Lecture 4: CNS Flashcards
(157 cards)
1
Q
What are the two main parts of the CNS
A
Brain and spinal cord
2
Q
1) Are there only a few neurons in early nervous system development, or a lot?
2) What happens to those neurons?
3) Give an example
A
1) There is an abundance of neurons
2) Depending on environmental factors and stimulation these may be kept, enhanced, or eliminated
3) Eyes can become lazy, and when you cover a non-lazy eye, it forces the lazy eye to start working again
3
Q
What are the 3 classes of neurons that make up the nervous system?
A
Afferent neurons
Efferent neurons
Interneurons
4
Q
Describe the basic chain of neurons path
A
Sensory receptor picks up a signal. Afferent neuron sends signal to interneuron, which sends signal to efferent neuron, which affects the muscle
5
Q
What makes up 90% of the cells in the CNS?
A
Glial cells
6
Q
Name 4 functions of glial cells
A
1) Physically and metabolically support neurons
2) Maintain composition of extracellular environment
3) Modulate synaptic function
4) Also important in learning and memory
7
Q
What cells maintain the composition of the extracellular environment of the CNS?
A
Glial cells
8
Q
List the 4 types of glial cells. Which is most abundant?
A
1) Astrocytes: most abundant
2) Oligodendrocytes
3) Microglia
4) Ependymal cells
9
Q
1) What are astrocytes shaped like?
2) Do they have a few functions, or many?
A
1) Star shaped (hence their name)
2) Many functions; the functions we talk about are only some
10
Q
List 5 jobs of astrocytes and elaborate on them
A
Glue, nutrients, degrade, ions, clear:
1) Main glue (“glia”) of the CNS
-Hold neurons in their spatial orientation
2) Transferring nutrients to neurons, helping the brain repair injuries
3) Degrade neurotransmitters (to help stop a transmission)
4) Help maintain optimal ion conditions for neural excitability
5) Clearing toxic metabolic byproducts from the brain
11
Q
1) What do oligodendrocytes do?
2) What are they shaped like?
A
1) Form insulative myelin around CNS axons
2) “Jelly roll”
12
Q
What are the 2 jobs of microglia?
A
1) Immune cells of the CNS
2) Release nerve growth factor, helping CNS cells survive
13
Q
1) What is unique about microglia?
2) What can happen if microglia are overactive?
A
1) Only CNS cell that can be infected by HIV, leading to AIDS-dementia
2) Will cause autoimmune damage in Alzheimer’s, MS, and other neurodegenerative diseases where nerves are damaged (causes demyelination)
14
Q
1) What do ependymal cells do?
2) What is unique about them (2 things)
A
1) These cells form the lining of fluid-filled cavities of the CNS like ventricles
2) They’re ciliated (helps CSF flow) and can form into other glial cells after they’re injured
15
Q
1) What cells are the main glue (“glia”) of the CNS?
2) What cells form insulative myelin around CNS axons?
3) What cells form the lining of fluid-filled cavities of the CNS like ventricles?
4) What is the only CNS cell that can be infected by HIV, and what does this lead to?
A
1) Astrocytes
2) Oligodendrocytes
3) Ependymal cells
4) Microglia; leads to AIDS-dementia
16
Q
1) What cells are ciliated? Why?
2) What are the immune cells of the CNS?
3) What cells cause autoimmune damage in Alzheimer’s, MS, and other neurodegenerative diseases where nerves are damaged when they’re overactive?
A
1) Ependymal cells; to help CSF flow
2) Microglia
3) Microglia
17
Q
1) Define neurogenesis. Where does it occur?
2) What causes it to happen?
3) What causes it to slow down?
A
1) Production of new neurons (in the hippocampus)
2) Increases with exercise
3) Declines with age and chronic stress
18
Q
1) What misconception about neurogenesis was around until the 90s?
2) What do we believe now?
3) What is an intense area of modern medical research?
A
1) Until the 90s, it was believed that the adult brain doesn’t form new cells
2) That most brain regions don’t regenerate neurons, but that the hippocampus does
3) Stimulating neurogenesis
19
Q
1) Do glial cells continue cell division? What about neurons?
2) Is CNS tissue durable or delicate? Can nerves be replaced?
