Transcript AP Psychology

AP Psychology
Biological Bases of Behavior
action potential
Action potential refers to the firing of a neuron. This occurs when
the charge inside the neuron becomes more positive than the
charge outside.
all-or-nothing principle
The concept of the all-or-nothing principle (or law), first used to
look at reactions in the heart, say that the strength of the stimulus
has no connection to whether a nerve or muscle fiber will react. As
long as the stimulus exceeds the threshold potential, the nerve or
muscle fiber will react fully. If it does not exceed the threshold
potential, the fiber will not react at all.
autonomic nervous system (ANS)
sympathetic and parasympathetic nervous systems
The autonomic nervous system (ANS) is the part of the peripheral
nervous system that controls internal biological functions.
The ANS is made up of two parts: one, the sympathetic nervous
system preps the body to deal with dangerous or stressful situations
by speeding up the heart rate and increasing oxygen intake. Blood
flow is sent to those parts of the body that needs it the most; two,
the parasympathetic nervous system, in contrast, conserves energy
and helps the body recover from strenuous activity.
behavioral geneticists
A behavioral geneticist is one who looks at genetics and
environment to explain behavior. Such things that can be explained
accordingly include personality, intelligence, disorders and even
what determines what we eat and how we choose to find a mate.
This science is a product over the discussion of nature-nurture
debate that, by the 1970s, was determined that both genetics and
the environment impact human behavior and actions.
brain:
convolutions, gyri, sulci, contralaterality
Animals with big brains, like humans, developed to pack as much
matter in the brain cavity as possible. To do so, the cerebral cortex
became wrinkled –these wrinkles are collectively known as
convolutions. The grooves made by the wrinkles are called sulci and
the ridges are known as gyri.
Contralaterality is the idea of one side of the brain controlling the
other side.
brain functions: amygdala
A part of the frontal lobe, the amygdala is one of the basal ganglia
within the limbic system. It is thought that it controls motivation
and emotion. Some theorize that it also might contain memories of
recent events.
Others have suggested that the amygdala might influence sexual
orientation, social ability, aggression, fear and even binge drinking.
brain functions: association areas
The association areas can be found in the cerebral cortex where
there is an integration of the motor and sensory functions.
However, the association areas deal more with sensory information
processing and multi- and sensorimotor integration.
brain functions: basal ganglia
The basal ganglia are clusters of neurons located deep within the
brain. They are responsible for regulating the start of movements,
balance, eye movements and one’s posture. They are located on
either side of the thalamus. These clusters include the caudate
nucleus, putamen, globus pallidus and substantia nigra.
If these clusters are over-active, they can create issues such as
obsessive compulsive disorder (OCD) and if underactive, can create
issues such as depression.
brain functions: cerebellum
The cerebellum is behind the spinal cord and responsible for
posture, balance and other voluntary movements.
brain functions: cerebral cortex
The cerebral cortex is the outer layer of the forebrain; gives one the
ability to learn and store information and abstract thoughts
brain functions: hippocampus
As a part of the limbic system and according to early doctors, looking
like a “seahorse” (hence its name), the hippocampus allows for the
accumulation of long-term memories. If there is damage to the
hippocampus, this could lead to amnesia.
brain functions: hypothalamus
Ok, this part of the brain does a great deal. The hypothalamus
controls hunger, thirst, sexual behavior and reactions to
temperatures. It also activates the sympathetic and
parasympathetic systems as well as the release of hormones from
the pituitary gland.
brain functions: medulla oblongata
The medulla oblongata is a part of the brainstem the regulates
respiration, blood circulation, heart rhythms and digestion. Its nuclei
regulates vomiting, swallowing, coughing and sneezing.
brain functions: pons
The pons bridges the gap between the brain and the spinal cord,
where messages are transmitting. It is responsible for activating
the systems for arousal and awareness.
brain functions: thalamus
The thalamus integrates sensory input, such as vision, hearing, taste
as well as skin sensation.
central nervous system (CNS)
The central nervous system (CNS) is made up of the brain and the
spinal cord.
