1. Chapter 2 Biology and Behavior

2. Chapter 2 Overview The Neurons and Neurotransmitters
The Human Nervous System
Discovering the Brain’s Mysteries
A Closer Look at the Brain
Age and Gender Differences in the Brain
The Endocrine System
Genes and Behavioral Genetics

3. What are the functions of the various parts of the neuron?
Cell body
Carries out life-sustaining functions
Dendrites
Receive signals from other neurons
Axon
Sends signals to other neurons, muscles, and glands
Synapse
Junction between neurons

4. What are neurotransmitters?
Neurotransmitters are chemical substances that transmit messages between neurons
Released into synapse by axon terminals of sending neuron
Bind to receptor sites on dendrites of receiving neuron
Taken back into axon terminal by the process of reuptake

5. What are the functions of some major neurotransmitters?
Acetylcholine
Affects movement, learning, memory, REM Sleep
Dopamine
Affects movement, attention, learning, reinforcement, pleasure
Norepinephrine
Affects eating, alertness, wakefulness
Epinephrine
Affects metabolism of glucose, energy release during exercise

6. What are the functions of some major neurotransmitters?
Serotonin
Affects mood, sleep, appetite, impulsivity, aggression
Glutamate
Active in areas of the brain involved in learning, thought, and emotion
GABA
Facilitates neural inhibition in the central nervous system
Endorphins
Provide relief from pain and produce feelings of pleasure and well-being

7. The Human Nervous System
Central nervous system
The brain and spinal cord
Peripheral nervous system
The nerves connecting the central nervous system to the rest of the body

8. Which brain structures are found in the hindbrain?
Medulla
Controls heartbeat, blood pressure, breathing, coughing, swallowing
Reticular formation
Plays a crucial role in arousal and attention
Screens sensory messages entering the brain

9. Which brain structures are found in the hindbrain?
Pons
Plays a role in body movement
Influences sleep and dreaming
Cerebellum
Helps the body execute smooth, skilled movements
Regulates muscle tone and posture

10. What important structure is located in the midbrain?
The midbrain links the physiological functions of the hindbrain to the cognitive functions of the forebrain
Substantia nigra
Controls unconscious motor movements

11. Which brain structures and functions are found in the forebrain?
Thalamus
A relay station for information flowing into or out of the brain
Hypothalamus
Regulates hunger, thirst, sexual behavior, body temperature, and a wide variety of emotional behaviors

12. Which brain structures and functions are found in the forebrain?
Amygdala
Structure in the limbic system that plays an important role in emotion
Hippocampus
Structure in the limbic system that plays a central role in storing new memories, responses to new or unexpected stimuli, and navigational ability

13. The Peripheral Nervous System
The peripheral nervous system has two subdivisions
The somatic nervous system consists of all sensory nerves and motor nerves
The autonomic nervous system transmits messages between the central nervous system and the glands, the cardiac muscle, and the smooth muscles

14. Two parts of the autonomic nervous system
Sympathetic nervous system
Mobilizes the body’s resources during stress and emergencies
Parasympathetic nervous system
Brings the heightened bodily responses back to normal following an emergency

15. What is the difference between the sympathetic and parasympathetic nervous systems?

16. Discovering the Brain’s Mysteries
Modern researchers do not have to wait to perform autopsies or wait for injuries to occur to learn about the brain
Today, researchers unlock the mysteries of the brain using a variety of techniques

17. What does the EEG reveal about the brain?
Electroencephalogram (EEG)
A record of brain-wave activity made by a machine called an electroencephalograph
Electrical activity in the brain is detected by electrodes placed on the scalp

18. How are imaging techniques helpful in the study of brain structure and function?
CT scan
Computerized axial tomography
Uses X-rays to produce cross-sectional images of the brain
MRI
Magnetic resonance imaging
Produces high-resolution images of the structures of the brain

19. How are imaging techniques helpful in the study of brain structure and function?
PET scan
Positron-emission tomography
Reveals activity in various parts of the brain based on blood flow, oxygen use, and glucose consumption
Functional MRI (fMRI)
Provides images of both brain structure and function
Can identify locations of brain activity more precisely and rapidly than PET scan

20. A Closer Look at the Brain
The cerebrum
The largest structure in the human brain
Its functions include language, planning, and logic

