chapter 3 what is another name for neuron? nerve impulse in the form of electrochemical impulse runs...
TRANSCRIPT
Chapter 3
What is another name for Neuron?
Nerve impulse in the form of electrochemical impulse runs through our entire body and communicate with each other (glands, muscles)
Regulates our internal functions
Learn new behavior or information - N.S.
Registers experience and changes to accommodate its storage
nerve cells
Why do you think the transparency show the anatomy of two neurons instead of one?
Because the function of the neurons is to communicate with one another.
TRANSMITS IN ONE DIRECTION
Chapter 3
EACH NEURON HAS: (pg. 54)
CELL BODY – produces energy that fuels cell activity
AXON – Carries messages away from the cell body
Axon has MYELIN - white fatty substance insulates and protects axon
MYELIN SHEATH - protects the axon and helps speed up the transmission of the message
DENDRITES - receives information from other neurons and pass information through the cell body
Leafy fibers branching out – contain neurotransmitters
AXON TERMINALS - pass messages from one neuron to the dendrites of the next neuron.
Neurotransmitters are chemicals stored in sacs in the axon terminals. When released chemicals cross the synapse to reach the
next neuron.
SYNAPTIC GAP - space between axon terminal and membrane of the postsynaptic cell (dendrite)
SYNAPSE - the space between 2 cells
that separates the axon terminals of sending neuron from the dendrites of its receiving neuron.New synapse can develop between neurons not previously connected when learn something new
Chapter 3NEURON IMPULSE TRAVELS ONLY IN ONE DIRECTION and takes a fraction of a second.
Pain is transmitted through SENSORY NEURONS which carry information received by senses to CNS
MOTOR NEURONS - carry information from CNS to muscles / glands
INTER NEURONS - specialized nerve cells within the brain and spinal cord that communicate internally and intervene between sensory inputs and motor inputs
Chapter 3NEUROTRANSMITTERS
Neuron releases only ONE type of neuron transmitter.
Each type of neurotransmitter has a specific structure and fits into a receptor site on the next neuron like a key fits a lock.
1. ACETYLCHOLINE
involves in the control of MUSCLES as well as AROUSAL, MEMORY, MOTIVATION (motor neurons - spinal cord stimulates muscles)
Patients who have low levels of acetylcholine may help Alzheimer disease if use a chemical stimulate enhances memory
Patients who have high levels lead to spasms and tremors
2. DOPAMINE
involved in MOTOR BEHAVIOR, LEARNING, REINFORCEMENT, maintain FOCUS and ATTENTION
deficiency - plays role in Parkinson’s (tremor, uncoordination)
excess - contribute to PD - schizophrenia
Chapter 3NEUROTRANSMITTERS
3. NORADRENALINE
involved in preparing the BODY FOR ACTION, CONTROL, ALERTNESS
4.**EPINEPHRINE (ADRENALINE)
prepare body fight/flight
**Hormone and/or neurotransmitter
5. NOREPINEPHRINE
brings body back to slow level, calm tranquilizes body after stress
6. ENDORPHINS
morphine; dulls pain; addictive pain suppressors brain response to pain
7. SUBSTANCE P - pain
8. SEROTONIN
involved in EMOTIONAL AROUSAL & SLEEP, EATING DISORDERS, MOOD
low levels - Depression, OCD
(Prozac raise serotonin level to brain)
Chapter 3CENTRAL NERVOUS SYSTEM
Made up of spinal cord and brain
FUNCTIONS OF THE SPINAL CORD
Spinal cord transmits messages between the brain and the muscle and glands of the body and is involved in reflex action.
WHAT IS THE SPINAL REFLEX ACTION? - simple automatic response to something.
ex. touching a hot stove; removal of hand is a spinal reflex by motor neuron
pain does not cause the reflex - a person may register pain in head but pain not felt until after the hand has been removed.
Ex. Blinking your eyes when lights are turned on in dark room because pupil automatically contracts when exposed to bright light;
Ex. knee jerk - lower leg swings.
Spinal reflex action DOES NOT receive its triggering message from the brain.
Message goes from the sensory nerve to the spinal cord where special cells send a message to appropriate motor neurons which stimulate the muscles to take action.
Chapter 3PERIPHERAL NERVOUS SYSTEM
Lies outside the central nervous system and is responsible for transmitting messages between central nervous system and all parts of the body.3 MAIN DIVISION OF peripheral nervous system:1.SOMATIC Nervous System • Transmits sensory messages to the central nervous system• Activated by touch, pain , changes in temperature, changes in
body position• Enables us to experience sensations of hot/cold and feel
pain/pressure• Also sends message to muscles and glands and helps maintain
posture and balance.
2. AUTONOMIC Nervous System• occurring involuntarily or automatic• regulates the body’s vital functions: Heartbeat, Breathing,
Digestion, and Blood Pressure, tear production
Psychologists are interested in this Nervous System because OBSERVING RESPONSE when a person experiences something STRESSFUL in the environment.
