Download Biological Basis of Behavior Review Sheet (1)

Unit 2 Review Sheet
The Nervous System:
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Two major divisions of your central nervous system:
1.
2.
Central - consists of your brain and spinal cord
Peripheral – two major divisions
i. Somatic nervous system (has motor neurons that stimulate skeletal muscles)
ii. Autonomic nervous system – two divisions
1. sympathetic – helps you deal with stressful events (hint: you are sympathetic when you see people
under go stress)
2. parasympathetic: calms your body after the sympathetic system does it’s thing
Neurons:
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3 major functions: 1)receive info; 2)process info; 3) transmit info to the rest of your body
3 types of neuron: (hint: SAME)
1.
sensory or afferent neurons: transmit information from senses to spinal cord or brain
(usually transmits reflexes)
2. interneurons: (located only in the spinal cord or brain) transmit info from sensory neurons
to motor neurons
3. motor or efferent neurons: transmit impulses from sensory or interneurons to muscle cells
or glands. Another way to say that is that they transmit info from the central nervous
system to the muscles or glands
Parts of a neuron:
soma (cell body)
dendrite (hint: den… in…)
axon (hint: on… passes on…)
myelin sheath (destruction can lead to Multiple sclerosis)
terminal buttons (axon terminal or synaptic knob)
nucleus
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receptor site
dendrite
neurotransmitter
terminal button
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Neurons at work:
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o
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o
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Neural impulses are electrical in nature along the neuron but then when the impulse reaches the terminal button it
is turned into a chemical process as neurotransmitters are released.
Many drugs work on these small electrical pulses to influence behavior
At rest, neurons are slightly neg. but when they receive a signal, cells open up on the neuron to allow some
positive sodium (Na) and potassium (K+) ions in. After the charge has passed, the neuron lets the positively
charged ions back out. This depolarization is called action potential.
All or nothing. They either fire or they don’t. There is no difference in the strength of the firing. If you feel
something stronger, it means more neurons are firing but they are NOT firing harder.
Myelin allows faster action potentials. This is important in performing small motor tasks
The Endocrine System: This interacts with your nervous system to regulate behavior and body functions. It consists of glands that
secrete chemical messengers called hormones into your blood. Important glands are below
 Hypothalamus: Produces hormones that stimulate or inhibit section of hormones by the pituitary.
 Pituitary gland: the “master gland” b/c it produces hormones that stimulate other glands to secrete their hormone; growth
 Thyroid gland: produces thyroxine which stimulates metabolic activities (lack can cause mental retardation in kids)
 Adrenal glands: procures stress hormones like cortisol. Also produce the flight or fight hormones of adrenaline
(epinephrine) and noradrenaline (norepinephrine)
 Pancreas: produces hormones that regulate blood sugar – imbalances can result in diabetes and hypoglycemia
 Ovaries and Testes: reproduction!
Unit 2 B Review Sheet
The Brain
 Plasticity: the lifelong ability of the brain to reorganize neural pathways based on new experiences
 Three Brain Regions:
1. Hindbrain (the first part of the brain to develop in the womb) – maintains homeostasis and instinctive behaviors
2. Midbrain –coordinates basic movements with sensory information. (like when you turn your head, it coordinates
your eyes to move with it.)
3. Forebrain – 80% of brain volume – higher functions of judgment, decision making, abstract thought, foresight,
language, sensation and perception.
 Major Structures
Cerebellum – coordinates motor function – helps maintain balance – controls fine motor movements
Medulla – where fibers cross (resulting in contralateral control – your left hand is controlled by the right side of brain);
regulates heart rhythm, blood flow, breathing rate, swallowing, digestion, vomiting
Pons – controls facial expressions, sleep, and dreaming
Reticular Formation - filters incoming stimuli and relays important information to other areas of the brain; arousal
Thalamus – “relay station” for sensory information to and from appropriate areas of cerebral cortex
Hypothalamus – Autonomic functions like temp., heart rate via control of sympathetic and parasympthatetic centers in
the Medulla; drives (sex, thirst, hunger); integrates with endocrine system by regulating pituitary (hint: the four F’s:
feeding, fighting, fleeing, and…. we’ll say sexual reproduction)
Amygdala – Aggression and fear –
Hippocampus – Longer term memories
Limbic system – contains hypothalamus, pituitary gland, amygdale, hippocampus
Cerebral Cortex – Receives and processes sensory information and directs movement. Center for higher order thinking,
planning, and judgment. The outer layer of the brain like the skin on an orange
 Association areas – regions of the cerebral cortex that do not have specific sensory or motor functions, but are
involved in higher mental functions, such as thinking, planning, remember, and communicating.
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Regions of the Brain
 Occipital lobes – vision (processed in the opposite side of the brain)
 Parietal lobes – Somatosensory cortex is the front strip on parietal lobes(for touch sensations). The amount of
space dedicated in the somatosensory cortex is directly related to the level of sensitivity in that area (like fingertips
have lots of space). Remember it’s contralateral!
 Frontal lobes – Motor cortex (right in front of the somatosensory cortex); interprets behaviors, makes decisions,
carry out plans also contralateral
 Broca’s area in left frontal lobe- controls production of speech; (hint: Tom Brokaw talks on the news)
 Temporal lobes – center for hearing; right temporal lobe important for understanding music; smell processed near
front of temporal lobes; sound is processed mostly contralaterally.
 Wernicke’s area: left temporal lobe; plays a role in understanding and making meaningful sentences
How we learn about the brain:
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How we look at brain structure:
 CAT or CT scans – uses x-ray to show two-dimensional slices. Can show the extent of a lesion
 MRI – uses magnetic field and pulses of radio waves that depend on the density of the tissue to show pictures.
More detailed than CAT scans.
How we measure brain function:
 EEG – electrodes placed on scalp – transmit info about electrical activity (“brain waves”) – produces those graphs
with the spikes
 PET – images depend on amount of metabolic activity in the brain. A radioactive glucose is inserted into the brain
and we study the movement as it moves with the blood flow
 fMRI – Shows higher resolution than PET. Changes in oxygen in the blood of an active brain area alters its magnetic
qualities and those are recorded.
Genetics:
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Humans have 23 pairs of chromosomes (so 46 in all) that code for our biological traits. The 23 rd determines sex (XY – male,
XX- female)
Sex-linked disorders (like color-blindness) are often found on that 23rd chromosome
We often study identical twins to determine genetic influences of behavior, diseases, and personality traits.