A
1) Glial cells do, neurons don’t
2) CNS tissue is delicate, damaged nerves cells are not replaced (bc they don’t continue cell division)
20
Q
What 4 things protect CNS tissue?
A
1) Cranium and vertebral column
2) Meninges
3) Cerebrospinal fluid
4) Blood-brain barrier (BBB)
21
Q
What are the 3 layers of the meninges from outer to inner?
A
Outer: Dura Mater
Middle: Arachnoid Mater
Inner: Pia Mater
22
Q
1) What does dura mater mean?
2) Describe this layer
3) What does this layer contain? What happens here?
A
1) “Tough mother”
2) Outermost layer; a tough, inelastic covering
3) Venous sinuses; blood from brain is returned to the heart and CSF reenters the blood
23
Q
What happens in the venous sinuses of the dura mater? (2 things)
A
1) Blood from brain returned to the heart
2) CSF reenters the blood
24
Q
1) What does arachnoid mater mean?
2) Describe this layer
3) What is its underlying space called? What is it filled with?
A
1) “Spiderlike mother”
2) Richly vascularized with cobweb appearance (arachnoid villi reabsorb CSF)
3) Subarachnoid space, filled with CSF
25
How is CSF reabsorbed from the subarachnoid space?
By villi
26
1) What does pia mater mean?
2) Describe this layer
3) Describe the location of this layer in relation to CNS structures
1) “Gentle mother”
2) Fragile, innermost layer; highly vascular
3) Closely adheres to CNS structures, every ridge and valley
27
1) What does CSF do?
2) Describe its density
3) Where is CSF found?
1) Surrounds and cushions the brain and spinal cord
2) Same density as the brain (brain floats/suspended in CSF)
3) Contained in subarachnoid space
28
1) Are CSF and IF the same?
2) What is the only thing that comes into contact with neurons and glial cells?
3) What is CSF important for?
1) No
2) Only interstitial fluid (IF) (not CSF or blood)
3) Material exchange to the brain
29
1) Describe the exchange of materials between CSF and interstitial fluid (IF)
2) Describe the exchange of materials between blood and IF
3) Describe the importance of IF
1) CSF and IF: materials exchanged freely
2) Blood and IF: limited exchange
3) IF is like the middle man between CSF and blood
30
1) What structure(s) produce CSF?
2) Where are the structure(s) that make CSF?
3) What are they made out of?
1) Choroid plexuses
2) Structures protruding from the ventricles
3) Pia mater
31
1) Where is CSF found?
2) What facilitates the flow of CSF?
3) What reabsorbs CSF? Where does it go?
1) Throughout the brain and central canal of the spinal cord
2) Ciliated ependymal cells
3) Reabsorbed by subarachnoid villi and ultimately reenters in dura mater
32
1) Is CSF balance a hardy process or is it delicate?
2) How much CSF do we have total? How often is the entire CSF volume replaced?
1) Delicate
2) Entire volume (125-150mL) replaced three times a day
33
1) What can removal of a few mLs of CSF cause? Give an example
2) What can cause CSF to accumulate? What can this lead to?
1) Can cause severe headaches (ex: spinal tap)
2) Obstruction (malformation, tumor); can lead to hydrocephalus and brain damage
34
What can lead to hydrocephalus and brain damage?
Accumulated CSF due to obstruction (malformation, tumor)
35
1) What does the blood brain barrier (BBB) do?
2) How are materials exchanged in the rest of the body?
1) Shields the brain from the blood
2) Between blood and IF only across capillary walls
36
1) In the body, when blood and IF exchange materials, what do they pass through?
2) Describe the flow of materials between the two
1) Single layer of endothelial cells
2) Materials flow almost freely around pores between endothelial cells
37
1) Describe the capillary wall cells of the brain
2) In the brain, when blood and IF exchange materials, what do they pass through?
3) True or false: Despite the BBB, the brain depends on a constant blood supply
1) Capillary wall cells have tight junctions; impermeable
2) Materials must go through the cells, not around
3) True
38
Why does the brain need a constant supply of blood? (2 reasons)
1) Cannot produce ATP without O2
2) Can (mostly) only use glucose for fuel production and cannot store any glucose (can also use liver ketones)
39
What can the brain use for fuel besides glucose?
