Biopsychology Questions

Front 1

What are neurons, and how do they transmit information?

Back 1

Neurons are the elementary components of the nervous system, the body's speedy electrochemical information system. Sensory neurons carry incoming information from sense receptors to the brain and spinal cord, and motor neurons carry information from the brain and spinal cord out to the muscles and glands. Interneurons communicate within the brain and spinal cord and between sensory and motor neurons. A neuron sends signals through its axons, and receives signals through its branching dendrites. if the combined signals are strong enough, the neuron fires, transmitting an electrical impulse (the action potential) down its axon by means of a chemistry-to-electricity process. The neuron's reaction is an all-or-none process.

Front 2

How do nerve cells communicate with other nerve cells?

Back 2

When action potentials reach the end of an axon (the axon terminals), they stimulate the release of neurotransmitters. These chemical messengers carry a message from the sending neuron across a synapse to receptor sites on a receiving neuron. The sending neuron, in a process called reuptake, then normally absorbs the excess neurotransmitter molecules in the synaptic gap. The receiving neuron, if the signals from that neuron and others are strong enough, generates its own action potential and relays the message to other cells.

Front 3

How do neurotransmitters influence behavior, and how do drugs and other chemicals affect neurotransmission?

Back 3

Each neurotransmitter travels a designated path in the brain and has a particular effect on behavior and emotions. Acetylcholine affects muscle action, learning, and memory. Endorphins are natural opiates released in response to pain and exercise. Drugs and other chemicals affect communication at the synapse. Agonists excite by mimicking particular neurotransmiters or by blocking their reuptake. Antagonists inhibit a particular neurotransmitter's release or block its effects.

Front 4

What are the functions of the nervous system's main divisions?

Back 4

One major division of the nervous system is the central nervous system (CNS), the brain, and spinal cord. The other is the peripheral nervous system (PNS), which connects the CNS to the rest of the body by means of nerves. The peripheral nervous system has two main divisions. The somatic nervous system enables voluntary control of the skeletal muscles. The autonomic nervous system, through its sympathetic and parasympathetic divisions, controls involuntary muscles and glands. Neurons cluster into working networks.

Front 5

How does the endocrine system - the body's slower information system - transmit its messages?

Back 5

The endocrine system is a set of glands that secrete hormones into the bloodstream, where they travel through the body and affect other tissues, including the brain. The endocrine system's master gland, the pituitary, influences hormone release by other glands. In an intricate feedback system, the brain's hypothalamus influences the pituitary gland, which influences other glands, which release hormones, which in turn influence the brain.

Front 6

How do neuroscientists study the brain's connections to behavior and mind?

Back 6

Clinical observation and lesioning reveal the general effects of brain damage. MRI scans reveal brain structures, and EEG, PET, and fMRI (functional MRI) recordings reveal brain activity.

Front 7

What are the functions of important lower-level brain structures?

Back 7

The brainstem is the oldest part of the brain and is responsible for autonomic survival functions. Its components are the medulla (which controls heartbeat and breathing), the pons (which helps coordinate movement), and the reticular formation (which affects arousal). The thalamus, the brain's sensory switchboard, sits above the brainstem. The cerebellum, attached to the rear of the brainstem, coordinates muscle movement and helps process sensory information.
The limbic system is linked to emotions, memory, and drives. Its neural centers include the amygdala (involved in responses to aggression and fear) and the hypothalamus (involved in various bodily maintenance functions, pleasurable rewards, and the controls of the hormonal system). The hypothalamus also controls the pituitary, which influences other glands to release hormones. The hippocampus processes memory.

Front 8

What functions are served by the various cerebral cortex regions?

Back 8

In each hemisphere the cerebral cortex has four lobes, the frontal, parietal, occipital, and temporal. Each lobe performs many functions and interacts with other areas of the cortex. The motor cortex controls voluntary movements. The sensory cortex registers and processes body sensations. Body parts requiring precise control (in the motor cortex) or those that are especially sensitive (in the sensory cortex) occupy the greatest amount of space. Most of the brain's cortex - the major portion of each of the four lobes - is devoted to uncommitted association areas, which integrate information involved in learning, remembering, thinking, and other higher-level functions.

Front 9

To what extent can a damaged brain reorganize itself?

Back 9

If one hemisphere is damaged early in life, the other will pick up many of its functions. This plasticity diminishes later in life. Some brain areas are capable of neurogenesis (forming new neurons).

Front 10

What do split brains reveal about the functions of our two brain hemispheres?

Back 10

Split-brain research (experiments on people with a severed corpus callosum) has confirmed that in most people, the left hemisphere is the more verbal, and that the right hemisphere excels in visual perception and the recognition of emotion. Studies of healthy people with intact brains confirm that each hemisphere makes unique contributions to the integrated functioning of the brain.

Front 11

How does handedness relate to brain organization?

Back 11

About 10% of us are left-handed. Almost all right-handers process speech in the left hemisphere, as do more than half of all left-handers.