Transcript Module 4 - Doral Academy Preparatory

Module 4
Incredible Nervous System
GENES & EVOLUTION
• Genetic information
– Brain/body develop according to complex chemical
instructions written in a human cell no larger than a grain
of sand
GENES & EVOLUTION (CONT’D)
• Fertilization
– Human life has its beginnings when the father’s
sperm, which contains ________________,
penetrates the mother’s egg, which contains 23
chromosomes
GENES & EVOLUTION (CONT’D)
GENES & EVOLUTION (CONT’D)
• Zygote
– The largest human cell, about the size
________________
– A zygote is a cell that results when an egg is fertilized
– A zygote contains ________________ arranged in 23
pairs
GENES & EVOLUTION (CONT’D)
• Chromosomes
– A short, rod-like, microscopic structure that contains a
tightly coiled strand of the chemical DNA, which is an
abbreviation for deoxyribonucleic acid
GENES & EVOLUTION (CONT’D)
GENES & EVOLUTION (CONT’D)
• Chemical alphabet
– Each chromosome contains a long, coiled strand of
DNA, which resembles a ladder that has been twisted
over and over upon itself
– Each rung of the DNA ladder is made up of four
chemicals
– The order in which the four different chemicals
combine to form rungs creates a microscopic
alphabet
GENES & EVOLUTION (CONT’D)
GENES & EVOLUTION (CONT’D)
• Genes and proteins
– Gene
• ________________________________________
________________________________________
– Proteins
• ________________________________________
________________________________________
________________________________________
GENES & EVOLUTION (CONT’D)
• Polymorphic genes
– ______________________________ (e.g. eye color)
– Combination of genes sibling receives from parents,
resulting in two siblings having different eye colors
• Dominant and recessive genes
– Dominant gene:
__________________________________________
__________________________________________
__________________________________________
– Recessive gene:
__________________________________________
__________________________________________
__________________________________________
___________________________
GENES & EVOLUTION (CONT’D)
• Genome
– The Human Genome Project
– Began in 1995 and cost over $2.7 billion
– Reached its first goal in 2003 of mapping all the
human genes
– Researchers found only about 30,000 human genes
instead of the estimated 100,000
GENES & EVOLUTION (CONT’D)
• Genetic factors
– Researchers are discovering how genetic factors
interact with the environment in the development of
mental retardation, emotional and personality traits,
mental disorders, and various cognitive abilities
• Fragile X syndrome
– An inherited developmental disability due to a defect
in the X chromosome
• Genetic testing
– Involves taking a blood, hair, skin, or other sample
and then examining donor’s genes to look for specific
diseases or disorders
EVOLUTION OF THE HUMAN BRAIN
• Evolution of the human brain
– 1859, Charles Darwin published The Origin of
Species
• Theory of evolution
– Different species arose from a common ancestor and
that those species that survived were best adapted to
meet the demands of their environment
– Humans and chimpanzees share at least 98% of their
DNA
EVOLUTION OF THE HUMAN BRAIN (CONT’D)
EVOLUTION OF THE HUMAN BRAIN (CONT’D)
• Genetic mutations
– __________________________________________
__________________________________________
__________________________________________
• Natural selection
– __________________________________________
__________________________________________
______________
– __________________________________________
__________________________________________
__________________________________________
EVOLUTION OF THE HUMAN BRAIN (CONT’D)
• Adaptations
– Common features of a species that provide it with
improved function
• Evolutionary approach
– Voluntary ideas, such as adaptation and natural
selection, explain human behaviors and mental
processes
STUDYING THE LIVING BRAIN
• Brain scans
– Techniques that can look through the thick
skull and picture the brain with astonishing
clarity yet cause no damage to the extremely
delicate brain cells
– Researchers are mapping a variety of
cognitive functions
• attention, language, memory, motor skills
• sites of emotional feelings and appetite
• MRI and fMRI
STUDYING THE LIVING BRAIN (CONT’D)
• MRI
• _____________________________
• __________________________________________
__________________________________________
• fMRI
• functional magnetic resonance imaging
• __________________________________________
__________________________________________
__________________________________________
STUDYING THE LIVING BRAIN (CONT’D)
STUDYING THE LIVING BRAIN (CONT’D)
• Brain scans and cognitive neuroscience
– PET scan
– Positron emission tomography
– __________________________________________
__________________________________________
__________________________________________
_
STUDYING THE LIVING BRAIN (CONT’D)
• Neuroimaging
– PET and fMRI scans are used to identify and map the
living brain’s neural activity as a person performs
complex behavioral and cognitive tasks, such as
• seeing
• moving
• thinking
• speaking
• empathizing
• trusting
• even reacting to TV violence
STUDYING THE LIVING BRAIN (CONT’D)
The Nervous System
ORGANIZATION OF THE BRAIN
• Central nervous system (CNS)
– Made up of the ____________________________
– Bottom of brain is where spinal cord emerges
– Made up of neurons, bundles of axons, and
dendrites that carry information back and forth
between the brain and the body
Central Nervous System
• The Brain
and spinal
cord
• CNS
ORGANIZATION OF THE BRAIN (CONT’D)
ORGANIZATION OF THE BRAIN (CONT’D)
• Peripheral nervous system (PNS)
– __________________________________________
__________________________________________
__________________________________________
______________________
• Subdivisions of the PNS
– Somatic nervous system
– Autonomic nervous system (ANS)
– Sympathetic division
– Parasympathetic division
Peripheral Nervous System
• All nerves that are
not encased in bone.