Ketones produced by liver
40
1) The brain is ____% of the body’s weight
2) Receives _____% of the blood
3) Uses _____ of the O2 (brain damage after________ if not supplied)
4) Uses ______ of the glucose (brain damage after _________ if not supplied)
1) 2%
2) 15% of blood
3) 20% of the O2; 4-5 mins and brain damage starts
4) 50%; 10-15min before brain damage
41
1) What is the most common cause of brain damage?
2) What causes 80% of these?
1) Strokes / cerebrovascular accidents (CVAs)
2) A blood clot in a cerebral blood vessel
42
Describe what happens in regards to cell death during a CVA/ stroke
1) Affected area’s cells die by necrosis
2) Release glutamate which binds with nearby NMDA receptors
3) Which opens Ca+ channels and triggers apoptosis in nearby cells
43
How do most neurons die following a stroke?
More neurons die by apoptosis than by necrosis
44
The brain is about _____ pounds and has _[big number]____ neurons with a ___[bigger number]_________ synaptic connections
1) 2
2) 85 billion
3) quadrillion
45
What do the quadrillion synapses in the brain enable?
1) Subconsciousness
2) Emotions
3) Movement
4) Perception and proprioception
5) Cognition (thought, memory, awareness, judgment)
46
List the 5 parts of brain from bottom to top (least to most evolved)
1) Brain stem
2) Cerebellum
3) Forebrain
4) Diencephalon (hypothalamus + thalamus)
5) Cerebrum (basal nuclei and cerebral cortex)
47
What is the most evolved part of the brain, and what parts does it consist of?
1) Cerebrum
2) Basal nuclei and cerebral cortex
48
1) What is the oldest region of the brain?
2) What is it continuous with?
3) What does it control?
1) Brainstem
2) Continuous with spinal cord
3) Vegetative processes: breathing, circulation, digestion
49
What are the 3 parts of the brainstem?
Midbrain
Pons
Medulla
50
1) Name 3 vegetative processes
2) What is the medulla a part of?
3) What controls skilled motor tasks (like dancing)
1) Breathing, circulation, digestion
2) Brainstem
3) Cerebellum
51
Name 4 things the cerebellum controls
1) Maintains body position
2) Coordination of motor activity
3) Skilled motor tasks like dancing
4) Subconscious control
52
1) What does the hypothalamus do?
2) What does the thalamus do?
1) Hypothalamus: Homeostatic control
2) Sensory processing
53
1) What part of the brain is larger in advanced species?
2) What does this part of the brain look like in less advanced species? What does this cause?
1) Cerebrum
2) Less advanced mammals have smooth cortices; causes less area and less circuitry
54
1) What makes up 80% of the brain's weight in humans?
2) What part of the brain controls sensory processing?
3) What controls voluntary movement?
1) Cerebrum
2) Thalamus
3) Cerebrum
55
What does the cerebrum control? (6 things)
1) Voluntary movement
2) Sensation
3) Thought
4) Language
5) Personality
6) Intelligence
56
1) What are Positron Emission Tomography (PET) scans?
2) What can they show?
1) Injection of small amounts of radioactive material which releases tiny bursts of energy that can be detected by PET equipment
2) Which parts of the brain “light up” with different tasks
57
What are the 4 lobes of the cerebral cortex? List what each does
1) Occipital lobes: Visual processing
2) Temporal lobes: Sound processing
3) Parietal lobes: Sensory processing
4) Frontal lobes: Voluntary movement, speech, & thought
58
1) What is the cerebrum divided into?
2) How are they connected?
1) 2 halves (left and right hemispheres)
2) By the corpus callosum
59
1) What part is an information superhighway in our brains?
2) How many neurons does it have?
1) Corpus callosum
2) It's a band of 300 million neurons
60
What type of brain matter makes up the cortex?
Cortex is an outer shell of gray matter covering a core of white matter
61
1) What makes up the gray matter of the cortex? What can this be compared to?
2) What makes up the white matter of the cortex? Why is it white?
What can this be compared to?