The spinal cord is a series of nerves that run along the spine and
transmit messages between the body and the brain.
The body provides protection for both the brain and the spinal cord
nerves in order to protect its functioning. Any damage to the spinal
cord could result in paralysis.
cerebral cortex lobes: aphasia
Aphasia is a condition where a person has lost the ability to speak or
to understand speech. This typically happens after some trauma or
damage to the brain, particularly the frontal and temporal lobes.
Speech therapy has been helpful but other areas of the brain have
also been seen taking on the language functions to compensate.
cerebral cortex lobes: Broca’s areas
Located in the frontal lobe, the Broca’s areas are associated with the
ability to speak.
cerebral cortex lobes: frontal lobes
The frontal lobe is responsible for the planning of movements and
working memory (recent memory). Additionally, it interprets and
controls emotional behavior, is responsible for decision making
and the aforementioned carrying out of action. It is the largest of
the five lobes.
cerebral cortex lobes: glial cells
In support of the nervous system, the glial cells help guide the
development of neurons. In so doing, these cells nourishes them,
sheds waste and protects the neurons.
cerebral cortex lobes: occipital lobes
Located in the back of the cerebral cortex, the occipital lobes are
responsible for vision.
cerebral cortex lobes: parietal lobes
Located at the top of the cerebral cortex, the parietal lobes are
responsible for processing information related to body sensations
such as touch, temperature and pain.
cerebral cortex lobes: temporal lobes
Along the side of the cerebral cortex, the temporal lobes deal
primarily with hearing, language comprehension (Wernicke’s area)
processing sound and smell. There are also some association areas
for memory and learning.
chromosome
Chromosomes are the structure of cell nuclei in which can be found
the genes that are determined by the DNA sequences. All species
have a certain number of chromosomes with humans having 23
pairs.
chromosome: albinism
Albinism is a recessive trait that does not produce pigment (giving
people a pale, ashen appearance), can cause the rapid quivering of
the eyes (which tend to be pink or red), photophobia (extreme
sensitivity to light) and a lack of depth perception. Worldwide, it
happens to one in twenty thousand individuals.
chromosome: color blindness
This inherited sex-link trait, which is more common in males, refers
to the inability to see certain colors, most commonly red or green.
Completely color-blind individuals can only see black, white and
shades of gray. While this condition can keep people from doing
various jobs, piloting among them, it does not effect one’s ability to
see.
chromosome: dominant gene
A dominant gene is one that is expressed when paired genes are
heterozygous (different).
Therefore, if your mother carried the gene for red hair and your
dad did not, yet you have red hair, that would be an example of a
dominant gene.
chromosome: Down syndrome
Down syndrome (formerly mongolism), also known as trisomy 21, is a
condition of mental retardation characterized by distinct physical
characteristics. People with Down syndrome tend to have shorter
life spans, aging earlier than normal. The condition is the result of an
extra chromosome that is incorporated into one of the pairs the
typical body has. The retardation is typically mild to moderate and
such individuals are capable of education and training.
chromosome: genotype
A genotype refers to a person’s genetic makeup. This is set at birth
and will never change. In the event of conflicting genes, the results
can be one or the other (i.e.: dominant gene) or a blending of the
two genes.
chromosome: heterozygous and
homozygous
A heterozygous condition is when two matched or paired genes are
different. This can cause one of the two genes to be dominant or
could lead to a blending of the two genes or it could lead to the
creation of recessive gene.
A homozygous condition is when two matched or paired genes are
alike.
chromosome: Huntington’s disease
Huntington’s disease is a rare inherited disease affecting the central
nervous system with symptoms that include progressive dementia,
abnormal posture and involuntary jerking and writhing. This disease
typically affects people between the age of 35 and 50. There is no
cure and typically, the disease proves fatal. One who has this
chromosome has a 50% change of developing the disease.
chromosome: Klinefelter syndrome
Klinefelter syndrome affects the physical and cognitive development
of males.
