Interacts with external enviornment

-Afferent: to CNS, efferent: away from CNS

Regulates bodies internal enviornment

-Afferent: carry from internal organ to CNS, efferent: carry from CNS to internal organs

Type of motor Efferent nerve projects from CNS in lumbar and thoracic

-synapse on 2nd stage neuron far away from target organ

-NT: NE

Type of motor Efferent nerve, project from brain and sacral in lower back

-Synpase on 2nd neuron very close to target neuron

-NT: ACh

1. sympathetic - stimulate and mobilize energy in threatning situation, para conserves energy

2. Each autonomic target organ recieves input from both, activity controlled by relative levels of both

3. sympathetic changes indicate arousal, para indicate relaxation

12 pairs of nerves part of PNS but extend from brain

-Includes purely sensory (olifactory and optic) and longest (vagus nerve)

-Most are both sensory and motor

-commonly assesed as basis of diagnosis: excellent cues for tumors

Fine web-like membrane inside the dura mater

-contains subarachnoid space: large blood vessels and CSF

-Also protects CNS by filling subarachnoid space, central canal, and ventricles

-supports and cushions brain, painful if removed

-Continuosly produced by Choroid Plexouses

-If blocked by a tumor, walls in ventricles expland causeing hydrocephalus

-Networks of capilaries that protrude into ventricles form pia mater

-Continually produces CSF

-Cerebral blood vessel walls tightly packed

-Barrier that blocks passage of certain molecules, esp proteins and other big ones

-Some big ones pass through: glucose, sex hormones

System of folded membranes in cell body

-Rough: have ribosomes, play role in protein synthesis

-Smooth: synthesis of fats

Lipid bilayer with proteins embedded in it.

-Very small capilaries made up of 3 endothelial cells and no openings -> astrocytes on top

-Channel Proteins: allow certain molecules to pass

-Signal Proteins: Transfer signal inside when molecule binds to surface

-restricts entrance to immune cells

-lipid soluble can move across, not water soluble

-Viruses exist that dont need diffusion and can get to brain

-Shwann cells can repair damaged neurons by releasing tropic factors and tubules that facilitate growth

-Oli releases substances that inhibit repair rather than repair with mistakes: why CNS damage cant be corrected

-microglia: respond to injury or disease by muliplying than engulfing than causing inflamation

-largest glial cells, star shaped

-buffers and regulates chemicals needed for transmission

-Guides axon growth during prenatal development

-Helps form BBB

-Sends/recieves signals from other neurons and glial cells

-Coat slices of neural tissue with electron absorbing susbstance, than pass beam of electrons through

-Captures neural structures in great detail

-Scanning: Provides 3D view, but less magnification

-Anterograde: trace axons projecting away from cell bodies in an area

retrograde: Same method, but trace axons going into an area, from axon to cell body

Dorsal: Surface of back or top of head

Ventral: Surface of chest or bottom of head

-Spinal nerve axon's attached to horns via Dorsal root

-Dorsal root axons are sensory (afferent) unipolar neurons grouped together to form Dorsal Root Ganglia

-handles incoming sensory info

Neurons are motor (efferent) multipolar neurons with cell bodies in ventral horns.

-In somatic: project to skeletal muscles

-In autonomic: Project to ganglia

-Outgoing motor commands

-Controls fixed, stereotyped behaviors necessary for survival often below concious level (breathing, heart rate, etc)

-Largely same design for all animals, oldest structure

-Damage to these structures is often fatal, but very sensitive to drug effects

-Composed of: medulla, cerebellum, pons, reticular formation

-Complex system of 100 tiny nuclei that lie on central core of brain stem

-Plays role in arousal, and various other tasks

-Process first brain info coming in from diff systems

-Controls "startled responce", monitors surrounding while sleeping, not directly involved with conscious

Contralateral (Left effects Right) crossing of bundles of axons

-Connects cerebellum to higher structures

-Serves as a means to route information

-Very active during sleep - regulates muscle paralysis

-Autonomic activites (breathing heart rate etc.)

