3 primary divisions: –Forebrain cortex (folded stuff) limbic system, etc (stuff around brain stem) –Midbrain (top of brainstem) –Hindbrain (bottom of brainstem + cerebellum ) The Brain

Hindbrain Medulla Pons Cerebellum unix.oit.umass.edu/~psyc335c/lectures/hindbrain.gif Pons Medulla Cerebellum

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 medulla…why…?...b/c receptors there!

Pons: Also has cranial nerves Location of axon decussation (where axons cross from one side of the brain to the other…so left brain controls right body and vice versa) Reticular formation: motor control, arousal, consciousness

Midbrain: Cerebral aqueduct More cranial nerves Superior colliculus (visual info) Inferior colliculus (auditory info) Substantia nigra: dopamine- producing cells, structure that is lost in Parkinson’s Disease

Brainstem Medulla Pons Midbrain Some forebrain structures

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

Cranial Nerves cranial_nerves.jpg Table 4.4, page 87 Olfactory nerve: Smell

Cranial Nerves cranial_nerves.jpg Table 4.4, page 87 Optic nerve: Vision

Cranial Nerves cranial_nerves.jpg Table 4.4, page 87 Occulomotor nerve: Eye movement, pupil constriction

Cranial Nerves cranial_nerves.jpg Table 4.4, page 87 Trochlear nerve: Eye movement

Cranial Nerves cranial_nerves.jpg Table 4.4, page 87 Trigeminal nerve: Skin senses from face Jaw muscles for chewing and swallowing (muscles of mastication)

Cranial Nerves cranial_nerves.jpg Table 4.4, page 87 Abducens nerve: Eye movements

Cranial Nerves cranial_nerves.jpg Table 4.4, page 87 Facial nerve: Taste Facial expressions Crying Salivation Dilation of head’s blood vessels

Cranial Nerves cranial_nerves.jpg Table 4.4, page 87 Acoustic nerve: Aka vestibulocochlear or statoacoustic Hearing Equilibrium

Cranial Nerves cranial_nerves.jpg Table 4.4, page 87 Glossopharynge al nerve: Taste Swallowing Salivation Throat movements during speech

Cranial Nerves cranial_nerves.jpg Table 4.4, page 87 Vagus nerve: Sensation from neck and thorax Control of throat, esophagus, larynx Parasympathetic nerves to stomach, intestines, etc

Cranial Nerves cranial_nerves.jpg Table 4.4, page 87 Spinal accessory nerve: Aka Accessory nerve Neck and shoulder movements

Cranial Nerves cranial_nerves.jpg Table 4.4, page 87 Hypoglossal nerve: Muscles of tongue

Cranial nerve signs help determine the location of a lesion in the brain Essential element in clinical neuroanatomy Neurological exam: examination.shtml Example: 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 OldOlfactorySay OlympusOcculomotorMarry = motor ToweringTrochlearMoney TopsTrigeminalBut = both (S&M) AAbducensMy FinFacialBrother AndAcoustic*Says GermanGlossopharyngealBad ViewedVagusBoys SomeSpinal accessory**Marry HopsHypoglossalMoney * Acoustic-vestibulocochlear, stateocochlear ** Spinal accessory = accessory

Forebrain Thalamus Hypothalamus Pituitary gland Basal ganglia Basal forebrain Hippocampus Limbic system

Thalamus: Relay station for all sensory info on its way to brain (except olfactory info) Many specialized nuclei (ex: LGN, MGN…don’t have to know these!)

Hypothalamus Communicates with pituitary gland to alter hormone release Involved in feeding, drinking, temperature regulation, sexual behavior, fighting, arousal (activity level)…4 Fs

Pituitary gland Endocrine gland (hormone producing) Attached to base of hypothalamus by stalk Makes and releases hormones into bloodstream

Basal Ganglia Motor control, but also memory and emotional expression Lose dopamine neurons in SN  Parkinson’s Disease Lose dopamine neurons in caudate & putamen  Huntington’s chorea thalamus.wustl.edu/ course/cbell6.gif Don’t memorize image!!! Just understand that this is a very complex system!

ssary/basalforebrain.jpg Basal forebrain Anterior and dorsal to hypothalamus Important for arousal, wakefulness, attention Lose cells in nucleus basalis  decreased attention & intellect (AD, PD)

press.com/Perennial_Tradition/hippocampus.gif Hippocampus Memory formation HM: temporal lobes removed for intractable epilepsy  no longer formed new memories

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

Ventricles Contain cerebrospinal fluid (CSF) CSF reabsorbed into blood vessels, so continuous turnover Protective Reservoir for hormones, nutrients

Ventricle size can indicate problems Enlarged ventricles as in Alzheimer’s patients (cell loss). Lack of ventricles due to tumors etc.

Cortex 2 hemispheres –Communicate via corpus callosum & anterior commisure 4 lobes

6 laminae (layers of cells)

The lobes of the cortex Frontal –Thinking –Prefrontal cortex Planning Working memory Socially appropriate behavior Delayed-response task Lobotomies –Primary motor cortex Broca’s aphasia

The lobes of the cortex Parietal –Sensing Primary sensory cortex

Homunculus

The lobes of the cortex Temporal –Spoken language comprehension Wernike’s aphasia –Hearing –Vision Movement perception Face recognition –Emotional motivational behavior

The lobes of the cortex Occipital –Vision Primary visual cortex Damage 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 chimpanzees Changes 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).

Functions Forebrain –the cool stuff (thinking, perceiving, big part of emotion) Midbrain –sensory pathways Hindbrain –motor control, reflexes (breathing, heart rate, etc)