Week 5 Readings Flashcards
1
Q
What is the nervous system composed of (cells)?
A
- two basic cell types: glial cells (aka glia) and neurons
2
Q
What is the typical role of glial cells?
A
- play a supportive role to neurons, both physically and metabolically
3
Q
What is the ratio of glial cells to neurons?
A
- 10:1
4
Q
What do glial cells do? (5)
A
- provide scaffolding on which the nervous system is built
- help neurons line up closely with each other to allow neuronal communication
- provides insulation to neurons
- transports nutrients and waste products
- mediate immune responses
5
Q
What do neurons do?
A
- serve as interconnected information processors that are essential for all of tasks of the nervous system
6
Q
How many neurons do we have at birth and what is their role? (2)
A
- 100 billion strong at birth
- central building blocks of the nervous system
7
Q
what is the semipermeable membrane and what does it do? (2)
A
- make up the outer surface of a neuron
- allows smaller molecules and molecules without an electrical charge to pass through, while stopping larger or highly charged molecules
8
Q
what is the soma and what does it contain? (2)
A
- cell body
- contains the nucleus of the neuron
9
Q
dendrites (2)
A
- branching extensions from the soma
- serve as input sites where signals are received from other neurons
10
Q
nucleus
A
- small information processor
11
Q
axon
A
- major extension of the soma
12
Q
terminal button
A
- axon terminal containing synaptic vesicles
13
Q
synaptic vesicles
A
- storage site for neurotransmitters
14
Q
neurotransmitters
A
- chemical messenger of the nervous system
15
Q
where do the signals go after they enter through the dendrites?
A
- transmitted electronically across soma and down the axon, which ends at multiple terminal buttons
16
Q
what is the myelin sheath and what is it made up of? (2)
A
- fatty substance that
coat and insulate axons - made up of glial cells
17
Q
what is the purpose of the myelin sheath? (2)
A
- increases speed at which signals travel
- crucial for normal operation of neurons within the nervous system
18
Q
multiple sclerosis (MS, 4)
- what is it
- what does this cause
- symptoms
- cure?
A
- autoimmune disorder that involves large-scale loss of myelin sheath on axons throughout nervous system
- interference in electrical signal prevents quick transmittal of information by neurons
- symptoms include dizziness, fatigue, loss of motor control and sexual dysfunction
- currently no cure
19
Q
synapse
A
- small gap between two neurons where communication occurs
20
Q
receptors (2)
A
- protein on the cell surface where neurotransmitters attach
- vary in shape, with different shapes matching different neurotransmitters
21
Q
in healthy individuals, how are neuronal signals transmitted? (2)
A
- neuronal signals move rapidly down axon to the terminal buttons, where synaptic vesicles release neurotransmitters into synapse
- neurotransmitters travel across synapse and bind with corresponding receptors on dendrite of an adjacent neuron
22
Q
how do neurotransmitters know which receptor to bind to?
A
- lock and key relationship: specific neurotransmitters fit specific receptors
23
Q
how does a neuron exist in a fluid environment? (2)
A
- surrounded by extracellular fluid
- contains intracellular fluid
24
Q
membrane potential
A
- difference in charge across the membrane which provides energy for signals
25
what is the role of the neuronal membrane?
