Chapter Two Flashcards
biological psychology
the scientific study of the links between biological (genetic, neural, hormonal) and psychological processes. Some biological psychologists call themselves behavioral neuroscientists, neuropsychologists, behavior geneticists, physiological psychologists, or biopsychologists.
What do phrenology and biological psychology have in common?
They share a focus on the links between the brain and behavior. Phrenology faded because it had no scientific basis—skull bumps don’t reveal mental traits and abilities.
plasticity
the brain’s ability to change, especially during childhood, by reorganizing after damage or by building new pathways based on experience.
neuron
a nerve cell; the basic building block of the nervous system.
cell body
the part of a neuron that contains the nucleus; the cell’s life-support center.
dendrites
a neuron’s often bushy, branching extensions that receive and integrate messages, conducting impulses toward the cell body.
axon
the neuron extension that passes messages through its branches to other neurons or to muscles or glands.
myelin [MY-uh-lin] sheath
a fatty tissue layer segmentally encasing the axons of some neurons; enables vastly greater transmission speed as neural impulses hop from one node to the next.
glial cells (glia)
cells in the nervous system that support, nourish, and protect neurons; they also play a role in learning, thinking, and memory.
action potential
a neural impulse; a brief electrical charge that travels down an axon.
threshold
the level of stimulation required to trigger a neural impulse.
refractory period
in neural processing, a brief resting pause that occurs after a neuron has fired; subsequent action potentials cannot occur until the axon returns to its resting state.
all-or-none response
a neuron’s reaction of either firing (with a full-strength response) or not firing.
When a neuron fires an action potential, the information travels through the axon, the dendrites, and the cell body, but not in that order. Place these three structures in the correct order.
dendrites, cell body, axon.
How does our nervous system allow us to experience the difference between a slap and a tap on the back?
Stronger stimuli (the slap) cause more neurons to fire and to fire more frequently than happens with weaker stimuli (the tap).
synapse [SIN-aps]
the junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron. The tiny gap at this junction is called the synaptic gap or synaptic cleft.
neurotransmitters
chemical messengers that cross the synaptic gaps between neurons. When released by the sending neuron, neurotransmitters travel across the synapse and bind to receptor sites on the receiving neuron, thereby influencing whether that neuron will generate a neural impulse.
reuptake
a neurotransmitter’s reabsorption by the sending neuron.
What happens in the synaptic gap?
Neurons send neurotransmitters (chemical messengers) across this tiny space between one neuron’s terminal branch and the next neuron’s dendrite or cell body.
What is reuptake? What two other things can happen to excess neurotransmitters after a neuron reacts?
Reuptake occurs when excess neurotransmitters are reabsorbed by the sending neuron. Neurotransmitters can also drift away or be broken down by enzymes.
endorphins [en-DOR-fins]
“morphine within”—natural, opiate-like neurotransmitters linked to pain control and to pleasure.
Serotonin, dopamine, and endorphins are all chemical messengers called ______________.
neurotransmitters
agonist
a molecule that increases a neurotransmitter’s action.
antagonist
a molecule that inhibits or blocks a neurotransmitter’s action.
Curare poisoning paralyzes its victims by blocking ACh receptors involved in muscle movements. Morphine mimics endorphin actions. Which is an agonist, and which is an antagonist?
Morphine is an agonist; curare is an antagonist.
nervous system
the body’s speedy, electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous systems.
central nervous system (CNS)
the brain and spinal cord.
peripheral nervous system (PNS)
the sensory and motor neurons that connect the central nervous system (CNS) to the rest of the body.
nerves
bundled axons that form neural cables connecting the central nervous system with muscles, glands, and sense organs.
sensory (afferent) neurons
neurons that carry incoming information from the body’s tissues and sensory receptors to the brain and spinal cord.
motor (efferent) neurons
neurons that carry outgoing information from the brain and spinal cord to the muscles and glands.
interneurons
neurons within the brain and spinal cord; they communicate internally and process information between the sensory inputs and motor outputs.
somatic nervous system
the division of the peripheral nervous system that controls the body’s skeletal muscles. Also called the skeletal nervous system.
autonomic [aw-tuh-NAHM-ik] nervous system (ANS)
the part of the peripheral nervous system that controls the glands and the muscles of the internal organs (such as the heart). Its sympathetic division arouses; its parasympathetic division calms.
sympathetic nervous system
the division of the autonomic nervous system that arouses the body, mobilizing its energy.
parasympathetic nervous system
the division of the autonomic nervous system that calms the body, conserving its energy.
What bodily changes does your ANS direct before and after you give an important speech?
Responding to this challenge, your ANS sympathetic division will arouse you. It accelerates your heartbeat, raises your blood pressure and blood sugar, slows your digestion, and cools you with perspiration. After you give the speech, your ANS parasympathetic division will reverse these effects.
reflex
a simple, automatic response to a sensory stimulus, such as the knee-jerk response.
endocrine [EN-duh-krin] system
the body’s “slow” chemical communication system; a set of glands that secrete hormones into the bloodstream.
hormones
chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream, and affect other tissues.
adrenal [ah-DREEN-el] glands
a pair of endocrine glands that sit just above the kidneys and secrete hormones (epinephrine and norepinephrine) that help arouse the body in times of stress.
pituitary gland
the endocrine system’s most influential gland. Under the influence of the hypothalamus, the pituitary regulates growth and controls other endocrine glands
Why is the pituitary gland called the “master gland”?
