Ap Psychology - Biological Psych, Sleep, Drugs

AP Psych 24/25 course Unit 2

Neuron

The types of cells that make up the brain and nervous system. The gray matter of the brain.

Cell body

What contains the nucleus. It produces energy for neuron activity.

Dendrites

Fibers that stick out and receive impulses/signals from other neurons on it’s receptor sites.

Axon

Carries impulses from one neuron to another. Can be several feet in length.

Axon terminal/Terminal buttons

Branch out at the end of the neuron. They contain vesicles that hold neurotransmitters.

Myelin Sheath

Insulates/protects the axon.

How do neurons generate activity?

Fluids inside and outside of the neuron contain positive and negative ions. The semipermeable gates open and close, allowing the ions to move back and forth. When they move back and forth, energy is created.

Positive ions

Sodium and potassium

Negative ions

Chlorine

Resting potential

The neuron is negatively charged on the inside and positively charged on the outside. This is a polarized state.

Depolarization

The ion channels allow positive ions to go through the semipermeable gates into the neuron.

All-or-Nothing Principal

When the electrical impulse reaches its threshold at a certain level of intensity, the impulse must fire. It moves down the axon without losing its intensity.

Action Potential

The wave of electrical charge. It lasts 1/1000 of a second.

Repolarization

Returning to a polarized state. Positive ions leave the neuron, and the neurons become negative again.

Refractory Period

The period of time before a neural impulse can be fired again. Also known as hyperpolarization.

Reuptake

When transporter proteins carry neurotransmitters back to the pre-synaptic neuron.

Excitatory

A type of neurotransmitter that makes it more likely for the post-synaptic neuron to fire an action potential.

Inhibitory

A type of neurotransmitter that decreases the likelihood of the post-synaptic neuron to fire an action potential.

Agonist

A type of chemical that mimics the action of a neurotransmitter.

ex: opioids mimic endorphins

Antagonist

A type of chemical that blocks the action of a neurotransmitter.

ex: Haldol blocks dopamine receptors.

SSRI

Serotonin supply uptake inhibitor.

Acetylcholine (ACh)

• Excitatory (stimulates neurons)

• Muscle action

• Learning and memory

• When ACh neurons deteriorate = alzheimers

GABA

• Major inhibitory neuron

• The brain’s break pedal

• Calms down the brain

• Undersupply = anxiety, seizures, tremors, insomnia

Glutamate

• A major excitatory neurotransmitter.

• The brain’s accelerator

• Learning and memory

• Most prevalent neurotransmitter

• Oversupply overstimulates the brain

• Oversupply = Headaches, migraines, seizures

Norepinephrine

• Inhibitory to neurons in the nervous system

• Excites heart muscles and intestines

• Alertness and arousal

• Undersupply = depressed mood

Dopamine

• Voluntary movement

• Learning and reward

• Affects sleep

• Attention

• Emotion

• Addiction

• Oversupply = Schizophrenia

• Undersupply = Tremors, decreased mobility in Parkinson’s

Serotonin

• Mood

• Hunger

• Sleep

• Arousal

• Learning

• Attention

• Undersupply = depression

• Drugs can raise serotonin to treat depression

Endorphins

• Perception of pain or pleasure

• Natural opiates

• Depress the immune system

• Eliminate pain

• Oversupply with opioid drugs = suppress body’s natural supply

Substance P

• Pain perception and immune response

• Oversupply = chronic pain

Neural networks

Connected pathways of nerves that produce motor output from sensory input.