- keeps extra and intracellular fluid separate which keeps the fluids electronically different
26
what causes the electrical charges in cellular fluids? (2)
- charged molecules (ions) dissolved in the fluids
- neuronal membrane restricts movement of charged molecules and some charged particles tend to become more concentrated on inside or outside of cell
27
resting potential (3)
- what is it
- what do ions do
- where do ions move after
- state of readiness of a neuron membrane's potential between signals
- ions line up on either side, ready to rush across membrane when neuron goes active and gates open
- ions in high-concentration are ready to move to low concentration and positive ions are ready to move to areas of negative charge
28
What are the concentrations of sodium and potassium inside and outside the cell and how does this affect movement? (2)
- sodium has higher [ ] outside the cell, so it will tend to move into the cell
- potassium is more [ ] inside the cell, so it will tend to move out of the cell
29
How does the charge inside the cell affect sodium movement? (2)
- inside of cell is slightly negatively charged compared to outside
- provides additional force on sodium, causing it to move into the cell
30
threshold of excitation
- level of charge in the membrane that causes neuron to become active
31
What happens after a neuron receives a signal and changes from the resting potential state? (3)
- small pores open on the neuronal membrane, allowing sodium ions to move into the cell
- influx of positive ions causes internal charge of cell to become more positive
- charge reaches threshold of excitement and neuron becomes active, action potential begins
32
peak action potential
- many pores open, causing a massive influx of sodium ions and a huge positive spike in membrane potential
33
What happens at the peak action potential?
- sodium gates close and potassium gates open to let positively charged potassium ions leave
34
repolarization (2)
- membrane potential returns to negative charge
- at first, it hyperpolarizes, becoming slightly more negative than the resting potential, and then levels off restoring resting potential
35
action potential (2)
- electrical signal that moves down the neuron's axon
| - constituted by the positive spike
36
how does the electric signal move through the axon?
- like a wave; at each point, some of the sodium ions that enter the cell diffuse to the next section of the axon, raising the charge past the threshold of excitation and triggering a new influx of sodium ions
37
all-or-none phenomenon(2)
- phenomenon that incoming signal from another neuron is either sufficient or insufficient to reach threshold of excitation
- there is no in-between and no turning off the action potential once it starts
38
Explain traits of the action potential as a result of the all-or-none phenomenon. (2)
- action potential is recreated/propagated at its full strength at every point along the axon
- does not fade away as it travels down the axon
39
reuptake
- neurotransmitter is pumped back into the neuron that released it to clear up synapse
40
After signals are delivered, what happens to excess neurotransmitters in synapse?
- drift away and are broken down into inactive fragments or are reabsorbed in reuptake
41
What does clearing the synapse do? (2)
- provides clear "on" and "off" state between signals
- regulates the production of neurotransmitter (full synaptic vesicles indicate no additional transmitters need to be produced)
42
biological perspective
- view that psychological disorders like depression and schizophrenia are associated with imbalances in one or more neurotransmitter systems
43
In the biological perspective, what helps improve disorders?
- psychotropic medications can help improve symptoms associated with disorders
44
psychotropic medications (2)
- drugs that treat psychiatric symptoms by restoring neurotransmitter balance
- act as agonists or antagonists for a given neurotransmitter system
45
agonists
- chemicals that mimic neurotransmitters at the receptor site, strengthening its effects
46
antagonists
- block or impedes normal activity of neurotransmitter at the receptor
47
What are agonists and antagonists drugs used for?
- prescribed to correct specific neurotransmitter imbalances underlying a person's condition
48
Parkinson's disease and treatment (2)
- progressive nervous system disorder associated with low levels of dopamine
- dopamine agonists are used to mimic effects of dopamine by binding to dopamine receptors
49
Schizophrenia and treatment (2)
- certain symptom are associated with overactive dopamine neurotransmission
- antagonists for dopamine used as they block dopamine's effects by binding to receptors without activating them
50
reuptake inhibitors
- prevent unused neurotransmitters from being transported back to neuron
- leaves more neurotransmitters in synapse for longer time, increasing its effects
51
depression and treatment (2)
- consistently linked with reduced serotonin levels
| - treated with selective serotonin reuptake inhibitors (SSRIs) that prevent uptake and strengthen serotonin effects
52
What drug is similar to serotonin
- LSD as it affects same neurons and receptors as serotonin
53
What are the downsides of psychotropic medications? (3)
- not an instant solution and must be taken for several weeks to see improvement
- many have significant negative side effects
- individuals vary dramatically in how they respond to the drugs
54
What is done to improve chances of success when taking psychotropic drugs?