21. What are the components of the cerebrum?
Cerebral hemispheres
The left and right halves of the cerebrum
Corpus callosum
Connects the two hemispheres
Cerebral cortex
Thin outer covering of cerebrum
Responsible for higher mental processes of language, memory, and thinking

22. What are the specialized functions of the left and right hemispheres?
The left hemisphere
Controls the right side of the body
Handles most language functions
Is specialized for mathematics and logic

23. What are the specialized functions of the left and right hemispheres?
The right hemisphere
Controls the left side of the body
Processes music
Interprets emotional messages conveyed by tone of voice and gestures
Is specialized for visual-spatial relations

24. Which psychological functions are associated with the frontal lobes?
Motor cortex
Area that controls voluntary body movement
Broca’s area
Area in the frontal lobe, usually in the left hemisphere, that controls the production of speech
Association areas
Areas involved in thinking, planning for the future, impulse control

25. What important structure is found in the parietal lobes?
Somatosensory cortex
Strip of tissue at the front of the parietal lobes where touch, pressure, temperature, and pain register in the cortex

26. Why are the occipital lobes critical to vision?
The occipital lobes are involved in the reception and interpretation of visual information
Primary visual cortex
Area at the rear of the occipital lobes where vision registers in the cortex

27. What are the major areas within the temporal lobes, and what are their functions?
Primary auditory cortex
Area in each temporal lobe where hearing registers in the cortex
Wernicke’s area
Language area in the left temporal lobe involved in comprehending spoken language and formulating coherent speech and written language

28. Age and Gender Differences in the Brain
The brain grows from conception until well into adulthood
Throughout development, the brains of males and females differ to some degree

29. How do the brains of men differ from those of women?
Women’s brains have equal proportions of gray and white matter in the left and right hemispheres; men’s brains have a lower proportion of white matter in the left hemisphere than in the right
This may explain men’s superior ability in spatial tasks
Women have more gray matter in the area of the brain that controls emotions
This may explain women’s superior ability to perceive emotions
Navigational information is processed in different parts of the brain in men and women
Women use right parietal cortex and right frontal cortex
Men use left hippocampus
Men and women use different areas to process location of sound
More research is needed to understand the meaning of these gender differences in the brain

30. The Endocrine System
A system of ductless glands that manufacture hormones and secrete them into the bloodstream

31. What functions are associated with the various glands of the endocrine system?
Pituitary gland
The “master gland”
Located in the brain
Releases hormones that activate other endocrine glands
Pineal gland
Located deep in the brain
Secretes the hormone melatonin which controls sleep/wakefulness cycle
Thyroid gland
Located below the voice box
Produces thyroxine, which regulates rate at which food is metabolized

32. What functions are associated with the various glands of the endocrine system?
Parathyroid glands
Attached to the thyroid
Produce parathyroid hormone which helps the body absorb minerals from the diet
Thymus gland
Produces hormones that are essential to immune system functioning
Adrenal glands
Release hormones that prepare the body for emergencies and stressful situations
Gonads
The ovaries in females and testes in males
Produce sex hormones

33. Genes and Behavioral Genetics
segments of DNA located on chromosomes that transmit all heredity traits
Chromosomes
rod shaped structures in the nuclei of cells that contain all genes and carry genetic information to make a human being
Behavioral Genetics
a field of research that uses twin and adoption studies to investigate the relative effects of heredity and environment on behavior

34. What patterns of inheritance are evident in the transmission of genetic traits?
Dominant-recessive pattern
a set of inheritance rules in which one dominant gene causes a trait to be expressed, but two recessive genes are required for expression of a recessive trait
Multifactorial inheritance
A pattern of inheritance in which a trait is influenced by both genes and environment
Sex-linked inheritance
Involves genes on the X and Y chromosomes
Example: red-green color blindness

35. Ishihara Test

36. What kinds of studies are done by behavioral geneticists?
Twin studies
Examine identical (monozygotic) and fraternal (dizygotic) twins
If identical twins are more alike on a trait, the trait is assumed to be more influenced by heredity
If identical and fraternal twin pairs do not differ on a trait, the trait is assumed to be more influenced by environment
Adoption studies
Compare adopted children’s abilities and traits to those of adoptive parents and biological parents