Responding to signals from the hypothalamus, the pituitary releases hormones that trigger other endocrine glands to secrete hormones, which in turn influence brain and behavior.
How are the nervous and endocrine systems alike, and how do they differ?
Both of these communication systems produce chemical molecules that act on the body’s receptors to influence our behavior and emotions. The endocrine system, which secretes hormones into the bloodstream, delivers its messages much more slowly than the speedy nervous system, and the effects of the endocrine system’s messages tend to linger much longer than those of the nervous system.
lesion [LEE-zhuhn]
tissue destruction. A brain lesion is a naturally or experimentally caused destruction of brain tissue.
electroencephalogram (EEG)
an amplified recording of the waves of electrical activity sweeping across the brain’s surface. These waves are measured by electrodes placed on the scalp.
magnetoencephalography (MEG)
a brain-imaging technique that measures magnetic fields from the brain’s natural electrical activity.
MRI (magnetic resonance imaging)
a technique that uses magnetic fields and radio waves to produce computer-generated images of soft tissue. MRI scans show brain anatomy.
fMRI (functional MRI)
a technique for revealing bloodflow and, therefore, brain activity by comparing successive MRI scans. fMRI scans show brain function as well as structure.
brainstem
the oldest part and central core of the brain, beginning where the spinal cord swells as it enters the skull; the brainstem is responsible for automatic survival functions.
medulla
[muh-DUL-uh] the base of the brainstem; controls heartbeat and breathing.
thalamus [THAL-uh-muss]
the brain’s sensory control center, located on top of the brainstem; it directs messages to the sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla.
reticular formation
a nerve network that travels through the brainstem into the thalamus and plays an important role in controlling arousal.
The _____________ is a crossover point where nerves from the left side of the brain are mostly linked to the right side of the body, and vice versa.
brainstem
cerebellum
[sehr-uh-BELL-um] the “little brain” at the rear of the brainstem; functions include processing sensory input, coordinating movement output and balance, and enabling nonverbal learning and memory.
In what brain region would damage be most likely to (1) disrupt your ability to skip rope? (2) disrupt your ability to hear? (3) perhaps leave you in a coma? (4) cut off the very breath and heartbeat of life?
- cerebellum, 2. thalamus, 3. reticular formation, 4. medulla.
amygdala
[uh-MIG-duh-la] two lima-bean-sized neural clusters in the limbic system; linked to emotion.
Electrical stimulation of a cat’s amygdala provokes angry reactions. Which autonomic nervous system division is activated by such stimulation?
The sympathetic nervous system
hypothalamus
[hi-po-THAL-uh-muss] a neural structure lying below (hypo) the thalamus; it directs several maintenance activities (eating, drinking, body temperature), helps govern the endocrine system via the pituitary gland, and is linked to emotion and reward.
hippocampus
a neural center located in the limbic system; helps process explicit (conscious) memories—of facts and events—for storage.
hat are the three key structures of the limbic system, and what functions do they serve?
(1) The amygdala is involved in aggression and fear responses. (2) The hypothalamus is involved in bodily maintenance, pleasurable rewards, and control of the hormonal systems. (3) The hippocampus processes memory of facts and events.
cerebral [seh-REE-bruhl] cortex
the intricate fabric of interconnected neural cells covering the cerebral hemispheres; the body’s ultimate control and information-processing center.
Which area of the human brain is most similar to that of less complex animals? Which part of the human brain distinguishes us most from less complex animals?
The brainstem; the cerebral cortex
frontal lobes
the portion of the cerebral cortex lying just behind the forehead; involved in speaking and muscle movements and in making plans and judgments.
parietal
[puh-RYE-uh-tuhl] lobes the portion of the cerebral cortex lying at the top of the head and toward the rear; receives sensory input for touch and body position.
occipital [ahk-SIP-uh-tuhl] lobes
the portion of the cerebral cortex lying at the back of the head; includes areas that receive information from the visual fields.
temporal lobes
the portion of the cerebral cortex lying roughly above the ears; includes the auditory areas, each receiving information primarily from the opposite ear.
motor cortex
an area at the rear of the frontal lobes that controls voluntary movements.
somatosensory cortex
an area at the front of the parietal lobes that registers and processes body touch and movement sensations.
Our brain’s ____________ cortex registers and processes body touch and movement sensations. The ____________ cortex controls our voluntary movements.
somatosensory; motor
association areas
areas of the cerebral cortex that are not involved in primary motor or sensory functions; rather, they are involved in higher mental functions such as learning, remembering, thinking, and speaking.
Why are association areas important?
Association areas are involved in higher mental functions—interpreting, integrating, and acting on information processed in other areas.
neurogenesis
the formation of new neurons.
corpus callosum
[KOR-pus kah-LOW-sum] the large band of neural fibers connecting the two brain hemispheres and carrying messages between them.
split brain
a condition resulting from surgery that isolates the brain’s two hemispheres by cutting the fibers (mainly those of the corpus callosum) connecting them.
(1) If we flash a red light to the right hemisphere of a person with a split brain, and flash a green light to the left hemisphere, will each observe its own color? (2) Will the person be aware that the colors differ? (3) What will the person verbally report seeing?
- yes, 2. no, 3. green
