motor skills… it primarily affects cognitive skills or personality
Neuroplasticity
the brain’s ability to ‘rewire’, especially during childhood, by reorganizing after damage or by building new pathways based on experiences
i. Studies show that the younger you are when the brain receives damage, the more likely it is to reorganize and make greater use of the unaffected areas
‘split-brain’ operation
corpus callosum is separated
cooperation between hemispheres isn’t possible so the separated systems work as best they can… one usually faster than the other
○ Right field of each eye/left hemi; left field of each eye/right hemi
i. Split brain operations do not affect optic chiasm - the place where the nerves connecting the eyes to the brain cross
Dual Processing
the principle that information is often simultaneously processed on separate conscious and unconscious tracks
Blindsight
a condition in which a person can respond to a visual stimulus without consciously experiencing it
Heredity
genetic transfer from parent to offspring; nature
Environment
non-genetic influences; nurture
Identical
monozygotic) - twins develop from a single egg that splits
Fraternal
(dizygotic) - twins develop from separate fertilized eggs; genetically no closer than ordinary brothers/sisters… they just share a prenatal environment
Heritability
the extent to which variation within a group can be attributed to inherited genetic factors
Ranged from 0 to 1; 0 indicated environment totally responsible for differences in the trait and 1 means that all variation in the trait can be accounted for genetically
Epigenetics
the study of environmental influences on gene expression that occur without a DNA change
i. Looks at what environmental factors turn genes on or off and how that info is passed to offspring
Evolutionary psychology
the study of the evolution of behavior and the mind, using principles of natural selection
natural selection
traits that better help an organism survive and procreate will likely be passed to offspring
mutations
random errors in gene replication that lead to change
