PSYC 1100 Section 1.4 Macroscopic Neuroanatomy

  1. Peripheral Nervous System
    • Ganglia (cell bodies)
    • Nerves (axons)

    • Sources of nerves:
    • - spinal nerves 
    • - cranial nerves

    • Functions of Peripheral Nerves:
    • - sensory
    • - motor
    • - autonomic
  2. Autonomic Nervous System
    Sympathetic and parasympathetic divisions: control automatic and regulatory functions such as heart rate, blood flow, excortion and breathing

    • They work in opposition to each other:
    • - Sympathetic. Tends to speed your up, or promote energy expenditure; is activated by exercise, stress, powerful emotions; symp. activation also causes adrenal glands to release adrenalin; effects of "synpathoadrenal activation" include increased heart rate, increased blood pressure and blood flow to large muscles of arms and legs, dry mouth, rapid shallow breathing. this is part of the "flight or fight"
    • - Parasympathetic. Tends to conserve energy, promote digestion, secretion (i.e. saliva or stomach acids), and excretion, reduce heart rate and rate of breathing
  3. Organization of the Brain
    • 1. forebrain: most advanced, more unique to mammels
    • -  telencephalon: contains important regions for cognition and memory
    • diencephalon: contains regions neccessary for motivated behaviors, other aspects of learning and memory
    • 2. midbrain: also known as mesencephalon
    • relays sensory info to the forebrain
    • - superior and inferior to the colliculi
    • 3. hindbrain
    • - metencephalon
    • - myelencephalon
  4. Hindbrain (Myelencephalon)
    • Mylencephalon:
    • medulla (medulla oblongata), drug overdose can suppress it
    • - life support, especially breathing
    • - control of digestion
    • - sensory and motor functions
    • - damage can be life-threatening

    • Metencephalon:
    • pons (meaning "bridge" in Latin)
    • - sensory and motor function
    • - connections to the cerebellum

    • Cerebellum:
    • sensory and motor integration (communication)
    • - motor coordination (damage produces "decomposition of movement")
    • - learning: motor skills
    • - damage can lead to motor impairment (drunk-like movement)
  5. Midbrain (Mesencephalon)
    • Tectum ("roof")
    • - superior colliculus: important for motor functions, vision-orient to visual stimuli, e.g. movement of the eyes
    • inferior colliculus: acts as a relay nucleus for hearing pathways, information from hearing gets processed here

    • Tegmentum ("floor")
    • substantia nigra ("black substance"): motor control; contains cells that uses dopamine(DA), and project to basal ganglia in forebrain; these cells die in Parkinson's Disease- not very familial (inherited in family)
  6. Forebrain
    • =Diencephalon
    • Hypothalamus: several discrete nulei
    • - involved in aspects of motivation (eating thirst, sex-different in different genders)
    • - point of communication between barin and endocrine system; regulates functions of pituitary gland
    • - controlling the autonomic nervous system: fight or flight, feed or mating (4F's) responses

    • Thalamus: several discrete nuclei
    • - important "relay" area; sensory relay for vision, hearing, touch, taste
    • - also has motor areas
    • - thalamic nuclei "map" on to overlying neocortex

    • =Telencephalon
    • Basal ganglia:
    • - includes several nuclei: caudate & putamen (Rich in DA, die/depleted in Parkinson's), globus pallidus
    • involved in motor function and sensory/motor integration
    • - receives dopamine (DA) input from sunstantia nigra; these cells die in Parkinson's, so DA is depleted in caudate and putamen
    • - loss of DA in basal ganglia induces motor symptoms of Parkinson's, including slowness of movement and tremor
    • L-DOPA is used to restore dopamine levels in patients with Parkinson's, but wears off in 5-10years

    • Limbic System:
    • Septum - involves in aspects of learning
    • Amygdala ("almond") - involved in aspects of learning, especially important for emotional processes
    •  - damage to the amygdala can affect emotional processes
    • Hippocampus ("Seahorse") - critical for forming new memories; degenerates in Alzheimer's, and is damaged in some people with strokes (hippocampus sensitive to lack of O2), which can lead to amnesia
  7. Major features of the Neocortex
    • - "new" evolutionary; large in mammals, especially primates, including humans; neocortex has 6 layers of cells; all mammals share common function of neocortex
    • - in animals with large cortex, including humans, it has "convolutions" or folds; increase surface area within amount of space
    • -- Gyrus or "hill", outward fold
    • -- Sulcus or "valley", inward fold
    • - divided into lobes: frontal, parietal, temporal, occipital
    • - examples of different functions: precentral gyrus is involved in motor function(especially fine motor skills, e.g. typing using fingers vs. back); postcentral gyrus is involved in somatosensory (e.g. touch) functions, both somatotopically organized: organized according to body parts
  8. Functional Areas in Neocortex
    • - divided into lobes (frontal, parietal, temporal, occipital)
    • - in each lobe there are specific neurocortical areas perform many "higher" functions (e.g. language, higher order sensory and motor: more critical than other organs, planning and organization, memory storage, spatial processing, computation: estimates)
    • - for each function represented in the various lobes of the neocortex, there are areas known as "Primary" functional areas and areas known as "Secondary" or "Association" areas: e.g. if damaged you can still see but cannot put things back together
    • - Frontal Lobe: Prefrontal cortex
    • - Parietal lobe: Postcentral Gyrus (primary somatosensory), somatosensory association cortex, linking touch and memory together, recognizing certain objects
    • - Occipital lobe: Primary visual cortex, visual association cortex
    • - Temporal lobe: Primary auditory cortex: detecting different frequencies of sound; auditory association cortex: discriminating differences in different sounds, different musical tunes
  9. Language Areas
    • Broca's Area: in the frontal lobe, important for motor production of speech, damage can lead to very "telegraphic" speech (slurred speech?)
    • Wernick's Area: mainly in temporal lobe, important for comprehension of language, and generation of meaningful language
    • - For most people, the left hemisphere is language dominant. That is true for virtually all right handers, and also for most left handers
  10. Axonal Fibers that Connect to the Two Hemispheres
    • Corpus callosum: axons that link left and right sides of the neocortex together, white fibers and axons, coordinates information between left and right hemisphere
    • - These fibers enable the brain to stitch together visual representations in each half of the cortex, and allow language related areas in one hemisphere to influence functions in the opposite hemisphere
    • - "split brain" people had their corpus colossum cut in a surgical intervention; it severed the communication between the two hemispheres
Card Set
PSYC 1100 Section 1.4 Macroscopic Neuroanatomy
Sec 1.4