The Brain ppt module 4
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Transcript The Brain ppt module 4
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
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
Verbal – left
Mathematical – left
Analytic – left
Self recognition – left
Nonverbal – right
Spatial – right
Holistic – right
Other recognition - right