-Lies on top of spinal cord, many cranial nerves run along side

-In hindbrain

-produces seratonin, plays role in activation of sleep

-"the little brain" large convoluted structure on brains stems dorsal surface

-regulates fine motor coordination and learning

-aquires new motor patterns over time "remembers"

-highly sensitive to drug effects

-Ataxia: damage to cerebellum, impairment of precise control over own movements

Regulates movements in responce to auditory and visual stimulation

-processes sensory info and begins to use it to produce movements

-Composed of Inferior/superior colliculi, substantia nigra, ventral tegmental area

Visual functioning, in lower organisms purely visual

-Blindsight: blind people can still recieve input from visual circuit, but not linked to conciousness

Dopamine producing neurons that are important for reward.

3 structures of importance:

1. periaqueductal grey: grey matter situated around the (2) cerebral aqueduct - mediates pain reducing effects from opiates

(3) Substantia Nigra and red nucleus

Dopamine producing neurons important for movement

-Degeneration is associated with parkinson's disease

Enormous in humans, layout differentiates us form other animals

-Most complicated memory, learning and emotional responces, regulate most behaviors that are conscious

- 2 hemipsheres connected by the corpus callosum and anterior commisure

-Most recent structure, highest development in humans

-6 different layers, not uniform tissue, columnar organization, largely grey matter (cell bodies, decision makers)

-Divided by fissures into 4 lobes

-Often most damaged structure in traumas

-the lobes are NOT functional units, only divided due to folding in from pressure folding itself in during development.

-Large, 2 lobed structure that constitutes top of brain stem, joined by massa intermedia

-On surface is white lamina (myleinated axons)

-many different pairs of nuclei, most project to the cortex (sensroy relay nuclei)

-Process incoming sensroy information

-contains primary and multimodal nuclei

Recieve signals from sensory reeptors, process, than transmit to cortex.

-locaed in the thalamus

-Important for visual, somatosensroy and audity systems

-Not one way street, recieve signals from where they project

Contains number of distinc nuclei that controls bodies internal states

-important role in regulation of motivated behaviors

-regulates pituitary gland

-optic chiasm and mammilary bodies also lie on the hypothalamus

-Optic nerves from each eye are connected together

-x-shape due to axons decussate (cross to other side of brain)

-decussing fibers are contralateral

-fissures: large furrows in convoluted cortex

-Largest is Longitudinal fissure

-Central Fissure and Lateral fissure partially divide each hemisphere into 4 lobes

-Sulci: smaller ones

-gyri: ridges between fissures and sulci

-c.c. - tracts spanning the longitudinal fissure, largest is corpus callosum.

-Analysis of visual information to guide behavior, primary visual cortex

-located in the back of brain above cerebellum

-Involved in touch, muscle stretching, joint receptors

-Has 2 parts:

1. postcentral gyrus: Analyzes touch

2. Remaining posterior areas: perceiving lcations of objects and own bodies, directs attention

-Located above temporal lobe

Processes "tones" hearing, language and has 3 central areas:

1. Superior Temporal Gyrus:hearing and langurage

2. inferior temporal cortex: complex visual patterns

3. Medial portion: memory

-located below parietal and frontal lobes

-has 2 parts

1. precentral gyrus: motor functioning

2. frontal cortex anterior to motor cortex: complex visual patterns

-90% of human cerebral cortex, 6 layers of cortex that has been recently added to to evolution

-2 diff kinds of cortical neurons: 1. Pyramidal cells 2. stellate cells

-6 layers differ in size and density

-Many long axons and dendrite course vertically through it - Columnar Organization

Large multipolar neurons with pyramidal shaped bodies and large dendrite (apical dendrite)

-In neocortex, extends from top of pyramid to cortex surface, very long axon

-Small star shaped interneurons located in the neocrotex

One important area that is not neocortex

-Located on edge of cerebral cortex and fold back on itself

-Formation of long term memory

-Circuit of midline structures that circle the thalamus and includes a number of forebrain structures

-Amygdala, hippocampus, Fornix, septum, cingulate cortex all involved

-Involved in regulation of motivated behaviors - including "4 F's"

-Process motivated and emotional stimuli

In limbic system and basal ganglia, almond-shaped nucleus in anterior temporal lobe.

-Multi-sensory memory with emotional over tones.

-Feelings of pleasure, reward, euphoria

-Part of limbic circuit

-midline nucleus located at anterior tip of cingulate cortex

-part of limbic system

-large strip of cortex in the cingulate gyrus on medial surface of the cerebral hemishpere

Integrates limbic and cortical decisions and produce movements in voluntary motor responces

-Particular interest: pathway to striatum from substantia nigra assoicated with Parkinson's disease

-Nucleus accimbens: medial portion of ventral striatum