chapter 3: biopsychology

neurons

primary brain cells

main function: communication with other cells

glial cells (glia)

support cells

support neuronal function in a variety of ways

semi permeable membrane

allows smaller molecules or molecules without an electrical charge to pass through it while stopping larger or highly charged molecules

dendrites

receive incoming electrical signals from other neurons, these signals are then sent down the axon

myelin sheath

fatty insulating substance that covers the axons

• helps electrical signal travel faster

• gaps between myelin are called nodes of Ranvier

terminal buttons

bulbs at the ends of axons

• contain synaptic vesicles

• these vesicles are storage sites for neurotransmitters

synapse

the space between the terminal button of one neuron and the dendrite of another

resting potential

the electrical charge inside the neuron at the base

• more Na ions outside the cell

• more K ions inside the cell

neurotransmitters from nearby neurons attach to receptors on dendrites —>

membrane potential (electrical charge) changes

depolarization

membrane potential becomes less negative making neuron more likely to fire

EXCITATION

hyperpolarization

membrane potential becomes more negative, making neuron less likely to fire

INHIBITION

threshold of excitation

level of charge in the membrane that causes neuron to become active

action potential

an electrical signal

act on all or none principle: either sufficient enough or is not

neurotransmitter

chemical messenger of the nervous system

glutamate

provides excitatory signal to post synaptic neurons

GABA

provides inhibitory signal to post synaptic neurons

biological perspective

view that psychological disorders like depression and schizophrenia are associated with imbalances in one or more neurotransmitter systems

acetylcholine

muscle action and memory

beta endorphin

pain and pleasure

dopamine

mood, sleep, learning

norepinephrine

heart, intestines, alertness

serotonin

mood and sleep

reuptake

moving a neurotransmitter from the synapse back intro the axon terminal from which it was released

psychotropic medication

drugs that treat psychiatric symptoms by restoring neurotransmitter balance

agonist

drug that mimics or strengthens the effects of neurotransmitter

antagonist

drug that blocks or impedes the normal activity of a given neurotransmitter

astrocytes

primary support cells

oligodendrocytes

myelinate axons in the CNS

schwann cells

myelinate axons in the PNS

microglia

primary immune cells in the CNS

two types of nervous systems

central and peripheral

two types of peripheral

somatic and autonomic

two types of autonomic

sympathetic and parasympathetic

somatic nervous system

relays sensory and motor information to and from the CNS

autonomic nervous system

controls our internal organs and glands

sympathetic nervous system

involved in stress related activities and functions; fight or flight

fight or flight

activation of sympathetic division of the autonomic nervous system

parasympathetic nervous system

associated with routine, day to day operations of the body under relaxed conditions

rest and restore

relaxes the body after fight or flight

the brain

• comprised of billions of interconnected neurons and glia

• bilateral

• can be separated into distinct lobes but all areas interact with one another

dorsal

areas of brain closer to top

ventral

areas of brain closer to bottom

anterior

areas of brain closer to front

posterior

areas of brain closer to back

lateral

areas of brain closer to sides

middle

areas of brian closer to middle

spinal cord

• delivers messages to and from the brain

• own system of reflexes

• top merges with the brain stem and bottom ends just below ribs

• 30 segments

• sensory nerves bring messages to brain, motor nerves send messages out to muscles and organs

lateralization

concept that each hemisphere of brain is associated with specialized functions

corpus callosum

connects the hemispheres of the brain

forebrain

• cerebral cortex

• thalamus

• hypothalamus

• pituitary gland

  • limbic system

cerebral cortex

associated with highest mental capabilities

broken into 4 lobes

frontal lobe

executive functioning

contains:

• motor cortex- planning and coordinating movement

• prefrontal cortex- higher level cognitive functioning and impulse control

• broca’s area- language production

parietal lobe

contains somatosensory cortex

somatosensory cortex

processing sensory information from across the body, ex touch, temp, pain

temporal lobe

hearing, memory, emotion, language

contains auditory cortex

auditory cortex

strip of cortex in the temporal lobe that is responsible for processing auditory information

wernicke’s area

speech comprehension

occipital lobe

visual processing

contains primary visual cortex

thalamus

relay center of the brain, all senses (BUT SMELL) are routed before sent to other areas of the brain

limbic system

mediating emotional response and memory

amygdala

emotion and tying emotional meaning to our memories

hippocampus

learning and memory

hypothalamus

regulates homeostatic processes

midbrain

movement, alertness, reward

reticular formation

regulating the sleep/wake cycle, arousal, alertness, motor activity

substantia nigra

where dopamine is produced, control of movement

ventral tegmental area

dopamine is produced, associated with mood, reward, and addiction

hindbrain

critical life support functions

medulla

controls automated processes like breathing, blood pressure, heart rate

pons

connects the brain and spinal cord, involved in regulating brain activity during sleep

cerebellum

controls balance, coordination, movement, motor skills

natural selection

organisms better suited for their environment will survive and reproduce, those that are poorly suited will die off

genetic variation

genetic difference between individuals

contributes to adaptation to environment

chromosome

long strand of DNA

DNA

helix shaped molecule made of nucleotide base pairs

gene

sequence of DNA that controls physical characteristics known as traits

range of reaction

asserts that our genes set the boundaries within which we can operate, and our environment interacts with the genes to determine where in that range we will fall

genetic environmental correlation

view of gene-environment interaction that asserts our genes affect our environment, and our environment influences the expression of our genes

epigenetics

study of gene-environment interactions such as how the same genotype leads to different phenotypes

CT scan

involves x rays and creates an image through xrays passing through varied densities within the brain

CT

shows structure not function

PET scan

showing activity in different parts of the brain

injecting individuals with mildly radioactive substance and monitoring changes in blood flow to different regions of the brain

PET

shows function

MRI

magnetic fields used to produce a picture of the tissue being imaged

MRI

structural imaging

fMRI

shows changes in metabolic activity over time

fMRI

functional imaging

EEG

records electrical activity of brain with electrodes on scalp

timing of overall brain activities by tracking amplitude and frequency of brainwaves

endocrine system

series of glands that produce hormones to regulate normal body functions

hypothalamus

links nervous system and endocrine system by controlling pituitary gland

pituitary gland

serves as the master gland, controlling secretions of all other glands

thyroid

secretes thyroxine which regulates growth, metabolism, and appetite

adrenal gland

secretes hormones involved in the stress response

gonad

secretes sex hormones

pancreas

secretes hormones that regulate blood sugar