Neurons Are Physically Held In Place By
Neurons: the basic elements of behavior
The nervous system and the endocrine system are support systems. The brain is NOT the mind, but a very vital support system that:
1. Facilitates COMMUNICATION between the outside world and a person.
2. INTEGRATES internal communications
3.COORDINATES bodily functions,some of which are involved in behavior.
Neurons
Nerve cells, the basic elements of the nervous system. The smallest unit of the nervous system; there are more than 100 billion nerve cells in the brain alone; billions more are in other parts of the nervous system, for the total of 1 trillion, that are involved in behavior.
The nerve cell consists of:
The cell body:
Like most cell in the body, neurons have a cell body that contains a nucleus.
The nerve cell consists of:
Dendrites:
A cluster of fibers at one end of a neuron that receives messages from other neurons.Those fibers which look like twisted branches of a tree.
The nerve cell consists of:
Axon:
The part of the neuron that carries messages received by the dendrites and from other neuron.
The nerve cell consists of:
Axon Terminals:
...
The nerve cell consists of:
Terminal Button:
Small bulges at the end of axons that send messages to other neurons.
The nerve cell consists of:
The myelin sheath:
A protective coat and protein that wraps around the axon.
The nerve cell consists of:
Glial cells:
Neurons are physically held in place by glial cells. Glial cells provide nourishment to neurons, insulate them, help repair damage and generally support neural functioning.
Afferent Neurons
Are sensory neurons.
Efferent Neurons
Motor neurons
Interneurons
Association Neurons
Nerves
Are groups or bundles of axon and dendrites.
The neural impulse
An electrical charge, that is picked up by the dendrites, and travels through the cell body, along axon,to the axon terminals.
All or none law
They are either ON or OFF, with nothing in between.the on state and the off state
Action potential
when a positive charge reaches a critical level, the TRIGGER is pulled and the electrical impluses known as an action potential travels along the axon to the neurons.
Mirror Neurons
Specialized neurons that fire not only when a person enacts a perticular behavior, but also when a person simply observes another person carriny out the same behavior.
Synapse
is the space between two neurons, where the axon of a sending neurons communicates with the dendrites or a recieving neurons by using chemical messages
Neurotransmitters
Chemicals that carry messages across the synapse to the dendrites and sometimes to the cell body of a reciever neurons.
Facts to know
Although message travels in electrical form within a neuron, they move between neurons through a chemical transmission system.
Types of neurotransmitters
Excitatory neurotransmitters: Causes the next neuron to fire.
Types of neurotransmitters
Inhibitory Neurotransmitters: Prevents the next neuron from firing
Reuptake
The reabsorption of neurotransmitters by the terminal button.
Neuroregulators
Are brain chemicals that act by adjusting or regulating the sensitivity of Synapses "UP" or "DOWN" such as endorphin.
(A).The nervous system
The nervous system has two main division
1.Central Nervous system (CNS)
2.Peripheral Nervous system (PNS)
1.Central Nervous system (CNS)
Is located in the center of the body, and consists of the brain and the spinal cord and is the central processing center.
2.Peripheral Nervous system (PNS)
is located at the periphery of the body ( the sense organs)and the internal body organs it carries messages to and from the (CNS)
Facts to know
The synapse consist of the axon terminals of the previous neuron + the synaptic space+ the dendrites and cell body of the next neuron
The central nervous system
1. The brain is not the seat of awareness and reason- that is the function of the mind.
The central nervous system
The spinal cord : a complex cable of nerves that connects the brain to the rest of the body; bundles of long, myelinated nerve fibers:
The spinal cord
A. Pairs of nerves exits through the spinal vertebrae ( bony structure) and carry sensory(afferent) and motor(efferent) information to and from the spinal cord
The spinal cord
Primary functions of the spine are: REFLEX ACTIONS and communication with the brain.
The peripheral nervous system
Links the brain and the spinal cord ( I. E the CNS) to the rest of the body; PSN consists of two subsystems:
PNS consist of 2 subsystems
Somatic nervous system: carries messages to and from those parts of the body that are on contact with the OUTSIDE WORLD.
