Textbook Notes (368,122)
Canada (161,660)
Psychology (1,957)
PS101 (452)
Chapter 4

Chapter 4.docx

7 Pages
130 Views
Unlock Document

Department
Psychology
Course
PS101
Professor
Kathy Foxall
Semester
Winter

Description
Chapter 4: The Brain: Source of Mind and Self The Nervous System: A Basic Blueprint The Central Nervous System  Portion of the nervous system consisting of the brain and the spinal cord  Receives, processes, and stores sensory information  Spinal cord o Collection of neurons and supportive tissue running from the base of the brain down the centre of the back, protected by a column of bones o Spinal reflexes  Automatic, require no conscious effort (hot iron)  Reflexes influenced by thoughts and emotions (e.g. erection)  Neural circuits underly many spinal reflexes linked to neural pathways that run up and down spinal cord, to and from brain The Peripheral Nervous System  Handles central nervous system input and output  Contains portions of the nervous system outside the brain and spinal cord  Sensory nerves o Carry messages from receptors in skin, muscles, and other internal and external sense organs to the spinal cord, which sends them to the brain  Motor nerves o Carry orders from central nervous system to muscle, gland, and internal organs o Cause glands to secrete hormones  Somatic nervous system o Subdivision of peripheral nervous system that connects sensory receptors to skeletal muscles  Autonomic nervous system o Subdivision of peripheral nervous system that regulates internal organs and glands  Sympathetic nervous system o Subdivision of the autonomic nervous system that mobilizes bodily resources and increases output of energy during emotion and stress  Parasympathetic nervous system o Subdivision of nervous system that operates during relaxed states and conserves energy Communication in the Nervous System  Neurons o Cell that conducts electrochemical signals, basic unit of the nervous system, called a nerve cell o Transmit info through central nervous system  Glia o Cells that support, nurture, and insulate neurons, remove debris, and enhance formation and maintenance of neural connections  Estimate 100 billion neurons in brain The Structure of the Neuron  Dendrites o Neuron’s branches that receive info from other neurons and transmit it towards the cell body  Cell body o Part of the neuron that keeps it alive and determines whether or not it will fire  Axon o Neuron’s extending fibre that conducts impulses away from the cell body and transmits them to other neurons  Myelin sheath o Fatty insulation that may surround the axon o Prevent signals in adjacent cells from interfering with each other, speeds up conduction of neural impulses  Nerve o Bundle of nerve fibres in the peripheral nervous system (axons and dendrites)  Cranial nerves o Connect directly to the brain Neurons in the News  Neurogenesis o The production of new neurons from immature stem cells  Stem cells o Immature cells that renew themselves and have the potential to develop into mature cells; given encouraging environments, stem cells from early embryos can develop into any cell type o ES cells useful, differentiate into any type of cell How Neurons Communicate  Synapse o Site where transmission of a nerve impulse from one nerve cell to another occurs o Includes the axon terminal, synaptic clef, and receptor sites in the membrane  Action potential o Brief change in electrical voltage that occurs between the inside and outside of an axon when a neuron is stimulated o In unmyelin sheath, gives rise to new action potential at next point o In myelin sheath, action potential hops from one node to the next at a faster rate, causes regeneration of action at each node  Neurotransmitter o Chemical substance released by a transmitting neuron at the synapse, alters activity of receiving neuron at tip o Molecules bind briefly with receptor sites  Excitatory o Shift in positive direction  Inhibitory o Voltage shift in negative direction The Plastic Brain  Plasticity o Brains ability to change and adapt in response to experience, reorganize neural connections  Unused connections pruned away as cells or branches die, leave more efficient neural network, explain critical development periods Chemical Messengers in the Nervous System Neurotransmitters  Serotonin affects neurons involved in sleep, appetite, perception, suppression  Dopamine affects movement, memory, learning, emotion (parkinsons loss of dopamine)  Acetylcholine affects muscle action, cognitive functioning, memory, function (Alzheimer’s can’t produce it)  Norepinephrine affects heart rate and intestinal activity  GABA is major inhibitory in the brain (sleep/eating disorders/EPILEPSY)  Glutamate major excitatory in brain (multiple sclerosis overproduce)  DISORDER MAY LEADS TO ABNORMAL NEUROTRANSMITTER RATHER THAN OTHER WAY AROUND Endrophins  Chemical substances in the nervous system that are similar in structure and action to opiates; involved in pain reduction, pleasure, memory, and are known technically as endogenous  Endorphin levels seem to shoot up when an animal or person is afraid or under stress/pain Hormones  Chemical substances secreted by organs called glands, that affect the functioning of other organs  Endocrine glands o Internal organs that produce hormones and release them into the bloodstream  Melatonin o Secreted by pineal gland, involved in daily regulation of biological rhythms  Oxytocin o Secreted by pituitary gland, stimulates contraction, milk, promotes trust in sexes  Adrenal hormone
More Less

Related notes for PS101

Log In


OR

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