Among the symptoms include low testosterone which leads to
delayed puberty, breast development (gynecomastia), reduced
body/facial hair and infertility. It can also delay/impair the dropping
of the testes and reduce the size of the penis (micropenis). Disease
such as breast cancer and lupus are common among affected men.
Learning disabilities are also a feature of the syndrome. Klinefelter
syndrome affects 1 in 500-1,000 newborn males. While the
disorder begins with changes occurring within chromosomes, it is
not an inherited disease.
chromosome: phenotype
A phenotype is the observable characteristic of one’s personality,
originating in their genes or influenced by environmental factors.
chromosome: phenylketonuria (PKU)
Phenylketonuria (PKU) is an inherited disorder that increases
phenylalanine in the blood, which can lead to cognitive impairment
and other serious health issues. The substance, an amino-acid, is
found naturally in proteins and artificially in sweeteners but high
levels of it in the blood can lead to severe developmental problems
as well as a musty odor and children tend to develop skin disorders.
chromosome: recessive gene
A recessive gene is one whose influence is masked when paired
genes are different (heterozygous).
chromosome: sex-linked traits
Sex-linked traits refer to the consequence of a recessive gene when,
in males, an X chromosome has no corresponding Y chromosome.
For females, the recessive gene would have to be in both X
chromosomes to show the same trait.
Such traits include color blindness and hemophilia.
chromosome: Tay-Sachs syndrome
Tay-Sachs syndrome is a rare inherited disorder that leads to a
progressive loss of nervous function. It shows itself during infancy
though for the first 3 to 6 months, the child appears normal. Babies
experience seizures, vision and hearing loss, cognitive impairment
and paralysis. Those with a severe form of the syndrome seldom
survive early childhood.
chromosome: Turner syndrome
Turner syndrome (TS) is a chromosomal disorder where girls and
woman have common traits because of a complete or partial
absence of a second sex chromosome. TS occurs in 1 of every 2,000
live female births and is responsible for roughly 10% of all
miscarriages. In short, the female body is not maturing the way it
should.
developmental model of the brain
The brain consists of three sections:
Hindbrain – includes the medulla, pons and cerebellum
Midbrain – deals with eye reflexes and movements
Forebrain – made up of the limbic system, thalamus,
hypothalamus and the cerebral cortex
endocrine system and hormones
The endocrine system is a chemical communication system, whereby
hormones (messages) are carried to and from the brain.
Hormones are created in the endocrine glands and are carried by
blood or other bodily fluids.
endocrine: adrenal and sex glands
The adrenal gland activates during times of anger or fright.
Releasing epinephrine and norepinephrine into the bloodstream, the
heartbeat and breathing increases. This, in turn, provides extra
energy to deal with a potential problem.
Sex glands are divided into two major types – testes in males and
ovaries in females. Ovaries produce eggs and the female hormone
estrogen and progesterone. Testes produces sperm and the male
hormone testosterone.
endocrine: hypothalamus
A part of the forebrain, the hypothalamus controls hunger, thirst,
sexual behavior and reactions to temperatures.
endocrine: pancreas
Located near the stomach, the pancreas is a gland that regulates
sugar levels in the blood. It secretes insulin and glucagon hormones.
If this is not operating properly, it can lead to diabetes (too much
sugar) or hypoglycemia (not enough sugar).
endocrine: parathyroids
The parathyroids are a part of the endocrine system, found in the
neck. It produces hormones that maintain the calcium ion levels in
the blood, allowing neurons to function normally.
endocrine: pineal gland
The pineal gland is a part of the endocrine system that produces
melatonin. Melatonin helps regulate circadian rhythms. It is
associated with seasonal affected disorder (SAD) and is also a
component in sleep aids. In the U.S., such an ingredient is not
regulated where in other countries, it is.
endocrine: pituitary gland
The pituitary gland (also known as the master gland) control the
endocrine system and is responsible for secreting a large number of
hormones. The pituitary gland is directed by the hypothalamus. The
hypothalamus monitors how many hormones are being sent into the
blood stream and corrects any imbalances.