- combine drug therapy and other forms of therapy (psychological and/or behavioural)
55
What two major subdivisions can the nervous system be divided into?
- central nervous sytem (CNS)
| - peripheral nervous sytem (PNS)
56
central nervous system (CNS)
- brain and spinal cord
57
peripheral nervous system (PNS)
- connects brain and spinal card to muscles, organs and senses in the periphery of the body
58
what is the peripheral nervous system made up of?
- thick bundles of axons, called nerves
59
What does the PNS do?
- carry messages back and forth between the CNS and the muscles, organs, and senses in the periphery of the body (everything outside CNS)
60
What are the 2 major subdivisions of the PNS? (2)
- somatic nervous system
| - autonomic nervous system
61
somatic nervous system (3)
- role
- associated with:
- consists of:
- relays sensory and motor information to and from CNS
- associated with activities traditionally thought of as conscious or voluntary
- consists of motor neurons and sensory neurons
62
autonomic nervous sytem
- role
- associated with:
- controls our internal organs and glands
| - associated with things outside realm of voluntary control
63
motor neurons
- carry instructions from CNS to muscles
| - are efferent fibers (moving away from)
64
sensory neurons
- carry sensory information to the CNS
| - afferent fibres (moving toward)
65
afferent
- moving toward
66
efferent
- moving away
67
What can the autonomic nervous system be divided into and how do they work together? (2)
- sympathetic, parasympathetic nervous systems
| - complementary function, operating in tandem to maintain homeostasis
68
sympathetic nervous system
- involved in preparing body for stress-related activities
69
parasympathetic nervous system
- associated with returning body to routine, day-to-day operations
70
homeostasis
- state of equilibrium where biological conditions are maintained at optimal levels
71
when is the sympathetic nervous system activated and how did it come about? (2)
- when we are faced with stressful or high-arousal situations
- adapted from early ancestors for increasing chance of survival
72
fight or flight response
- activation of sympathetic division of autonomic nervous system, allowing access to energy reserves and heightened sensory capacity so we might fight off a given threat or run away to safety
73
what are some symptoms of the flight or fight response?
- pupils dilate, heart race and blood pressure increase, bladder relaxes, liver releases glucose, and adrenaline surges bloodstream
74
What are some negative consequences of persistent and repeated exposure to stressful situations that trigger the flight or fight response in the modern world? (2)
- increase in susceptibility to heart disease
| - impaired function of immune system
75
when does the parasympathetic nervous system take over?
- once threat has been resolved
76
what symptoms are associated with activation of parasympathetic nervous system?
- returning bodily functions to relaxed state: heart rate and blood pressure returns to normal, regain control of bladder, liver stores glucose in glycogen form
77
which nervous system controls our ability to move our legs?
- somatic
78
spinal cord function (2)
- routes messages to and from the brain
| - has own system of automatic processes, called reflexes
79
where is the top of the spinal cord and what is controlled there? (2)
- top of spinal cord merges with brain stem
| - basic processes of life are controlled, such as breathing and digestion
80
where does the spinal cord end?
- just below rib cage
81
How is the spinal card functionally organized?
- into 30 segments that correspond with the vertebrae
| - each segment is connected to a specific part of the body through peripheral nervous system
82
How is the spinal cord involved with messages to the rest of the body? (2)
- nerves branch out from the spine in each vertebrae
- sensory nerves bring messages in and motor nerves send messages out to the muscles and organs; messages travel to and from the brain through every segment
83
spinal reflexes (4)
- what are they
- 2 examples
- how does it work
- purpose
- when some sensory messages are immediately acted on by spinal cord without any input from brain
- withdrawal from heat or knee jerk
- signal passes from sensory nerve to simple processing center, which initiates a motor command
- allows body to react extraordinarily fast to save seconds that would occur from messages being sent to the brain and back
84
how is the spinal cord protected?
