PSYC210 Exam 1

Ventricles

fluid-filled spaces that run through the nervous system

Brainstem

Medulla, pons, midbrain

What does the brainstem do?

it is a conduit for several major tracts of the central nervous system that relays information between the forebrain and the spinal cord

Hindbrain

cerebellum and brainstem

coordinates and plans movements

What does the cerebellum do?

occipital, temporal, parietal, and frontal

4 brain lobes

Lateral Fissure/Sylvain Fissure

divides the temporal lobe from the frontal and parietal lobe

Parieto-occipital sulcus

separates the parietal lobe from the occipital lobe

Veritable Column parts

cervical, thoracic, lumbar, sacral, and coccygeal

Dorsal roots

where sensory information carried by afferent axons of the spinal nerves enter the spinal cords

ventral roots

where motor commands carried by efferent axons leave the spinal cord

Dorsal Columns

carry ascending sensory information from somatic mechanoreceptors

Ventral Columns

carry both ascending information about pain and temperature and descending motor information from the brainstem and motor cortex

somatic, branchial, visceral

3 types of brainstem nuclei

somatic motor nuclei

project to striated muscles

branchial motor nuclei

project to muscles called branchial arches (arches that raise bones like jaws)

Visceral Motor Nuclei

project to peripheral ganglia that innervate smooth muscle or glandular targets

Motor cortex

contains neurons whose axons project to the lower motor neurons in the brainstem and spinal cords

Insular cortex

is in charge of taste

somatic sensory cortex

concerned with bodily sensation

Occipital lobe

in charge of vision

frontal lobe

plans responses to stimuli

parietal lobe

attends to stimuli

temporal lobe

recognizes stimuli

Hippocampus

in charge of memory

Limbic system

in charge of the experience and expression of emotion as well as the regulation of visceral motor activity

Dorsal Thalamus

relay information to the cerebral cortex and other parts of the brain

Hypothalamus

sexy time baby!!!

Amygdala

hangs out on the hippocampus and helps with memory

why does blood have to get to the brain?

neurons are more sensitive to oxygen deprivation due to their high metabolic rate

Blood-brain barrier

protects the brain by only letting in certain blood. makes getting drugs to the brain difficult

Meninges

protective tissue layers around the brain

How many neurons?

there are 100 to 150 billion

Glia

Speed up nerve impulses and form the blood brain barrier

excitation

creates potential

inhibition

depletes potential

graded potentials

small voltage fluctuation in the cell membrane restricted to the vicinity on the axon where the ion concentrations change to cause a brief increase or decrease in electrical charge across the membrane

neurotransmitters

agonists

chemical compounds that mimic the action of neurotransmitters

antagonists

chemical compounds that block the action of neurotransmitters (drugs and poisons)

Resting potential

electrical charge across the membrane in the absence of stimulation; stores potential energy

Excitatory Postsynaptic Potential

reduce the charge on the membrane toward the threshold level and increase the probability of an action potential

Inhibitory Postsynaptic Potential

increase the charge on the membrane toward the threshold level and decrease the probability of an action potential

Action Potential

brief but large reversal in the polarity (negative/positive) or an axon's membrane that lasts about a millisecond. Occurs when a large concentration of sodium ions, then potassium ions cross the membrane rapidly

How do neurons work?

has an extensive dendritic tree covered with spines that establishes it's 50,000 connections to other neurons, communicating back and forth to create impulses

Conduction of the action potential

Action potential is a graded conduction, it is conducted along the axon and doesn't change shape or size

Regeneration of Action Potential

Potential is regenerated at each point along the axon

Absolute refractory period

Limits neuron to maximum of 1000 action potentials per second

Relative refractory period

Makes it hard to generate action potential but it is possible, this is when the action potentials set up

Conduction velocity

Speed of conduction in uninsulated axons varying from .1 meter/sec to 35 meter/sec

