Study Guides (234,283)
Canada (113,082)
Psychology (623)
PS101 (143)

Psychology Day 7.docx

11 Pages
122 Views
Unlock Document

School
Wilfrid Laurier University
Department
Psychology
Course
PS101
Professor
Lawrence Murphy
Semester
Fall

Description
Psychology Day 7 Chapter 4 Lecture: Monday, October 1 The Brain: Source of Mind and Self The Nervous System  Two main parts: o Central nervous System (CNS)- receives, processes, interprets and stores incoming sensory information  Sends out messages to muscles gland and organs o Peripheral nervous system (PNS)- handles input and output from the CNS  All portions of the nervous system outside the brain and spinal cord  Central nervous system o Spinal cord- is a bridge between the brain and parts of the body below the neck o Spinal nerves protected by the spinal column o Enables spinal reflexes  Peripheral nervous system o Contains two subdivisions (messages carried through sensory and motor nerves)  Somatic Nervous System- nerves connected to sensory receptors and skeletal muscles  Autonomic nervous system- regulates functions of blood vessels, glands and internal organs  Contains two systems: Parasympathetic and Sympathetic o Parasympathetic- to conserve bodily functions (decreased heart rate, decreased respiration, pupils constricted) o Sympathetic- mobilize or flee (heart races, goosebumps, sweats, pupils dilate, increased respiration) Communications in the Nervous System  Nervous system made up of: o Neurons- cells that conduct electrochemical signals; basic unit of the nervous system  Combination of shock telling cell to release a chemical which inhibits a reaction from the brain o Glia- cells that support, nurture and insulate neurons, remove debris when neurons die, enhance the formation and maintenance of neural connections, and modify neural functioning  Almost the glue that holds the cells together  Structure of the neuron: o Approximately 100 billion neurons in the brain o Neurons vary in size and shape o Electrical signal goes down the dendrites and along the axon which is received by the synapse and if it is strong enough the cell will release the chemical o Dendrites- branch-like fibres that receive information from other neurons and transmit towards cell body o Cell body- keeps neuron alive and plays key role in determining whether neuron will “fire” o Axon- extending fibre that conducts impulse away from cell body and transmits to other cells  Branches at the end called axon terminals  May be collected together in bundles called nerves o The myelin sheath- many axons are insulated by surrounding layer of fatty materials called myelin sheath  In the CNS, this is made up of glial cells  Constrictions in covering (nodes) divide myelin into segments  Purpose to speed conduction of neural impulses and prevent interference from neighbouring signals Neurons in the News  Neurogenesis- production of new neurons from immature stem cells o Controversial because you need stem cells from embryos  Stem cells: o Immature cells that renew themselves and have potential to develop into mature cells o Stem cells from early embryos can develop into any cell type o Hold the potential to cure pretty much any disease, illness or even injuries Stem-Cell Research  Embryonic stem cells can differentiate into any type of cell; adult stem cells limited o Use is controversial and surrounded by ethical debates regarding extractions and when the embryo is technically living o Most promising in developing treatments for cancer, blood, organ and brain disorders (Alzheimer’s) o Canadian researchers have had some success with adult stem cells transforming to brain cells How Neurons communicate  No direct contact between neurons  Communicate through synapse o Includes the axon terminal, symnaptic cleft, and receptor sites in the membrane of the receiving cells o This is what happens when a person is on drugs, the chemicals in the drug mimic that of a chemical from the brain and reacts on the receptor sites on the receiving cell  Communication occurs through electrical and chemical signals o Stimulation causes charge between, inside and outside the cell o Inflow of sodium ions causes an action potential- the electric signal o Synaptic vesicles release chemicals called neurotransmitters  Neurotransmitters bind to receptor sites on receiving neuron and causes changes in the cell membrane o Excitatory changes- a voltage shift in a positive direction  Increases probability of receiving neuron firing o Inhibitory changes- a voltage shift in the negative direction  Decreases probability of receiving neuron firing  Consider alcohol causing you to pass out or die this is an inhibitory reaction Brain Plasticity  Plasticity: o The brains ability to change and adapt in response to experience (recognizing or growing new neural connections) o Behavioural