1) Gray matter: cell bodies, dendrites, glial cells
-The computer
2) White matter: bundles of myelinated axons (white from lipid)
-The wires
62
1) True or false: The brain has complex interplay among regions
2) What is the corpus callosum?
1) True
2) A band of 300 million neurons that connects the two hemispheres of the cortex
63
1) What do the parietal lobes do?
2) What 5 things do they have primary control of?
3) What helps them in doing these things?
1) Control sensory processing
2) Touch, pressure, heat, cold, pain
3) Thalamus plays a lesser/more basic role in these senses
64
1) What 3 things do the parietal lobes aid in/ are important in?
2) Where do they transmit their signals?
1) Proprioception, discerning shapes of objects being held, and detecting subtle differences in similar objects that contact the skin
2) To the somatosensory cortex on the opposite side of the brain
65
1) What does the frontal lobe contain?
2) What does this do?
1) Primary motor cortex
2) Voluntary control over skeletal muscles of opposite side of body & fine motor control over fingers, thumbs, lips, tongue
66
The primary motor cortex has the main control over movement, but what two things aid in this? When?
Lower brain regions and spinal cord involved with involuntary muscles like those for maintaining posture
67
True or false: Sensory motor mapping can vary between individuals and change over time. Explain your answer.
True; use-dependent competition for cortical space
68
1) Define plasticity
2) Do adults have plasticity? Elaborate.
3) Do we fully understand plasticity?
1) Functional remodeling according to demands
2) Yes; even in adults, if one brain area is destroyed the other regions attempt to take over the functions
3) Not fully understood, perhaps dendrites form more branches
69
1) What is language ability an example of?
2) Where does it take place in the brain for most people?
3) What age is it best at?
1) Early cortical plasticity and subsequent permanence
2) Only in left hemisphere in most people
3) Easiest when younger (birth until 2-6, sharp decrease around 6-8 years old)
70
1) Language is complex, what does the brain need to do to for it to occur?
2) What are the two main language areas of the brain?
1) Integration of expression and comprehension
2) Broca's and Wernicke's areas
71
1) What does Broca's area do?
2) Where is it found?
1) Governs speaking
2) Left frontal lobe
72
1) What does Wernicke's area do? (generally)
2) Where is it found?
3) What are its two more specific functions?
1) Language comprehension
2) Left cortex junction near parietal, temporal, and occipital lobes
3) Understanding spoken and written messages; formulating coherent speech and sending information to Broca’s area
73
1) What does damage to the Broca's area do?
2) What does damage to Wernicke's area do?
1) Broca’s: can understand but can’t form words
2) Wernicke’s: can say words, speech is incoherent
74
What could happen if there was a lesion in the left frontal lobe?
Broca's area is located there and could be damaged; this would cause the pt to be able to understand but not form words
75
1) What makes up 50% of the cerebral cortex?
2) What makes up the other half?
1) Motor, sensory, and language areas
2) Association areas (3)
76
List the 3 association areas of the cerebral cortex and what they do
1) Prefrontal association cortex: Planning, decision-making, creativity, personality
2) Parietal-temporal-occipital association cortex: Complex perception processing
-Ex: Laying on your side but still know that a cup is upright on a table
3) Limbic association cortex: Motivation, emotion, memory
77
If you're lying on your side looking at a cup on a table, but still know it's upright, what area is working?
Parietal-temporal-occipital association cortex
78
1) What is the left side of the cortex often more dominant in? Give examples
2) What about the right side? Give examples
1) Left side more often is the dominant side for fine motor control
-Exs: Math, language, philosophy
2) Right side excels in nonlanguage skills
-Exs: Spatial perception, artistic and musical talents
79
True or false: In many individuals, the skills of one hemisphere are more strongly developed
True
80
1) What is the basal nuclei also called?
2) What is it?
1) Basal ganglia
2) A cluster of subcortical neurons
81
What are the 3 functions of the basal nuclei?
1) Inhibits muscle tone
(muscle tone is a balance of excitatory and inhibitory signals; keeps from contracting all the time)
2) Facilitates slow, sustained contractions (like posture)
3) Inhibits (refines) thalamus’ control of muscles to eliminate unnecessary movements
82
1) What is muscle tone?
2) What creates posture? What part of the brain does this?
