PSY220 Exam 1

anterior/posterior

front/back

dorsal/ventral

Relative to the body: Towards the spine/Towards the stomach

Relative to the brain: Top of the head/towards the chin

Lateral/Medial

Toward the outside of the body, away from the midline/ toward the middle

Superior/Inferior

Above/Below

Ipsilateral/Contralateral

On the same side of the body/On opposite sides of the body

Horizontal/Transverse

A plane that shows brain structures as seen from above

Saggital

From the side

Splits the left from the right

Coronal

From the front

Splits anterior from posterior

Central nervous system

Brain and the spinal cord

Peripheral Nervous System

Made up of somatic and autonomic nervous system

Connects CNS to the rest of the body

Somatic Nervous System

Controls voluntary movements; muscles

Ventral and dorsal roots

Peripheral Neuropathy

Damage to the somatic nervous system

Motor symptoms: Spasms, tremors, twitches, loss of control

Ventral roots

Carries motor information away from the spinal cord to the muscles of the body

Motor

Dorsal roots

Carries sensory information away from the body to the spinal cord

Sensory

Autonomic Nervous System

Controls the organs

Sympathetic and parasympathetic nervous system

Sympathetic

“Fight or flight”

Origins: thoracic and lumbar nerves

Increase breathing, sweating, and heart rate, and decrease digestive activity

Norepinephrine

Parasympathetic

Facilitates vegetative, nonemergent response

Decreases heart rate, improves digestion, and increases sexual arousal

Origin: Cranial and sacral nerves

Acetylcholine

The Hindbrain

The bottom part of the brain

Medula, pons, cerebellum

Medulla

Vital reflexes, heart rate, respiration

Pons

Connects the cerebellum to the rest of the brain

Motor/sensory control

Cerebellum

Movement, balance, and coordination

The Midbrain

Between the hindbrain and forebrain

Tectum, tegmentum, reticular formation

Tectum

The roof of the midbrain

Vision and hearing

The swellings on each side are the superior and inferior colliculi

Superior colliculus

Vision

Inferior colliculus

Hearing

Tegmentum

Sleep, arousal

Reticular formation

Consciousness, alertness, attention

Thalamus

Relays information from the senses to the cerebral cortex

Hypothalamus

Controls temperature, hunger, thirst, sex drivre

Amygdala

Processes emotional information, especially concerning fear and anxiety

Olfactory bulb

Smell

Does not get routed through the thalamus

Hippocampus

Memory

Damage leads to trouble making new memories and is associated with dementia and cognitive decay

Forebrain

The largest structure in the brain

Subcortical

Thalamus, hypothalamus, olfactory bulb, amygdala, hippocampus

Sulci

Fissures

Central sulcus

Divides frontal and parietal lobes

Sylvian fussure

Divides temporal from the frontal and parietal lobes

Gyrus

Raised ridges of the brain

Precentral and postcentral

Corpus collosum

Connects right and left hemispheres, allows for communication between them

Occipital lobe

Visual cortex

Processes visual stimuli

Parietal Lobe

Primary somatosensory cortex (controls sensory information about touch, temp, pain)

Monitors information about eye, head, and body positions and passes it on to brain areas that control movement

Essential for spatial and numerical information

Temporal Lobe

Primary auditory cortex

Processes complex visual stimuli

Left side contains Wernicke’s area

Essential for speech (Wernicke’s area, in the left lobe)

Wernicke’s area

Located in the left temporal lobe

Essential for speech

Damage causes difficulty in understanding/pulling the correct words

Kluver-Bucy Syndrome

Damage to the temporal lobe

Leads to inappropriate or sexual behaviors, overeating, excessive lip-smacking or other mouth movements

Frontal Lobe

Primary motor cortex (controls movement and coordination, cognitive control, decision-making, personality expression)

Case studies

Elaborate study for knowledge acquisition, following the scientific research method

Ablation

The act of removing a brain area, generally with a surgical knife, to see how it affects someone

Lesion

A damaged part of the brain, sometimes from ablation

Transcranial magnetic stimulation (TMS)

Magnetic stimulation to treat certain conditions

Functional Magnetic Resonance Imaging (fMRI)

Takes photos of the brain based on changes in blood oxygen

Asking people to do an aciivty and see which parts of the brain are being activated

Computerized Axial Tomography (CT/CAT scan)

Used in emergencies to take photos of the brain

Contrast dye is injected, and an X-ray is taken

Magnetic Resonance Imaging (MRI)

Takes photos of the brain

Takes longer

Can detect smaller changes than CT

Dendrite

At the end of the cell, receives information

Dendritic spines

Increase surface area to be able to recieve more information

Soma/cell body

Where the mitochondria are

Nucleus

Where the chromosomes are

Axon hillock

Between the soma and axon

Axon

Where information travels down

Presynaptic terminals

End points of an axon that release chemicals

Myelin sheath

Covers the axon to make messages go faster

Nodes of Ranvier

Gaps in the myelin sheath

Synapse

Gaps between two neurons

Astrocytes

Provide structure

Synchronize information

Provide nutrients

Take care of waste

Microglia

Part of the immune system

Cleans up dead cells, viruses and fungi

Assists with the pruning process

Oligodendrocytes

Super long

Myelinates axons

Schwann cells

Make up the myelin sheath

Aid the transportation of signals

Radial glia

Long rods that aid the transportation of other neurons

When they are no longer needed they turn into other glia cells

Resting potential of a neuron

When the inside of the membrane is more negative and the outside is more posive

Rests at -70 mV

Are Na+ and K+ channels open or closed during resting potential?

