Chapter 3 Flashcards
neurons
cells in the nervous system that communicate with one another to perform information-processing tasks
cell body
the part of a neuron that coordinates information-processing tasks and keeps the cell alive
dendrite
the part of a neuron that RECIEVES information from other neurons and relays it to the cell body
axon
the part of the neuron that TRANSMITS information to other neurons, muscles, or glands
myelin sheath
An insulating layer of fatty material that covers axons
Glial cells
support cells found in the nervous system
myelin sheath is composed of glial cells
demyelinating diseases
the myelin sheath deteriorates, slowing the transmission of information from one neuron to another
synapse
the junction or region between the axon of one neuron and the dendrites or cell body of another
sensory neurons
neurons that recieve information from the external world and convey this information to the brain via the spinal cord
responds to light, sound, touch, taste, and smell
motor neurons
neurons that carry signals frm the spinal cord to the muscles to produce movement
interneurons
compose most of the nervous system
neurons that connect sensory neurons, motor neurons, or other interneurons
mirror neurons
you see someone else doing something and that part of your brain acts up too
- helps us understand emotion, empathy
- mirror neurons may be lacking in autism patients
purkinje cells
a type of interneuron that carries information from the cerebellum to the rest of the brain and spinal cord
(looks kind of like a tree)
pyramidal cells
found in the cerebral cortex
have a triangular cell body and a single long dendrite with other small dendrites
bioplar cells
a sensory neuron found in the retinas of the eye
-have a single axon and a single dendrite
conduction
conduction of electric signal over relatively long distances within neurons, from the dendrites, to the cell body, then throughout the axon
transmission
transmission of electric signals between neurons over the synapse
conduction + transmission = electrochemical action of neurons
resting potential
the difference in electric charge between the inside and outside of a neuron’s cell membrane
the resting potential is negative
action potential
an electric signal that is conducted along a neuron’s axon to a synapse
only occurs when the electric shock reaches a certain threshold
action potential occurs when:
there is a change in the state of the axon’s membrane channels
refractory period
the time following an action potential during which a new action potential cannot be initiated
Nodes of Ranvier
break points in the myelin chain covering the axon
electric charges jump from node to node— this is called saltatory conduction
terminal buttons
at the end of axons
knoblike structures that branch out from an axon
filled with tiny vesicles that contain neurotransmitters
neurotransmitters
chemicals that transmit information across the synapse to a recieving neuron’s dendrites
receptors
parts of the cell membrane that recieve the neurotransmitter and initiate or prevent a new electric signal
Neurotransmitters leave the synapse through three processess:
- Reuptake occurs when neurotransmitters are reabsorbed by the terminal buttons of the presynaptic neuron’s axon
- Neurotransmitters can be destroyed by enzymes in the synapse in a process called enzyme deactivation
- Neurotransmitters can bind to the receptor sites called sutoreceptors on hte presynaptic neurons.
Acetylcholine (ACh)
A neurotransmitter involved in a number of functions including voluntary motor control
Alzheimers = deterioration of ACh neurons
Dopamine
A neurotransmitter that regulates motor behavior, motivation, pleasure, and emotional arousal
high levels = scizophrenia
low levels = parkinsons
Glutamate
A major excitatory neurotransmitter involved in information transmission throughout the brain
too much = seizures
GABA
The primary inhibitory neurotransmitter in the brain
Norepinephrine
A neurotransmitter that influences mood and arousal
-hightened awareness
Serotonin
A neurotransmitter that is involved in the regulation of sleep and wakefulness, eating and agressive behavior
Endorphins
chemicals that act within the pain pathways and emotion centers of the brain
Agonists
drugs that increase the action of a neurotransmitter
Antagonists
drugs that block the function of a neurotransmitter
methamphetamine
affects the pathways for dopamine, serotonin, and norepinephrin at the neuron’s synapses
amphetamine
drug that stimulates the release of norepinephrine and dopamine
*this and cocaine prevent reuptake of norep. and dopamine
Prozac
treats depression
agonist
blocks reuptake of seratonin (making it an SSRI drug)
Propranalol
drug that is an antagonist
obstructs receptor sites for norepinephrine in the heart
nervous system
an interacting network of neurons that conveys electrochemical information throughout the body
Central Nervous System (CNS)
the brain and spinal cord
-recieves sensory info and sends commands to the skeletal and muscular systems for action
Peripheral Nervous System (PNS)
- connects the CNS to the body’s organs and muscles
- has 2 subdivisions: somatic and autonomic nervous systems
The somatic nervous system
a set of nerves that conveys information in and out of the CNS
- have conscience control over this system
- percieve, think, coordinate behaviors
the autonomic nervous system (ANS)
set of nerves that carries involuntary and automatic commnads that control blood vessels, body organs, and galnds