Chapter 3PERIPHERAL NERVOUS SYSTEM
2 DIVISIONS of AUTONOMIC NERVOUS SYSTEM:
1. SYMPATHETIC Nervous System Activated when a person is going into an action,
perhaps because of some stressful event. Prepares body either to confront the situation OR
run away = FIGHT or FLIGHT response
Ex. Attack by a dog Prepares body by suppressing digestion, increasing
heart & respiration rates, elevates blood pressure
Ex. POP QUIZ Sympathetic Nervous System is overly active in people
who are anxious, including people with anxiety disorders. Over activity in SNS leads to high blood pressure, stroke, or heart problems
Chapter 3PERIPHERAL NERVOUS SYSTEM
AUTONOMIC NERVOUS SYSTEM
2. PARASYMPATHETIC Nervous System Restores the body’s reserves of energy after an action
has occurred. Heart rate and blood pressure are normalized Breathing slowed, digestion returns to normal
REMEMBER: Sympathetic starts with S = STRESS
Parasympathetic starts with P = PEACE
PERIPHERAL NERVOUS SYSTEM
3RD DIVISION
3. ENTERIC Nervous System Meshwork of nerve fibers that innervate the viscera
(gastrointestinal tract, pancreas, and gallbladder)
Chapter 3Brain functions effectively because intricate system of support and protection receives from other parts of body.
Brain supported by nutrients and oxygen carried by blood vessels
PROTECTED:
By bones of the skull
3 layers of membranes (meninges) (meningeez)
Fluids surrounds brain acts as a SHOCK ABSORBER
LOCALIZATION OF FUNCTION - different parts of brain carry out different functions
LATERALIZATION - some functions are carried out exclusively on one side of the brain, even for functions that take place on both sides of brain. Right/Left sides usually take care of different aspects of same functions.
Chapter 3VITAL FUNCTIONS
HINDBRAIN
heart rate
blood pressure
respiration
balance/coordination
MIDBRAIN
Vision and hearing
FOREBRAIN
Complex function: thought & emotion
Chapter 3MAIN STRUCTURE
HINDBRAIN - Basic body activities. Connects spinal cord with rest of body.
Medulla - directly connects the spinal cord with brain and helps regulate HEART RATE, BLOOD PRESSURE and BREATHING
Cerebellum - next to the medulla behind the brain stem (“little brain”); controlling balance & coordination, posture and maintaining equilibrium; allows us to walk and run
without tripping
Pons - just above the medulla; Regulates BODY MOVEMENT (facial expression), ATTENTION, SLEEP, ALERTNESS, EATING
(Produces chemicals help maintain sleep wake cycle)
Chapter 3Reticular Activating System (RAS) -
network of neurons extending from the medulla to forebrain
(acts as a filter)
Allows sensory information to enter brain
i.e. sleep & arousal
ex. AIR TRAFFIC CONTROL OF BRAIN
regulates the flow of traffic
ex. Teacher calls your name your RAS stimulates the higher brain centers that allows you to become alert.
When asleep RAS restricts most environmental stimuli from entering your brain.
Chapter 3MIDBRAIN - important for hearing and sight; one place in brain where pain is registered
Connects HINDBRAIN and FOREBRAIN
Midbrain appears to function mainly as a relay station for messages coming into the brain.
It also contains structures that play a role in seeing, hearing, and movement.
Reticular Activating System - network of neurons extending from the medulla to forebrain; allows relevant sensory information such as AROUSAL or SLEEP to enter the brain. (air traffic control of the brain - regulates the flow of traffic); controls overall level of activity of central nervous system including WAKEFULNESS and SLEEPEx. teacher calls your name - RAS stimulates higher brain centers that allow you to become alert. OR while sleeping your reticular formation restricts most environmental stimuli from entering your brain.
Chapter 3FOREBRAIN
Biggest and most complex part
It not only influences many of the basic life-support functions controlled by the midbrain and hindbrain but is also responsible for such higher level behaviors as thinking and speaking.
Major structures of the forebrain:
Thalamus • major sensory relay center to cerebral cortex • influences mood and movement. • Includes visual, auditory, touch stimuli. • Messages from these sense organs are channeled into
the thalamus and from there are carried into specific parts of the forebrain for interpretation and action.
Chapter 3Hypothalamus (Size of pea) maintains stable internal
environmental state involved in the motivation of such behaviors as:
eating drinking, sexual drive, sleeping, and regulating body temperature, storage of nutrients.
It also influences the pituitary gland which regulates biochemical reactions in the body and the part of the peripheral nervous system that regulates the internal body organs. pg.60
Chapter 3Limbic System - autonomic response to SMELL, EMOTION, MOOD & other functions like sex, aggression, fear , pressure, pain.
4 important parts:
hypothalamus, thalamus, hippocampus, amygdala The hypothalamus regulates motivation and
emotion. The thalamus primarily relays sensory information to
the cerebrum, the part of the brain that allows humans to think and store information.
The hippocampus is involved in memory processing and learning. (Alzheimer’s disease patients often have low levels of acetylcholine in the hippocampus.) People with severe damage to this area can still remember, names, faces, events, before incident; can’t remember anything new.
