The Nervous System and Endocrine Systems Flashcards
action potential
A neural impulse. A brief electrical charge that travels down an axon when it fires.
adrenal glands
Small glands that produce steroid hormones, adrenaline, and noradrenaline, which help control heart rate, blood pressure, and other important bodily functions. There are two adrenal glands, one located on top of each kidney.
all-or-none law
This law states that the process by which a neuron fires is all or none. Either a neuron receives sufficient stimulation from surrounding cells to fire, or it doesn’t. There is no variation in the size of the electrical impulse once the neuron fires.
amygdala
A portion of the limbic system of the brain that is linked to emotions and forming long-term memories.
applied research
Research that is conducted to solve a specific or practical problem.
association areas
Portions of the cerebral cortex that integrate material from many parts of the brain. These areas are responsible for higher brain functions such as remembering, learning, and interpreting sensory information.
autonomic nervous system
The portion of the nervous system that controls glands and muscles of the internal organs.
axon
A long, hair-like extension of a nerve cell (a neuron) that transmits electrical impulses away from the cell body.
blood-brain barrier
The protective barrier, composed of glia, that keeps certain substances in the blood from reaching brain tissue.
brain stem
The portion of the brain that connects the upper brain with the spinal cord. The brain stem is responsible for life-sustaining functions such as heartbeat and respiration, as well as maintaining alertness.
CAT (Computerized Axial Tomography)
A computerized series of X-rays taken from different angles that are compiled to create an image of the area in question.
central fissure
A long, deep fissure on the lateral surface of the cerebral cortex.
central nervous system
The portion of the nervous system consisting of the brain and spinal cord.
cerebellum
The portion of the hindbrain that helps to control posture, balance, and motor coordination.
cerebral cortex
The outer layer of nerve cells covering the cerebrum that is responsible for most higher cognitive functions.
cerebral hemispheres
The right and left halves of the cerebrum.
chromosomes
Structures made of deoxyribonucleic acid (DNA) that contain genes. Chromosomes are located in the nucleus of a cell. Humans normally have 23 pairs of chromosomes, or a total of 46.
corpus callosum
The bundle of nerve fibers that connects the left and right hemispheres of the brain.
dendrites
The bushy ends of a neuron that pick up information from neighboring cells and transmit it to the cell body.
depolarize
To make the cell membrane charge less negative. If the cell membrane is sufficiently depolarized, the neuron will fire.
DNA (deoxyribonucleic acid)
The substance inside a cell’s nucleus that contains instructions for all of the structures and processes that the body needs to function.
electrochemical
A process that is both electrical and chemical. Neuron transmission is electrochemical because there is an electrical process within the neuron, but there is a chemical process that takes place in the synapse, or the gap between neurons.
endocrine system
A system of glands that release hormones into the blood.
endorphins
Substances produced by the body that are involved in pain relief and positive mood.
epinephrine
A hormone secreted by the adrenal medulla that is stimulated by the central nervous system in response to stress or fear. It acts to increase heart rate, blood pressure, cardiac output, and carbohydrate metabolism.
excitatory
A substance that increases the likelihood a neuron will fire.
forebrain
The largest and most recently evolved division of the brain. It contains the cerebral cortex, the basal ganglia, the thalamus, and the hypothalamus.
GABA
The main inhibitory receptor in the central nervous system.
glial cells
Cells that surround neurons, providing support and insulation.
hemisphere
The left or right half of the brain
hindbrain
The hindbrain is the portion of the brain that is responsible for many basic life-support functions such as the coordination of motor activity, posture, equilibrium, and sleep patterns. It also helps regulate breathing and blood circulation.
hippocampus
A portion of the brain located inside the temporal lobes. It is part of the limbic system and is involved in learning and formation of long-term memories.
hormone
A substance that is released by the endocrine glands and travels through the blood to influence other glands and organs.
hypothalamus
A region of the brain beneath the thalamus in the forebrain. It is involved in the regulation of hunger, thirst, sex drive, body temperature, and other states. It also secretes hormones that stimulate the pituitary gland, the “master gland” of the endocrine system.
inhibitory
A substance that decreases the likelihood a neuron will fire.
interneuron
A neuron that connects a sensory and a motor neuron.
hypothesis
A prediction about the relationships between two or more variables
limbic system
A group of brain structures that are involved with emotions, the autonomic nervous system, and olfactory processing.
medulla
The portion of the brain stem that is associated with life-sustaining functions such as heartbeat and respiration.
midbrain
The area between the forebrain and the hindbrain, it primarily serves as a relay station for information.
motor neurons
Neurons that carry information from the brain and spinal cord to the muscles and glands.