Typically, the hormones interact with the organs on matters of
regulating and storing nutrients. They also control growth and
reproduction (ovulation and lactation in females).
endocrine: thyroid gland
The thyroid gland produces the hormone thyroxin. Not enough
thyroxin and a person feels lazy or lethargic. Too much thyroxin can
create hyperthyroidism which leads to weight and sleep loss as well
as over-activeness.
evolutionary model of the brain
The evolutionary concept of the brain includes three sections:
Reptilian brain – is made up of the parts of the hindbrain
(medulla, pons and cerebellum).
Old mammalian brain – made up of, minus the cerebral
cortex, the parts of the forebrain (limbic system,
thalamus and hypothalamus).
New mammalian brain – is composed of the cerebral cortex.
function tests:
electroencephalogram (EEG)
An EEG refers to a machine that can record the electrical impulses
of most of the brain. An EEG can monitory brain waves or rhythms.
By being able to monitor and stimulate with electrical currents
certain parts of the brain, it can trick the brain in accentuating or
ignoring certain signals. It has been used in the past to eliminate
the pain of cancer patients as well as curbing violent tendencies.
Check out the story of Phineas Gage to discover the impact when
certain parts of the brain are damaged.
function tests:
positron emission tomography (PET)
A PET scan is designed to showcase the brain as its different parts
are engaged in different functions. Active neurons absorb more of
the radioactive solution that is injected into the blood than nonactive neurons – ergo, the ability to see what part of the brain is
being engaged.
function tests:
functional MRI (fMRI)
A new component of MRI technology is the functional magnetic
resonance imaging (fMRI) which highlights the signals the brain
receives and the neural activity it engenders. However, the fMRI
does not use radio frequencies to do its job as the MRI does.
gene
Genes are the basic building blocks of heredity.
heritability
Heritability refers to the genetic causes of individual traits.
lesions
Lesions refer to the destruction of part of the brain. This surgical
damaging of brain tissue allows for the study of the loss of function;
making a connection between the loss of structure and the loss of
function.
Extensive work was done on rats to figure out what part of the brain
might play a role in one’s registering of appetite or fullness.
neuron and parts thereof
Neurons are long, thin cells of nerve tissue along which messages
travel to and from the brain.
The neuron has three basic parts: cell body, dendrites and axon.
An axon is a long fiber that carries impulses away from the cell body
towards the dendrites of the next neuron.
A cell body contains the nucleus and produces energy.
A dendrite is a short, thin fibers that stick out from the cell body.
neuron: Myelin sheath
The myelin sheath is a protective, insulating wrapping around some
axons and neurons. The material comes from the glial cells.
neuron: terminal buttons
Found at the end of axons, terminal buttons are small clusters of
knobs that secrete neurotransmitters that are picked up by other
neurons by activating those that are nearby.
neuropsychologists
A neuropsychologist focuses on the interaction between the brain
and one’s mental or cognitive processes.
neurotransmitters
excitatory and inhibitory
In order for one neuron to pass information to another neuron, it
sends out chemicals called neurotransmitters. These
neurotransmitters can either spur a neuron into activity (excitatory)
or stop it from doing something (inhibitory).
The main types of neurotransmitters include norepinephrine,
endorphin, acetylcholine and dopamine.
neurotransmitters: acetylcholine (ACh)
Acetylcholine neurotransmitters are involved with memory and
movement (associated with paralysis and Alzheimer’s disease).
neurotransmitters: dopamine
Dopamine neurotransmitters are involved with learning, arousal
and movement (associated with Parkinson’s disease).
neurotransmitters: endorphin
Endorphin neurotransmitters are involved with pain.
neurotransmitters:
gamma-aminobutyric acid (GABA)
Gamma-aminobutyric acid is an neurotransmitter that sends
messages and modulates its own function. It is an inhibitor, leading
to a “calming down” of nerves.
Drugs such as valium, Ambien and Lunesta basically helps the GABA
to bind itself to receptors sites. As a result, it leads to relaxation,
reducing anxiety, inducing sleep and suppressing seizure activity.
neurotransmitters: glutamate
Glutamate is considered the most important neurotransmitter for
the brain to operate normally. It is estimated that over half of all
brain synapses release this neurotransmitter.
