Exam 2: Central Nervous System, Language Centers, Rhythms, Memory

Neurons can be classified by their

shape, function (or what they are connected to), and by the neurotransmitter they release

Multipolar neuron is the

most common neuron categorized by shape (dendrites-cell body-axon-terminal)

Bipolar neuron is a

rare, sensory neuron categorized by shape (dendrites-axon-cell body-axon-terminal)

Unipolar neuron is a

sensory neuron in the skin categorized by shape (dendrites-axon-extended cell body-terminal)

Sensory neurons detect

changes from the external environment: touch, light, sight, sound, pain, danger, temperature

Interneurons detect

signals and neurotransmitters transmitted by other neurons (inbetween neurons)

Motor neurons receive

instructions from the brain and spinal cord and carry those signals away to command muscles and glands to contract or react

Glutamatergic neurons release the neurotransmitter

glutamate

Glutamate is an

amino acid and the most abundant excitatory neurotransmitter in the body

GABAergic neurons release the neurotransmitter

GABA

What is GABA?

a molecule derived from glutamate and is the most abundant inhibitory neurotransmitter in the body

Glutamate is the most abundant

excitatory neurotransmitter in the body

GABA is the most abundant

inhibitory neurotransmitter in the body

The nervous system is a giant network of all the

interconnected neurons in your body

The entire nervous system is divided into the

Central NS and the Peripheral NS

The Central Nervous system includes the

spinal cord, brain stem, cerebellum, and cerebrum

The spinal cord is like a

information “super highway” for both sensory and motor information going up to and down from the higher brain centers

The spinal cord controls

basic motor programs

Locomotion and reflexes are controlled by the

spinal cord

The brain stem includes

the pons and medulla

The brain stems controls

vital functions like breathing and blood pressure

The cerebellum “little brain“ controls

balance and coordination

The cerebellum “little brain“ creates, stores, and modifies

complex motor programs

Throwing a baseball, playing the piano, typing are controlled by

the cerebellum “little brain“

The cerebrum is the

site of higher brain functions

Consciousness, emotion, memory, processing sensory are controlled by

the cerebrum

The cerebrum has … on … hemisphere

four lobes; each of the left and right

The outer covering of the cerebrum is called the

cortex “bark“

The cerebrum is the site of

higher brain functions such as consciousness, emotion, memory, and processing sensory info

The frontal lobe consists of the

prefrontal cortex, premotor cortex, and the primary motor cortex

The Prefrontal Cortex is responsible for

higher brain functions like logic, reason, and decision-making

Damage to the prefrontal cortex can cause

disruptions in planning, organizing, impulsivity, and personality changes

The Premotor cortex is responsible for

planning motor movement and send it to the primary motor cortex

Damage to the premotor cortex can cause

disrupts the brain's ability to plan, sequence, and execute complex voluntary movements, even though the primary motor cortex and individual muscle fibers may still function

The primary motor cortex is responsible for

sending motor signals down the spinal cord to the appropriate muscles

Damage to the primary motor cortex can cause

muscle weakness, paralysis, stiffness, and lost of fine/precision movement and dexterity

The parietal lobe consists of the

primary Somatosensory Cortex and the Somatosensory Association Cortex

The Primary Somatosensory Cortex is responsible for

providing basic, raw awareness where and what kind of physical sensation is occurring

Damage to the Primary Somatosensory Cortex can cause

inability to feel/detect bodily sensations/changes from external environment

Somatosensory Association Cortex is responsible for

receives processed signals from S1 and integrates them with memory and other sensory modalities

Allows for higher-level recognition, such as identifying an object by its shape and texture through touch alone (stereognosis) or forming a complete sense of body image

Example of Somatosensory Association Cortex

Damage to Somatosensory Association Cortex can cause

inability to recognize objects by touch; neglect syndrome ignoring specific regions of one's own body or space

The temporal lobe consists of the

Primary Auditory Cortex and the Auditory Association Cortex

The Primary Auditory Cortex is responsible for

basic processing of raw acoustic features such as pitch, loudness, volume, timbre, and initial sound localization

Damage to the Primary Auditory Cortex can lead to

subtle hearing loss or difficulty localizing sounds

The Auditory Association Cortex is responsible for

integrating basic sound features into meaningful, complex perceptions like speech, melodies, and environmental noises, linking them to memory, context, and past experiences

