Neuroscience CH 4 Flashcards
Examining autopsy tissue has the allowance but also the drawback of…
Allowing neuroscientists to see what our brains look like but has the obvious drawbacks of telling them about how the systems work alive
What do neuropsychologists do? What does this help us conquer?
test the behaviour of patients with damage to certain parts of their brain. This allows us to know which parts of the brain do what depending on what part of the brain is damaged and what the patient therefore lacks in.
What is the drawback of neuropschologist work?
Inferences are made about the brain without possible smaller abnormalities being recognized that may cause the problem
Electroencephalograms are used for
recording brain activity or brain waves from the surface of the scalp during certain states such as awake or asleep
What is lesioning
destroying specific brain areas to see how behaviour changes
What are neuroimaging techniques used for
show visual images in awake humans
MRI, fMRI, PET, CT scans are all
neuroimaging techniques
Clinical observation allows
discovering of a number of brain disorders
What is a brain lesion?
Experimentally destroys brain tissue to study animal behaviours after such destruction
What is PET?
Positron Emission Tomography Scan is a visual display of brain activity that detects a radioactive form of glucose while the brain performs a given task
What is MRI scan?
Magnetic resonance imaging uses magnetic fields and radio waves to produce computer generated images that distinguish among different types of brain tissue
What are neurone?
(nerve cell) main building block of the brain
What are the three types of neurons?
sensory, motor, interneuron
Which neurone gathers sensory info
sensory
which neurone communicates info to muscles
motor
which neurone carries info between neurone in the brain and the spinal cord?
interneuron
Which neuron is unipolar?
interneuron
which neurone is bipolar?
sensory
which neurone is multipolar
motor
What is a cell body?
it contains the nucleus which provides energy for the neuron
What are dendrites
receive messages from other neurons
what does the axon fo
carries info away from the cell body
what does the axon terminals do
transmits signals to the dendrites on the next neurone
What is the myelin sheath?
a substance that speeds up the firing of the neuron
What do the nodes of ranvier do?
they are the small gaps on the neurone that have no myelin covering
what is the order of the neurone from one dendrite to the next
dendrite - cell body - axon - myelin sheath - nodes - terminals - muscle
Glia?
cells that help support neurons and basically also make up the nervous system
What do astrocytes do? (3)
They create blood-brain barrier, influences communication between neurone and helps heal brain damage
what are oligodendroglia
provide myelin to speed up transmission of neurons
what are microglia?
clean up dead cells and prevent infections in the brain
list the three types of glia
astrocytes, oligodendroglia, microglia
Cells are surrounded by (a) and contain (b). Both fluids contain charged particles called (c)
extracellular fluid/intracellular fluid/ions
When is the resting potential?
when a neurone is at rest
The neurone is more negatively charged inside or outside of the cell? (-70mv)
inside
The resting charge is maintained through the actions of….
sodium-potassium pumps
neurone send messages to one another via electrochemical actions meaning….
chemicals cause an electrical signal to be generated
A sudden charge of a neurone axon causes it to release a chemical called….. thereby passing an electrical signal from one neurone to the next
neurotransmitter
Neurons are covered by a
membrane
ions are molecules that contain a relative imbalance of…..
protons or electrons and thus either are negatively or positively charged
When a neuron is said to not be sending a message it is considered to be
resting
What is the term that is described as allowing crtain ions to flow back and forth through ion channels?
selective permeability
Ion channels open and close in response to messes received from
the cells
Resting potential is maintained or changed by these specific ions
Na+, K+ and CL-
What ion is positively charged and higher concentration outside the cell?
sodium Na+
What ion is positively charged and higher concentration inside the cell?
Potassium K+
What ion is negatively charged and has higher concentration outside the cell?
CL- Chloride
unequal distribution of ions inside and outside cell establishes a
concentration gradient
Concentration gradient changes when…
electrical charge causes ion channels to open and allow more Na+ to flow into the cell
When a neurone fires it is the…
action potential
What is the four steps of action potential?
- Ion channels open to let the positive chard (Na) in.
- If inside of cell reaches a certain threshold of -50mv and action potential occurs
- The action potential moves down the membrane of the axon
- As the action potential moves past a part of the membrane the na/k pump works to restore the membrane to resting potential
Na+ goes (a) the cell during action potential while K+ goes (b)
in/out
What are the regions of bare axon that are between the areas wrapped in myelin called?
nodes of ranvier
What allows action potentials travel down the axon by jumping?
nodes of ranvier
What is plasticity
repeated release of neurotransmitters that can cause permanent change to the neurons
What is all or none?
Either a neurone is sufficiently stimulated in threshold to start an action potential or it is not
After firing, a neurone can’t fire for a 1000th of a second. What is this called?
