The Brain3 primary divisions:Forebraincortex (folded stuff)limbic system, etc (stuff around brain stem)Midbrain (top of brainstem)Hindbrain (bottom of brainstem + cerebellum)

HindbrainMedullaPonsCerebellumhttp://www-unix.oit.umass.edu/~psyc335c/lectures/hindbrain.gifPonsMedullaCerebellum

Medulla:Controls vital reflexes: breathing, heart rate, vomiting, salivation, coughing, sneezing - Via cranial nerves

Damage to medulla can be fatal

Large doses of opiates can be fatal b/c suppress activity of medullawhy?...b/c receptors there!

Pons:Also has cranial nerves

Location of axon decussation (where axons cross from one side of the brain to the otherso left brain controls right body and vice versa)

Reticular formation: motor control, arousal, consciousness

Midbrain:Cerebral aqueductMore cranial nervesSuperior colliculus (visual info)Inferior colliculus (auditory info)Substantia nigra: dopamine-producing cells, structure that is lost in Parkinsons Disease

http://en.wikipedia.org/wiki/Midbrain

BrainstemMedullaPonsMidbrainSome forebrain structures

Senses: Information comes in the cranial nerves and eventually ends up in the cortex

Cranial Nerveshttp://www.besthealth.com/besthealth/bodyguide/reftext/images/cranial_nerves.jpgTable 4.4, page 87Olfactory nerve:Smell

Cranial Nerveshttp://www.besthealth.com/besthealth/bodyguide/reftext/images/cranial_nerves.jpgTable 4.4, page 87Optic nerve:Vision

Cranial Nerveshttp://www.besthealth.com/besthealth/bodyguide/reftext/images/cranial_nerves.jpgTable 4.4, page 87Occulomotor nerve:Eye movement, pupil constriction

Cranial Nerveshttp://www.besthealth.com/besthealth/bodyguide/reftext/images/cranial_nerves.jpgTable 4.4, page 87Trochlear nerve:Eye movement

Cranial Nerveshttp://www.besthealth.com/besthealth/bodyguide/reftext/images/cranial_nerves.jpgTable 4.4, page 87Trigeminal nerve:Skin senses from faceJaw muscles for chewing and swallowing (muscles of mastication)

Cranial Nerveshttp://www.besthealth.com/besthealth/bodyguide/reftext/images/cranial_nerves.jpgTable 4.4, page 87Abducens nerve:Eye movements

Cranial Nerveshttp://www.besthealth.com/besthealth/bodyguide/reftext/images/cranial_nerves.jpgTable 4.4, page 87Facial nerve:TasteFacial expressionsCryingSalivationDilation of heads blood vessels

Cranial Nerveshttp://www.besthealth.com/besthealth/bodyguide/reftext/images/cranial_nerves.jpgTable 4.4, page 87Acoustic nerve:Aka vestibulocochlear or statoacousticHearingEquilibrium

Cranial Nerveshttp://www.besthealth.com/besthealth/bodyguide/reftext/images/cranial_nerves.jpgTable 4.4, page 87Glossopharyngeal nerve:TasteSwallowingSalivationThroat movements during speech

Cranial Nerveshttp://www.besthealth.com/besthealth/bodyguide/reftext/images/cranial_nerves.jpgTable 4.4, page 87Vagus nerve:Sensation from neck and thoraxControl of throat, esophagus, larynxParasympathetic nerves to stomach, intestines, etc

Cranial Nerveshttp://www.besthealth.com/besthealth/bodyguide/reftext/images/cranial_nerves.jpgTable 4.4, page 87Spinal accessory nerve:Aka Accessory nerveNeck and shoulder movements

Cranial Nerveshttp://www.besthealth.com/besthealth/bodyguide/reftext/images/cranial_nerves.jpgTable 4.4, page 87Hypoglossal nerve:Muscles of tongue

Cranial nerve signs help determine the location of a lesion in the brainEssential element in clinical neuroanatomyNeurological exam: http://www.vhct.org/case1799/neurologic_examination.shtmlExample: patient is asked to stick out tongue. If the tongue deviates to the left, the lesion involves the nucleus of the left hypoglossal nerve.

