Contains several bilateral nuclei, named for location

◦Nuclei project and receive fibers from cerebral cortex

act as relay station for information coming into cortex

 Overall, it acts to mediate sensation, motor activities, cortical arousal, learning, and memory

Sorts, edits, and relays ascending input such as:

◦Impulses from hypothalamus for regulating emotion and visceral function

◦Impulses from cerebellum and basal nuclei to help direct motor cortices

◦Impulses for memory or sensory integration

Located below thalamus

 Infundibulum: stack that connects to pituitary gland

Controls endocrine system functions such as:

◦Secretions of anterior pituitary gland

◦Production of posterior pituitary hormones

Main visceral control and regulating center that is vital to homeostasis

◦Controls autonomic nervous system

Examples: blood pressure, rate and force of heartbeat, digestive tract motility, pupil size

◦Initiates physical responses to emotions

◦Part of limbic system: perceives pleasure, fear, rage, biological rhythms, and drives (sex drive)

What regulates

Body temperature: sweating or shivering

◦Hunger and satiety in response to nutrient blood levels or hormones

◦Water balance and thirst

◦Sleep-wake cycles

Which one causes these disorders

Severe body wasting

◦Obesity

◦Sleep disturbances

◦Dehydration

◦Emotional imbalances

Can be damaged by tumors, radiation, surgery or trauma

 Most dorsal portion of diencephalon

 Contains pineal gland (body)

◦Secretes melatonin that helps regulate sleep-wake cycle

Midbrain

Pons

Medulla oblongata

 Similar in structure to spinal cord but contains nuclei embedded in white matter

 Controls automatic behaviors necessary for survival

 Contains fiber tracts connecting higher and lower neural centers

Located between diencephalon and pons

 Cerebral peduncles

 Cerebral aqueduct

 Periaqueductal gray matter

 Substantia nigra

Parkinson's disease is degeneration of this area

two ventral bulges that contain pyramidal motor tracts

channel running through midbrain that connects third and fourth ventricles

nuclei that play a role in pain suppression and fight-or-flight response

functionally linked to basal nuclei

 Located between midbrain and medulla oblongata

 Composed of conduction tracts:

◦Longitudinal fibers connect higher brain centers and spinal cord

◦Transversal/dorsal fibers relay impulses between motor cortex and cerebellum

 Some nuclei play role in reticular formation, and some help maintain normal rhythm of breathing

 Blends into spinal cord at foramen magnum

 Contains fourth ventricle

◦Continuation of central canal of spinal cord

Contains choroid plexus:

capillary-rich membrane that forms cerebral spinal fluid

Pyramids

Decussation of the pyramids

Olives

Vestibular and cochlear nuclei

two ventral longitudinal ridges formed by pyramidal tracts from motor cortex

point where pyramidal tracts cross over to opposite side of body

swellings caused by underlying inferior olivary nuclei that relay stretch information from muscles and joints to cerebellum

mediate responses that maintain equilibrium

is an autonomic reflex center

◦Many functions overlap with hypothalamus

Hypothalamus relays instructions via medulla

Cardiovascular center, respiratory center, reflexes

What functional group is this in the medulla

Cardiac center adjusts force and rate of heart contraction

◦Vasomotor center adjusts blood vessel diameter for blood pressure regulation

What functional group is this in the medulla

◦Generate respiratory rhythm

◦Control rate and depth of breathing (with pontine centers)

What functional group is this in the medulla

Vomiting, Hiccupping, Swallowing, Coughing, Sneezing

 11% of brain mass

 Processes input from cortex, brain stem, and sensory receptors to provide precise, coordinated movements of skeletal muscles

 Plays a major role in balance

 Cerebellar hemispheres connected by wormlike vermis

 Folia: transversely oriented gyri

 Contains thin cortex of gray matter with distinctive treelike pattern of white matter called arbor vitae

 Purkinje fibers projecting from the cerebellar cortex synapse within the cerebellum for motor coordination

 Cerebellar homunculi show sensory maps of entire body

Receives impulses from cerebral cortex of intent to initiate voluntary muscle contraction

Receives signals from proprioceptors throughout body, as well as visual and equilibrium pathways that:

◦Pathways continuously “inform” cerebellum of body’s position and momentum

Cerebellar cortex calculates the best way to smoothly coordinate muscle contraction

Sends “blueprint” of coordinated movement to cerebral motor cortex and brain stem nuclei

plays role in thinking, language, and emotion

 As it does for motor processes, it may compare actual output of higher functions with expected output and adjust accordingly

large part of emotional or affective brain

amygdala

cingulate gyrus

interacts with prefrontal cortex

◦Allows us to react emotionally to things we consciously understand to be happening