Refractory period
What is an absolute refractory period?
a short time after an action potential during which a neurone is completely unable to fire again
what is a relative refractory period?
just after the absolute refractory period during which a neurone can only fire if it receives a stimulus stronger than its usual threshold level
When an action potential reaches the end of the axon it triggers the release of
neutransmitters
Neurotransmitters are chemicals that help neighbouring neurons
talk to eachother
Neurotransmitters float from the (a) of one neurone and are taken up by the (b) in a neighbouring neuron
synaptic vessel and neurotransmitter receptors
What is the synapse?
the small space between neurons
What is the lock and key mechanism?
neurotransmitters bind to the receptors of the receiving neuron in a key-lock mechanism
3 functions of acetylcholine
activate motor neurons for skeletal muscles, contribute to the regulation of attention/arousal/memory, some AVh receptors are stimulated by nicotine
5 functions of dopamine
voluntary movement, pleasurable emotions, decreased levels of it is involved with parkinsons disease, overactivity of DA synapses is associated with schizophrenia, cocaine elevates activity at DA synapses
2 functions of norepinephrine
contributes to modulation of mood and arousal, cocaine elevate activity at NE synapses
Abnormal levels of serotonin may contribute to
depression and OCD
serotonin is involved in regulation or
sleep, wakefulness, eating, agression
Antidepressant drugs and prozac affect
seritonin circuits
What serves as widely distributed inhibitory transmitter?
GABA
Endorphins resemble
opiate drugs in structure and effects
Endorphins contribute to
pain relief and some pleasurable moments
What is psychopharmachology
the study of how drugs affect behviour
Drugs either have an (a) or an (b) effect on the system
agonistic/antagonistic
an agonist mimics a
neurotransmitter
an (b) block neurotransmitter
antagonsit
Electrival events in postsynaptic neurons that occur when a neurotransmitter binds to one of its receptors is called
postsynaptic potentials
the electrical response of the postsynaptic cell is determined by the
recepter
regions of postsynaptic membranes have been stimulated by excitatory neurochemicals to open their ion channel are…..
depolarized
What is a hyper polarized area?
areas of a cell the have had their negative charade increased in an inhibitory fashion making it less likely that the cell will generate an action potential
Neural networks are
patterns of neural activity that interconnect and fire together or sequentially
synaptic connections create
elimination and creation, synaptic pruning
What is the central nervous system?
neurons in the brain and spinal cord
what is in the peripheral nervous system?
neurons in the rest of the body
what are the two categories of the peripheral nervous system
somatic and autonomic
What does the autonomic nervous system contain? what do they do
sympathetic and parasympathetic. symp is for stress and para is rest
What does the somatic nervous system do?
transmits info about the senses and movement
the pain reflex circuit consists of
sensory neuron, inter and motor only
What does pain reflex circuit allow for?
rapid motor reactions to pain and controls pain reflexes without any communication with the brain
Hindbrain is the part of the brain closest to the
spinal cord
what part of the brain regulates basic life functions
hindbrain
hindbrain consists of the (4)
pons, reticular formation, cerebellum and medulla
the midbrain is found right on top of the
brain stem
The midbrain has a large
variety of functions
the midbrain consists of the (6)
thalamus, hypothalamus, hippocampus, substantia, nigra and pituitary gland
The neocortex is located at
the top part of the brain
The neocortex is responsible for (6)
visual, auditory, motor, sensory, cognitive and complex thought
The medulla is the base of the brainstem that controls…
heartbeat and breathing
The reticular formation is a nerve network in the brainstem that plays an important role in controlling
arousal
The cerebellum is also known as the
little brain
The cerebellum helps coordinate…
voluntary movements and balance
The cerebellum has many …. on its surface
folds
The (4) form the limbic system
thalamus, hypothalamus, amygdala and hippocampus
What is the brains sensory switch board?
thalamus
Where is the thalamus located
top of the brain stem
The thalamus directs messages to the sensory areas in he cortex and transits replies to the
cerebellum and medulla
The hypothalamus lies below the
thalamus
The hypothalamus directs several maintenance activities like
eating, drinking, temperature, emotion control
The hypothalamus helps govern the … system and …. gland
endocrine system and pituitary gland
What is the doughnut shaped system of neural structure at the border of the brain stem and cerebrum?
The Limbic System
What emotions is the limbic system associated with?
fear, aggression, drives for food and sex
What does the Limbic System include?
hippocampus, amygdala and hypothalamus
What is the Amygdala linked to in terms of emotion?
fear and anger
What structure consists of two lima bean sized neural clusters?
Amygdala
What does the HPA Axis consist of? (4)
The hypothalamus, the anterior pituitary, adrenal gland and cortisol
The HPA Axis is a….