1) A balance of excitatory and inhibitory signals
2) Slow, sustained contractions; basal nuclei
83
1) What causes Parkinson's?
2) What does Parkinson's cause?
1) Destruction of neurons that release dopamine in the basal nuclei
2) Increased muscle tone / rigidity and tremors
84
What are the two primary jobs of the thalamus? Describe each
1) Sensory relay station
-All sensory input goes to thalamus before going to the cortex
2) Screens and routes signals
-Directing attention to stimuli of interest (like hearing your name in a loud room)
-Important in motor control
-Reinforces movement initiated by the cortex
85
What is the homeostatic regulator of the brain?
What does this mean?
1) The hypothalamus
2) Links the autonomic nervous system and endocrine system
86
What does the hypothalamus control?
1) Temperature (shivering, vasoconstriction when cold)
2) Thirst
3) Urine output
4) Hormones
5) Smooth and cardiac muscle
6) Emotions
7) Sleep
8) Sexual behavior
9) Circadian rhythms
87
What is the "master biological clock"? Describe this
The hypothalamus's Suprachiasmatic Nucleus
controls circadian rhythms
88
What two parts of the brain activate when you're cold? What do they tell you to do?
1) Cerebral cortex: put on sweater, turn up heat
2) Hypothalamus: shivering, vasoconstriction
89
1) What is the limbic system?
2) Is it made of unique structures? Explain
1) A complex network associated with emotions, behavior, motivation, language, memory
2) Not made of unique structures, rather a network of neuron pathways connecting various brain structures
90
What is the mnemonic to remember the functions of the limbic system? Explain each letter
HOME:
-Homeostatic functions: autonomic/neuroendocrine control
-Olfaction
-Memory
-Emotions and motivational drives
91
1) What system plays a central role in all aspects of emotion?
2) What kind of behavioral activities is this system involved in?
1 )The limbic system
2) Both basic and complex
92
What 3 primary aspects of emotion does the limbic system play a role in? Give examples of each
1) Subjective emotional feelings
-Anger, fear, sadness, joy, etc.
2) Physical behavioral patterns
-Preparing to attack or defend when angered
3) Observable emotional expressions
-Laughing, crying, blushing
93
Describe both the basic and the complex behavioral functions of the limbic system.
State what is involved in each, and give examples of each.
1) Basic: Hypothalamus is extensively involved in limbic system; controls autonomic regulation during emotional states
-e.g. anger: increased heart rate and respiration, diversion of blood to skeletal muscles
2) Complex: Higher cortical involvement for things like attacking, fleeing, mating, etc
94
The limbic system can also be activated for frustration/anger; what are its basic and complex responses?
1) Basic response: autonomic preparation for physical confrontation
2) Complex/cortical response: restraining oneself while angry if the setting is inappropriate
95
1) What part of the brain has reward and punishment centers?
2) Give an example of how these centers can be detrimental
1) The limbic system
2) Animals with implanted stimulators at reward centers will activation up to 5,000 stimulations per hour, ignoring food even when starving
96
1) How is the limbic system involved in motivation?
2) What are some basic versions of this? Give an example. Is this relevant to most behaviors?
3) What are some higher-level versions of this? Give an example.
1) Directs behavior towards specific goals
2) Some goals are physical and guided by homeostatic drives. E.g. thirst. Most behavior is not related to simple tissue deficits.
3) Involved in higher level processes that help guide the organism including: memory, learning, experience
-It is an example of higher-level functioning to move through short-term punishment for long-term pleasure (like PA school)
97
1) True or false: we understand the neurophysiological mechanisms behind emotion completely
2) What 3 neurotransmitters are implicated in influencing emotion?
1) False; underlying mechanisms not well understood
2) Norepinephrine, dopamine, and serotonin
98
1) What are the known transmitters in the regions with the highest rates of self-stimulation in animal studies?
2) Define depression and list the neurotransmitters involved
1) Norepinephrine and dopamine
2) Pervasive negative mood and inability to experience pleasure; a functional deficiency of serotonin, norepinephrine, or both
99
1) Define learning
2) Define memory
1) The acquisition of knowledge from experience or instruction
2) The storage of knowledge for later recall
100
1) What does memory involve changes in?