Afferent nerves or (sensory nerves)
Sense organ provides input from the outside world via the afferent nerves or sensory nerves
Efferent nerves or ( motor nerves)
B.Skeletal muscles provide output or response to the outside world via the efferent nerves or motor nerves
Somatic nervous system
Somatic nervous system controls voluntary behavior
Automatic nervous system (ANS)
Carries messages to and from internal organs of the body, such as glands , and smooth, involuntary muscles
Automatic nervous system consists of two branches:
Sympathetic division:
Automatic nervous system consists of two branches:
Parasympathetic division:
Evolutionary foundations of the nervous system:
1. Evolutionary psychology: attempts to identify those behaviors that are the result of genetic evolution.
Evolutionary foundations of the nervous system:
2. Behavioral genetics: focuses on the genetic basis of behavior, and the role that heredity plays in individual differences in behavior:
Evolutionary foundations of the nervous system:
Genetics: the study of how living creatures pass on traits from one generation to another.
Evolutionary foundations of the nervous system:
A. Genes: are the basic units of heredity
Evolutionary foundations of the nervous system:
Chromosomes: are strands of DNA molecules, found in the nucleus of every cell of the body; these DNA strands are arranged in pairs, and the number of pairs differ from different species.
The units of heredity, the genes, are located on the chromosomes.
Evolutionary foundations of the nervous system:
The GENOME is the total of all genes, available to the human species, located in the 46 chromosomes
The genome
The result of the largest research on Human Genome project now places the number of genes at 20-25,000 NOT 100,000 as originally thought
The genome
Human characteristics are influenced by genes occurring as pairs located on specific chromosomes
Facts
The interaction of genes and the environment determines human traits
Molecular genetics
Is a technique of identifying genes that influence human behavior:
Molecular genetics: Is a technique of identifying genes that influence human behavior:
A. The human genome project has mapped the genes of the 23 pairs of chromosomes to determine the location of genes that influence specific traits and behaviors
Molecular genetics:Is a technique of identifying genes that influence human behavior:
All the geneticist need to do is to determine if an individual has the genes for a specific behavior such as schizophrenia or autism
Endocrine system
Is a system of ductless glands that regulate various functions via chemical messengers called hormones
Hormones
Are like transmitter chemical, but Are release directly into the blood stream(rather than the synapse) and are designed to affect specific organs in specific ways
Hormones
The primary function of hormones is to organize nervous system's and body tissue at certain stage of development example puberty
B. hormones also activate behaviors
The glands
A. Pituitary gland: produces the largest number of hormones and has widest range of effects: is called the master gland because it stimulates other endocrine glands
B. pituitary gland is the servant of the brain
The brain
The human species has the largest brain in relation to body size, humans have the most highly developed brain
The brain
The organization of the brain and its association functions can be viewed from an evolutionary perspective from them most primitive the sophisticated.
The Central core: ( or sub cortex,or old brain)
The part of the brain that lies under the cortex as we move upward from the top end of the spinal cord the various brain structures become involved in increasingly more complex sophisticated levels of mental functioning
The hindbrain(or brainstem)
Is sometimes referred to as the early brain or the reptilian brain
The limbic system
Plays a role in producing in emotion and motivated behavior sometimes referred to as mammalian brain
The limbic system
Is located between the central core and the cerebral Hemisphere
The cerebral cortex(the new brain)
Consists of two cerebral hemispheres that sit on top of the brainstem is 80% of the weight of the brain has 70% of all the neurons
In the CNS is convoluted to fit inside the skull.
Corticalization
Is greatest in human species cortex is a wrinkle and folded in humans but smaller and smoother in animals
A. The outer layer is called cerebral cortex
Cerebral lobes
Cerebral cortex is divided into functional areas that are structurally delineated by deep Fissures called lobes.
The Motor area of the cortex
The motor area lies in the frontal lobe is responsible for voluntary movements
The Sensory areas of the cortex: consists of three lobes of the cortex
1. The parietal lobe is responsible for processing information from skin muscles and joints
The Sensory areas of the cortex: consists of three lobes of the cortex
The temporal lobe is responsible for processing auditory information for our sense of hearing
The Sensory areas of the cortex: consists of three lobes of the cortex
The occipital lobe is responsible for processing of visual information for our sense of vision.
