Chapter 4 Flashcards
Central Nervous System
The portion of the nervous system consisting of the brain and spinal cord.
Spinal Cord
A collection of neurons and supportive tissue running from the base of the brain down the center of the back, protected by a column of bones (the spinal column).
Peripheral Nervous System
All portions of the nervous system outside the brain and spinal cord; it includes sensory and motor nerves.
Somatic Nervous System
The subdivision of the peripheral nervous system that connects to sensory receptors and to skeletal muscle; sometimes called the skeletal nervous system. Permits sensation and voluntary actions.
Autonomic Nervous System
The subdivision of the peripheral nervous system that regulates the internal organs and glands. Usually functions without conscious control
Sympathetic Nervous System
The subdivision of the autonomic nervous system that mobilizes bodily resources and increases the output of energy during emotion and stress.
Parasympathetic Nervous System
The subdivision of the autonomic nervous system that operates during relaxed states that conserves energy.
Neuron
A cell that conducts electrochemical signals; the basic unit of the nervous system.
Glia
Cells that nourish, insulate, protect, and repair neurons.
Dendrites
A neuron’s branches that receive information from other neurons and transmit it toward the cell body.
Cell body
The part of the neuron that keeps it alive and determines whether or not it will fire.
Axon
A neuron’s extending fiber that conducts impulses away from the cell body and transmits them to other neurons.
Myelin sheath
A fatty insulation that may surround the axon of a neuron.
Nerve
A bundle of nerve fibers in the peripheral nervous system
Neurogenesis
The production of new neurons from immature stem cells.
Stem cells
Immature cells that renew themselves and have the potential to develop into mature cells.
Synapse
Where an axon of one neuron meets a dendrite of another. The gap between them in the synaptic cleft.
Action potential
A brief change in electrical voltage that occurs between the inside and the outside of an axon when a neuron is stimulated; it serves to produce an electrical impulse.
Neurotransmitter
A chemical substance that is released by a transmitting neuron at the synapse and that alters the activity of a receiving neuron.
Hormones
Chemical substances, secreted by organs called glands, that affect the functioning of other organs/
Endocrine glands
Internal organs that produce hormones and release them into the bloodstream.
Melatonin
A hormone, secreted by the pineal gland, that is involved in the regulation of daily biological rhythms.
Oxytocin
A hormone, secreted by the pituitary gland, that stimulates uterine contractions during childbirth, facilitates the ejection of milk during nursing, and seems to promote. in both sexes, attachment and trust in relationships.
Brain stem
The part of the brain at the top of the spinal cord, consisting of the medulla and the pons.
Pons
A structure in the brain stem involved in, among other things, sleeping, waking, and dreaming.
Medulla
A structure in the brain stem responsible for certain autonomic functions, such as breathing and heart rate.
Cerebellum
A brain structure that regulates movement and balance, is involved remembering simple skills and acquired reflexes, and plays a role in cognitive and emotional reasoning.
Thalamus
A brain structure that relays sensory messages to the cerebral cortex.
Hypothalamus
A brain structure involved in emotions and drives vital to survival; it regulates the autonomic nervous system.
Pituitary gland
A small endocrine gland at the base of the brain that releases many hormones and regulates other endocrine glands.
Hippocampus
A brain structure involved in the storage of new information in memory.
Cerebrum
The largest brain structure, consisting of the upper part of the brain, divided into two hemispheres, it is in charge of most sensory, motor, and cognitive processes.
Cerebral hemispheres
The two halves of the cerebrum.
Corpus callosum
The bundle of nerve fibers connecting the two cerebral hemispheres.
Cerebral cortex
A collection of several thin layers of cells covering the cerebrum; it is largely responsible for higher mental functions.
Occipital lobes
Lobes at the lower back part of the brain’s cerebral cortex; they contain areas that receive visual information.
Parietal lobes
Lobes at the top of the brain’s cerebral cortex; they contain areas that receive information on pressure, pain, touch, and temperature as well as handle attention and awareness of spatial relationships.
Temporal lobes
Lobes at the sides of the brain’s cerebral cortex; they contain areas involved hearing, memory, perception, emotion, and language comprehension (left one).
Frontal lobes
Lobes at the front of the brain’s cerebral cortex; they contain areas involved in short-term memory, higher-order thinking, initiative, social judgment, and speech production (left one).
Plasticity
The brain’s ability to change and adapt in response to experience, through neurogenesis, or by reorganizing or growing new neural connections.