2) What is usually stored?
1) Neural changes
2) Concepts, not words, are usually stored
101
What are the two stages of memory? Describe each and how long they last
1) Working-memory: etch-a-sketch of the mind, type of short-term memory for immediate tasks/daily activities; stored for seconds to hours
2) Long-term memory: stored for days to years
102
Define consolidation
The movement from short term memory to long term memory
103
1) How long does it take to store short and long term memories?
2) How long do short and long term memories last?
3) What is short term memory capacity like? What about long term?
1) Short term is immediate; long term must be consolidated through exposure, repetition, practice, etc.
2) Short term is seconds to hours, long term is days to years
3) Short term capacity is small, long term is large
104
1) How fast can short term memories be retrieved? What about long term?
2) Are short term memories permanently forgotten? What about long term?
3) What is the mechanism of short term memory?
4) What is the mechanism of long term memory?
1) Short term can be retrieved rapidly, long term is slower
2) Short term is permanently forgotten; long term is usually only transiently unable to access, stable memory trace
3) Short term: Transient modifications in preexisting synapses
4) Long term: Relatively permanent structural changes in neurons like forming new synapses
105
1) Define amnesia
2) What are its two types? Which is more common?
1) The loss of memory from entire portions of time rather than forgetting isolated bits of information
2) Retrograde (more common) and anterograde
106
1) What is retrograde amnesia? What can cause it?
2) What is anterograde amnesia?
1) Retro: Unable to recall past events due to trauma, concussion, or stroke
2) Antero: Unable to consolidate future memories into long-term storage
107
Is there a single “memory center” in the brain? Explain
-No, but recent evidence shows a single memory might be stored in a small number of neurons in a specific location of a brain.
-Meaning, all memories are NOT stored in the same place, but all of ONE memory could be
108
What two brain regions are involved in memory? What does each do?
1) Hippocampus
-Temporarily holds new LTM until they are stored in the cortical/subcortical neurons
-Important in DECLARATIVE memories, which are specific memories of events/people/fact/objects that could be summarized in a sentence
2) Cerebellum: Important in PROCEDURAL memories like motor skills acquired through training and repetition
109
1) Give an example of a declarative memory
2) What part of the brain is responsible for procedural memories?
1) “I saw the Statue of Liberty last year”
2) Cerebellum = procedural
110
1) What 3 things is the cerebellum important in?
2) What is unique about it
3) How many parts does it have?
1) Balance, planning, movement
2) Has four times as many individual neurons as the rest of the brain
3) Three, each with different participation in subconscious motor control
111
List the 3 parts of the cerebellum and what each is involved in?
1) Vestibulocerebellum: maintaining balance, eye movements
2) Spinocerebellum: Coordinating complex voluntary movements
3) Cerebrocerebellum: Planning and coordinating movements by providing input to cortical motor areas
112
What does cerebellar disease involve? Give 4 symptoms of this
Disruptions in coordinated movement:
1) Poor balance
2) Wide, unsteady gait
3) Nystagmus (oscillating eye movements)
4) Inability to perform rapidly alternating motions
113
1) What must pass through the brain stem?
2) What originates from the brain stem?
1) All signals between the brain and periphery
2) All cranial nerves
114
How is the brain stem organized, and what does the brain stem control?
Has centers (clusters of neurons) that control respiration, heart function, blood vessel function, digestion
115
1) What makes up the reticular formation?
2) What is the reticular formation?
1) Brain stem and thalamus
2) Network of neurons which receives all sensory input and integrates it into the cortical fibers (called the reticular activating system)
116
1) What receives all sensory input?
2) What is it integrated into? What is this also called?
1) The reticular formation
2) Integrated into the cortical fibers called the reticular activating system
117
1) What are brain waves?
2) How are they measured?
1) Extracellular current flow from electrical activity in the brain
2) Can be detected and graphed via Electroencephalogram (EEG)
118
What are the 5 forms of brain waves from most to least active? List the states you're in during each
1) Gamma: highest levels of cognition, trying to coordinate sights and sounds
2) Beta: focused and alert, dominant wave form in wakefulness
3) Alpha: awake but relaxed and not processing much information
-Cortex dramatically shifts from alpha to beta just from closing and opening eyes
4) Theta: drowsiness, extreme relaxation, light sleep
5) Delta waves: deep dreamless sleep
119
1) What causes the cortex to dramatically shift from alpha to beta waves?