• Everything but the
brain and spinal
cord.
• Is divided into two
categories….somatic
and autonomic.
ORGANIZATION OF THE BRAIN (CONT’D)
ORGANIZATION OF THE BRAIN (CONT’D)
• Somatic nervous system
– Network of nerves that connect either to sensory
receptors or to muscles that you can move voluntarily,
such as muscles in your limbs, back, neck, and chest
– Nerves contain two kinds of fibers
• afferent
– _____________________________________
• efferent
– _____________________________________
_____________________________________
_____________________________________
Somatic Nervous System
• Controls voluntary
muscle movement.
• Uses motor
(efferent) neurons.
ORGANIZATION OF THE BRAIN (CONT’D)
• Autonomic nervous system (ANS)
– Regulates heart rate, breathing, blood pressure,
digestion, hormone secretion, and other functions
– Sympathetic division
• triggered by threatening or challenging physical or
psychological stimuli, increases physiological
arousal and prepares the body for action
– Parasympathetic division
• returns the body to a calmer, relaxed state and is
involved in digestion
Autonomic Nervous System
• Controls the
automatic functions
of the body.
• Divided into two
categories…the
sympathetic and the
parasympathetic
ORGANIZATION OF THE BRAIN (CONT’D)
• Major parts of the brain
– Forebrain
– Midbrain
– Hindbrain
• pons
• medulla
• cerebellum
ORGANIZATION OF THE BRAIN (CONT’D)
ORGANIZATION OF THE BRAIN (CONT’D)
• Forebrain
– Largest part of the brain
– Has right and left sides called hemispheres
– Hemispheres are responsible for a number of
functions, including learning and memory, speaking
and language, emotional responses, experiencing
sensations, initiating voluntary movements, planning,
and making decisions
ORGANIZATION OF THE BRAIN (CONT’D)
• Midbrain
– Has a reward or pleasure center, which is stimulated
by
__________________________________________
__________________________________________
– Has areas for visual and auditory reflexes
– Contains the __________________, which arouses
the forebrain so that it’s ready to process information
from the senses
ORGANIZATION OF THE BRAIN (CONT’D)
• Hindbrain
– Has three distinct structures
• pons
• medulla
• cerebellum
ORGANIZATION OF THE BRAIN (CONT’D)
• Pons
– Functions as a bridge to interconnect messages
between the spinal cord and brain
• Medulla
– Located on top of the spinal cord
– Includes a group of cells that control vital reflexes,
such as respiration, heart rate, and blood pressure
• Cerebellum
– Located in the very back and underneath the brain
– Involved in coordinating motor movements but not in
initiating voluntary movements
CONTROL CENTERS: FOUR LOBES
• Wrinkled cortex
– A thin layer of cells that essentially covers the entire
surface of the forebrain
CONTROL CENTERS: FOUR LOBES (CONT’D)
CONTROL CENTERS: FOUR LOBES (CONT’D)
• Frontal lobe
– __________________________________________
_________________________________________
• Parietal lobe
– __________________________________________
• Occipital lobe
– __________________________________________
• Temporal lobe
– __________________________________________
_
CONTROL CENTERS: FOUR LOBES (CONT’D)
CONTROL CENTERS: FOUR LOBES (CONT’D)
• Anencephaly
– Condition of being born _______________________
– If some brain or nervous tissue is present, it’s totally
exposed and often damaged because the top of the
skull is missing
– Survival is limited to days
CONTROL CENTERS: FOUR LOBES (CONT’D)
CONTROL CENTERS: FOUR LOBES (CONT’D)
• Frontal lobe: functions
– Located in front part of brain
– Includes huge area of cortex
– Many functions
• voluntary motor movements, interpreting and
performing emotional behaviors, behaving normally in
social situations, maintaining a healthy personality,
paying attention to things in the environment, making
decisions, executing plans
• executive functions
CONTROL CENTERS: FOUR LOBES (CONT’D)
• Phineas Gage
• Frontal lobotomy
– __________________________________________
__________________________________________
__________________________________________
__________________________________________
Ways to study the Brain!!!
