Brains, Bodies, Behavior Flashcards
central nervous system
made up of the brain and spinal cord, is the major controller of the body’s functions, charged with interpreting sensory information and responding to it with its own directives
peripheral nervous system
the neurons that link the CNS to our skin, muscles, and glands.
PNS links the CNS to the body’s sense receptors, muscles, and glands
divided into autonomic and somatic nervous systems
endocrine system
the chemical regulator of the body that consists of glands that secrete hormones.
works together with the nervous system to influence many aspects of human behavior, including growth, reproduction, and metabolism. And the endocrine system plays a vital role in emotions
neuron
cell in the nervous system whose function it is to receive and transmit information
soma
contains the nucleus of the cell and keeps the cell alive
dendrite
collects information from other cells and sends the information to the soma
axon
transmits information away from the cell body toward other neurons or to the muscles and glands
have terminal buttons at end that form junctions with other cells
myelin sheath
a layer of fatty tissue surrounding the axon of a neuron that both acts as an insulator and allows faster transmission of the electrical signal.
neurotransmitters
a chemical that relays signals across the synapses between neurons
travel across the synaptic space between the terminal button of one neuron and the dendrites of other neurons, where they bind to the dendrites in the neighboring neurons
synapses
areas where the terminal buttons at the end of the axon of one neuron nearly, but don’t quite, touch the dendrites of another
resting potential
a state in which the interior of the neuron contains a greater number of negatively charged ions than does the area outside the cell.
action potential
change in electrical charge that occurs in a neuron when a nerve impulse is transmitted
When the segment of the axon that is closest to the cell body is stimulated by an electrical signal from the dendrites, and if this electrical signal is strong enough that it passes a certain level or threshold, the cell membrane in this first segment opens its gates, allowing positively charged sodium ions that were previously kept out to enter.
it operates in an all or nothing manner. What this means is that the neuron either fires completely, such that the action potential moves all the way down the axon, or it does not fire at all.
node of Ranvier
a series of breaks between the sausage-like segments of the myelin sheath.
refractory period
a brief time after the firing of the axon in which the axon cannot fire again because the neuron has not yet returned to its resting potential
excitatory or inhibitory effects of neurotransmitters
When neurotransmitters are accepted by the receptors on the receiving neurons their effect may be either excitatory (i.e., they make the cell more likely to fire) or inhibitory (i.e., they make the cell less likely to fire). Furthermore, if the receiving neuron is able to accept more than one neurotransmitter, then it will be influenced by the excitatory and inhibitory processes of each. If the excitatory effects of the neurotransmitters are greater than the inhibitory influences of the neurotransmitters, the neuron moves closer to its firing threshold, and if it reaches the threshold, the action potential and the process of transferring information through the neuron begins.
reuptake
a process in which neurotransmitters that are in the synapse are reabsorbed into the transmitting terminal buttons, ready to again be released after the neuron fires
agonist
a drug that has chemical properties similar to a particular neurotransmitter and thus mimics the effects of the neurotransmitter.
cocaine is an agonist for the neurotransmitter dopamine
antagonist
a drug that reduces or stops the normal effects of a neurotransmitter.
Acetylcholine
A common neurotransmitter used in the spinal cord and motor neurons to stimulate muscle contractions. It’s also used in the brain to regulate memory, sleeping, and dreaming.
Dopamine
Involved in movement, motivation, and emotion, Dopamine produces feelings of pleasure when released by the brain’s reward system, and it’s also involved in learning.
Endorphins
Released in response to behaviors such as vigorous exercise, orgasm, and eating spicy foods.
GABA (gamma-aminobutyric acid)
The major inhibitory neurotransmitter in the brain.
Alcohol stimulates the release of GABA, which inhibits the nervous system and makes us feel drunk. Low levels of GABA can produce anxiety, and GABA agonists (tranquilizers) are used to reduce anxiety.
Glutamate
The most common neurotransmitter, it’s released in more than 90% of the brain’s synapses. Glutamate is found in the food additive MSG
Excess glutamate can cause overstimulation, migraines and seizures.
Serotonin
Involved in many functions, including mood, appetite, sleep, and aggression.
Low levels of serotonin are associated with depression, and some drugs designed to treat depression (known as selective serotonin reuptake inhibitors, or SSRIs) serve to prevent their reuptake.
brain stem
oldest and innermost region of the brain
basic functions of life, including breathing, attention, and motor responses
consists of medulla, pons and reticular formation
medulla
the area of the brain stem that controls heart rate and breathing, where the spinal cord enters the skull
pons
spherical shape above the medulla
a structure in the brain stem that helps control the movements of the body, playing a particularly important role in balance and walking
reticular formation
Running through the medulla and the pons is a long, narrow network of neurons
filter out some of the stimuli that are coming into the brain from the spinal cord and to relay the remainder of the signals to other areas of the brain
important roles in walking, eating, sexual activity, and sleeping
thalamus
above brain stem;
the egg-shaped structure above the brain stem that applies still more filtering to the sensory information that is coming up from the spinal cord and through the reticular formation, and it relays some of these remaining signals to the higher brain levels
thalamus also receives some of the higher brain’s replies, forwarding them to the medulla and the cerebellum. The thalamus is also important in sleep because it shuts off incoming signals from the senses, allowing us to rest.