2) What type of brain waves indicate deep dreamless sleep?
1) Just from closing and opening eyes
2) Delta waves
120
1) Does your brain activity slow during sleep? Why?
2) What two parts of the brain govern sleep?
3) How are the two types of sleep distinguished?
1) Brain activity does not decrease (overall) bc sleep is an active process
2) Brain stem and hypothalamus
3) Brain wave patterns
121
1) What are the two types of sleep?
2) What does a sleep cycle consist of?
1) Slow-wave sleep and Paradoxical sleep (REM sleep)
2) 4 stages of slow-wave sleep, from Stage 1 light sleep to Stage 4 deep sleep
122
Describe a sleep cycle
1) Move through Stage 1 to 4 in 30-45min, then reverse
2) Followed by REM sleep which has similar brain activity to wakefulness
3) Subsequent REM stages are longer and longer
This is the sleep-cycle, occasionally with moments of wakefulness
123
Describe the state of the muscles, movement, and vitals during deep wave sleep. Do you dream?
1) A person still has considerable muscle tones and changes in position
2) Respiration, heart-rate, blood pressure remain normal 3) Dreams are rare
124
Describe the state of the muscles, movement, and vitals during deep wave sleep. Do you dream?
1) Muscles relax except there are rapid eye movements
2) Respiration and heart-rate become irregular, blood pressure can fluctuate
3) Yes dreams
125
What allows for the sleep-wake cycle? List how each does its job
1) Arousal system in the RAS: wakes you up
(RAS = reticular activating system)
2) Slow-wave sleep center in the hypothalamus: GABA release
3) Paradoxical sleep center in the brain stem: molecular mechanisms poorly understood
126
Why is it easier to stay awake while sleepy rather than going to sleep while being wide awake?
The arousal system is better at overriding the other two involved in the sleep-wake cycle
127
Describe the evolutionary, biochemical, restorative, mood, and neural explanations behind sleep
1) Evolutionary: ancient humans sleeping at night were eaten less than those wandering at night
2) Biochemical: brain is playing chemical catch-up
3) Restorative: brain’s IF is “cleaned” by glymphatic system during sleep
4) Mood: wakefulness = constant norepinephrine and serotonin activity, desensitizing receptors, sleep restores
5) Neural: synaptic modifications and memory consolidation (babies sleep more receptor sensitivity
128
1) What is the spinal cord?
2) What protects it?
3) What emerges from it and where?
4) How is the spinal cord organized?
1) A long thin tube of nerve tissue descending from brain stem
2) Protected by vertebral column, descends through vertebral canal
3) Paired spinal nerves emerge from openings between vertebrae
4) Into tracts
129
1) How many pairs of spinal nerves?
2) How many in each section of the spinal column?
31 total:
-8 cervical (first above C1, 8th below C7)
-12 thoracic
-5 lumbar
-5 sacral
-1 coccygeal
130
1) Define spinal tracts
2) Where does each begin and carry?
1) Bundles of nerve fibers, long axons of interneurons grouped into columns that extend the length of the cord
2) Each begins or ends in the brain and each carries a specific type of information (2 general types)
131
What are the two types of spinal tracts? What does each contain and do?
1) Ascending tracts: afferent neurons, cord-to-brain
2) Descending tracts: efferent neurons, brain-to-cord
132
1) How is spinal cord gray matter divided?
2) List these divisions
1) Into horns
2) Dorsal, lateral, and ventral horns
133
List 3 ascending tracts, what each does, and where they cross over
1) Dorsal column-medial lemniscal pathway: Fine touch, vibration
-Crosses over in the brainstem
2) Anterolateral system (aka spinothalamic): Pain, temperature, crude touch, pressure
-Crosses over in the spinal cord
3) Spinocerebellar: Unconscious, proprioceptive info to cerebellum
-Crosses over in spinal cord (I think, not on slide)
134
1) How do spinal nerves connect with each side of the spinal cord?
2) Which ascending tract is responsible for crude touch?
