Chapter 3

• Central: 
• brain and spine

• Peripheral:
• outside of the skull and spine
• brings info into the CNS and carry signals out of the CNS
• *Somatic vs. autonomic ->afferent vs. efferent ->Sympathetic vs. Parasympathetic 

• Somatic: 
• Afferent (sensory)
• Efferent (motor)

• Autonomic:
• Afferent (sensory)
• Efferent (motor); Sympathetic vs. parasympathetic

Sensory nerves that travel to the CNS are Afferent

Motor nerves that travel away from the CNS are Efferent 

• two stages of neural paths, neuron exiting the CNS synapses on a second stage neuron before the target organ

• thoracic and lumbar
• fight or flight
• second stage neurons are far from the target organ

• cranial and sacral
• rest and restore
• second stage neurons are near the target organ

•        CNA          
•         ⇓
• Brain & Spine   

•                             PNS
•                                 ⇓
•            Somatic                Autonomic
•                ⇓                           ⇓
•    Afferent & Efferent    Afferent & Efferent
•                                                   ⇓    
•                                Sympathetic &                                         Parasympathetic

• Dura Mater (tough outer membrane)
• Arachnoid membrane (middle, web like)
• Pia Matter (Inner, adheres to CNS surface)
• D.A.P.
• Cerebrospinal fluid (CSF):
• fluid serves as cushion

specialized cells from the reception, conduction, and transmission of electrochemical signals

• support neurons
• outnumber neurons 10:1
• 4 classes:
•    1. oligodendrocytes (myelin sheath in CNS)
•    2. schwann cells (myelin sheath in PNS)
•    3. astrocytes (largest, many functions)
•    4. microglia (respond to injury or disease)

• Myelin providing glia are called
• Oligodendrocytes in the CNS
• Schwann cells in the PNS
• Clusters of cell bodies are called
• Nuclei in the CNS
• Ganglia in the PNS

• Bundles of axons are called
• Tracts in the CNS
• Nerves in the PNS

• medial vs. lateral 
• dorsal vs. ventral 
• anterior vs. posterior 
• superior vs. inferior
• proximal vs. distal

middle, side

top of head, back & bottom of head, chest

face & upward spine direction

top, bottom

close and far

• horizontal
• frontal
• sagittal
• cross

slice parallel to the ground

(coronal) slicing bread or salami

midsagittal section separates the left and right halves

slice through spinal cord

• forebrain (top)
• midbrain (middle)
• hindbrain (bottom)

• longututindal fissure
• gyrus: each ridge
• sulcus: space between two gyri
• cortex: outer surface, cell bodies of neurons 
• 4 lobes
• cerebral cortex
• thalamus and hypothalamus
• corpus callosum
• ventricles

• frontal
• parietal
• occipital
• temporal

area anterior to the central sulcus and superior to the lateral fissure

• *brocas area; speech production
• *perfrontal cortex; panning, organization, impulse control

located superior to the lateral fissure and between the central sulcus and the occipital lobe

• *postcentral gyrus; skin senses (touch, warmth, cold and pain) along with senses that inform us about body position and movement
• *damage would lead to neglect the person ignores objects, people and activity on the side opposite the damage

area posterior to the temporal lobe and inferior to the parietal lobe

• *visual cortex; visual info in processed
• *contains a map of visual space because adjacent receptors int he back of the eye send neurons to adjacent cells in the visual cortex

• area inferior to the lateral fissure and anterior to the occipital lobe 
•  
• *auditory cortex; receives sound info from the ears, lies on the superior gyrus of temp. lobe
• *wernickes area; interprets language input arriving from the nearby auditory and visual areas -> damage can cause trouble understanding speech or writing
• *inferior temp.; major role in the visual identification of objects

• outer most part of the forebrain
• responsible for analyzing sensory processing and higher brain functions

thalamus:lies just below the lateral ventricles, where it receives info from all the sensory systems (except smell) and relays it to the projection areas

hypothalamus: smaller structure just inferior to the thalamus, plays a major role in controlling emotion and motivated behaviors such as eating/drinking/sexual activity

dense band of fibers that carry info between hemispheres 

• *incoming info is directed to the opposite side that it comes in from and it is sent out to the opposite side that it goes out of. 
• *left to right, right to left

hollow interior of the nervous system develops into cavities within the brain and central canal in the spinal cord

*filled with cerrbrospinal fluid which carries materials from the blood vessels to the CNS and transports waste materials in the other direction

• structure that have secondary roles in vision, audition and movement
• mesencephalon: tectum -> superior & inferior collicili

superior: help guide eye movements and fixation of gaze

inferior: help locate the direction of sounds

• metencephalon (pons and cerebellum) top
• myelencephalon (medulla) bottom

contains centers related to sleep and arousal, which are part of the recticular formation

*recticular formation: collection of many nuclei running through the middle of the hindbrain and midbrain

• lower part of hindbrain
• its nuclei are involved with control of essential life processes, such as cardio activity and respiration (breathing)

perched on the back of the brain stem, wrinkled and divided down the middle like the cerebral hemispheres 

• *refining movements initiated by the motor cortex by controlling their speed, intensity and direction
• *damage: trouble making precise reaching movements, and walks with difficulty because the autonomic patterning of movement routines has been lost

• regulation of motivated behaviors, emotions
• structures:
• mammillary bodies 
• hippocampus
• amygdala
• fornix 
• cingulate (left and right)
• septum

structures that help control movement by integrating and smoothing movements using info from the primary and secondary motor areas and the somatosemsory cortex 

• *damage contributes to parkinsons disease 
• *structures: amygdala, stratum, globus pallidus

• cerebral cortex (neocotex, hippocampus)
• major fissures (central, lateral, longitudinal)
• major gyri (precentral, postcentral, superior temporal, cingulate)
• four lobes (frontal, temporal, parietal, occipital)
• limbic system  (amygdala, hippo, fornix, cingulate cortex, septum, mammllary bodies)
• basal ganglia (amygdala, caudate, putamen, globus pallidus)

• thalamus
• hypothalamus (mammillary bodies)
• optic chiasm
• pituitary gland

• tectum (superior and inferior colliculis)
• tegmentum (reticular formation)

• reticular formation
• pons
• cerebellum

reticular formation