Negative feedback loop
What four lobes does the neocortex consist of
Parietal, frontal, occipital, and temporal
The frontal lobe is located where?
the front of the brain
Which lobe is for higher intellectual thinking?
frontal lobe
The Broca’s area is found where and for what?
in the frontal lobe and speech production
The prefrontal cortex is found where? what is it responsible for? (4)
Frontal lobe, memory, morality, mood and planning
The temporal lobe is located on the
sides of the brain
The temporal lobe is responsible for (2)
speech comprehension and recognizing complex visual stimuli like faces
Where and what is the Wenicke’s area?
language comprehension in the temporal lobe
The occipital lobe is found where
back of the brian
The occipital lobe is for
vision
The visions crossed pathway means that the pathways…
divide
What happens when visual pathways divide?
visual cues form temporal side of visual field are sen to opposite side of brain. Visual cue from medial or nasal side are sent to the same side of the brain
Where is the parietal lobe
at the top of the brain
the parietal lobe functions for
the perception of touch and complex visual information, especially about locations
What is the somatosensory and where is it?
a strip containing neurons that register the sensation of touch
Areas of the neocortex include:
sensory cortex, motor cortex and association cortex
What cortex registers sensory neurons (touch)
sensory cortex
What cortex registers the motor neuron (muscles)
motor cortex
What cortex registers complex functions, includes higher-order sensory processing, integrating information from from different sense, thinking, planning
association cortex
What is the location of the corpus callosum
connects the two brain hemispheres
What is the function of the corpus callosum
a dense bundle of neural fibres (axons) that allow communication of information from one side of the brain to the other
What does evolutionary psychology examine?
how the process of evolution has shaped the body and brain via the interaction of our genes and the environment to produce our thoughts and behaviours
What is phylogeny
the development of unique species over time
mammals evolved from an offshoot of…
reptiles
all life on earth is interrelated and derives from one common ancestor….
LUCA - last universal common ancestor
What are the 3 super kingdoms
Eucharia, Archea, and Bacteria
What is the Tiktaalik?
a fish in the Canadian Arctic that had a primitive wrist with finger-like bones
What are homologous traits
characteristics that are similar between species and can be traced back to a common ancestor
What are analogous traits?
characteristics that have evolved independently in different species
What is the development of similar physical characteristics or behaviours in different species that do not share a common ancestor
convergent evolution
Who is the father of evolution?
Charles Darwin
What is the evolution by natural selection?
when animals with physical and behavioural attributes well suited to their environment are more like to survive and reproduce
What is an individuals ability to successfully to successfully grow to maturity and have offspring
their fitness
What were darwin’s four observations?
animals were changing over time, aspects of species that seem different on the surface such as humans hands, bat wings have structural similarities underneath, selective breeding of captive animals leads to changes in appearance of the animal, not all animals that are born will survive to maturity and be able to reproduce
What is the encephalization factor?
the ratio of brain weight to body weight
The size of the …. is most important
neocortex
what percentage of the brain is the neocortex?
80%
The australopithecus skull is what fraction of the size smaller than present day skull
2/3
what area is much smaller than usual on the australopithecus skull?
frontal cortex
Two behaviours that influence the likelihood of reproductive success and survival are
mate choice and parental investment
what is brain lateralization?
brain areas that are specialized for certain functions are found in different hemispheres of the brain
An example of brain laterization is…
speech is usually found in the left hemisphere of right handed persons
Some people have their brain surgically severed to prevent spreading of…
seizures from one side of the brain to the other
What are split brain patients?
patients that have their brain surgically split
There is no relationship between brain size and…
IQ
Gender differences in brain structure are very…
small and therefore do not predict much
Explain splitting the brain
A procedure in which the two hemispheres of the brain are isolated by cutting the connecting fibres (mainly those of the corpus callosum) between them
What does the visual field have to do with the severing of the corpus callosum?
objects in the right visual field can be named while objects in the left visual field cannot
What are neurological diseases?
structural, biochemical, or electrical circuit abnormalities of the brain, spinal cord and nerves
Multiple sclerosis is…
the loss of myeline on the axons resulting in poor motor skills, poor sensory capabilities and pain
What is amyotrophic lateral sclerosis? What are they also called?
ALS or Lou Gehrig’s disease, is the degeneration of motor neurons in the spinal cord, leading to loss of movement and eventual death
What is parkinsons disease?
dopaminergic neurons die causing tremors and muscle rigidity
What is Huntington’s disease?
neurons in the striatum die which causes awkward movements and symptoms of psychosis
Some disorders may respond to what kind of transplant?
stem cell transplant
What is a stem cell?
and undifferentiated cell that can divide to replace itself and create new cells that have the potential to become all other cells of the body including neurons