- bony vertebrae and cushioned in cerebrospinal fluid
85
what can occur when the spinal cord is injured?
- damage to a particular segment will cut off all lower segments connection to the brain causing paralysis
86
cerebral cortex definition and its features
- surface of brain
| - uneven, characterized by distinctive patterns of folds or bumps (gyri) and grooves (sulci)
87
gyrus
- bump or ridge on cerebral cortex
88
sulcus
- depressions or grooves in cerebral cortex
89
how can gyri and sulci help us?
- form important landmarks that allow us to separate brain into functional centers
90
longitudinal fissure
- most prominent sulcus
| - deep grove that separates brain into two hemispheres
91
hemisphere
- right or left half of the brain
92
lateralization
- concept that each hemisphere of brain is associated with specialized functions, mainly regarding language ability
93
what side of the body does the left hemisphere control (and vice versa)?
- right side of the body
94
corpus callosum (2)
- what is it
- what does it consist of
- function
- thick band of neural fibers connecting brain's two hemispheres
- consists of 200 million axons
- allows two hemispheres to communicate with each other and allows information being processed one one side of the brain to be shared with the other side
95
how is severe epilepsy sometimes treated?
- doctors elect to sever corpus callosum as means of controlling spread of seizures
96
What behaviour do split-brain patients show? (3)
- unable to name a picture show in patient's left hand because information is only available to largely nonverbal right hemisphere
- still able to recreate picture with their left hand as that is controlled by the right hemisphere
- when more verbal left hemisphere sees picture that is hand drawn, patient is able to name it
97
How do we know information about functions of different areas of the brain?
- studying changes in behaviour and ability of individuals who have suffered damage to the brain
98
stroke
- caused by interruption of blood flow to a region in the brain, causes loss of brain function in affected region
99
What does the front portion of the right hemisphere contain? (2)
- main motor centers are located at front of head, in frontal lobe
- another region in the frontal lobe, the prefrontal cortex, is associated with judgement, reasoning, and impulse control
100
forebrain
- largest part of the brain, containing cerebral cortex, thalamus, and limbic system, among other structures
101
cerebral cortex (2)
- what is it
- associated with:
- outer surface of the brain which can be subdivided into four lobes with different functions
- associated with higher level processes
102
What are some higher level processes associated with cerebral cortex? (6)
- consciousness, thought, emotion, reasoning, language, and memory
103
What are the four lobes of the brain? (4)
- frontal
- parietal
- temporal
- occipital
104
frontal lobe (3)
- location
- involved in:
- contains:
- located at forward part of brain, extending back to a fissure known as central sulcus
- involved in reasoning, motor control, emotion, and language
- contains motor cortex, prefrontal cortex and Broca's area
105
motor cortex
- involved in planning and coordinating movement
106
prefrontal cortex
- responsible for higher level cognitive functioning
107
Bronca's area
- essential for language production
108
What happens if you damage Bronca's area? (3)
- great difficulty producing language in any form and loss of ability to speak
- although nothing is wrong with her mouth or vocal cords, she is unable to form words
- can follow directions but can't respond verbally, and can no longer read or write
109
What happened to Phineas Gage?
- when using explosives to remove rock, iron rod created a spark and caused rode to explode into Gage's face
- Gage remained conscious and was able to walk and speak despite brain injuries
110
What were the consequences of Gage's accident? (2)
- personality change: Gage was once a well-mannered, soft-spoken man but began to behave in odd and inappropriate ways after accident
- consistent with loss of impulse control, a frontal lobe function
111
What might be the reason Gage changed after his accident? (2)
- front lobe damage and rod's path also identified probable damage to pathways between frontal lobe and other brain structures, including limbic system
- with connections between planning functions of frontal lobe and emotional processes of limbic system severed, Gage had difficulty controlling emotional impulses
112
Is it possible that Gage's case was falsified?
