Chapter 2 Flashcards
Neurons
A nerve cell; the basic building block of the nervous system.
Dendrite
the neuron’s bushy, branching extensions that receive messages and conduct impulses toward the cell body.
Axon
the neurons extension that passes messages through its branching terminal fibers that form junctions with other neurons, muscles, or glands.
Action Potential
A neural impulse; a brief electrical charge that travels down an axon.
Threshold
The level of stimulation required to trigger a neural impulse.
Neurotransmitter
Chemical messagers that cross the synaptic gaps between neurons. When released by the sending neuron, neurotransmitters travel across the synapse and bind to receptor sites on the receiving neuron, thereby influencing whether that neurons will generate a neural impulse.
Endorphins
“Morphine within” - Natural, opiate like neurotransmitter linked to pain control and to pleasure.
Nervous System
The body speedy, electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous system.
Central Nervous System (CNS)
the brain and spinal cord
Peripheral Nervous System (PNS)
the sensory and motor neurons that connect the central nervous system (CNS) to the rest of the body.
Nerves
Bundled axons that form neural “cables” connecting the central nervous system with muscles, glands, and sense organs.
Three Types of Neurons
- Sensory Neurons
- Motor Neurons
- Interneurons
Somatic Nervous System
The division of the peripheral nervous system that controls the body’s skeletal muscle. Also called the skeletal nervous system.
Acetlycholine (ACh)
Enables muscle action, learning, and memory.
Dopamine
Influences movement, learning, attention, and emotion.
Serotonin
Affects mood, hunger, sleep, and arousal.
Norepinephrine
Helps control alertness and arousal
Autonomic Nervous System
Controls the glands and the muscles of the internal organs (such as the heart)
Sympathetic Nervous System
the division of the 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 the energy.
Reflex
A simple, automatic response to a sensory stimulus, such as the kee-jerk response.
Endocrine System
The bodys “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 tissue.
Adrenal gland
a pair of endocrine glands that sit just above the kidneys and secrete hormones (epinephrine and norepinephrine) that help arouse the body in times of stress.
Pituitary gland
the endocrine system’s most influential gland. Under the influence of the hypothalamus, pituitary regulates growth and controls other endocrine glands.
Lession
Tissue Destruction
Brainstem
Oldest part and central core of the brain, beginning where spinal cord swells as it enters the skull; the brainstem is responsible for automatic survival functions.
EEG (Electroencophalogram)
an amplified recording of the waves of electrical activity that sweep the brain’s surface. These waves are measured by electrodes placed on the scalp.
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 taks.
MRI (Magnetic Resonance Imaging)
A technique that uses magnetic fields and radio waves to produce computer-generated imaged of soft tissue. MRI scans show brain anatomy.
fMRI (Fucntional MRI)
a technique for revealing bloodflow and, therefore, brain activity by comparing successive MRI scans. fMRI scans show brain function.
Medulla
The base of the brainstem; controls heartbeat and breathing.
Thalamus
Receives signals from senses (except smell) and routes it to the higher brain region that deal with seeing, hearing
Reticular Formation
a nerver network in the brainstem that plays a important role in controlling arousal
Cerebellum
The “little brain” at the rear of the brainstem; functions include some nonverbal learning, processes sensory input, and coordinating movement output and balance.
Limbic System
Neural System (including the hippocampus, amygdala, and hypothalamus) located below the cerebral hemispheres; associated with emotions and drives.
amygdala
two lima-bean sized neural cluster in the limbic system; linked to emotion.
Hypothalamus
Structure below (Hypo) the thalamus; it directs several maintenance activities (eating, drinking, body temperature), helps govern the endocrine system via the pituitary gland, and is linked to emotion and reward.
Cerebral Cortex
The intricate fabric of interconnected neural cells covering the cerebral hemispheres; the body’s ultimate control and information-processing center.
Frontal Lobes`
Portion of the cerebral cortex lying just behind the forehead; involved in speaking and muscle movement and in making plans and judgement.
Parietal Lobes
Portion of the cerebral cortex lying at the top of the head and toward the rear; receives sensory input for touch and body position.
Occipital Lobes
Portions of the cerebral cortex lying at the back of the head; includes areas that receive information from the visual fields.
Temporal Lobes
Portion of the cerebral cortex lying roughly above the ears; includes the auditory areas, each receiving information primarily from the opposite ear.
Motor Cortex
An area at the rear of the frontal lobe that controls voluntary movements.
Sensory Cortex
area at the front of the parietal lobes that registers and processes body touch and movement sensations.
Association Areas
Areas of the cerebral cortex that are not involved in primary motor or Sensory functions; rather, they are involved in higher mental functions such as learning, remembering, thinking, speaking, and integrating information.
Aphasia
Impairment of language , usually caused by left-hemisphere damage either to Broca’s area (impairing speaking) or to Wernicke’s (impairing understanding)
Broca’s Area
Controls Language expression; an area of the frontal lobe, usually in the left hemisphere, that directs the muscle movement involved in speech.
Wernicke’s Area
controls language reception; a brain area, usually in the left temporal lobe that is involved in language comprehension and expression.
Plasticity
the brains ability to change, especially during childhood, by reorganizing after damage or by building new pathways based on experience.
Neurogenesis
The formation of new neurons
Corpus Callosum
The large band of neural fibers connecting the two brain hemispheres and carrying messaged between them.
Split Brain
a condition resulting from surgery that isolates the brain’s two hemispheres by cutting the fibers (mainly those of the corpus callosum) connecting them.