The association areas
Consists of the largest portion of the cortex that do not fall directly within the motor or sensory lobes
The association areas
1. Combine and integrates information from the various lobes
2. Is involved in the higher mental processes
3.aphasia
Neuroplasticity and neurogenesis
The brain is very plastic in the sense that the brain is very dependent on environmental stimulation for growth and development
Neuroplasticity and neurogenesis
1. Case of Jacob illustrates: neuroplasticity
2. Neurogenesis
3. Roles of specific life experiences
Specialization of the cerebral hemisphere
Two separate cerebral hemisphere are connected by a thick band of nerves fibers called Corpus callosum
Specialization of the cerebral hemispheres; Corpus Callosum
1. Interconnects two hemispheres facilitates communication between two hemispheres
Specialization of the cerebral hemispheres; Corpus Callosum
The left side of brain controls the right side of the body; rights side or the brain controls the left side of the body
Specialization of the cerebral hemispheres; Corpus Callosum
However cerebral hemispheres are not identical in function; it is as if we have two brains
Hemispheric lateralization, or specialization: both sides of the brain have different functions
Left brain:
Right brain:
Diversity in the brain
Sex differences
Split-brain research(per roger Sperry)
Split -brain vs blindfolded ss.
Sensation:
Is the activation or stimulation of the entire sensory system the sense organs and the sensory cortex of the brain
A. The Stimulus is some form of physical energy such as light sound etc.
Perception
2.Here is really defined as neurological processing that takes place somewhere in between the physical stimulation of the sense organs and the sensory cortex in the brain
Mental process
But there is the mental process of making sense of the sensory information that has been process etc. creating meaning from sensory information
Psychophysics
Is the study of the relationship between the physical and neurological aspects of stimuli; and our psychological or mental experience of them
Purpose or function of sensation and perception
1. To bring information to us from the outside world; also to bring information to us from the internal body
Purpose or function of sensation and perception
Does this mean that all of our knowledge come from the external environment; does everything that we know come from the external environment
A. Role of instincts
Purpose or function of sensation and perception
It is the role of the mental processing to create meaning and knowledge
A. Knowledge that we create via perception must be appropriate or relevant to the original stimulus in order that we may cope effectively with reality
B. one major cause of abnormal behavior is perception distortion created meaning that irrelevant or inappropriate to the original stimulus reality
Sensory perceptual models
Physical reality --> The sense organs->> The Sensory Cortex( brain)-->> The mind
Physical reality
Physical energies emanated by various objects or aspects of the physical environment this physical energy impacts on the physical sense organ; examples of physical energy
Examples of physical energies
1. Electromagnetic energy (light waves)
2. Disturbances in air molecules (sound waves)
3. Temperature (heat/cold)
4. Mechanics (pressure)
5. Movement (of the body)
6. Chemical molecules (airborne and on the tongue)
The sense organs
Although the various physical energies impact upon our bodies only certain types of body cells are capable of responding to the physical energies called receptors
Receptors
A. There is a different receptor for each type of physical energy, and the receptors are located in specific organs of the body the (sense organs)
Receptors
The receptor converts the physical energy into a nerve impulse which is then picked up by a Peripheral nerve and transmitted to certain parts of the brain neurological processing
Both A. B: This Whole process is called Sensation
Absolute Thresholds
The smallest intensity of a stimulus that must be present in order for the stimulus to be detected
A. Absolute threshold is the stimulus intensity that can be detected 50% of the time
B. Noise
The different threshold
The smallest change in stimulation that allows to detect the difference between two stimuli
Sensory adaptation
The Adjustments to sensory stimulation after prolonged exposure
Visual spectrum
1. Electromagnetic energy or light waves within the visible spectrum
The rods
Especially sensitive to light even at low levels of illumination
The cones
Are especially sensitive to specific wavelengths of light for, and perception
Challenge
Does grass really have a green color or do we color grass green?