- yes, evidence suggesting that dramatic changes in Gage's personality were exaggerated and embellished to support debate over localization in the brain exists
113
parietal lobe (3)
- location
- involved in:
- contains:
- located immediately behind frontal lobe
- involved in processing information from body's senses
- contains somatosensory cortex
114
somatosensory cortex (2)
- function
- organization
- essential for precessing sensory information from across body such as touch, temperature, and pain
- organized topographically so that spatial relationships that exist in body are maintained on surface or cortex
115
temporal lobe (3)
- location
- associated with:
contains:
- located on side of head, near temples
- associated with hearing, memory, emotion, and some aspects of language
- contains auditory cortex and Wernicke's area
116
auditory cortex
- main area responsible for processing auditory information
117
Wernicke's area
- important for speech comprehension
118
What happens when Wernicke's area is damaged?
- can produce sensible language, but unable to understand it
119
occipital lobe (3)
- location
- contains:
- organizational structure
- located at very back of brain
- contains primary visual cortex
- organized retinotopically so there is close relationship between position of an object in a person's visual field and positions of object's representation on the cortex
120
primary visual cortex
- responsible for interpreting visual information
121
thalamus (2)
- sensory relay for brain
| - all senses except smell are routed through thalamus before being directed to other areas of brain for processing
122
limbic system (2)
- function
- consists of:
- involved in processing emotion and memory
| - made up of a number of different structures, but three most important are hippocampus, amygdala, and hypothalamus
123
What system is smell projected through and how does this change it compared to other senses? (2)
- smell is projected through limbic system
| - smell can evoke emotional responses in way that other sensory modalities cannot
124
hippocampus
- essential structure for learning and memory
125
amygdala
- involved in our experience of emotion and in tying emotional meaning to our memories
126
hypothalamus (3)
- regulates number of homeostatic processes, including regulation of body temperature, appetite, and blood pressure
- serves as interface between nervous system and endocrine system
- regulates sexual motivation and behaviour
127
What happened to Henry Gustav Molaison and what were the consequences? (2)
- due to severe seizures, Molaison underwent brain surgery to remove hippocampus and amygdala
- lost ability to form any type of new memories and taught scientists the role the hippocampus plays in consolidation of new learning into explicit memory
128
midbrain (2)
- location
- contains:
- division of brain located between forebrain and hindbrain
| - contains reticular formation, substantia nigra and ventral tegmental area (VTA
129
reticular formation (2)
- location
- function
- centred in midbrain, but extends up into forebrain and down into hindbrain
- important in regulating sleep/wake cycle, arousal, alertness, and motor activity
130
substantia nigra (2)
- midbrain structure where dopamine is produced
| - involved in control of movement
131
ventral tegmental area (VTA) (2)
- midbrain structure where dopamine is produced
| - associated with mood, reward and addiction
132
hindbrain (2)
- location
- contains:
- located at back of head and looks like extension of spinal cord
- contains medulla, pons, and cerebellum
133
medulla
- controls automatic processes of the autonomic nervous system such as breathing, blood pressure, and heart rate
134
pons (3)
- means...
