Neuro Study Guide

THE HUMAN NERVOUS SYSTEM

OVERVIEW 1. The human nervous system a. Central Nervous System (CNS)
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b. Peripheral Nervous System (PNS)
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2. Brain Structures and their Function
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3. Cerebral lateralisation
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THE HUMAN NERVOUS SYSTEM

Central Nervous System * Consists of the brain and spinal cord

Peripheral Nervous System * Consists of somatic nervous system (SNS) and autonomic nervous system (ANS)

Somatic Nervous System * Interacts with the environment * Carries information from the muscles, skin, etc, to the CNS through afferent nerves * Carries motor signals from CNS via efferent nerves to muscles
(Afferent – approach, Efferent – Exit)

Autonomic Nervous System * Regulates body’s internal environment * Consists of nerves connecting to the heart and blood vessels, glands, smooth muscles * Afferent nerves carry sensory info to CNS from internal organs * Efferent nerves carry information from CNS to the internal organs * ANS consists of sympathetic and parasympathetic systems
(Sympathetic – marshals resources for crises, Parasympathetic – conserves resources)

THE HUMAN NERVOUS SYSTEM

CNS
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PNS
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SNS
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ANS
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THE SPINAL CORD

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DIVISION IN THE BRAIN

Hindbrain * Cerebellum * Balance and coordination * Execute motor commands * Fine motor skills * Some cognitive ability * Pons * “Bridges” of Fibres that connect brainstem to Medulla and Cerebellum * Regulates sleep and arousal level, respiration and movement * Medulla Oblongata * Extension of Spinal cord linking to brain * Controls heartbeat, breathing and circulation * Part of the Reticular Formation

HINDBRAIN

Cerebellum
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Pons
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Medulla
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Reticular Formation
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DIVISION OF THE BRAIN

Midbrain * Tectum * Vision and Hearing * Tegmentum * Movement * Reticular Formation * Runs through hind and mid brain * Implicated in sleep, attention, muscle tone, movement, respiratory reflexes, etc * Modulates neuronal activity throughout CNS

Tectum
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Tegmentum
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Reticular Formation
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DIVISION OF THE BRAIN

Forebrain * Cerebrum * 2 cerebral hemispheres with subcortical structures * Basal Ganglia * Limbic System* * Cortex * Hypothalamus * Controls ANS * Regulates basic biological drvies – feeding, mating, fighting, fleeing * Homeostasis * Tied to endocrine system – stimulates pituitary gland * Thalamus * Set of nuclei – neuron ceel bodies * Relay station and info integration – visual, auditory, taste and touch * Interacts with reticular formation, possibly to direct attention

DIVISION OF THE BRAIN

* Limbic System * Consists of interconnected structures * Includes parts of * Thalamus * Hypothalamus * Hippocampus - Memory * Amygdala – Emotional process * Septum – Emotion laden learning, pain relief, pain avoidance * Regulates emotion, memory and motivation

DIVISION OF THE BRAIN

* Basal Ganglia

DIVISION OF THE BRAIN

Cerebrum
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Hypothalamus
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Thalamus
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Limbic System
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Basal Ganglia
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DIVISION OF THE BRAIN

Cerebral Hemispheres * Corpus Callosum * Thick mass of nerve fibres connecting the hempisheres

Contralateral Control * The left hemisphere controls the right side of the body * The right hemisphere controls the left side of the body

(For reference – Primary Cortex – raw signals are processed or responses initiated. Association Cortex – processing and integration of complex information.)

Cerebral Cortex * Frontal Lobes * Primary motor cortex – voluntary movement * Association cortex – sequencing; planning and social skills, representational memory, impulse control, language * Parietal Lobes * Primary somatosensory cortex – sensory info * Association cortex – body awareness (L), space awareness (R) * Facial recognition * Temporal Lobes * Primary auditory cortex – hearing * Association cortex – meaning * Occipital Lobes * Primary visual cortex – simple features * Association cortex – complex integration

DIVISION OF THE BRAIN

Central Hempishere
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Contralateral Control
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Cerebral Cortex
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DIVISION OF THE BRAIN

Primary Sensory & Motor Cortex * Space is devoted according to importance, neural density and complexity of the region * Contralateral connections with sensory organs and muscles

Speech Centres * Damage to left auditory association cortex = language comprehension deficits * Damage to left frontal lobe cause problems with speech production

Parietal Lobes * Primary function – perception of body * Damage to left parietal association cortex – deficit in reading and/or writing, correct sequence or use of hand tools and identification of body parts * Damage to right parietal association cortex – deficit in perception, keeping track of extra-body space and unilateral neglect

Cerebral Laterality * Hemispheric Specialisation or Dominance * Left hemisphere – language, logic and complex motor behaviour * Right hemisphere – non-linguistic functions including forming visual maps of the environment * Information has been gathered from split brain patients

Visual Pathways to Brain * Optic nerves cross-over at the optic chiasm * Information from left visual field goes to the right hemisphere * Information from right visual field goes to left hemisphere * Contra-lateral hemisphere is nonetheless ‘informed’ because of the transmission via the corpus callosum

DIVISION OF THE BRAIN

Primary Sensory & Motor Cortex
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Speech Centres
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Parietal Lobes
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Cerebral Laterality
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Visual Pathways to Brain
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DIVISION OF THE BRAIN

Split Brain Surgery

Testing a Split Brain Patient