Third test on the biological basis of behavior Flashcards
neuron
nerve cell, basic building block of the nervous system
dendrites
neuron’s bushy, branching extensions that receive messages and conduct impulses toward the cell body
axon
neuron extensions that passes messages through its branches to other neurons
Myelin sheet
fatty tissue layer that segmentally encases the axons of some neurons; enables vastly greater transmission seed as neural impulses hop from sausage like node to the next
action potential
neural impulse; a breif electrical charge that travels
refractory period
a period of inactivity after a neuron has fired
threshold
the level of stimulation required to trigger a neural impulse
all or non response
a neurons reaction of either firing (with a full strength response) or not firing
synapse
the junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron. this tiny gap is called the synaptic gap or the synaptic cleft
neurotransmitters
chemical messengers that cross the synaptic gap between neurons. these 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 nuerotransmitters reabsorption by the sending neuron
endorphins
natural opiate like neurotransmitters linked to pain control and to pleasure
agonist
a molecule that, by binding to a receptor site, stimulates a response
antagonist
a molecule that, by binding to a receptor site, inhibits oe blocks a response
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 chord
peripheral nervous system
the sensory and motor neurons that connect the central nervous system 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 sensory receptors to the brain and spinal chord
motor (afferent) neurons
neurons that carry outgoing information from the brain and spinal chord to the muscles and glads
interneurons
neurons within the brain and spinal chord that communicate internally and intervene between the sensory inputs and motor inputs
somatic nervous system
the division of the peripheral nervous system that control’s the body’s skeletal muscles. also call the skeletal muscle system
autonomic nervous system (ANS)
the part of the peripheral nervous system tha 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 tha autonomic nervous system that arouses the body, mobilizing its energy in stressful situations
parasympathetic nervous system
the division of the autonomic nervous system that calms the body, conserving its energy
sympathetic nervous system does what?
arouses
Parasympathetic nervous system does what?
calms
endocrine 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 glands
a pair of endocrine glands that sit just above the kidneys and secrete hormones that hep arouse the body in times of stress
pituitary gland
the endocrine system’s most influential gland , regulates growth and controls other endocrine glands
lesion
tissue destruction. a brain lesion is a naturally or experimental caused destruction of brain tissue
electroencephalogram
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
CT (computed tomography)
a series of x ray photographs taken from different angles and combined by computer into a composite representation of a slice of the brains structure
PET (positron emission tomography) scan
a visual display of brain activity that detects where a radioactive form of glucose goes while the brain performs a given task
MRI (magnetic resonance imaging)
puts the head in a strong magnetic field which spins the atoms of the brain molecules. Then radio waves are pulsed to momentarily disorient the atoms. When the atoms return, they provided detailed images of the brains soft tissue
fMRI (functional MRI)
a technique for revealing blood flow, and therefore, brain activity by comparing successive MRI scans
What does fMRI show?
brain function as well as its structure
brainstem
the oldest part of the brain, beginning where the spinal chord swells as it enters the skull
what is the brainstem responsible for
automatic survival functions
Medulla
controls heartbeat and breathing, base of the brainstem
Thalamus
brain’s sensory control center located on top of the brainstem
what does the thalamus do
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 and thalamus
what does the reticular formation play a role in
arousal
Cerebellum
at the rear of the brainstem, enables nonverbal learning and memory, deals with coordinating movement output and balance, helps you know if you are staring up straight or sitting up straight
Limbic system
associated with emotions and drives
what makes up the limbic system
hippocampus, amygdala, and hypothalamus
Amygdala
linked to emotions, including perceiving emotions and the processing of emotional memories
Hypothalamus
directs several activities like eating, drinking, body temperature
hippocampus
linked to memory
Corpus callosum
connects two hemispheres and helps relay messages to them