cerebellum
consists of two wrinkled ovals behind the brain stem. It functions to coordinate voluntary movement
walking, keeping their balance, and holding their hands steady
contributes to emotional responses, helps us discriminate between different sounds and textures, and is important in learning
limbic system
brain area, located between the brain stem and the two cerebral hemispheres, that governs emotion and memory. It includes the amygdala, the hypothalamus, and the hippocampus
amygdala
consists of two “almond-shaped” clusters (amygdala comes from the Latin word for “almond”) and is primarily responsible for regulating our perceptions of, and reactions to, aggression and fear
hypothalamus
Located just under the thalamus
brain structure that contains a number of small areas that perform a variety of functions, including the important role of linking the nervous system to the endocrine system via the pituitary gland
helps regulate body temperature, hunger, thirst, and sex, and responds to the satisfaction of these needs by creating feelings of pleasure
hippocampus
consists of two “horns” that curve back from the amygdala. The hippocampus is important in storing information in long-term memory.
cerebral cortex
the outer bark-like layer of our brain that allows us to so successfully use language, acquire complex skills, create tools, and live in social groups
The folding of the cerebral cortex is referred to as corticalization.
two hemispheres, four lobes each separated by folds (fissures)
glial cells (glia)
cells that surround and link to the neurons, protecting them, providing them with nutrients, and absorbing unused neurotransmitters.
e.g., myelin sheath
frontal lobe
(behind the forehead), which is responsible primarily for thinking, planning, memory, and judgment.
parietal lobe,
which extends from the middle to the back of the skull and which is responsible primarily for processing information about touch.
occipital lobe
at the very back of the skull, which processes visual information.
temporal lobe,
responsible primarily for hearing and language.
contralateral control
brain is wired such that in most cases the left hemisphere receives sensations from and controls the right side of the body, and vice versa.
motor cortex
the part of the cortex that controls and executes movements of the body by sending signals to the cerebellum and the spinal cord
somatosensory cortex
an area just behind and parallel to the motor cortex at the back of the frontal lobe, receives information from the skin’s sensory receptors and the movements of different body parts.
visual cortex
the area located in the occipital lobe (at the very back of the brain) that processes visual information
auditory cortex,
contained in the temporal lobe
which is responsible for hearing and language. The temporal lobe also processes some visual information, providing us with the ability to name the objects around us
association areas
motor and sensory areas of the cortex account for a relatively small part of the total cortex, the rest is association areas in which sensory and motor information is combined and associated with our stored knowledge
involved in higher mental functions, such as learning, thinking, planning, judging, moral reflecting, figuring, and spatial reasoning.
Neuroplasticity
refers to the brain’s ability to change its structure and function in response to experience or damage. Neuroplasticity enables us to learn and remember new things and adjust to new experiences.
neurogenesis
the forming of new neurons
brain lateralization
idea that the left and the right hemispheres of the brain are specialized to perform different functions
corpus callosum
the region that normally connects the two halves of the brain and supports communication between the hemispheres,
left hemisphere
ability to speak, write, and understand language
better at math and at judging time and rhythm. It is also superior in coordinating the order of complex movements—for example, lip movements needed for speech.
right hemisphere
only very limited verbal abilities, and yet it excels in perceptual skills
recognize objects, including faces, patterns, and melodies, and it can put a puzzle together or draw a picture
electroencephalography (EEG)
technique that records the electrical activity produced by the brain’s neurons through the use of electrodes that are placed around the research participant’s head.
Functional magnetic resonance imaging (fMRI)
a type of brain scan that uses a magnetic field to create images of brain activity in each brain area
Transcranial magnetic stimulation (TMS)
a procedure in which magnetic pulses are applied to the brain of living persons with the goal of temporarily and safely deactivating a small brain region
nerves
bundles of interconnected neurons that fire in synchrony to carry messages
sensory (or afferent) neuron
carries information from the sensory receptors
motor (or efferent) neuron
transmits information to the muscles and glands
interneuron
by far the most common type of neuron, is located primarily within the CNS and is responsible for communicating among the neurons.
allow the brain to combine the multiple sources of available information to create a coherent picture of the sensory information being conveyed.
spinal cord
the long, thin, tubular bundle of nerves and supporting cells that extends down from the brain
reflex
an involuntary and nearly instantaneous movement in response to a stimulus. Reflexes are triggered when sensory information is powerful enough to reach a given threshold and the interneurons in the spinal cord act to send a message back through the motor neurons without relaying the information to the brain
autonomic nervous system (ANS)
division of the PNS that governs the internal activities of the human body, including heart rate, breathing, digestion, salivation, perspiration, urination, and sexual arousal.
dovded into sympathetic and parasympathetic nervous systems
somatic nervous system (SNS)
division of the PNS that controls the external aspects of the body, including the skeletal muscles, skin, and sense organs.
sympathetic division of the ANS
involved in preparing the body for behavior, particularly in response to stress, by activating the organs and the glands in the endocrine system.
parasympathetic division of the ANS
tends to calm the body by slowing the heart and breathing and by allowing the body to recover from the activities that the sympathetic system causes.
homeostasis
the natural balance in the body’s systems.
gland
groups of cells that function to secrete hormones.
hormone
a chemical that moves throughout the body to help regulate emotions and behaviors.
pituitary gland
small pea-sized gland located near the center of the brain, is responsible for controlling the body’s growth
secretes hormones that influence our responses to pain as well as hormones that signal the ovaries and testes to make sex hormones
pancreas
secretes hormones designed to keep the body supplied with fuel to produce and maintain stores of energy
pineal gland
located in the middle of the brain, which secretes melatonin, a hormone that helps regulate the wake-sleep cycle;
thyroid and parathyroid glands
responsible for determining how quickly the body uses energy and hormones, and controlling the amount of calcium in the blood and bones
adrenal glands
one atop each kidney
produce hormones that regulate salt and water balance in the body, and they are involved in metabolism, the immune system, and sexual development and function
produce the hormones epinephrine (also known as adrenaline) and norepinephrine (also known as noradrenaline)
