Download Module 4 - the Brain

Module 4
Our Incredible Nervous System
Development and Functioning
What influences our brains?
Evolution
Birth defects
Brain Damage
Genetic defects
Study of the Living Brain
 MRI (magnetic resonance) highlights different
areas of the brain
 fMRI (functional MRI) highlights the active
neurons as the brain thinks
 PET (positron emmission tomography)
 These allow us to understand what parts of
the brains have different functions, and
where damage has occured
Organization of the nervous
system
Central Nervous System:
Brain and spinal cord
Carries information between the brain
and the body
Peripheral Nervous System:
Nerves that extend from the spinal cord
to carry messages to and from the
muscles, glands and sense organs
Subdivisions of the Peripheral
nervous system
Somatic Nervous System:
Nerves connected to sensory receptors or
voluntary muscles (ie neck, back, limbs)
Afferent (sensory): nerve fibers carry
information to the spinal cord/brain from
sensory receptors
Efferent (motor): nerve fibers carry
information from the brain/spinal cord to the
muscles
Subdivisions of the Peripheral
nervous system (con’t)
Autonomic Nervous System:
Regulates heart, breathing, blood
pressure, digestion, mostly involuntary
actions
2 parts: Sympathetic and
Parasympathetic
Subdivisions of the Peripheral
nervous system (con’t)
Sympathetic Nervous System
Triggered by threatening/challenging stimuli,
increases physiological arousal and prepares
body for action
Parasympathetic Nervous System
Returns body to calmer, relaxed state and is
involved with digestion
Homeostasis means these two systems
work together to keep arousal balanced for
optimal functioning
Comparing the Systems
Sympathetic
 Pupils dilated/dry Eyes
 Dry
Mouth
 Goosebumps
Skin
 Sweaty
Palms
 Increased rate heart
Parasympathetic
 Pupils constricted/moist
 Salivation
 Smooth
 Dry
 Decreased rate
Igor - where is my brain????
Get into your head …
Major parts of the brain
Forebrain - hemispheres involved in
thinking,learning,memory, spoeech and
language, emotions,sensations, voluntary
movement, planning and decisions
Midbrain - reward/pleasure centre stimulatedby
food, sex, money, music, attractive faces and
drugs: visual and auditory reflaxes, and
reticular formation to process sensory
information
Hindbrain - Pons, Medulla and Cerebellum
Major brain stuff, continued
Pons: bridge for messages from the spinal cord
to brain, also makes sleep chemicals
Medulla: controls vital reflexes such as
breathing, heart rate and blood pressure
Cerebellum: coordinates motor movements
(but does not initiate them), timed motor
movements, and reflexive learning
The Cortex and 4 Lobes of the
brain
The Cortex
 Wrinkled surface of the brain
 Majority of neurons found here
 Wrinkled to fit many many cells into a
small space (paper analogy)
 Has four different functional lobes
Frontal Lobe
 Huge area of cortex
 Interprets and performs emotional behaviour,
dictates social behaviour,basis of
personality,makes decisions, plans and pays
attention to environment
 Contains motor cortex, which controls
voluntary movements
 Executive control: like boss of a company
Parietal Lobe
 Processes sensory information from body
parts: touch, location of body in
space,temperature sensing and pain, and
cognitive functions such as attention to and
perception of objects. Also involved in
language abilities
 Includes somatosensory cortex, which
processes sensory information from the body:
found next to the motor cortex
Temporal Lobe - 4 parts
 Involved in hearing, speaking coherently,
understanding verbal and written material
 Primary Auditory Cortex transforms info from
ears into sound sensations
 Auditory Association Area takes those
sensations and makes them recognizable (ie
words/music)
 Broca’s Area combines sound into words and
arranges them meaningfully (actually in
frontal lobe)
 Wernicke’s Area is necessary from speaking
coherent sentences and understanding
speech
Occipital Lobe
 processes visual information including seeing
colour and perceiving and recognizing
animals, people and objects
 Primary Visual Cortex is at the very back,
receives electrcal signals from receptors in
the eye and changes them to basic visual
sensation (ie light, shadow, texture)
 Visual Association Cortex interprets the basic
sensations into complete meaningful
perceptions such as people, objects or
animals
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Broca’s Asphasia
Wernicke’s Asphasia
Visual Agnosia
Neglect Syndrome
The Limbic System (old!)
 Core of the forebrain
 Regulates motivational behaviour such
as obtaining food drink and sex; stores
memories; also organizes emotional
behaviours such as fear, anger and
aggression
Endocrine System
Endocrine System
 This system is made up of many glands
throughout the body, which secrete
various chemicals called hormones
which affect organs, muscles, and other
glands.
 The Hypothalamus controls much of
this system by regulating the pituitary
gland
Are Men and Women Really
Different?
men & women
Problem Solving
Emotional Memories
Movement and Coordination
Parts of Limbic System
 Hypothalamus: regulates motivational
behaviour, emotional behaviour and secretion
of hormones
 Amygdala: evaluates emotional significance
of stimuli and facial expression
 Thalamus:receives sensory information and
relays it to different areas of the cortex
 Hippocampus: puts fleeting memories into
permanent storage in different areas of the
brain
Functions of Hemispheres
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Verbal – left
Mathematical – left
Analytic – left
Self recognition – left
Nonverbal – right
Spatial – right
Holistic – right
Other recognition - right