UNIT 1 - biological neuron

why are psychologists concerned with human biology?

psychologists from the biological perspective study the links between our biology and our behavior & mental processes.

what is the cell body (soma)?

the part of the neuron that contains the nucleus

the life-support center

what are the dendrites?

bushy, branched extensions that receives & combines messages from other neurons

transmits those impulses towards the cell body (soma)

what is the axon?

attached to the soma

the long cable of a neuron that helps passes messages from the soma down to other neurons, muscles, or glands

(acts like a highway)

what is the myelin sheath?

the insulating fatty tissue layer that covers the axon of some neurons

helps speed the transmission of neural impulses

(protective covering - the pink parts in the pic )

what is myelin and why is it so important?

myelin is a protective covering that wraps around the axon of neurons. it’s so important because deterioration of the myelin sheath can lead to motor impairments, like multiple sclerosis.

at birth, babies haven’t myelinated the axons of their neurons. the development of the myelin sheath (not complete until around age 25) is crucial to Behavior, Movement, and Thought.

what are the terminal branches?

the ends of the axon containing terminal buttons. it converts electrical signals into chemical ones

the “roads” that allow a neuron to communicate with other neurons

what are glial cells?

cells that support, nourish, & protect neurons to help them function properly

they play a role in learning, thinking, & memory

the most abundant cells in the Central Nervous System (CNS)

how is a neural impulse generated?

a neural impulse is generated when a neuron reaches its minimum threshold. once the threshold is hit, the neuron triggers an action potential, the electrical impulse that travels down its axon

chemical → electrical signals process

neurotransmitters that are involved in learning & memory?

acetylcholine (ACh)

glutamate

neurotransmitters involved in movement?

acetylcholine (ACh)

dopamine

neurotransmitters involved in mood?

seratonin

endorphins

feel-good neurotransmitter, influences motivation & goal-directed behavior, cognition

dopamine

neurotransmitter that regulates your appetite & digestion

seratonin

neurotransmitters involved in pain perception?

endorphins

substance P

a major inhibitory neurotransmitter, reduces your brain activity making it less likely for a neuron to fire

GABA (gamma amino butyricacid)

major excitatory neurotransmitter, increases brain activity making it more likely for a neuron to fire

glutamate

neurotransmitter that gives you feelings of euphoria & pleasure, can reduce the body’s stress response

endorphins

neurotransmitter that is released in fight or flight response, wakefulness & alert neurotransmitter (adrenaline), also a hormone!

norepinephrine

neurotransmitter that promotes inflammation in response to injury, regulates emotion & social behavior

substance P

schizophrenia = too much of…

dopamine

too little acetylcholine (ACh) =

alzheimers (memory loss)

myasthenia gravis (muscle weakness)

too little dopamine =

parkinsons disease (problems with moving your body)

ADHD

too much dopamine =

schizophrenia

euphoria, difficulty sleeping, overly-energized

too much norepinephrine =

stress

anxiety

bipolar disorder

too much GABA =

drowsiness

impaired cognition (reduced brain activity)

too much glutamate =

seizures

migraines

too little GABA?

insomnia, seizures, chronic pain

MRI

best for structural imaging

use it when: you want detailed images of brain anatomy, like looking for tumors, brain injuries, or structural abnormalities

fMRI

best for brain activity

use it when you wanna see which parts of the brain are active during specific tasks, like thinking or moving. great for research on brain functions!

EEG

best for electrical activity

use it when you need to measure brain waves & electrical activity. super useful for diagnosing conditions like epilepsy or sleep disorders.

PET

best for metabolic processes

use it when: you wanna see how the brain uses glucose & other substances. often used in cancer diagnosis & to study brain disorders.

CT

best for quick structural imaging

use it when: you need a fast way to look for bleeding, fractures, or tumors, especially in emergency situations

MEG

best for magnetic fields

use it when: you want to measure the magnetic fields produced by brain activity. great for recording brain functions w/ high precision & high temporal resolution

selective permeable

a membrane allows certain substances to pass through while blocking others (like a concert bouncer)

- helps maintain right balance of ions inside & out the cell