Chapter 1 Flashcards
Biological psychologists try to explain behavior in terms of
its physiology, development, evolution, and function.
called the mind-brain problem or the mind-body problem
the question of how mind relates to brain activity; why are certain types of brain activity conscious?
Chalmers and Rensch proposed
that we regard consciousness as a fundamental property of matter. A fundamental property is one that cannot be reduced to something else. For example, mass and electrical charge are fundamental properties. But consciousness isn’t like other fundamental properties. Matter has mass all the time, and protons and electrons have charge all the time. So far as we can tell, consciousness occurs only in certain parts of a nervous system, just some of the time- not when you are in a dreamless sleep, and not when you are in a coma.
Biological psychology is
behavioral neuroscience; the study of the psychological evolutionary, and developmental mechanisms of behavior and experiences; Biological psychology is not only a field of study, but also a point of view. It holds that we think and act as we do because of brain mechanisms, and that we evolve those brain mechanisms because ancient animals built this way survives and reproduced. deals mostly with brain activity.
two kinds of cells in the brain
the neurons and the glia. The activities of neurons and glia somehow produce an enormous wealth of behavior and experience.
Neurons
- receive information and transmit it to other cells. they convey messages to one another and to muscles and glands, vary enormously in size, shape, and functions.
- The adult human brain contains approximately 86 billion neurons, the exact number varies from person to person.
The glia
cells that enhance and modify the activity of neurons in many ways. generally smaller than neurons, have many functions but do not convey information over great distances.
where does perception occur? give 2 examples
Perception occurs in your brain. When something contacts your hand, the hand sends a message to your brain. You feel it in your brain, not your hand. (Electrical stimulation of your brain could produce a hand experience even if you had no hand. A hand disconnected from your brain has no experience.) Similarly, you see when light comes into your eyes. The experience is in your head, not “out there.” You do NOT send “sight rays” out of your eyes, and even if you did, they wouldn’t do you any good.
what is the relationship between mental activity and certain types of brain activity?
Mental activity and certain types of brain activity are, so far as we can tell, inseparable. This position is known as monism, the idea that the universe consists of only one type of being. (The opposite is dualism, the idea that minds are one type of substance and matter is another.)
monomism
Mental activity and certain types of brain activity are, so far as we can tell, inseparable. Nearly all neuroscientists and philosophers support the position of monism. According to monism, your thoughts or experiences are the same thing as your brain activity. People sometimes ask whether brain activity causes thoughts, or whether thoughts direct the brain activity. According to monism, that question is like asking whether temperature causes the movement of molecules, or whether the movement of molecules causes temperature. Neither causes the other; they are just different ways of describing the same thing.
Biological psychologists address four types of questions about any behavior.
- Physiological: How does the behavior relate to the physiology of the brain and other organs?
- Ontogenetic: How does it develop within the individual? - Evolutionary: How did the capacity for the behavior evolve?
- Functional: Why did the capacity for this behavior evolve? That is, what function does it serve, or did it serve
main founders of neuroscience
Charles Sherrington, and the Spanish investigator Santiago Ramon y Cajal
Camillo Golgi
found a way to stain nerve cells with silver salts. This method, which completely stains some cells without affecting others at all, enabled researchers to examine the structure of a single cell.
Cajal’s research demonstrated
that nerve cells remain separate instead of merging into one another
membrane (or plasma membrane)
The surface of a cell; a structure that separates the inside of the cell from the outside environment. Most chemicals cannot cross the membrane, but protein channels in the membrane permit a controlled flow of water, oxygen, sodium, potassium, calcium, chloride, and other important chemicals.
nucleus
All animal cells have a nucleus, the structure that contains the chromosomes.
A mitochondrion (plural: mitochondria)
the structure that performs metabolic activities, providing the energy that the cell uses for all activities. Mitochondria have genes separate from those in the nucleus of a cell, and mitochondria differ from one another genetically. People with overactive mitochondria tend to burn their fuel rapidly and overheat, even in a cool environment. People whose mitochondria are less active than normal are predisposed to depression and pains. Mutated mitochondrial genes are a possible cause of autism)
Ribosomes
the site within a cell that synthesizes new protein molecules. Proteins provide building materials for the cell and facilitate chemical reactions. Some ribosomes float freely within the cell, but others are attached to the endoplasmic reticulum, a network of thin tubes that transport newly synthesized proteins to other locations.
