the body's speedy, electrochemical communication system, consisting of all the nerve cells of the peripheral and central nervous systems
Cells in the nervous system that are not neurons but that support, nourish, and protect neurons
the extension of a neuron, ending in branching terminal fibers, through which messages pass to other neurons or to muscles or glands.
a neural impulse; a brief electrical charge that travels down an axon. The action potential is generated by the movement of positively charged atoms in and out of channels in the axon's membrane.
the time following an action potential during which a new action potential cannot be initiated
sites on the surface of a cell that allow only one type of neurotransmitter to fit through and trigger a chemical response that may lead to an action potential
the change in the membrane potential of a neuron that has received stimulation from another neuron
Excitatory Postsynaptic Potential
a postsynaptic potential that depolarizes the neuronal membrane, making the cell more likely to fire an action potential
Inhibitory Postsynaptic Potential
a postsynaptic potential that hyperpolarizes the neuronal membrane, making a cell less likely to fire an action potential
Three Functions of the Nervous System
1. INPUT: the sound of the alarm clock is conveyed to your brain by your ears
2. PROCESSING: your brain knows from past experience that it is time to get up
3. OUTPUT: your brain directs the muscles of your arm and hand to reach out and shut off the alarm clock
How Do Neurons Communicate?
1. An ACTION POTENTIAL shoots down the AXON, away from the cell body.
2. A NEUROTRANSMITTER is release into the SYNAPSE, where the DENDRITES or the neighboring neurons detect it.
3. If there is a receptor for this neurotransmitter on the dendrites, the neurotransmitter and receptor bind, creating an electrochemical signal.
4. If that signal is strong enough, it spreads down the dendrites and across the cell body of the next neuron, and begins another action potential.
the parts of the nervous system that influence muscles and other organs to respond to the environment in some way
Central Nervous System (CNS)
the part of the nervous system that are located in bone (the brain and spinal cord)
Somatic Nervous System
(AKA Skeletal Nervous System) the division of the peripheral nervous system that controls the body's skeletal muscles
Autonomic Nervous System
the part of the nervous system of vertebrates that controls involuntary actions of the smooth muscles, heart, and glands; divided into Sympathetic and Parasympathetic systems
Sympathetic Nervous System
a branch of the autonomic nervous system and prepares the body for quick action in emergencies; "fight or flight"
Parasympathetic Nervous System
the division of the autonomic nervous system that calms the body, conserving its energy
unlearned, involuntary responses that occur automatically in the presence of certain stimuli
cycle of events in which body's status is monitored, changed, and reevaluated; EXAMPLE: when you touch a hot stove, your muscles contract away from the stimulus, but in order to do that, another set of muscles would have had to relax
(AKA motor neurons) nerves that carry impulses away from the brain and spinal cord to the muscles and glands
division which includes the cerebellum, Pons, and medulla; responsible for involuntary processes: blood pressure, body temperature, heart rate, breathing, sleep cycles
part of the brain nearest the spinal cord which controls breathing, heart rate and blood pressure
a network of cells in the brainstem that filters sensory information and is involved in arousal and alertness
the "little brain" attached to the rear of the brainstem; its functions include processing sensory input and coordinating movement output and balance; also involved in impulse control, emotion, and language
the part of the brain that lies between the cerebellum and spinal cord that controls the body's involuntary actions
a brain structure located at the top of the brain stem that is involved in respiration, movement, and sleep
the middle division of brain responsible for hearing and sight; location where pain is registered; includes temporal lobe, occipital lobe, and most of the parietal lobe
an area of the midbrain that is involved in motor control and contains a large concentration of dopamine-producing neurons.
portion posterior to the frontal lobe, responsible for sensations such as pain, temperature, and touch
the large band of neural fibers connecting the two brain hemispheres and carrying messages between them
endocrine system's most influential gland; under the influence of the hypothalamus, the pituitary regulates growth and controls other endocrine glands
controls language reception - a brain area involved in language comprehension and expression; usually in the left temporal lobe
responsible for the production of the sounds of speech; brocca's area and the wernicke's area are only in humans
top of the brain which includes the thalamus, hypothalamus, and cerebral cortex; responsible for emotional regulation, complex thought, memory aspect of personality
front of the brain; associated with reasoning, planning, parts of speech, movement, emotions, and problem solving
neural system (including the hippocampus, amygdala, and hypothalamus) located below the cerebral hemispheres; associated with emotions and drives.
brain structure that receives messages from the sense organs and relays the information to the proper region of the cerebrum for further processing
brain structure below the thalamus; directs eating, drinking, body temperature; helps govern the endocrine system via the pituitary gland, and is linked to emotion
neural centre located in the limbic system that helps process explicit memories for storage.
pair of hypothalamic nuclei, one on the left and one on the right, that play a role in the timing of 24 hour biological rhythims; they are located just dorsal to the optic chiasm.
the layer of unmyelinated neurons (the gray matter) forming the cortex (outer surface) of the cerebrum
the area at the front of the parietal lobes that registers and processes body touch and movement sensations; includes visual, auditory, and somatosensory cortexes
located in the occipital lobe; the main information-processing center for visual information
a brain area at the front of the parietal lobes that registers and processes body sensations
areas of the cortex that communicate with the sensory and motor areas and house the brain's higher mental processes
referring to the tendency for one cerebral hemisphere to excel at a particular function or skill compared with the other hemisphere
a neurotransmitter that triggers muscle contraction and enables learning and memory; loss of acetylcholine causes Alzheimer's disease
neurotransmitter that is involved in arousal and the fight-or-flight system (also mood, sleep, and learning)
affects mood, appetite, sleep, and arousal; ongoing research suggests that a lack of seratonin is linked to depression
neurotransmitter related to pleasure; addictions are caused by the addict searching for a drug that causes a firing of dopamine through the body; lack of dopamine linked with Parkinson's disease, too much is linked with schizophrenia
Gamma Amino Butyric Acid (GABA)
the body's chief inhibitory neurotransmitter, which plays a role in regulating arousal; loss of GABA causes Huntington's Disease
major excitatory neurotransmitter (strengthens synaptic bonds in the CNS); affects memory and learning
The Endocrine System
is a collection of glands that produce hormones which help regulate the body's growth, metabolism, and sexual development and function
chemical messengers released by the endocrine glands that travel through the bloodstream and affect other tissues
gland that produces hormones that regulate blood sugar by releasing glucagon or insulin as needed
located one on each side of the uterus in the female pelvis, functioning to secrete estrogen and progesterone
The Immune System
complex group of defenses found in the body that fight against harmful substances and pathogens