3) Which ascending tract crosses over in the brainstem?
1) A dorsal and a ventral root
2) Anterolateral system (aka spinothalamic)
3) ) Dorsal column-medial lemniscal pathway
135
1) What do afferent fibers carry and where do they go into the spine?
2) What do efferent fibers carry and where do they go into the spine?
3) Where are cell bodies at each level clustered?
1) Afferent fibers with incoming signals go through dorsal root
2) Efferent fibers carry outgoing signals through ventral root
3) Dorsal root ganglia
136
What do dorsal and ventral roots join together to form?
A nerve
137
1) What is a nerve?
2) What does a nerve contain?
1) Bundle of axons covered with connective tissue
2) The axons of many neurons
138
What does each spinal nerve contain? What is this called?
Afferent sensory fibers from a particular region of the body surface, called dermatomes
139
1) Define dermatome.
2) What is shingles?
1) An area of skin innervated by a specific nerve root level
2) An infection of a single nerve fiber from varicella-zoster
140
1) Define reflex
2) The spinal cord is the link between the brain and the body, but what does it also do?
1) A fast, unconscious, involuntary response to stimulus
2) Can also integrate activity without involving the brain (thus, not a conscious event)
141
List the 5 steps of a reflex arc
1) Sensory receptor
2) Afferent pathway
3) Integrating center
4) Efferent pathway
5) Effector organ
142
Define spinal reflex and cranial reflex and give an example of each
1) Spinal reflex: spinal cord is the integration center
-Touching a hot object
2) Cranial reflex: subconscious integration from lower brain levels
-Pupillary light reflex
143
What are the categories of reflexes?
1) Spinal vs Cranial
2) Innate vs Acquired
3) Somatic vs Autonomic
4) Mono vs polysynaptic
144
1) Define innate spinal reflex
2) Define acquired spinal reflex
1) Innate: withdrawal reflex from touching a hot object
2) Acquired: salivating at the smell of a favorite food
145
1) Define somatic reflex
2) Define autonomic reflex
1) Somatic: output carried to skeletal muscle
2) Autonomic: output carried to smooth muscle, cardiac muscle, gland
146
What is the difference between a monosynaptic and polysynaptic reflex?
How many synapses are in the reflex arc
147
What are most tumors in the brain? Why?
Most brain tumors are gliomas, neurons don’t divide so they don’t form tumors
148
Name some non-glial cell CNS tumors
Metastases or meningiomas (membrane of CNS)
149
1) What is the sensory relay station of the brain?
2) What initiates movement? What refines it?
1) Thalamus
2) Cortex initiates, thalamus refines
150
What does the suprachiasmatic nucleus do? What is it a part of?
Controls circadian rhythms, a part of the hypothalamus
151
What part of the brain causes you to put on sweater and turn up heat when you're cold?
Cerebral cortex
152
What part of the brain does SSRIs affect?
The limbic system
153
1) What can cause vertical nystagmus? Is it common?
2) What can cause horizontal nystagmus? Is it common?
3) What part of the brain is involved in both?
1) Stroke, not as common
2) Alcohol inebriation, more common
3) Cerebellum
154
Give simple examples of the 5 brain wave types
1) Gamma: studying
2) Beta: chilling, talking to a friend
3) Alpha: awake but zoned out
4) Theta: starting to fall asleep on the couch while watching TV, light sleep
5) Delta: deep sleep
155
1) What happens if you're able to move during REM sleep?
2) How does sleep help with mood?
1) Sleepwalking
2) Wakefulness means constant norepinephrine and serotonin activity, which desensitizes receptors, so sleep restores
156
1) What is in the dorsal horn? What synapses here?
2) What about the lateral horn?
3) What about in the ventral horn?
1) Dorsal = interneuron neuron bodies (afferent neurons synapse here)
2) Lateral = autonomic efferent neuron bodies
3) Ventral = somatic efferent neuron bodies
157
Summarize the differences between CNS and PNS
1) CNS
-Brain and spinal cord
-Bundle of cell bodies: center
-Bundle of axons: tract
2) PNS
-12 cranial nerves and 31 spinal nerve pairs
-Bundle of cell bodies: ganglion
-Bundle of axons: nerve