◦Makes us consciously aware of emotional richness in our lives

recognizes angry or fearful facial expressions, assesses danger, and elicits fear response

plays role in expressing emotions and behavior regulation

ends impulses to cerebral cortex to keep it conscious and alert

◦Filters out repetitive, familiar, or weak stimuli (~99% of all stimuli is not relayed to consciousness)

◦Inhibited by sleep centers, alcohol, drugs

◦Severe injury can result in permanent unconsciousness (coma)

Language

◦Memory

◦Brain waves and EEGs

◦Consciousness

◦Sleep and sleep-wake cycles

implementation system involves association cortex of left hemisphere

Broca's area

Wernicke's area

involved in speech production

Patients with lesions understand words, but cannot speak

involved in understanding spoken and written words

Patients with lesions can speak, but words are nonsensible

storage and retrieval of information

Declarative memory, procedural memory, motor memory, emotional memory

of facts (name, faces, words, dates)

◦of skills (playing piano)

memory of motor skills (riding a bike)

memory of experiences linked to an emotion (heart pounding when you hear rattlesnake)

What is these two stages of

Short-term memory

Long-term memory

temporary holding of information

◦Limited to seven or eight pieces of information

has limitless capacity

Emotional state

Rehearsal

Association

Automatic memory

best if alert, motivated, surprised, or aroused

repetition and practice

tying new information with old memories

subconscious information stored in LTM

What involves fitting new facts into categories already stored in cerebral cortex. SLEEP is important for this

Hippocampus, temporal cortical areas, thalamus, and prefrontal cortex are involved in

Damage to hippocampus or surrounding temporal lobe structures on either side result in only slight what?

 Bilateral destruction causes widespread amnesia

 consolidated memories are not lost, but new inputs are not associated with old one

◦Person lives in the here and now

◦Memory of conversations from just 5 minutes before would not be remembered

 loss of memories formed in the distant past

 reflect electrical activity of higher mental functions

◦Normal brain functions are continuous and hard to measure

records electrical activity that accompanies brain function

◦Used for diagnosing epilepsy and sleep disorders

◦Localizes lesions, tumors, infarcts, infections, abscesses

◦Used in research and also to determine brain death

◦Electrodes placed on scalp measure electrical potential differences between various cortical areas 

 measures patterns of neuronal electrical activity generated by synaptic activity in cortex

◦Each person's brain waves are unique

Patterns change with age, sensory stimuli, brain disease, and chemical state of body

 Hertz (Hz), numbers of peaks per second (1 Hz = 1 peak per second)

What four classes can measured waves be grouped into

(8–13 Hz)—regular and rhythmic, low-amplitude, synchronous waves indicating an “idling” brain

(14–30 Hz)—rhythmic, less regular waves occurring when mentally alert

(4–7 Hz)—more irregular; common in children and uncommon in awake adults

(4 Hz or less)—high-amplitude waves of deep sleep and when reticular activating system is suppressed, as during anesthesia; indicates brain damage in awake adult

torrent of electrical discharges by groups of neurons

prevent any other messages from getting through

Victim of may lose consciousness, fall stiffly, and have uncontrollable jerking

is not associated with intellectual impairments

occurs in 1% of population

◦Genetic factors play a role, but brain injuries, stroke, infections, or tumors can also be causes

◦Aura (sensory hallucination) may precede seizure

◦Absence seizures (formerly petit mal)

Mild seizures of young children: expression goes blank for few seconds

◦Tonic-clonic seizures (formerly grand mal)

◦Most severe; last few minutes

◦Victim loses consciousness, bones broken during intense convulsions, loss of bowel and bladder control, and severe biting of tongue

Involves simultaneous activity of large cortical areas

◦Superimposed on other neural activities

◦Holistic and totally interconnected

brief loss of consciousness

◦Most often due to inadequate cerebral blood flow

◦Due to low blood pressure or ischemia from hemorrhage or sudden, severe emotional stress

unconsciousness for extended period

◦Not the same as deep sleep; oxygen consumption is lowered

 irreversible coma

◦Ethical and legal issues surround decisions on whether person is dead or alive

 state of partial unconsciousness from which person can be aroused by stimulation

Cortical activity is depressed, but brain stem activitydoesn’t change

What are the two major types of sleep

 sleep disorder involving abrupt lapse into sleep from awake state

◦Cataplexy is a related condition where person can lose muscle tone while awake.

◦Orexins (hypothalmic “wake-up” chemicals) probably destroyed by patient’s  immune system; orexin replacement possible treatment

 chronic inability to obtain amount or quality of sleep needed, possibly caused by depression, anxiety, overuse of caffeine, computer/cell phone use too close to bedtime

◦May be treated by blocking orexin action