UNIT 2 (CH 3/5) Flashcards
a nerve cell; the basic building block of the nervous system
neuron
neurons that carry incoming information from the sensory reseptors to the brain and spinal cord
sensory neuron (afferent neuron)
neurons that carry outgoing information from the brain and spinal cord to the muscles and glands
motor neurons (efferent neuron)
neurons within the brain and spinal cord that communicate internally and intervene between the sensory inputs and motor outputs
interneurons
the bushy, braching extentions of a neuron that receive messages and conduct impulses toward the cell body
dendrite
the extension of a neuron, ending in branching terminal fibers, through which messages pass to other neurons or to the muscles or glands
axon
a layer of fatty tissue segmentally encasing the fibers of many neurons; enables vastly greater transmission speed of neural impluses as the impulse hops from one node to the next
myelin sheath
a neural impulse; a brief electrical charge that travels down an axon
action potential
the level of stimulation required to trigger a neural impulse
threshold
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
synapse
chemical messengers that cross the synaptic gaps between neurons. When released by the sending neuron, neurotransmitters travel across the synapse and bind to reseptor sites on the receiving neuron, thereby influencing whether that neuron will generate a neural impulse
neurotransmitters
a neurotransmitter’s reabsorption by the sending neuron
reuptake
morphine within - natural . opiatelike neurotransmitters linked to pain control and to pleasure
endorphins
the body’s speedy, electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous systems
nervous system
the brain and spinal cord
central nervous system (CNS)
the sensory and motor neurons that connect the central nervous system to the rest of the body
peripheral nervous system (PNS)
bundled axons that form neural “cables” connecting the central nervous system with muscles, glands, and sense organs
nerves
the division of the peripheral nervous system that controls the body’s skeletal muscles.
somatic nervous system
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.
autonomic nervous system (ANS)
the division of the autonomic nervous system that arouses the body, mobilizing its energy in stressful situations
sympathetic nervous system
the division of the autonomic nervous system that calms the body, conserving its energy
Parasympathetic nervous system
In neural processing, a brief resting pause that occurs after a neuron has fired; subsequent action potential cannot occur until the axon returns to its resting state
Refractory period
a simple, automatic response to a sensory stimulus, such as the knee-jerk response
reflex
the body’s “slow” chemical communication system; a set of glands that secrete hormones into the bloodstream
endocrine system
chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream, and affect other tissues
hormones
a pair of endocrine glands that sit just above the kidneys and secrete hornomes (epinephrine and norepinephrine) that helps arouse the body in times of stress
adrenal glands
the endocrine system’s most influential gland. Under the influence of the hypothalamus, the pituitary regulates growth and controls other endocrine glands
pituitary gland
tissue destruction; a brain lesion is a naturally or experimentally caused destruction of brain tissue
lesion
an amplified recording of the waves of electrical activity that sweep across the brain’s surface. These waves are measured by electrodes placed on th scalp.
electroencephalogram (EEG)
a series of X-ray photos taken from different angles and combined by computer into a composite representation of a slice through the body - also called a CAT scan
CT (computed tomography) scan
a visual display of brain activity that detects where a radioactive form of glucose goes while the brain performs a given task
PET (positron emission tomography) scan
a technique that uses magnetic fields ans radio waves to produce computer-generated images of soft tissue. MRI scans show brain anatomy
MRI (magnetic resonance imaging)
a technique for revealing bloodflow and, therefore, brain activity by comparing successive MRI scans, fMRI shows brain functions
fMRI (functional MRI)
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
brainstem
the base of the brainstem; controls heartbeat and breathing
medulla
a nerve netowrk in the brainstem that plays an important role in controlling arousal
reticular formation
the brain’s sensory switchboard, located on top of the brainstem; it directs messages to the sensory receiving areas in the cortex and transmits replies to the cerebellum amd medulla - all senses, but smell are processed here
thalamus
the “little brain” at the rear of the brainstem; functions include processing sensory input and coordinating movement output an balance
cerebellum
doughnut-shaped neural system (including the hippocampus, amygdala, and hypothalamus) located below the cerebral hemispheres; associated with emotions and drives
limbic system
two lima bean-sized neural clusters in the limbic system; linked to raw emotions such as fear and anger
amygdala
a neural structure lying below the thalamus; it directs several maintenance activities (eating, drinking, body temp). helps govern the endocrine system via the pituitary gland, and is linked to emotion and reward (think 4 F’s!!)
hypothalamus
the intricate fabric of interconnected neural calles covering the cerebral hemispheres; the body’s ultimate control and information processing center
cerebral cortex
cells in the nervour system that support, nourish, and protect neurons
glial cells (glia)
portion of the cerebral cortex lying just behind the forehead; involved in speaking and muscle movements and in making plans and judgements
frontal lobes
portion of the cerebral cortex lying at the top of the head and toward the rear; received sensory input for touch and body postion
Parietal lobes
portion of the cerebral cortex lying at the back of the head, includes areas that receive information from visual fields
occipital lobes
portion of the cerebral cortex lying roughly above the ears; includes the auditory areas, each receiving information primarily from the opposite ear
temporal lobes
an area at the rear of the frontal lobes that controls voluntary movements
motor cortex