-has 2 subdivisions: the sympathetic and parasympathetic nervous systems
sympathetic nervous system
a set of nerves that prepares the body for action in threatening situations
parasympathetic nervous system
a set of nerves that helps the body return to a normal, resting state
-reverses sympathetic system
spinal cord functions
breathing, responding to pain, moving your muscles, allowing you to walk, connects brain and rest of body
spinal reflexes
simple pathways in the nervous system that rapidly generate muscle contractions
hindbrain
an area of the brain that coordinates information coming into and out of the spinal cord
-consists of the medulla, the pons, and the cerebellum
medulla
an extension of the spinal cord into the skull that coordinates heart rate, circulation and respiration
reticular formation
- inside the medulla
- small cluster of neurons
- regulates sleep, wakefullness, and levels of arousal
cerebellum
- behind the medulla
- a large structure of the hindbrain that controls fine motor skills
pons
a structure that relays information from the cerebellum to the rest of the brain
midbrain
- sits on top of the hindbrain
- consists of the tectum and the tegmentum
tectum
orients an organism in the environment
tegmentum
involved in movement and arousal
forebrain
- highest level of the brain
- contains cerebral cortex and subcortical structures
- controls cognative, emotional, sensory and motor functions
cerebral cortex
outermost lyaer of the brain, visible to the naked eye and divided into two hemispheres
subcortical structures
the areas of the forebrain housed under the cerebral cortex near the very center of the brain
-contains the thalamus, hypothalamus, pituitary gland, limbic system, and basal ganglia
thalamus
relays and filters information from the senses and transmits the information to the cerebral cortex
hypothalamus
- located below the thalamus
- regulates body temperature, hunger, thirst and sexual behavior
pituitary gland
- located below the hypothalamus
- the “master gland” of the body’s hormone-producing system, which releases hormones that direct teh functions of many other glands in the body
limbic system
a group of forebrain structures including the hypothalamus, the amygdala, and the hippocampus, which are involved in motivation, emotion, learning and memory
hippocampus
a structure critical for creating new memories and integrating them into a network of knowledge so that they can be stored indefinitely in other parts of the cerebral cortex
amygdala
a part of the limbic system that plays a central role in many emotional processes, particularly the formation of emotional memories
-almond shape
basal ganglia
a set of subcortical structures that directs intentional movements
-get input from cerebra cortex and send signals out to motor centers of the brain
gyri
the smooth, raised part of the cerebral cortex
sulci
the indentations or fissures in the cerebral cortex
Three levels of organization of the cerebral cortex:
- the separation of the cortex into two hemispheres
- the functions of each hemisphere
- the role of specific cortical areas
commissures
bundles of axons that make possible communication between parallel areas of the cortex in each half
contralateral control
each hemisphere controls functions of the opposite side of the body
corpus callosum
a thick band of nerve fibers that connects large areas of the cerebral cortex on each side of the brain and supports communication of information across the hemispheres
occipital lobe
- located at the back of the cerebral cortex
- processes visual information
parietal lobe
- located in front of the occipital lobe
- processes information about touch
- contains the somatosensory cortex
somatosensory cortex
a strip of brain tissues running from the top of the brain down the sides
-represents the skin areas of the opposite side of the body
motor cortex
- directly in front of the somatosensory cortex
- different parts respond to different body parts
temporal lobe
- located on teh lower side of each hemisphere
- responsible for hearing and language
- contains the primary auditory cortex
frontal lobe
- behind the forehead
- specialized areas for movement, abstract thinking, planning, memory, and judgement
association areas
areas of the cerebral cortex that are composed of neurons that help provide sense and meaning to information registered in the cortex
brain placticity
functions that were assigned to certain areas of the brain may be capable of being reassigned to other areas of the brain to accomodate changing input from the environment
ontogeny vs. phylogeny of the brain
ontogeny = how the brain develops within a given individual
phylogeny = how the brain developed within a particular species
gene
the unit of hereditary transmission
chromosomes
strands of DNA wound around each other in a double-helix configuration
heritability
a measure of th variability of behavioral traits among individuals that can be accounted for by genetic factors
electroencephalograph (EEG)
A device used to record electrical activity in the brain
CT scan
- takes x-ray photos of brain
- used to locate lesions or tumors
MRI (magnetic resonance imaging)
- applying magnetic pulses to the head and recording hown the pulses are absorbed throughout the brain
- get clear picture of the brainbut reveal nothing about the function of the brain
functional brain-imaging techniques
- PET scan (use radioactive substance and see where brain lights up)
- fMRI