- structural function
- function
- means "bridge"
- serves to connect brain and spinal cord
- involved in regulating brain activity during sleep
135
brainstem
- medulla, pons, and midbrain
136
cerebellum (2)
- receives messages from muscles, tendons, joints, and structure in our ear to control balance, coordination, movement, and motor skills
- important for processing procedural memories (memories involved in learning and remembering tasks)
137
brain imaging
- a way to find out about functions of the brain using radiation, magnetic fields or electrical activity within the brain
138
computerized tomography (CT) scan (3)
- what is it
- how it works
- often usage
- involves taking a number of x-rays of a particular section of a person's body or brain
- x-ray passes through tissues of different densities at different rates, allowing computer to construct overall image of area being scanned
- often used to determine whether someone has a tumor, or significant brain atrophy
139
positron emission tomography (PET) (2)
- what is it
- how it works
- scans create pictures of living, active brain
- patient drinks or is injected with mildly radioactive substance called tracer; computer monitors tracer in bloodstream and creates rough map of active and inactive areas of brain during given behaviour
140
What are the downsides of PET (3)
- scans show little detail
- unable to pinpoint events precisely in time
- require brain to be exposed to radiation
141
Why is using both CT and PET useful? (2)
- scans allow better imaging of activity of neurotransmitter receptors and open new avenues in schizophrenia research
- CT contributes clear images of brain structures and PET shows brain's activity
142
magnetic resonance imaging (MRI) (3)
- how does it work
- how is it displayed
- person is placed inside machine that generates strong magnetic field; causes hydrogen atoms in body's cell to move and when field is turned off, hydrogen atoms emit electromagnetic signals as they return to original positions
- tissues of different densities give off different signals which a computer interprets and displays on a monitor
143
functional magnetic resonance imagine (fMRI) (2)
- operates on same principles as MRIs but shows changes in brain activity over time by tracking blood flow and oxygen levels
- provides more detail on brain structure and better accuracy in time than possible in PET scans
144
What are MRI and fMRIs used for? (2)
- often used to compare brains of healthy individuals to brains diagnosed with psychological disorders because of high level of detail
- helps determine what structural and functional differences exist between these populations
145
electroencephalography (EEG) (3)
- what is it
- what does it look like
- helpful for...
- recording the electrical activity of the brain via electrode on the scalp
- shown as brainwaves, showing frequency and amplitude with accuracy in milliseconds
- especially helpful to researched studying sleep patterns along individuals with sleep disorders
146
endocrine system
- series of glands that produce chemical substances known as hormones
147
hormones (3)
- what is it
- how does it work
- attributes
- chemical messenger released by endocrine glands that must bind to receptor in order to send signal
- released in bloodstream and travel throughout body, affecting any cells that contain receptors for them
- slower to take effect but more long lasting
148
What are the functions of hormones and how are they controlled? (2)
- involved in regulating bodily functions
- ultimately controlled through interactions between hypothalamus ( in central nervous system) and pituitary gland (in endocrine system)
149
What causes imbalances in hormones?
- related to a number of disorders
150
where is the pituitary gland and what is it referred to as? (2)
- descends from hypothalamus at base of brain and acts in close association with it
- often referred to as "master gland" because its messenger hormones control all other glands in endocrine system, although it mostly carries out instructions from the hypothalamus
151
What does the pituitary gland secrete? (4)
- messenger hormones
- growth hormone
- endorphins for pain relief
- number of key hormone that regulate fluid levels in body
152
thyroid gland (2)
- location
- function
- located in neck
| - releases hormones that regulate growth, metabolism, and appetite including thyroxine
153
hyperthyroidism/Grave's disease
- thyroid secretes too much of hormone thyroxine causing agitation, bulging eyes, and weight loss
154
hypothyroidism
- reduced hormones cause tiredness and coldness
155
adrenal glands (2)
- location
- function
- sit atop our kidneys
| - secrete hormones involved in stress response, such as epinephrine (adrenaline) and norepinephrine (noradrenaline)
156
pancreas (2)
- internal organ that secretes hormones that regulate blood sugar levels: insulin and glucagon
- essential for maintaining stable levels of blood sugar throughout the day by lowering blood glucose levels (insulin) or raising them (glucagon)
157
diabetes and treatment (2)
- patient does not produce insulin
- must take medications to stimulate or replace insulin production and must closely control the amount of sugar and carbs they consume
158
gonads (2)
- secrete sexual hormones important to reproduction
| - mediate both sexual motivation and behaviour
159
female gonads and what they secrete (2)
- ovaries
| - secrete estrogen and progesterone
160
male gonads and what they secrete (2)
- testes
| - secrete androgens (like testosterone)