• Accidents: Phineas
Gage.
CONTROL CENTERS: FOUR LOBES (CONT’D)
CONTROL CENTERS: FOUR LOBES (CONT’D)
• Frontal lobe: functions
– Motor cortex
– Narrow strip of cortex that’s located on the
back edge of the frontal lobe and extends
down its side
– Involved in the
______________________________
– Right side controls left
– Left side controls right
CONTROL CENTERS: FOUR LOBES (CONT’D)
• Other functions of frontal lobe
– Much knowledge of other frontal lobe functions comes
from individuals who had damage to that area
– Frontal lobes are involved in paying attention,
organizing, planning, deciding, and carrying out
various cognitive tasks and social-emotional
behaviors
– Executive function
CONTROL CENTERS: FOUR LOBES (CONT’D)
• Parietal lobe: function
– Location of somatosensory cortex
– Narrow strip of cortex that’s located on the front edge
of the parietal lobe and extends down its side
CONTROL CENTERS: FOUR LOBES (CONT’D)
CONTROL CENTERS: FOUR LOBES (CONT’D)
• Other functions of parietal lobe
–
–
–
–
–
–
Sensory integration
Spatial orientation
Language abilities
Visual and auditory attention
Memory
Numerical processing (counting)
CONTROL CENTERS: FOUR LOBES (CONT’D)
• Temporal lobe: functions
– Primary auditory cortex
– Located on top edge of each temporal lobe,
__________________________________________
__________________________________________
__________________________________________
__________________________________________
__________________________________________
CONTROL CENTERS: FOUR LOBES (CONT’D)
CONTROL CENTERS: FOUR LOBES (CONT’D)
• Temporal lobe: functions
– Auditory association area
– Located directly below the primary auditory cortex
– Transforms basic sensory information, such as noises
or sounds,
__________________________________________
__________________________________________
__________________________________________
CONTROL CENTERS: FOUR LOBES (CONT’D)
• Temporal lobe: functions
– Broca’s area
• located in left frontal lobe
• necessary for combining sounds into words and
arranging words into meaningful sentences
• damage: Broca’s aphasia
– person can’t speak in fluent sentences but can
understand written and spoken words
CONTROL CENTERS: FOUR LOBES (CONT’D)
– Wernicke’s area
• located in the left temporal lobe
• necessary for speaking in coherent sentences and
for understanding speech
• damage: Wernicke’s aphasia
– Difficulty understanding spoken or written
words and difficulty putting words into
meaningful sentences
BROCA’S v. WERNICKE’S
CONTROL CENTERS: FOUR LOBES (CONT’D)
• Occipital lobe: functions
–
–
–
–
Vision
Primary visual cortex
Located at the very back of the occipital lobe
Receives electrical signals from receptors in the eyes
and transforms these signals into meaningless, basic
visual sensations, such as lights, lines, shadows,
colors, and textures
CONTROL CENTERS: FOUR LOBES (CONT’D)
CONTROL CENTERS: FOUR LOBES (CONT’D)
• Occipital lobe: functions
– Visual association area
– __________________________________________
__________________________________________
__________________________________________
__________________________________________
__________________________________________
__________________________________________
CONTROL CENTERS: FOUR LOBES (CONT’D)
• Visual agnosia
– Individual fails to recognize some object, person, or
color
– Has ability to see and even describe pieces or parts
of some visual stimulus
CONTROL CENTERS: FOUR LOBES (CONT’D)
CONTROL CENTERS: FOUR LOBES (CONT’D)
• Neglect syndrome
– Refers to the failure of a patient to see objects or
parts of the body on the side opposite the brain
damage
– May dress only on one side of body
– May deny that opposite body parts are theirs
CONTROL CENTERS: FOUR LOBES (CONT’D)
LIMBIC SYSTEM: OLD BRAIN