MRI/fMRI (Functional Magnetic Resonance Imaging)
A neuroimaging technique that uses a magnetic field and radio waves to create images of the body without the use of radiation.
myelin sheath
A fatty sheath that wraps around axons, it aids in the conduction of nerve impulses.
neuron
A nerve cell.
neurotransmitter
A chemical substance that is released by one neuron into the synapse, or gap between neurons, to influence the functioning of another neuron.
neuroscience
The scientific study of the nervous system.
norepinephrine
A hormone secreted by the adrenal gland. It increases blood pressure and rate and the depth of breathing, raises the level of blood sugar, and decreases the activity of the intestines. It is also the main neurotransmitter of sympathetic nerve endings supplying the major organs and skin.
occipital lobes
The lobes of the cerebral cortex located in the rear of the brain that are primarily responsible for processing visual information.
ovaries
The pair of organs in a woman’s body that produce eggs. Also the part of any female animal or plant that produces eggs or seeds.
pancreas
A gland situated near the stomach that secretes a digestive fluid into the intestine and also secretes the hormone insulin.
parasympathetic nervous system
The division of the autonomic nervous system that calms the body down.
parietal lone
The lobe of the cerebral cortex that is responsible for processing the sense of touch.
peripheral nervous system
The portion of the nervous system that relays information between the central nervous system and the rest of the body.
PET (Positron Emission Tomography)
A neuroimaging technique that monitors the utilization of glucose in different parts of the brain. This allows researchers to view parts of the brain as they work.
pineal gland
A small gland located between the hemispheres of the brain that secretes the hormone melatonin, which aids in the onset of sleep.
pituitary gland
A gland located at the base of the brain producing hormones that control other glands and affect metabolism, bone growth, and sexual maturity.
plasticity
The brain’s ability to reorganize, or “rewire” itself, by reassigning neurons to different functions.
polarize
To create a difference in electric potential between two surfaces. This occurs in neurons when there is a positive charge outside the axon, and a negative charge inside.
pons
A portion of the brain stem that is involved in coordinating muscular action and facial expressions.
prefrontal cortex
The portion of the cerebral cortex that is the primary area for cognition, such as prediction, calculation, and motor planning.
primary motor cortex
The portion of the cerebral cortex that is the primary processing area for motor information.
primary somatosensory cortex
The portion of the cerebral cortex that is the primary processing area for the sense of touch.
pruning
The process by which unused synapses are eliminated, making the brain more efficient at processing information.
refractory period
The period shortly after a neuron has fired during which it is unable to fire again.
resting potential
The slightly negative charge (-70 millivolts) that is present in a neuron that is at rest.
reticular activating system/RAS
The part of the reticulara formation involved in regulating arousal, alertness, and sleep/wake cycles.
reuptake
The process by which neurotransmitters are taken back into the neuron after being released into the synapse. Reuptake stops the action of the neurotransmitter on the receptors of neighboring cells.
sample
A portion of a population of interest that is identified for the purposes of scientific study. If the sample is representative and randomly selected, characteristics of the sample can be used to make inferences about the population in question.
sensory neurons
Neurons that are responsible for relaying sensory information to the brain and spinal cord.
soma
The body of a neuron or other cell.
somatic nervous system
The portion of the peripheral nervous system that carries messages to and from the sense organs, skin, and muscles.
steroids
A class of hormones that influence a variety of processes, such as sexual functioning, body growth, and metabolism.
substance P
A substance that increases pain signals by stimulating nerve endings at the site of an injury.
suprachiasmic nucleus
The portion of the hypothalamus that controls the cycles of the endocrine system.
sympathetic nervous system
The portion of the autonomic nervous system that is aroused in response to stress. It is responsible for creating the “fight or flight” response, including raising heart rate and blood pressure, as well as suppressing digestive activity.
synapse
The tiny gap between two neurons into which a neurotransmitter is released by one neuron to stimulate receptors in the dendrites of another neuron.
temporal lobes
The lobes of the cerebral cortex that are responsible for processing information from the auditory system.
testes
A pair of male reproductive glands that produce sperm and are contained in the scrotum in most mammals.
testosterone
A male sex hormone produced by the testes.
thalamus
The portion of the brain whose primary function is to relay information from sensory systems (such as the visual system) to the cerebral cortex.
thyroid gland
An endocrine gland located in the necks of people and other vertebrate animals that secretes the hormones that control metabolism and growth.
trigeminal nerve
The largest cranial nerve, which carries both sensory and motor fibers, and affects the jaws and parts of the mouth.
visual cortex
The portion of the cerebral cortex responsible for processing visual information; it is located in the occipital lobes.