Structure

A part of the brain that carries out a specific function

Lobe

A section of the brain that seems to be involved in specific functions

• There are 4

Cortex

The brain’s surface area

Midbrain structures

Reticular Formation

Recticular Formation

Tells the brain a signal is coming

Forebrain structures

• Amygdala

• Hypothalamus

• Hippocampus

• Thalamus

• Limbic system (not a structure, but in the forebrain)

• Cerebral cortex and cerebrum

Limbic System

Motivation, memory, and regulating emotions

Cerebral Cortex and Cerebrum

• Learn and store complex info

• Reading

• Understanding language

Amygdala

• Handles intense emotions like fear and aggresion

• Differentiation of things essential for survival like food and mates

Hypothalamus

• Keeps the body in homeostasis (inner state regulation, body temperature)

• Hunger

• Thirst

• Fight or flight reflex

Hippocampus

• Recalling information by ‘waking up’ parts of the brain

• Creating memories

Thalamus

• Sensory input

• Sends sensory signals to the correct part of the brain that handles them

• All senses except smell

Hindbrain structures

• Cerebellum

• Medulla

• Pons

Cerebellum

Motor coordination

Medulla

• Essential life functions

• Breathing, heart rate, reflexes

Pons

Sleep and arousal

Corpus Callosum

Fibers that connect the left and right hemispheres, allowing them to communicate with each other

Frontal Lobe

• Personality

• Intelligence

• Control of voluntary movements

Pre-frontal cortex

• Higher cognitive functions

• Planning, reasoning, self control

Motor Cortex

Body movement

Parietal Lobe

• Spatial reasoning

• Attention

• Motor control

Occipital Lobe

Visual signals (interpretation)

Temporal Lobe

• Hearing

• Memory

• Emotion

• Speaking

• Connects to limbic system

Association cortexes

Cortexes that integrate outside information into newly processed information

Broca’s Area

Production of speech, in the left hemisphere

Wernicke’s Area

Comprehension of speech, in the left hemisphere

Nervous system

Electrochemical communication circuitry

Plasticity

The brain’s adaptablility

• It’s special ability to change and adapt

Central Nervous System

The brain and spinal cord

Peripheral Nervous System

Smaller nerve branches that reach all over the body

Somatic Nervous System

Voluntary activities

Autonomic Nervous System

Involuntary activities

Sympathetic Nervous System

Arouses the body, mobilizing it for action

‘fight or flight’

Parasympathetic Nervous System

Calms down the body

‘rest and digest’

Reflex arc

Afferent neurons conducting signals from receptors (PNS) → interneurons (confined to CNS) → Efference neurons conduct signals to effectors (muscles and glands)

Afferent Neurons

Sensory Neurons

Efferent Neurons

Motor Neurons

Endocrine System

Made up of glands that secrete hormones

Pituitary Gland

The ‘mastergland’ of the endocrine system

• Releases hormones = stimulate actions of other endocrine glands

Hormones

• Melatonin

• Adrenaline

• Oxytocin

• Ghrelin

• Leptin

Melatonin

Sleep/waking up

Adrenaline

Actviates the sympathetic nervous system

• Fight or flight

Oxytocin

Social bonding (child/parent bond)

Ghrelin

• Stomach contractions (growling)

• Promotes hunger

Leptin

• Decreases hunger by providing info to the hypothalamus

Rodger Sperry

Taught cats with a severed corpus callosum to solve a puzzle

Mike Gazzaniga

• Performed split brain operation

• Can be used to treat epilepsy by stopping spread of electrical activity

Lateralization

The specialization of the different hemispheres of the brain

Epigenetics

The study of environmental influences of gene expression that occur without a gene change

Twin Studies

Comparing identical twins to fraternal twins

Adoption Studies

Examining the resemblance between adopted children with both their biological and adoptive parents

How do scientists study the brain?

• Recording

• Stimulation

• Lesions

• Accidentals

• TMS

• Images

EEG

• Recording

• Electrodes on the scalp detect brain wave activity

Lesions

Scientists cut or destroy part of an animals brain

TMS

Magnets send brief electrical currents to the brain to trigger action potential

CT scan

• Image

• Produces 3D image from x-rays

PET scan

• Positron emission typography

• Metabolic changes in the brain related to activity

• Image

MRI

• Image

• Magnetic field around the person

• Radiowaves construct images of tissue and biochemical activity

• FMRI is similar (functional, person is doing something)