Nerve keyNerveType of function

OnOpticSome = sensory OldOlfactorySayOlympusOcculomotorMarry = motorToweringTrochlearMoneyTopsTrigeminalBut = both (S&M)AAbducensMyFinFacialBrotherAndAcoustic*SaysGermanGlossopharyngealBadViewedVagusBoysSomeSpinal accessory**MarryHopsHypoglossalMoney* Acoustic-vestibulocochlear, stateocochlear** Spinal accessory = accessory

ForebrainThalamusHypothalamus Pituitary glandBasal gangliaBasal forebrainHippocampusLimbic system

Thalamus:Relay station for all sensory info on its way to brain (except olfactory info)Many specialized nuclei (ex: LGN, MGNdont have to know these!)

HypothalamusCommunicates with pituitary gland to alter hormone releaseInvolved in feeding, drinking, temperature regulation, sexual behavior, fighting, arousal (activity level)4 Fs

Pituitary glandEndocrine gland (hormone producing)Attached to base of hypothalamus by stalkMakes and releases hormones into bloodstream

http://www.uni.edu/walsh/basalganglia-2.jpgBasal GangliaMotor control, but also memory and emotional expressionLose dopamine neurons in SN Parkinsons DiseaseLose dopamine neurons in caudate & putamen Huntingtons choreathalamus.wustl.edu/ course/cbell6.gif Dont memorize image!!! Just understand that this is a very complex system!

http://memorylossonline.com/summer2003/glossary/basalforebrain.jpgBasal forebrainAnterior and dorsal to hypothalamus Important for arousal, wakefulness, attentionLose cells in nucleus basalis decreased attention & intellect (AD, PD)

http://www.hermes-press.com/Perennial_Tradition/hippocampus.gifHippocampusMemory formationHM: temporal lobes removed for intractable epilepsy no longer formed new memorieshttp://www.umassmed.edu/bnri/graphics/crusiofig1.gif

important for motivated & emotional behaviors (eating, drinking, sexual activity, aggressive behavior) Limbic System

Ventricleshttp://mywebpages.comcast.net/epollak/PSY255_pix/ventricles.PNGContain cerebrospinal fluid (CSF)CSF reabsorbed into blood vessels, so continuous turnoverProtectiveReservoir for hormones, nutrients

Ventricle size can indicate problemsEnlarged ventricles as in Alzheimers patients (cell loss).

Lack of ventricles due to tumors etc.

Cortex2 hemispheresCommunicate via corpus callosum & anterior commisure4 lobes

http://pegasus.cc.ucf.edu/~Brainmd1/brmodelc.gifhttp://www.urmc.rochester.edu/neuroslides/slides/slide201.jpghttp://trc.ucdavis.edu/mjguinan/apc100/modules/Nervous/grosscns/images/brain10.jpg

6 laminae (layers of cells)

The lobes of the cortexFrontalThinkingPrefrontal cortexPlanningWorking memorySocially appropriate behaviorDelayed-response task LobotomiesPrimary motor cortexBrocas aphasia

The lobes of the cortexParietalSensingPrimary sensory cortex

Homunculus

The lobes of the cortexTemporalSpoken language comprehensionWernikes aphasia HearingVision Movement perceptionFace recognitionEmotional motivational behavior

The lobes of the cortex

Occipital VisionPrimary visual cortexDamage causes cortical blindness

Evolution of Gene Related to Brain's Growth A gene that helps determine the size of the human brain has been under intense Darwinian pressure in the last few million years.It has changed its structure 15 times since humans and chimps separated from their common ancestor. Evolution has been particularly intense in the five million years since humans split from chimpanzeesChanges in the architecture of the ASPM protein over the last 18 million years are correlated with a steady increase in the size of the cerebral cortex (2002) Dr. Bruce T. Lahn at U. Chicago. A disrupted form of this gene was identified as the cause of microcephaly (people born with an abnormally small cerebral cortex).

FunctionsForebrainthe cool stuff (thinking, perceiving, big part of emotion)Midbrainsensory pathwaysHindbrainmotor control, reflexes (breathing, heart rate, etc)