Elevated concentrations of glutamate can lead to neural damage
because of toxicity to neurons.
neurotransmitters: serotonin
An example of monoamines, serotonin plays a major role in
sleeping, wakefulness as well as eating.
More recent studies have linked serotonin to aggressiveness and
obsessive-compulsive behavior. Drugs such as Prozac are designed
to affect serotonin circuits.
Nodes of Ranvier
The Nodes of Ranvier are gaps between myelin sheath cells and are
capable of generating electrical activity.
peripheral nervous system (PNS)
The PNS refer to the nerves that branch out from the spinal cord.
reflex: afferent and efferent neurons
A part of the somatic nervous system, the afferent neurons are nerve
fibers (axons) that carry information inward to the central nervous
system from the periphery of the body.
Also a part of the somatic nervous system, the efferent neurons are
nerve fibers (axons) that carry information outward from the central
nervous system to the periphery of the body.
reflex: effector
An effector is an organ (muscle or gland) that facilitates overt
behavior, either movement or secretion.
This is seen when a muscle contracts to move an arm, when a
muscle squeezes saliva from salivary gland or when a gland
releases a hormone into the blood.
reflex: interneuron
An interneuron is a nerve cell found completely in the central
nervous system and serves as a conduit between sensory and
motor neurons.
reflex: reflex arc
The reflect arc is the route followed by nerve impulses to produce a
reflect act. It comes from the receptor organ through the afferent
nerve to the nervous system and then through the efferent nerve to
the effector organ.
reflex: sensory receptor
A sensory receptor is a cell found in sense organs (tongue, eye,
etc.) that initiates action potentials by traveling along sensory
neurons to the central nervous system.
They are found in:
Retina of the eye
Cochlea of the ear
Taste buds of the tongue
Olfactory epithelium in the nasal cavity
They are also found in:
Skin
Tendons
Muscles
Joints
saltatory conduction
Action potentials have the ability to jump from node to node,
across the Nodes of Ranvier. The ability to jump is referred to
saltatory conduction.
This is a faster way to travel down an axon than traveling in an
axon without a myelin sheath.
somatic nervous system
The somatic nervous system (SNS) is a part of the peripheral nervous
system that controls the voluntary movement of the skeletal
muscles. It is also referred to as the voluntary nervous system.
It carries motor and sensory information both to and from the
central nervous system.
On a completely useless but interesting aside, the term stems from
the Greek word for “body” – soma.
structure tests:
computerized axial tomography (CAT)
A CAT scan is a computer enhanced X-ray of the brain structure.
Doctors use CAT scans to see abnormalities in the brain structure of
patients with mental disorders.
structure tests:
magnetic resonance imaging (MRI)
A MRI is designed to combine the functions of a CAT and PET, using
magnetic fields, radio waves and computerized enhancements to
show the structure and the function of the brain.
MRI scans have a higher resolution and are more specific than CAT
scans. MRI studies have shown a connection between enlarged
ventricles in the brain and schizophrenic disturbance.
synapse
The synapse is the gap between the individual cell nerves.
twins: identical and fraternal
Identical twins, also known as monozygotic twins, are siblings who
share all genes and heredity because they originated from the same
zygote. They have been heavily researched to determine levels of
influence by heredity and the environment on certain behavior.
Fraternal twins, also known as dizygotic twins, are siblings that share
half of the same genes, developing from two different zygotes. Like
identical twins, they are studied for many of the same reasons.
zygote
A zygote is a one-celled organism that formed by the union of a
sperm and an egg. Within a zygote can be found all of the
chromosomes and genes that will eventually determine the entirety
of a person.
During the germinal stage during the first seven days, the zygote
attaches itself to the uterine wall. However, one in five pregnancies
end at this junction with the woman having no idea she was
pregnant.
The development of the zygote can also determine whether a
woman will have a twin or single-birth.