Ch. 2

The Biological Basis of Behavior

1. Neurons: The Messengers A. Dendrites

Carries information to the cell body B. Cell Body

Also called soma C. Axon

Carries information to the next cell

A typical myelinated neuron

D. Myelin Sheath Covers axon Insulates Speeds up impulse

E. Sensory Afferent

F. Motor Efferent

G. Interneurons Association

H. Support Cells - Glial Cells Cells that insulate and support neurons

2. The Neural Impulse or Action Potential

A. Ions Charged molecules

B. Resting Potential Potential Energy

C. Polarization/ Depolarization Away/toward zero (neutral)

The neural impulse --communication within the neuron

D. Action Potential Sudden change in charge

E. Graded Potentials Subthreshold stimulation Summation

F. Threshold of Excitation Results in Action Potential

G. All-or-None Law Cells either fire or not (no halfway)

H. Absolute Refractory Period Another Action Potential cannot occur

I. Relative Refractory Period Neuron would only respond to very strong impulse

The neural impulse --communication within the neuron

3. The Synapse A. Synaptic Space or synaptic cleft

Tiny gap between neurons B. Terminal button

Enlarge area at end of axon C. Synapse

Terminal button of one neuron, the space and the next neuron

Synaptic transmission – communication between neurons

D. Synaptic Vesicles Sacs in terminal button that release chemicals into

synapse E. Neurotransmitters

Chemicals released by synaptic vesicles F. Receptor Sites

Location on receptor neuron for specific neurotransmitter

4. Neurotransmitters Acetylcholine

Important role in arousal and attention Dopamine

Affects neurons associate with voluntary movement

Serotonin Sets an emotional tone

Endorphins Reduce pain by turning down neurons

5. Psychopharmacology Cocaine

Prevents reabsorption of dopamine, leading to heightened arousal

Antidepressant and antipsychotic medications use the same processes

6. Neural Plasticity Brain shaped by environment Possible child abuse marker

7. Neurogenesis Production of new brain cells

Brain growth and experience

8. The Central Nervous System A. The Organization of the Nervous System

Central and Peripheral Nervous Systems B. The Brain

The central core Hindbrain

Medulla - controls breathing, heart rate, and blood pressure

Pons - controls sleep-wake cycle Cerebellum - coordination of movement

A schematic diagram of the divisions of the

nervous system and their various subparts

Midbrain Thalamus - Relay from sense receptors Hypothalamus

Emotions and motivation Feeding, fleeing, fighting, and sex

Reticular formation Network of neurons Alert and arouse higher brain

Limbic system Ring of structures important to learning and

emotional behavior

Four lobes of the cerebral cortex Frontal lobe

Voluntary movement, attention, goal behavior, appropriate emotions

Parietal lobe Sensory information from body

Occipital lobe Interprets visual information

Temporal lobe Hearing, balance, some emotions and motivations

Parts of the brain

9. Hemispheric Specialization A. Corpus Callosum

Fibers that connect hemispheres B. Language

Usually located in the left hemisphere C. Cognitive and Emotional Style

Left hemisphere may operate more analytically Right hemisphere may excel in spatial tasks and

expression of emotions

The cerebral hemispheres

10. New tools for Studying the Nervous System

A. Microelectrode Techniques Very small pipette to stim. Individual cells

B. Macroelectrode Techniques EEG

C. Structural Imaging Computerized Axial Tomography (CT-scan)

X-ray 3-D image Magnetic Resonance Imaging (MRI)

Magnetic field/radio waves

D. Functional Imaging EEG-electrical activity on the scalp from millions of

neurons Magentoencephalography (MEG)

More precise than EEG Magnetic source imaging (MSI)

Similar to EEG

Positron Emission Tomography (PET) - radioactive glucose

Single Photon Emission Computed Tomography (SPECT)

Functional magnetic resonance imaging (fMRI) Show function and structure

11. Spinal cord

• Complex cable of nerves that connects brain to rest of the body

• Carry motor impulses to internal organs and muscles

• Carry information from extremities and internal organs to the brain

• Permit some reflex movements

12. The Peripheral Nervous System• A. Afferent neurons

• Neurons that carry messages from sense organs to spinal cord

• B. Efferent Neurons• Neurons that carry messages from the spinal cord or

brain to muscles and glands

C. Somatic Nervous System Body systems

D. Autonomic Nervous System Parasympathetic Nervous System

Relaxation, repair, sleep, digestion, sexual arousal

Sympathetic Nervous System Emergency response

The sympathetic and parasympathetic divisions of the autonomic nervous system

13. The Endocrine System A. The Thyroid Gland

Controls metabolism B. The Parathyroid Glands

Controls calcium and phosphate C. The Pineal Gland

Regulates activity levels D. The Pancreas

Regulates blood-sugar levels

E. The Pituitary Gland Regulates many behaviors and other glands

F. Gonads Ovaries and testes

G. Adrenal Glands Reaction to stress

The glands of the endocrine system

14. Genes, Evolution, and Behavior

A. Genetics Heredity - transmission of trait from one generation to

next Chromosomes

Pairs of thread like bodies that contain genes Deoxyribonucleic acid (DNA)

Molecular in double-helix Code of life

Traits Characteristics on which we differ

B. Behavior Genetics Family studies Twin studies Identical twins Fraternal twins

Dominant and Recessive Traits

C. Evolution D. Evolutionary Psychology

Natural selection E. Social Implications