The amygdala is involved in anger and aggression.
Automatic response to smell, emotion, mood, and other such functions: sex, aggression, fear, pressure and pain.
Chapter 3 Basal Ganglia (base of forebrain) lie to the side of the thalamus and are important in
voluntary motor responses (movement). The neuromuscular disorder Parkinson’s disease is
associated with a breakdown of the neurotransmitter dopamine in the basal ganglia.
If part of the limbic system is damaged people can recall old memories but don’t create new memories. May make you more passive/aggressive.
Chapter 3
Cerebrum is the largest part of the forebrain; consists of two distinct structures called HEMISPHERES;
Hemispheres are connected by the corpus callosum= bundle of neurons that keeps each hemisphere informed about what is happening in the other.
Left Hemisphere controls the right side of the body and
Right hemisphere controls the left side.
Left Hemisphere - logical, analytical and verbal - reading, language, and understanding speech
Right Hemisphere - process nonverbal info and concerned with emotion, imagination, and artistic information.
Most people are left dominant
Chapter 3
Paul Broca - BROCA’s AREA
located in Frontal lobe
essential ability to talk (produces speech sounds)
important for talking
If Broca’s area damaged:
APHASIA = (speechlessness) tends to expressive; language difficulty lies predominantly in sequencing and producing language (talking)
Results from patients who suffered left hemisphere strokes and result brain damage. Produce language problems = APHASIA
Chapter 3
Karl Wernicke later modified - Wernicke’s AREA
toward back of temporal lobe
processing and understanding what others saying
important to listening
If Wernicke’s area damaged:
APHASIA = tends to be RECEPTIVE; difficulty understanding language
Chapter 3WHAT IS THE RELATIONSHIP BETWEEN THE CEREBRAL CORTEX AND THE CEREBRUM?
Cerebral Cortex - is outer layer of the cerebrum (wrinkle ridges) ; controls overall level of activity of CNS
Part of the brain used for THINKING - where messages from our SENSE ORGANS are interpreted and stored and where decisions about behavior are made.
Has distinct sections/lobes that control different activities.
(thought, voluntary movement, language, reasoning, perception)
BRAIN STEM –
area between thalamus and spinal cord
structure within brain stem includes medulla, pons, RAS
Functions: breathing, heart rate, blood pressure
Chapter 3LOBES – Frontal, Occipital, Temporal, Parietal
Vision - Occipital - allow you to interpret what you see in the environment
Hearing - Temporal - when you hear your teacher talking
Somatosensory- Parietal - temperature, touch, pain
Movement/memory - Frontal - when you remember past events or giving an answer to a question
Left frontal more active than right frontal - tend to be more cheerful, sociable, self-confident
Right frontal more active than left frontal - more stressed, frightened, upset by unpleasant things more suspicious and depressed
Chapter 3
METHODS OF STUDYING THE BRAIN
EEG - Electroencephalography - records general wave patterns of electrical activity
CAT - Computerized Axial Tomography - x-rays reveal brain abnormalities; creates cross sectional pictures of brain only shows density of tissue of how much radiation absorbed [contrast]
PET - Positron Emission Tomography - injects with radioactive glucose; examines brain activity
MRI - Magnetic Resonance Imaging -use radio waves and magnetic fields to study chemical activity of brain cells.
Chapter 3ENDOCRINE SYSTEM
Consists of glands that secrete substances called HORMONES into the BLOODSTREAM
Hormones stimulate growth and many kinds of reactions - activity levels and moods
Hormones affect behavior & emotional reactions
Hormones have specific receptor sites.
Hormones produced by several different glands.
Glands include: PITUITARY GLAND = MASTER GLAND (lies under the hypothalamus)
Stimulated by Hypothalamus - responsible for secretion of various hormones affect various behaviors
a. Growth hormone - regulates growth of muscle, bone, glands
b. Females to pregnancy and Production of milk
THYROID
ADRENAL
TESTES & OVARIES
Chapter 3THYROID GLAND
Produces THYROXIN
affects body’s metabolism and converts food to energy
ADRENAL GLAND
Located above kidneys
Outerlayer or cortex - secrete CORTICAL STEROIDS - increase resistance to stress and promote muscle development.
Also produces ADRENALINE & NORADRENALINE
These hormones arouse body enabling person to cope with stress
Adrenaline - can intensify emotions such as fear & anxiety, raise blood pressure
This hormone acts as a neurotransmitter as well
Chapter 3HEREDITY
Transmission of characteristics from Parents to offspring
plays key role in development of traits
shown to be one factor involved in psych disorders (PD): anxiety, depression, schizophrenia, bipolar disorder, alcoholism
KINSHIP STUDIES
Common way to sort out roles that heredity and environment play determining a trait
Kinship refers to degree how people related.
Identical twins share 100% of genes
Psych use info to determine how much a trait is influenced by genetics and how much by environment
2 Types of KINSHIP STUDIES
1. Twin
2. Adoptees