Introduction to Psychology

Psychology chapter three vocabulary nervous system, a collection of hundreds of billions of specialized and interconnected cells through which messages are sent between the brain and the rest of the body. The nervous system consists of the central nervous system (CNS), made up of the brain and the spinal cord, and the peripheral nervous system (PNS), the neurons that link the CNS to our skin, muscles, and glands. And we will see that our behavior is also influenced in large part by the endocrine system, the chemical regulator of the body that consists of glands that secrete hormones.

A neuron is a cell in the nervous system whose function it is to receive and transmit information soma, which contains the nucleus of the cell and keeps the cell alive dendrite, which collects information from other cells and sends the information to the soma axon- which transmits information away from the cell body toward other neurons or to the muscles and glands.. axon is very fast—it can happen up to 1,000 times each second myelin sheath is a layer of fatty tissue surrounding the axon of a neuron that both acts as an insulator and allows faster transmission of the electrical signal. esting potential, a state in which the interior of the neuron contains a greater number of negatively charged ions than does the area outside the cell. change in electrical charge that occurs in a neuron when a nerve impulse is transmitted is known as the action potential. breaks between the sausage-like segments of the myelin sheath.

Each of these gaps is a node of Ranvier synapses- areas where the terminal buttons at the end of the axon of one neuron nearly, but don’t quite touch the dendrites of another. neurotransmitter is a chemical that relays signals across the synapses etween neurons. reuptake, a process in which neurotransmitters that are in the synapse are reabsorbed into the transmitting terminal button ready to again be released after the neuron fires. agonist is a drug that has chemical properties similar to a particular neurotransmitter and thus mimics the effects of the neurotransmitter. antagonist is a drug that reduces or stops the normal effects of a neurotransmitter.

The Major Neurotransmitters and Their Functions Neurotransmitter Description and function Notes Acetylcholine (ACh) A common neurotransmitter used n the spinal cord and motor neurons to stimulate muscle contractions. It’s also used in the brain to regulate memory, sleeping, and dreaming. Alzheimer’s disease is associated with an undersupply of acetylcholine. Nicotine is an agonist that acts like acetylcholine. Dopamine Involved in movement, motivation, and emotion, Dopamine produces feelings of pleasure when released by the brain’s reward system, and it’s also involved in learning. Schizophrenia is linked to increases in dopamine, whereas Parkinson’s disease is linked to reductions in opamine (and dopamine agonists may be used to treat it).

Endorphins Released in response to behaviors such as vigorous exercise, orgasm, and eating spicy foods. Endorphins are natural pain relievers. They are related to the compounds found in drugs such as opium, morphine, and heroin. The release of endorphins creates the runner’s high that is experienced after intense physical exertion. GABA (gammaaminobutyric acid) The major inhibitory neurotransmitter in the brain. A lack of GABA can lead to involuntary motor actions, including tremors and seizures.

Alcohol stimulates the release of GABA, which inhibits the nervous system and makes us feel drunk. Low levels of GABA can produce anxiety, and GABA agonists (tranquilizers) are used to reduce anxiety. Glutamate The most common neurotransmitter, it’s released in more than 90% of the brain’s synapses. Glutamate is found in the food additive MSG (monosodium glutamate). Excess glutamate can cause overstimulation, migraines and seizures.

Serotonin Involved in many functions, including mood, appetite, sleep, and aggression. Low levels of serotonin are associated with depression, nd some drugs designed to treat depression (known as selective serotonin reuptake inhibitors, or SSRIs) serve to prevent their reuptake. brain stem is the oldest and innermost region of the brain. It’s designed to control the most basic functions of life, including breathing, attention, and motor responses. medulla, the area of the brain stem that controls heart rate and breathing. In many cases the medulla alone is sufficient to maintain life pons, a structure in the brain stem that helps control the movements of the body, playing a particularly important role in balance and walking.

Running through the medulla and the pons is a long, narrow network of neurons known as the reticular Formation. The job of the reticular formation is to filter out some of the stimuli that are coming into the brain from the spinal cord and to relay the remainder of the signals to other areas of the brain. thalamus is the egg-shaped structure above the brain stem that applies still more filtering to the sensory information that is coming up from the spinal cord and through the reticular formation, and it relays some of these remaining signals to the higher brain levels erebellum (literally, “little brain”) consists of two wrinkled ovals behind the brain stem.

It functions to coordinate voluntary movement. limbic system is a brain area, located between the brain stem and the two cerebral hemispheres, that governs emotion and memory. It includes the amygdala, the hypothalamus, and the hippocampus. amygdala consists of two “almond-shaped” clusters (amygdala comes from the Latin word for “almond”) and is primarily responsible for regulating our perceptions of, and reactions to, aggression and fear. ippocampus consists of two “horns” that curve back from the amygdala.

The hippocampus is important in storing information in long-term memory. If the hippocampus is damaged, a person cannot build new memories, living instead in a strange world where everything he or she experiences just fades away, even while older memories from the time before the damage are untouched. cerebral cortex—the outer bark-like layer of our brain that allows us to so successfully use language, acquire complex skills, create tools, and live in social groups lial cells (glia), cells that surround and link to the neurons, protecting them, providing them with nutrients, and absorbing unused neurotransmitters. frontal lobe (behind the forehead), which is responsible primarily for thinking, planning, memory, and judgment. parietal lobe, which extends from the middle to the back of the skull and which is responsible primarily for processing information about touch occipital lobe, at the very back of the skull, which processes visual information.

Finally, in front of the occipital lobe (pretty much between the ears) is the temporal lobe, responsible primarily for hearing and language he somatosensory cortex, an area just behind and parallel to the motor cortex at the back of the frontal lobe, receives information from the skin’s sensory receptors and the movements of different body part visual cortex is the area located in the occipital lobe (at the very back of the brain) that processes visual information auditory cortex, which is responsible for hearing and language. association areas in which sensory and motor information is combined and associated with our stored knowledge

The association areas are involved in higher mental functions, such as learning, thinking, planning, judging, moral reflecting, figuring, and spatial reasoning. Neuroplasticity refers to the brain’s ability to change its structure and function in response to experience or damage. Neuroplasticity enables us to learn and remember new things and adjust to new experiences. neurogenesis, the forming of new neurons brain lateralization— the idea that the left and the right hemispheres of the brain are specialized to perform different functions