Both the voltage-gated Na+ and K+ channels are closed, although there are some channels that allow the ions to flow out

Concentration gradient

Ions want to go where there are fewer of them

Going from more to less concentrated areas to even things out

Sodium wants to go into the cell because there is less on the inside.

K+ wants to leave because there are fewer on the outside

Electrical gradeint

Sodium is + and wants to enter the cell

Potassium is - and wants to stay in the cell

Describe how the movement of Na+ and K+ across the cell membrane produces the action potential and recovery

Sodium-potassium pump works to maintain the resting potential

When stimulated, sodium channels open and the positive ions flow in until the -70 reaches -55 and once it reaches that threshold, more NA+ ions flow in (depolarization).

Then, sodium channels refract and potassium channels open for the K+ ions to flow out (re-polarization)

They continue flowing out which causes hyper-polarization and then potassium channels close and then the sodium-potasium pump works to reach resting potential

Propagagtion

When an action potential starts in the axon hillock, it continues down the axon by triggering other action potentials without losing strength

All or none

All action potentials are about the same strength

An action potential either occurs or doesn’t depending on whether it hits the threshold or not

Spontaneous activity

Neurons have a baseline level of firing

Refractory period

Absolute action potential cannot be triggered

Relative refractory-period

A stronger-than-normal stimulus can trigger an action potential

Saltatory conduction and how is myelin involved

When action potentials can only occur during the nodes of Ranvier, so they “jump” from node to node while they travel through the myelin since it is insulated, making the process much faster

How neurotransmitters are released into the synapse

The action potential travels down the axon, and as it reaches the axon terminal, calcium channels open.

Calcium enters the axon and binds to the vesicles that contain the neurotransmitters

The vesicles then bind to the presynaptic membrane

The neurotransmitters are then released via exocytosis into the synaptic cleft, and then they bind to the receptors on the dendrites

The remaining neurotransmitters are then cleared from the synaptic cleft via reuptake, diffusion, and degradation

Ionotropic receptors

Ligand-gated ion channels

Activated by a ligand that binds to the receptor and then it opens and allows for other chemicals to flow through

Faster

Short-lasting

Can be excitatory or inhibitory

Metabotropic receptors

Longer process

A protein binds to a receptor, where it initiates a sequence of metabolic reactions that then opens the channel for neurotransmitters to enter

Slower, lingering effects

Can be excitatory or inhibitory

Temporal summation

When there are repeated stimuli (EPSPs) at the same location

Spatial summation

When there is stimulation at various areas but it gets added together

How do EPSPs and IPSPs relate to the probability of action potentials?

EPSPs can build up to create an action potential (sodium flows into the cell), but IPSPs can prevent one (K+ leaves the cell and Cl- enters)

Reputake

Neurotransmitters re-enter the presynaptic neuron

Diffusion

Neurotransmitters drift away

Degradation

An enzyme breaks down the neurotransmitter

Neurotransmitter clearance

After what happens to the neurotransmitters, they prevent reuptake, diffusion, and degradation so that neurotransmitters stay there longer

Presynaptic processes

Alters what happens in the presynaptic neuron

Either enhance or inhibit neurotransmitter release

Postsynaptic processes

Alters what happens in the postsynaptic neuron

Agonist - the drug acts like a neurotransmitter and binds to the receptor

Antagonist - prevents neurotransmitters from binding to receptors

Stimulants

A form of neurotransmitter clearance - they block reuptake so that more dopamine is available

Increases excitement, alertness, mood

Decreases fatigue

Marijuana

Presynaptic process - decreases GABA (dopamine inhibitor)

Vivid sensory experiences, slowing of time, sense of well-being, relaxation

Hallucinogens

Postsynaptic process - act as serotonin receptor agonist

Ecstasy, vivid sensory experiences, synesthesia, perceptual distortions

Antidepressants

Neurotransmitter clearance, block reuptake of serotonin

Antipsychotics

Postsynaptic process, block receptors, antagonist

Why is it more appropriate to associate dopamine with “wanting” instead of “pleasure”?

Dopamine affects motivation and how much you’ll do something to get it

Not very enjoyable

Differentiate between chromosomes, DNA, and genes

Chromosomes are in the nucleus of cells

DNA makes up chromosomes

Genes are segments of DNA

Homozygous

Same gene on both copies of the chromosomes

Heterozygous

Unmatched pair of genes

Dominant genes

Show a strong effect in either the homo or heterozygous condition

Recessive genes

Will only show effect in the homozygous condition