the most distinctive feature of neurons is
their shape- varies enormously from one neuron to another. Unlike most other body cells, neurons have long branching extensions. All neurons include a soma (cell body), and most also have dendrites, an axon, and presynaptic terminals. The tiniest neuron lacks axons, and some lack well-defined dendrites.
soma
cell body; contains the nucleus, ribosomes, and mitochondria. Most of a neuron’s metabolic work occurs here. Cell bodies of neurons range in diameter from 0.005 millimeter (mm) to 0.1 mm in mammals and up to a millimeter in certain invertebrates. In many neurons, the cell body is like the dendrites- covered with synapses on its surface.
motor neuron
soma in the spinal cord, receives excitation through its dendrites and conducts impulses along its axon to a muscle
A sensory neuron
Specialized at one end to be highly sensitive to a particular type of stimulation, such as light, sound, or touch. Conducts touch information from the skin to the spinal cord. Tiny branches lead directly from the receptors into the axon, and the cell’s soma is located on a little stalk off the main trunk.
Dendrites
branching fibers that get narrower near their ends. (The term dendrite comes from a Greek root meaning “tree.” A dendrite branches out like a tree.) The dendrite’s surface is lined with specialized synaptic receptors, at which the dendrite receives information from other neurons. The greater the surface area of a dendrite, the more information it can receive. Many dendrites contain dendritic spines, short outgrowths that increase the surface area available for synapses.
axon
a thin fiber of constant diameter. (The term axon comes from a Greek word meaning “axis.”) The axon conveys an impulse toward other neurons, an organ, or a muscle. Axons can be more than a meter in length, as in the case of axons from your spinal cord to your feet. The length of an axon is enormous in comparison to its width, and in comparison, to the length of dendrites.
myelin sheath
an insulating material with interruptions known as nodes of Ranvier. Invertebrate axons do not have myelin sheaths. Although a neuron can have many dendrites, it can have only one axon, but the axon may have branches. The end of each branch has a swelling, called a presynaptic terminal, also known as an end bulb (French for “button”). At that point the axon releases chemicals that cross through the junction between that neuron and another cell.
presynaptic terminal
also known as an end bulb (French for “button”). At that point the axon releases chemicals that cross through the junction between that neuron and another cell.
An afferent axon
brings information into a structure; . Every sensory neuron is an afferent to the rest of the nervous system; afferent starts with a as in admit
efferent axon
carries information away from the structure; every motor neuron is efferent from the nervous system. efferent starts with an e as in exit;
an interneuron
If a cell’s dendrites and axon are entirely contained within a single structure, the cell is an interneuron or intrinsic neuron of that structure. For example, an intrinsic neuron of the thalamus has its axon and all its dendrites within the thalamus
variations amond neurons
Neurons vary enormously in size, shape, and function. The shape of a neuron determines its connections with other cells and thereby determines its function.
For example, the widely branching dendrites of the Purkinje cell in the cerebellum enable it to receive input from up to 200,000 other neurons. By contrast, bipolar neurons in the retina have only short branches, and Some receive input from as few as two other cells.
Glia
Glia (or neuroglia), the other components of the nervous system, preform many functions. The term glia, derived from a Greek word meaning “glue,” reflects early investigators’ idea that glia were like glue that held the neurons together. Although that concept is obsolete, the term remains. Glia outnumbered neurons in the cerebral cortex, but neurons outnumber glia in several other brain areas, especially the cerebellum. Overall, the number are almost equal.
Oligodendrocytes
in the brain and spinal cord ; produce myelin sheaths that insulate certain vertebrate axons in the central nervous system.
Schwann cells
in the periphery of the body build the myelin sheath that surround and insulate certain vertebrate axons. They also supply an axon with nutrients necessary for proper functioning; have a similar function as oligodendrocytes in the periphery.
Astrocytes
pass chemicals back and forth between neurons and blood among neighboring neurons. They are also star shaped; wrap around the synapses of functionally related axons. By surrounding a connection between neurons, an astrocyte shields it from chemicals circulating in the surround. Also, by taking up the ions and transmitters released by axons and then releasing them back, an astrocyte helps synchronize closely related neurons, enabling their axons to send messages in waves. Astrocytes are therefore important for generating rhythms, such as your rhythm of breathing.