Conduction velocity of a thick axon

fast conduction, more charge carriers

Conduction velocity of a thin axon

slow conduction, fewer charge carriers

Myelin

axon insulation formed by Schwann cells in the peripheral nervous system and oligodendrocytes in the central nervous system

Myelinated axons

action potential can't occur when axons are insulted by myelin

Two types of synapses

chemical and electrical

Chemical synapse

are the most common and are a terminal filled with vesicles that release neurotransmitters

electrical synapse

is very fast and it's electrical potential travels directly to neurons

electrical stimulation

passing an electrical current from the uninsulated tip of an electrode onto a nerve produces a muscle contraction

electroencephalogram (EEG)

a standard tool used to monitor sleep stages and record waking activity, used to diagnose epilepsy

Oscilloscope

a device that serves as an voltmeter sensitive enough to record very small electrical signals from a nerve

Microelectrode

a microscopic insulated wire or a salt-water filled tube of which the uninsulated tip is used stimulate or record neurons

Nerve impulse

changes in ion concentration across the cell membrane

Cations

positively charged ions (sodium and potassium)

Anions

negatively charged ions (proteins and chloride)

Diffusion

Molecules move constantly and try to spread out from where they are heavily concentrated to where they are less concentrated

hyperpolarization

charge of the membrane increases

depolarization

charge of the membrane decreases

refractory periods

Limits how frequently an action potential can occur and prevents them from switching directions

Two types of chemical synapse receptors

Ionotropic and metabotropic

Ionotropic receptor

ligand channel, fast. Produces EPSP or IPSP

metabotopic receptor

protein coupled; slow

Ligand

a chemical that binds receptors and may or may not be a neurotransmitter

Affinity

how well a compound binds to a receptor

Competitive antagonists

block binding site

non-competitive antagonists

do not prevent binding but neurotransmitter has no effect

Major targets for medications and drugs of abuse

chemical synapses

Two major dopamine systems

mesolimbocortical(reward) and mesostriatal(movement)

What drugs increase the concentration of dopamine in the synapse?

cocaine, amphetamine, and methylphenidate

two

How many cells does it take to make a synapse?

Reuptake

When transmitters are rapidly cleared from the synaptic cleft by being taken up by special proteins called transporters

How do cells communicate?

They closely resemble having a language, much like a computer chip

Bali Theory

look at the number and pattern of the action potentials to find the frequency of pitch

ERPs

a potential that is related to an external event

inhibition

What does GABA invoke

what does GABA make?

glutamine for re-uptake and resynthesis

G proteins

a class of proteins that reside next to the intracellular portion of a receptor and are activated when the receptor binds an appropriate signal on the extracellular surface

iontropic

Which is faster? iontropic or metabotropic?

Any drug that enhances or mimics the action of an endogenous transmitter is classified as..

an agonist

A drug that prevents re-uptake will prolong the activity of the transmitter at the synapse. re-uptake serves to promptly cut off the synaptic activity making this drug a

agonist

antagonistic

A drug that inhibits transmitter storage in synaptic vesicles would be classified as

Somatosensory System

Relays information about the body such as touch, temperature, body position, and pain

Receptors

neurons that change a physical stimulus into neural events that are located in the skin.

Labeled Line System

Different receptors for different qualities and have different lines to the brain

When does a pacinian corpuscle respond to pressure?

When deformed sodium channels are opened which depolarizes the ending

Receptor or generator potential

the potential measured in the specialized ending. If the ending is depolarized enough, it will produce an action potential

Adaption

loss of sensitivity to continuous presence of stimulus

Receptive fields

the region of the receptor surface that excites or inhibits a sensory neuron

Does the size of receptive fields vary?

Yes, they are smaller and larger dependent on the nerve endings (hands: smaller, forearm: larger)

How do the somatosensors move?

from the cell body in the dorsal root ganglion the information ascends to the medulla then to the thalamus and then to somatosensory cortex

Where is the somatosensory cortex?

just posterior to the central sulcus