The brain and behavior Flashcards
kapittel 4
neurons
the functional building blocks of the nervous system; cells that transmit the electrical activity that underlies psychological processes.
glial cell
from the Greek for “glue”, glial cells surround the neurons, holding them in place, providing the nutrients they need and isolating toxins that would harm them.
synapse
a connection between neurons.
sensory neurons
carry input messages from the sense organs to the spinal cord and brain.
motor neurons
transmit output impulses from the brain and spinal cord to the body´s muscles and organs.
interneurons
perform connective or associative functions within the nervous system.
peripheral nervous system
contains all the neural structures that lie outside the brain and spinal cord.
somatic nervous system
consists of sensory neurons that are specialized to transmit messages from the eye, ears and other sensory receptors, and motor neurons that sed messages from the brain and spinal cord to the muscles that control our voluntary movements.
automatic nervous system
senses the body´s internal functions and controls the glands and the smooth (involuntary) muscles that form the heart, the blood vessels, and the lining of the stomach and intestines.
sympathetic nervous system
has an activation or arousal function, and tends to act as a total unit.
parasympathetic nervous system
for more specific than the sympathetic nervous system in it opposing actions, it affects one or a few organs at the time; in general, it slows down body processes and maintain a state of tranquillity.
homeostasis
a delicately balanced or constant internal state.
central nervous system
contains the brain and the spinal cord, which connects most parts of the peripheral nervous system with the brain.
dendrites
specialized receiving units like antennae that collect messages from neighboring neurons and send them on to the cell body.
axon
conducts electrical impulses away from the cell body to other neurons, muscles or glands.
resting potential
internal difference of around 70 millivolts (mV)
action potential
electrical shift across the neural membrane, which lasts about a millisecond and propagates electrical signals down an axon.
absolute refractory period
period during which the membrane is not equitable and cannot discharge another impulse.
graded potentials
changes in the negative resting potential that do not reach the -50 millivolt action potential threshold.
myelin sheath
a whitish, fatty insulation layer derived from glial cells during development.
synaptic cleft
a tiny gap between the axon terminal and the next neuron.
neurotransmitters
chemicals released by nerve cells that allow them to communicate with one another.
synaptic vesicles
chambers within the axon terminals
receptor sited
large protein molecules embedded in the receiving neurons cell membrane.
re-uptake
the transmitter molecules are taken back into the presynaptic axon terminals.
acetylcholine (ACh)
a neurotransmitter involved I muscle activity and memory.
botulinum bacteria
toxin-forming bacteria, a mild form of which is known commonly as botox.
neuromodulators
chemicals that modulate the activity of diverse populations of neurons in the nervous system.
neuropsychology
the study of the function of the brain by investigating the effects of brain damage on mental functions.
Wernickes aphasia
results from damage in the temporal lobe, and is primarily manifested as difficulties with speech comprehension.
Brocas aphasia
results from damage in the frontal lobe and is primarily manifested as difficulties with the production of speech.
electroencephalography (EEG)
measures the activity of large groups of neurons through a series of large electrodes placed on the scalp.
magnetoencephalography (MEG)
a brain imaging method that detects activity via magnetic fields generated by brain activity.
magnetic resonance imaging (MRI)
creates images based on how atoms in living tissue respond to a magnetic pulse delivered by the device.
diffusion tensor imagina (DTI)
measures how water molecules diffuse in tissue.
functional MRI (fMRI)
can produce pictures of blood flow in the brain taken less than a second apart.
position-emission tomography (PET) scans.
measure brain activity, including metabolism, blood flow and neurotransmitter activity.
functional near-infrared spectroscopy (fNIRS)
by shining near-infrared light into the brain and measuring the ways in which it is reflected, fNIRS can tell us about which parts of the brain are using most oxygen.
transcranial magnetic stimulation (TMS)
electral stimulation of a targeted part og the brain via magnetic pulses sent from an electromagnetic coil.
transcrainal electrical stimulation (TES)
electrical stimulation of the brain by applying a low current to the scalp.
hindbrain
the lowest and most primitive level of the brain.
brainstem
spans the hindbrain and midbrain; hindbrain structures in the brainstem include the medulla and the pons; the brainstem supports a number of vital physiological functions.
medulla
plays an important role in vital body functions such as heart rate and respiration.
pons
lies just above the medulla and relays sensory information between the cerebral cortex and the cerebellum.
cerebellum
concerned primarily with muscular movement co-ordination, but also plays a role in learning and memory.
midbrain
contains clusters of sensory and motor neurons.
reticular formation
act as a kind of sentry, alerting higher centers of the brain that messages are coming, and then either blocking those messages or allowing them to go forward.
forebrain
the brains most recently evolved portion. the forebrain is responsible for receiving and processing sensory information, thinking, perceiving, producing and understanding language, and controlling motor function.
cerebrum
the most superior part of the forebrain, comprising the cerebral cortex and several more central structures.
thalamus
sometimes likened to a switchboard that organizes inputs from sensory organs and tours them to the appropriate areas of the brain.
hypothalamus
plays a major role in many aspects of motivation and emotion, including sexual behavior, temperature regulation, sleeping, eating, drinking and aggression.
limbic system
helps co-ordinate the behaviors needed to satisfy the motivational and emotional urges that arise in the hypothalamus; it is also involved in memory.
hippocampus
structure in the limbic system involved in forming and retrieving memories.
amygdala
structure in the limbic system that underlies emotional behaviors, particulate those linked to aggression and fear.
cerebral cortex
0,63 cm thick sheet, consisting primarily of grey matter.
motor cortex
controls the 600 or more muscles involved in voluntary body movements.
somatosensory cortex
receives sensory input that gives rise to our sensations of heat, touch and cold, and to our senses of balance and body movement.
association cortices
involved in many important mental functions, including perception, language and thought.
prefrontal cortex
located just behind the forehead, the seat of the so-called executive functions.
corpus callosum
a neural bridge consisting of white matter tracts that acts as a major communication link between the two hemispheres and allows them to function together.
lateralization
the relatively greater localization of a function in one hemisphere or the other.
aphasia
the partial or total loss of the ability to communicate
endocrine system
consists of numerous hormone secreting glands distributed throughout the body.
hormones
chemical messengers that are secreted from the glands of the endocrine system into the bloodstream.
adrenal glands
twin structures perched on top of the kidneys that serve as “hormone factories”, producing and secreting about 50 different hormones.
antigens
foreign substances that trigger a biochemical response from the immune system.
neural plasticity
the ability of neurons, brain areas and networks to change in structure and function.
