Brain and Cognition

rostral / anterior

the front

caudal / posterior

the back

dorsal / superior

the top

ventral / inferior

the bottom

medial

towards middle

lateral

towards side

axial / transverse cross section

horizontal

sagittal cross-section

vertical / between eyes

coronal cross section

split between front to back

central nervous system

brain and spinal cord

peripheral nervous system

nerves that project out of spinal cord

autonomic nervous system

unconscious processes (glands, muscles)

somatic nervous system

allows us to sense/respond to environment

4 layers of protection for the brain

• skull

• cerebrospinal fluid

• meninges

• blood-brain barrier

cerebrospinal fluid (salty liquid)

removes metabolic waste and cushions sudden impact

meninges

3 membranes that cover brain and spinal cord

the 3 membranes of the meninges

pia mater, dura mater, arachnid mater

blood-brain barrier

tightly packed barrier within blood vessels that prevent pathogens from entering

commissures

white matter pathways that connect both hemispheres

grey matter

outside of cerebral cortex; neuronal cell bodies and dendrites (40%)

white matter

inside cerebral cortex; covered in myelin for protection (60%)

corpus callosum

structure that connects/sends signals between both hemispheres

difference between grey and white matter in SPINAL CORD

the white matter is on the outside, the grey matter is on the inside

spinal cord

densely packed bundle of nerve fibers; transmits messages from sensory and motor neurons

gyri and sulci

folds in brain (gyrus is peak, sulcus is valley)

fissures

large sulci that separate hemispheres and/or lobes

longitudinal fissure

separates left from right

lateral/Sylvian fissure

separates frontal and temporal lobe

central fissure

separates frontal from parietal lobe

Parieto-occipital sulcus

separates parietal from occipital lobe

Precentral/postcentral gyrus

surrounds central fissure

Superior temporal gyrus

surrounds lateral fissure

Cingulate gyrus

surrounds corpus callosum

how many cortical layers of grey matter?

6

how many brodmann areas?

52

localized theory

specific areas control different aspects of behavior

not localized theory

brain acts as a single functional unit

sparse representation theory

specific function has a strong activation of a relatively small set of neurons

distributed representation theory

specific function is coded by its unique pattern of activity over a large group of neurons widely distrubuted in the brain (neural networks)

lateralization

split between two hemispheres

left brain abilities

• verbal abilities

• speech

• math/logic

right brain abilities

• spatial relations

• mental imagery

• music/art abilities

• faces

• overall picture

contralateral control of movement

crossover of information from the CNS to the PNS (left controls right, right controls left)

visual field

info from each retina is passed to the opposite side of the brain by the optic nerve

4 lobes of the brain

• frontal

• parietal

• temporal

• occipital

frontal lobe main purpose

executive function (judgement, decision making, planning, problem solving, self control, etc)

what is the frontal lobe made of?

• prefrontal cortex

• premotor cortex

• primary motor cortex

• broca’s area

prefrontal cortex

controls cognitive processes, judgement, and behavior

phineas gage suffered damage to his _____

prefrontal cortex

premotor cortex

selection of appropriate motor plans for voluntary motion

primary motor corte

control of body’s skeletal muscles to produce voluntary movement (executes plan of premotor cortex)

broca’s area

speech production

cortical homunculus

parts of the body with the most function have a larger portion of brain allocated to them, regardless of their size

temporal lobe

hearing/understanding

what is the temporal lobe made of?

• primary auditory cortex

• wernicke’s area

primary auditory cortex

receives and processes pitch and volume; receives impulses from hair cells in cochlea through the auditory nerve

wernicke’s area

understanding speech and language

double dissociation

when two processes are shown to function independently to each other and localized in two separate brain regions (ex. speech production vs comprehension)

parietal lobe

perception and integration of sense

what is the parietal lobe made of?

• somatosensory cortex

somatosensory cortex

receives and processes senses in the body (except for hearing and vision)

proprioception

gauging where you are in relation to the world around you

occipital lobe

vision

what is occipital lobe made of?

• primary visual cortex

primary visual cortex

processing vision, such as depth, color, size, and motion via optic nerve impulses

amygdala

emotions, fight or flight, fear**

hippocampus

memory/recollection of events

hypothalamus

hormones and temperature control

thalamus

everything—receives and relays all info in the brain

brainstem

subconscious life functions

cerebellum

posture, balance, coordination, tone of body

Neurotransmitters

chemical messengers that allow signals to be sent between neurons

neurons

cells that transmit info of the nervous system

glial cells

cells that offer structural support to neurons, and modulate neuronal activity

sensory neurons

carry messages from organs to spinal cord and brain

afferent neurons (sensory)

carry signals from sensory receptors to CNS

ganglia

clusters of afferent neurons

motor neurons

transmit impulses from brain and spinal cord to muscles and organs

efferent neurons (motor)

connected to tissues that respond according to what was detected

interneurons

perform connective or associative functions between neurons

associative neurons (inter)

receive incoming signals from sensory neurons and out coming signals to neurons responsible for the response

what do neurons sit in

extracellular fluid

cytoplasm

salty intracellular fluid made up of ions, molecules, and proteins

neuronal membrane

two layers of lipid/fat (phospholipids); water-repelling

3 main parts of a neuron

• soma

• dendrites

• axons

soma

cell body; metabolic machinery that maintains the cell (nucleus, organelles, etc)

dendrites

receives messages from neighboring neurons and sends them to the soma

axons

conducts electrical impulses away from cell body to other neurons, muscles, or glands

myelin

fatty substance that wraps axons

nodes of ranvier

gaps in myelin

synapse

structure at axon terminal where chemical or electric signals can be passed

presynaptic neuron

departure neuron that sends message

post-synaptic neuron

arrival station neuron that receives info

myelin sheath

fatty layer that insulates the axon os they send signals efficiently

CNS glial cells purpose

manage inflammation, create myelin sheath, etc

CNS glial cell types

• astrocytes

• microglia

• oligodendrocytes

PNS glia type

• schwann cells

resting potential mV value

70 mV

resting potential

at rest, neurons are more negative INSIDE the cell so ae POLARIZED

Na+ and K+ at resting potential

• more Na+ outside

• more K+ inside