If the Auditory Association Cortex is damaged

a person may physically hear sounds and words but can not link them to meaning

The occipital lobe consists of the

Primary Visual Cortex and the Visual Association Cortex

The Primary Visual Cortex is responsible for

processing raw visual sights

If the Primary Visual Cortex is damaged, this causes

permanent vision loss; inability to process depth and color

The Visual Association Cortex is responsible for

putting what we see into context and add meaning to it

Damage to the Visual Association Cortex results in the

inability to recognize objects, faces, or motions despite clear sight

The thalamus is considered a

sensory relay station

In the thalamus, all sense except … first comes through it before being sent out to the appropriate primary sensory cortex

smell

The thalamus can filter out

what is deemed as unimportant stimuli so that you don’t get overwhelmed with sensory information

Broca’s area of the brain determines

how to move the mouth, tongue, lips, lungs, etc., to make the sounds associated with a thought, and how to write letters to form words associated with a thought

Damage to Broca’s area results in a condition called

expressive aphasia

What is expressive aphasia?

can understand what people are saying, but can not express themselves in language to others

Wernicke’s area of the brain determines

what sound combinations or letters combinations correspond with different thoughts and ideas

Damage to Wernicke’s area results in a condition called

receptive aphasia

What is receptive aphasia?

they can express their thoughts in language, but can not understand other’s language

Broca’s area hint

I am broken and can not express myself

Wernicke’s area hint

Who can not understand others

The body has an internal clock with a …. circadian rhythm

24-hour cycle

Circadian rhythm affects

nearly all physiological variables in the body

Hormone levels, ion concentrations, temperature, digestive functions, and immunes systems are affected by the

circadian rhythm

The term circadian comes from the Latin “circa diem“ meaning

about one day

Growth hormones are fairly low throughout the day then…

spike at night

Melatonin is produced by the

pineal gland

In the day, melatonin levels fall…

promoting wakefulness

As night approaches, melatonin production increases

boosting blood levels and causing drowsiness

The internal clock is located in the part of the hypothalamus called the

suprachiasmatic nucleus (SCN)

The suprachiasmatic nucleus (SCN) got its name because it is located

right above where the portions of the optic nerves cross called the optic chiasm

Neurons in the SCN have a negative feedback loop in which

DNA —>time keeping protein —> builds up in cell —> enters cell proteins to stop them from producing more of themselves —> time-keeping protein breaks down and level drop back down —> genes coding no longer blocked (goes back to step 1)

What is step 1 of the Neurons in the SCN with a negative feedback loop?

Genes of the cell’s DNA are read to make time-keeping proteins

What is step 2 of the Neurons in the SCN with a negative feedback loop?

The time-keeping protein levels build up in the cell

What is step 3 of the Neurons in the SCN with a negative feedback loop?

The proteins enter the nucleus and block the genes that coded for them, stopping further production

What is step 4 of the Neurons in the SCN with a negative feedback loop?

The time-keeping proteins are slowly broken down and their levels drop back down

What is step 5 of the Neurons in the SCN with a negative feedback loop?

The genes coding for the time-keeping proteins are no longer blocked by the proteins (go back to step 1)

The he inherent negative feedback cycle of the time-keeping proteins in neurons of the SCN

does not always take exactly 24 hrs (can be longer or shorter)

The inherent negative feedback loop is also known as

a person’s free-running state

The inherent negative feedback loop is when there is no

external stimuli (e.g., light, noise, etc.) affecting the neurons of the SCN

Light and dark are the most powerful adjusters of the

internal clock

Memory

the brain’s ability to store, retain, and recall information

What are the two types of memory?

short term and long term

Short-term memory

holds information for a short period, like a few seconds or minutes

Long-term memory

stores information for extended periods

How many types of long-term memory are there?

declarative and non-declarative

Declarative long-term memory

is conscious recall of facts and events

Remembering dates, facts, and events are examples of

declarative memory

Non-declarative long-term memory

is unconscious recall of skills

Muscle memory of sports, driving a bike/car, playing an instrument are all examples of

non-declarative memory

Consolidation

short-term memories important/repeated enough to be moved to long-term memory

Memory storage has a prevailing idea that memories are stored via

the making/strengthening connections between neurons/synapses in the brain

In memory storage, different neurons will

fire action potential associated with different things or ideas —> all interconnected in the brain

Memory experience is experienced/recalled only if

that sensory input is memorable enough to cause groups of neurons to fire and signal/connect with each other

Neurons that fire together…

wire together

Simultaneous activation of neurons leads to

pronounced increases in synaptic strength between those neurons

Amnesia

is the inability to remember memories

What are the different types of amnesia?

retrograde and anterograde