Chapter 4 Flashcards
What are the 2 main parts of the nervous system?
central nervous system and peripheral nervous system
what is the central nervous system?
the portion of the nervous system consisting of the brain and spinal cord
what is the spinal cord?
a 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 (the spinal column)
what is the peripheral nervous system?
all portions of the nervous system outside the brain and spinal cord; it includes sensory and motor nerves
what subsystems are included in the peripheral nervous system
somatic, autonomic, sympathetic, and parasympathetic
what is the somatic nervous system?
the subdivision of the pns that connects to sensory receptors and to skeletal muscles
what is the autonomic nervous system?
the subdivision of the pns that regulates the internal organs and glands
what is the parasympathetic nervous system?
the subdivision of the pns that operates during relaxed states and that conserves energy
what is a neuron?
a cell that conducts electrochemical signals; the basic unit of the nervous system (nerve cell)
what is glia?
cells that support, nurture, and insulate neurons, remove debris when neurons dies, enhance the formation of neural connections, and modify neural functioning
what 6 parts are there in the neuron?
dendrites, cell body, myelin sheath, nodes, syapse, and axons
what are dendrites?
a neuron’s branches that receive information from other neurons and transmit it toward the cell body
what is the cell body?
the part of the neuron that keeps it alive and determines whether or not it will fire
what is the axon?
a neuron’s extending fibre that conducts impulses away from the cell body and transmits them to other neurons
what is the myelin sheath?
a fatty insulation that may surround the axon of a neuron
what is a nerve?
the build-up of nerve fibres (axons and sometimes dendrites) in the pns
what is neurogenesis?
the production of new neurons from immature stem cells
what are stem cells?
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 type of cell
what is the synapse?
the site where transmission of a nerve impulse from one nerve cell to another occurs; it includes the axon terminal, the synaptic cleft, and the receptor sites in the membrane of the receiving cell
what is action potential?
a brief change in electrical voltage that occurs between the inside and the outside of an axon when a neuron is stimulated; it serves to produce an electrical impulse
what are neurotransmitters?
a chemical substance that is released by a transmitting neuron at the synapse and that alters the activity of a receiving neuron
what is plasticity?
the brains ability to change and adapt in response to experience– for example, by reorganizing or growing new neural conncetions
what are endorphins?
chemical substances in the nervous system that are similar in structure and action to opiates; they are involved in pain reduction, pleasure, and memory and are known technically as endogenous opioid peptides
what are hormones
chemical substances, secreted by organs called glands, that affect the functioning of other organs
what are some well-known neurontransmitters?
serotonin, dopamine, actylcholine, GABA, glutamine, and norepiniphrine
what are 3 types of neurons?
- sensory neurons (carry to brain)
- motor neurons (carry from brain to muscle in body)
- interneurons (most found in brain and spinal cord)
what are nodes?
constrictions in myelin sheath which speed up movement of neural impulses
what charge does the inside of a neuron have during resting potential?
negative
what is polarization?
when there is a balance between the negative and positive
what is the ‘all or none’ principle?
if something is sufficiently stimulated, it will fire to its full potential
what is reuptake?
after communication, a neurotransmitter is taken back in the neuron that released it
what does dopamine effect?
emotional arousal, learning, and memory
what does GABA effect?
motor behaviour and level of arousal
what does serotonin effect?
activity, sleep, appetite, emotion
what does acetylcholine effect?
muscle activity and memory
what is glutamate?
Major excitatory neurotransmiter in the brain
what does norepiniphrine effect?
increased heart rate, slowed intestinal activity during stress, learning, memory, dreaming, walking, emotion
what are endocrine glands?
internal organs that produce hormones and release them into the bloodstream
what are 4 major hormones?
- melatonin: daily biological rhythms
- oxytocin: child birth and milk secretion
- adrenal hormones: emotion and stress
- sex hormones: regulate development and functioning of reproductive organs (androgen/estrogen)
what is the brain stem?
the most primitive part of the brain
what are the 3 parts of the brain stem?
medula, pons, and reticular activating system
what is the medulla?
it is responsible for automatic functions such as breathing and heart rate
what are pons?
involved in sleeping, waking, and dreaming
what is the reticular activating system?
some that extends from the brain stem; arouses cortex and screen incoming information
what is the cerebellum?
a brain structure that regulates movement and balance and is involved in the learning of certain kinds of simple responses
what is the thalamus?
a brain structure that relays sensory messages to the cerebral cortex
what is the hypothalamus?
brain structure involved in emotions and drives that are vital to survival (fear, hunger, thirst, reproduction), it regulates the autonomic nervous system
what is the pituitary gland?
endocrine gland at base of brain that releases many hormones and regulates other endocrine glands
what is the amygdala?
involved in arousal and regulation of emotion; initial emotional response to sensory information
what is the hippocampus?
involved in the storage of new information in memory
what is the cerebrum?
largest brain structure, consisting of the upper part of the brain, divided into two hemispheres, it is in charge of most sensory, motor, and cognitive processes
what is the cerebral cortex?
collections of several thin layers of cells covering the cerebrum; largely responsible for higher mental functions
what are the lobes in the cerbral cortex?
- frontal lobe: front. memory, movement, speech and language
- occipital lobe: lower back. visual sense
- parietal lobe: top. touch and body awareness
- temporal lobe: sides. speech, hearing, some visual system processing
what is flouroscopy?
A continuous X-ray beam is passed through the body part being examined. The beam is transmitted to a TV-like monitor so that the body part and its motion can be seen in detail.
what is an electron microscope?
Microscope uses electron beam to illuminate specimen to produce a magnified image
what is the lesion method of studying the brain?
damaging or removing section of brain in animals and then observing the effects
what is imaging used for when studying the brain?
can watch how brain behaves (CT, PET, and fMRI)
what are computerized tomography (CT) scans?
Use Xray technology to provide structural info
about the brain and the ventricles in the brain. Originally only 2D, now 3D.
what is positron emission tomography (PET)
Uses a tracer and then lies in a tunnel shape apparatus that emits Xrays
Look for blood flow and metabolism when the individual is doing different tasks or activities (what parts light up)
what is functional magnetic resonance imaging?
a moving picture that uses extremely strong magnets
what is diffuse optical tomography?
Near infrared spectography: optic fibres and infrared light is beamed at the babies brain
what is recording used for and how is it uses?
record electrical and magnetic output from brain and is used to treat depression and anxiety (EEG and TMS)
what is the electroencephalogram (eeg)?
Measure brain wave activity (electrical patterns that are created by the rhythmic firing of neurons in brain)
what does the left hemisphere of the brain specialize in?
speech processing and language
what does the right hemisphere of the brain specialize in?
creative, spatial, and musical tasks
what is neuroplasticity?
If one section is damaged another section of the brain may take over the skills (relearning of skills)
what does lateralization of function refer to?
localization of a function in one hemisphere or the other
what is a hemispherectomy
removal of parts of cerebral cortex of 1 hemisphere
radical treatment for severe seizure disorder
what is Rasmussen’s syndrome
seizures in one hemisphere of brain
what is the split brain?
what pathways connecting the left and right hemispheres are severed
what is the role of prenatal androgens in the development of lateralization?
prenatal androgens (primarily testosterone) play a
role in lateralization of language and visual-spatial
skills. testosterone play a role in language in the brain, girls have higher levels of prenatal testosterone
how does someones dominant hand relate to their language lateralization?
generally the dominant hand will be opposite to what side of the brain is in charge of language processing.
how are people who have dominant left in comparison to people with dominant right?
left brain: more analytical and sequential
right brain: more holistic in their thinking
