Chapter 4: The Brain Flashcards
Central nervous system
Receives, processes, interprets and stores incoming sensory information about taste sound smell color and pressure. Composed of brain and spinal cord.
Spinal cord
Extension of the brain, produces Behaviors on its own without help from the brain
Spinal reflexes:
Automatic without conscious effort
Afferent neurons: sensory
Carries informations from the senses to the spinal cord
Efferent neurons: motor
Carries information from the spinal cord to muscles and glands
Interneuron
Neurons in the center if the spinal cord that connects sensory neurons to motor neurons
Peripheral nervous system
Handles the central nervous system input and output. Contains all portions of the nervous system outside brain and spinal cord.
Sensory nerves: afferent
Carry messages from special Skin receptors in skin, muscles and other internal and external organs to the spinal cord
Motor nerves: efferent
Carry order from the central nervous system to muscles, glands and internal organs
Hormones
Chemical messengers
Somatic nervous system: skeletal
The subdivisions of the peripheral nervous system that connects to sensory receptors to skeletal muscles
Autonomic nervous system:
The subdivision of the peripheral
nervous system that regulates the internal organs and glands
Sympathetic nervous system
The subdivision of the autonomic nervous system that mobilizes bodily resources and increases the out of energy During stress
Parasympathetic nervous system
The subdivision of the autonomic nervous system that operates during relaxed states and conserves energy
Neurons
A cell that conducts electrochemical signals; that basic unit of the nervous system.
Glial cells
90% of the cells in the brain. Makes the myelin sheath, provide nutrition for cells and removes waste
Dendrites
Receives messages from nerve cells
Cell body: soma
Keeps neuron alive and determines when it should fire
Axon
Transmits messages from the dendrites to the axon terminals and out to the other neurons/glands/muscles
Axon terminals
Shoot messages out to the other neurons, glands or muscles
Synaptic vesicles
A sac like structure found with in the axon terminal buttons holding the neurotransmitters
Myelin sheath
Mostly in joints (PSN), fatty insulation that may surround the axon of a neuron.
Nerves
Bundles of neurons/ nerves in PSN
Tracts
Bundles of neurons in the brain and spinal cord (CSN)
Cranial nerves
Same as tracts; bundles of neurons in the brain and spinal cord
Neurogenesis
The production of neurons from immature stem cells
Stem cells
Immature cells that renew themselves and have potential to develop to mature cells
Stem cell research
Stem cells that are used to develop into new cell types when using early embryos
Synaptic cleft
The separation in neurons where the axon terminals of one neuron nearly touches a dendrite or cell body of another
Synapse
The entire site: the axon terminals, the cleft, and the covering membrane of the receiving dendrite
Plasticity
Regeneration of neurons
Action potential
Produces an electric impulse; a brief change in electric voltage that occurs between inside and outside of axon
Nodes of ranvier
Breaks between myelin sheath where the action potential hops
Synaptic vesicles
Tiny sacs in the tip of the axon terminal, release neurotransmitters
Neurotransmitter
A chemical substance that is released by the transmitting neuron at the synapse and alters the activity of a receiving neuron
Excitatory
Stimulate
Inhibitory
Voltage shift in a negative direction
Resting potential
The electric charge of a neuron at rest (70mil volts)
Threshold
The point at which a neuron fires 50 mil volts
Serotonin
(Low levels = depression)
(High levels = autism)
Responsible for changes in mood, sleep pattern, appetite
Dopamine
“Feel good drug” involved in movement and memory
(High levels = schizophrenia)
(Low levels = Parkinsense)
Acetylcholine
Muscle movement and memory and cognitive functions
(Low levels = Alzheimer)
(High levels = spasms)
Norepinephrine
Elevates mood; increases sympathetic nervous system
GABA
“Drags ya” slows everything down including thoughts and reaction time
Abnormal levels= sleeping and eating disorders
Glutamate
Major exciting neurotransmitter (caffeine)
Blood brain barrier
Stem of densely packs capillary and glial cells, whose function is to prevent potentially harmful substance from entering the brain
(Alcohol, weed pass straight through)
Agonist
A drug that enhances the operation of neurotransmitters
Antagonist
A drug the blocks the operation of a neurotransmitter
Endorphins
A chemical substance in the nervous system that are similar in structure and acts as opiates
Enkephalins
Natural pain killer
Neuromodulators
A chemical messenger that increases or decreases action of specific neurotransmitter
Endocrine system
A gland hat releases and produces hormones
Hormones
Chemical substance secreted by organs called glands that are affect the functioning of other organs
Endocrine glands
Internal organs that produce hormones and release them into the blood stream
Hypothalamus
Food, fight, flight, sex
Pituitary