• Group of about half a dozen interconnected structures
that make up the core of the forebrain
• Involved with regulating many motivational behaviors,
such as obtaining food, drink, and sex
• Organizing emotional behaviors, such as fear, anger,
and aggression; storing memories
• Structures and functions
– Hypothalamus
– Amygdala
– Thalamus
– Hippocampus
LIMBIC SYSTEM: OLD BRAIN (CONT’D)
LIMBIC SYSTEM: OLD BRAIN (CONT’D)
• Hypothalamus
– Regulates many ______________ behaviors,
including eating, drinking, and sexual responses;
emotional behaviors, such as arousing the body when
fighting or fleeing; and secretion of hormones, such
as occurs at puberty
• Amygdala
– Located in the tip of the temporal lobe
– __________________________________________
– Evaluates
__________________________________________
__________________________________________
__________________________________________
LIMBIC SYSTEM: OLD BRAIN (CONT’D)
• Thalamus
– __________________________________________
– Involved in receiving sensory information, doing some
initial processing, and then relaying the sensory
information to areas of the cortex
• Hippocampus
– __________________________________________
– Involved in saving many kinds of fleeting memories by
putting them into permanent storage in various parts
of the brain
LIMBIC SYSTEM: OLD BRAIN (CONT’D)
• Autonomic nervous system
– Sympathetic
– Parasympathetic
LIMBIC SYSTEM: OLD BRAIN (CONT’D)
• Autonomic nervous system
– Sympathetic
• ________________________________________
________________________________________
________________________________________
– Fight or flight
• state of increased physiological arousal caused by
activation of the sympathetic division
• helps body cope and survive threatening situations
– Physiological responses
• increased heart rate, increased blood pressure,
and dilated pupils
LIMBIC SYSTEM: OLD BRAIN (CONT’D)
• Autonomic nervous system
– Parasympathetic
• _____________________________________
• _____________________________________
• ______________________________________
– Physiological responses
• ________________________________________
• ________________________________________
• ________________________________________
• ________________________________________
LIMBIC SYSTEM: OLD BRAIN (CONT’D)
• Autonomic nervous system
– Homeostasis
• sympathetic and parasympathetic systems work
together to keep the body’s level of arousal in
balance for optimum functioning
ENDOCRINE SYSTEM
• Endocrine system
– Made up of numerous glands located throughout the
body
– Glands secrete various chemicals called hormones
• pituitary
• pancreas
• thyroid
• adrenal glands
• gonads
ENDOCRINE SYSTEM (CONT’D)
ENDOCRINE SYSTEM (CONT’D)
• Pituitary gland
– Hangs below the hypothalamus
– Divided into anterior and posterior
• Posterior (rear portion)
– Regulates water and salt balance
• Anterior (front portion)
– Regulates growth through secretion of growth
hormone
– Produces hormones that control the adrenal cortex,
pancreas, thyroid, and pancreas
ENDOCRINE SYSTEM (CONT’D)
ENDOCRINE SYSTEM (CONT’D)
• Pancreas
– Regulates the level of sugar in the bloodstream by
secreting insulin
• Thyroid
– Located in the neck
– Regulates metabolism through secretion of hormones
ENDOCRINE SYSTEM (CONT’D)
• Adrenal glands
– Adrenal cortex (outside part)
– Secretes hormones that regulate sugar and salt
balance
– Adrenal medulla (inside part)
– Secretes two hormones that arouse the body to deal
with stress and emergencies
– Epinephrine (adrenaline)
– Norepinephrine (noradrenaline)
ENDOCRINE SYSTEM (CONT’D)
• Gonads
– Females
• ovaries produce hormones that regulate sexual
development, ovulation, and growth of sex organs
– Males
• testes produce hormones that regulate sexual
development, production of sperm, and growth of
sex organs