deficits that occur as a result of brain damage may be lessened by enriching the environments people live in Chemical Messengers  Neurotransmitters: o A chemical substance that is released by a transmitting neuron at the synapse and that alters the activity of receiving neuron  Major neurotransmitters: o Serotonin, dopamine, acetylcholine, norepinephrine, GABA, glutamate  Each neurotransmitter has different effects: o Serotonin: sleep, appetite, sensory perception, temperature regulation, pain suppression, mood o Dopamine: voluntary movement, learning, memory, emotion, pleasure or reward, response to novelty  This is what makes drugs addictive by hijacking the reward centre of the brain o Acetylcholine: muscle action, cognitive functioning, memory and emotion o Norepinephrine: increases heart rate, slowed intestinal activity during stress, learning, memory, dreaming, waking, emotion o GABA: major inhibitory neurotransmitter  Inhibits your body’s ability to say no o Glutamate: major excitatory neurotransmitter in the brain o Endorphins:  Chemical substances in the nervous system that are similar in structure and action to opiates  Involved in pain reduction, pleasure and memory  Technically known as endogenous o Hormones:  Chemical substances, secreted by organs called endocrine glands, that affect the functioning of other organs  Regulate growth, metabolism, sexual development and behaviour  Major hormones:  Melatocin- regulate daily biological rhythms (sleep)  Oxytocin- childbirth contraction, milk ejection  Adrenal hormones- emotion, stress, epinephrine  Sex hormones- androgens and estrogens Psychology Day 11 Lecture Monday, October 22 Chapter 5 Body Rhythms and Mental States Biological Rhythms  A periodic, more or less regular fluctuation in a biological system o Hormones o Temperature in the body  Rhythms can be synchronized with external (entrainment) or internal cues (endogenous)  Biological rhythms influence effectiveness of medication, alertness, job performance Circadian Rhythm  Circadian rhythm occur approximately every 24 hours (e.g. sleep-wake cycle) o Commonly entrained to external time cues o Endogenous rhythms averages around 24.3 hours  When you take away all the external cues (alarms etc.) and put people in a cave the average endogenous is 24.3 hours of sleep o Removed from cues about 10% of people have clocks running lower and 10% running faster o Increase in accidents at transition to Daylight Savings Time o Controlled by biological clock in suprachiasmatic nucleus (SCN)  Regulates levels of Melatonin secreted by pineal gland Out of Sync?  Internal de-synchronization o A state in which biological rhythms are not in phase (synchronized) with one another o Changes I your normal routines can cause de-synchronization o May also occur in response to jet lag, rotating shift work, daylight savings time Moods and Long-Term Rhythms  Seasonal Affective Disorder (SAD) o A disorder in which a person experiences depression during the winter and an improvement of mood in the spring o Treatments may involve phototherapy or exposure to fluorescent light o Inconsistent findings with respect to prevalence (2-20%) and effectiveness of treatments o Not a form of de-synchronization Moods and Menstrual Cycles  Premenstrual Syndrome (PMS) o Vague cluster of physical and emotional symptoms associated with the days preceding menstruation that was labeled as an “illness” o Physical symptoms (e.g., cramps, water retention are common) o Emotional symptoms (e.g., irritability, depression) are rare. Moods, PMS and Research  Estimates of prevalence range from 13% to “most women”  Expectations and beliefs may be related to PMS Symptom reporting  Evidence supports that women often experience physical symptoms but emotional symptoms are relatively rare  Recent research……… The Rhythms of Sleep  During sleep, we cycle between periods of REM and non-REM sleep (~90 minutes) o Rapid Eye Movement (REM) – characterized by eye movement, loss of muscle tone, and dreaming o Non REM (NREM) sleep – characterized by fewer eye movements then REM The stages of Sleep  Stage 1 o Feel on the edge of consciousness; light sleep  Stage 2 o Presence of sleep spindle; minor noises wont disturb you  Stage 3 o Delta waves begin; breathing and pulse have slowed down; hard to awaken  Stage 4 o Delta waves predominant; deep sleep; most likely stage for sleepwalking  Rapid eye movement (REM) sleep: increased eye movement, loss of muscle tone and dreaming, this is where most of the dreaming happens Why we sleep  Exact function of sleep unclear…  But allows for certain processes to occur o Body eliminates waste products from muscles o Cells are rep
More Less

Related notes for PS101

Log In


OR

Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


OR

By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.

Submit