“Master gland” controls all endocrine gland functions, responsible for growth
Pineal gland
Secrets melatonin
Thyroid gland
Regulates metabolism
Ovaries and testes
Produces estrogen and androgen
Melatonin
Secreted by pineal gland; regulates daily biological rhythms and promotes sleep
Adrenal hormones
Produces by the adrenal glands are involved in emotion and stress. Also activated by heat, cold, pain, injury, burns, exercise, drugs and caffeine
Sex hormones
Androgens- (testosterone), estrogen, progesterone. Hormones that regulate the development and function of reproductive organs. Stimulate and regulate male and female sexual characteristics
Lesion method
Damage and remove sections of the brain in animals and observe the affects
Stereotaxic instrument
A tool used in precise area of the brain to cut or destroy tissue
Electoncephalogram
A recording of a neutral activity detected by electrodes
Evoked potentials
Patterns of brain activity produced in response to events
Needle electrodes
Thin wire or hollow glass tubes that are inserted into the brain used to record electrical activity in brain or stimulate brain with electrical currents
Micro electrodes
Inserted into a single cell
Transcranial magnetic stimulate (TMS)
A method of stimulating brain cells, using a powerful magnetic field produced by a wire coil placed on a persons head. Can be used for therapy
PET Scan
A method for analyzing biochemical activity in the brain using injections of glucose like substance containing a radioactive element
CAT scan
X-ray of the brain
MRI
allows exploration of “inner-space” by injecting chemicals. Used to study the brain/body tissue using magnetic fields and radio receivers
fMRI
Captures brain changes in the brain while a person performs a given task
Localization of function
Specialization of particular brain areas for particular functions
Phrenology
Personality can be determined by bumps in the head
Brain stem
The part of the brain at the top of the spinal cord, consisting of the medulla and the pons
Medulla
A structure in the brain responsible for certain autonomic functions such as breathing and heart rate
Pons
A structure in the brain stem involved in sleeping, waking, dreaming
Reticular formation
Arousal and alertness
Reticular activating system
A dense network of neurons found in the core of the brain stem; arouses the cortex and screens incoming information
Cerebellum
A brain structure that regulates movement and balance and that involved in the learning of certain kinds of simple responses
Pituitary gland
A small endocrine gland at the base of the brain, which releases many hormones and regulates other endocrine glands
Limbic system: emotions memory motivations and learning
A group of brain areas involved in emotional reactions and motivated behavior
Thalamus
A brain structure that relays sensory messages to the cerebral cortex
Hypothalamus
A brain structure involved in emotions and drive, vital to survive (food flight fight and sex)
Amygdala
A brain structure involved in arousal and regulates emotion of sensory information
Hippocampus
A brain structure that is involved with the storing of new information (HM)
Cingulate gyrus
Emotional cognitive and motor tasks
Basal ganglia
Involved in movement (voluntary muscle control) and learning
Cerebrum
The largest brain structure, consisting of the upper part of the brain. Sensory motor and cognitive processes
Cerebral hemispheres
The 2 gavels of the cerebrum
Corpus callosum
A bundles of never fibers connecting the 2 cerebral hemispheres
Lateralization
Specialization of the two cerebral hemispheres for a particular operation
Cerebral cortex
Several thin layers of cells covering the cerebrum for higher mental functions
Grey matter
Cell bodies in the cortex
White matter
Lon myelinated axons
Occipital lobes
At the lower back part if the cerebral cortex, receive visual information
Parietal lobes
At the top of the cerebral cortex, receive information on pressure pain touch and temperature
Somatosensory
Receives signals from hands and face because of particular sensitivity
Temporal lobes
Sides of the cerebral cortex involved in hearing memory perception, emotions and language comprehension
Frontal lobes
front of the cerebral cortex involved in short term memory, higher order thinking, imitative, social judgement, and speech
Motor cortex
Movement
Association cortex
The silent area, involved in higher order mental processes when stimulated produce no obvious response
Broca’s area
(Left) speech, left frontal lobe “broken speech”
Wernicke’s area
Language comprehension and understanding “what ya say”
Aphasia
Impaired abilities to use language
Prefrontal cortex
Controls personality
Phineas gage
A rod went through his prefrontal correct personality was different after wards
Spilt brain surgery
Severe the corpus callosum and separate the two hemispheres completely
Left hemisphere
Language; usually exerts control over the right side. Left side is always trying to explain actions and emotions
Right side
Visual; is dominate in visual abilities and active during creation and appreciation of art and music
