Nervous system - Lectures 4-5 Flashcards
(62 cards)
1
Q
What are the 3 primary brain vesicles during embryonic development?
A
- prosencephalon (forebrain)
- mesencephalon (midbrain)
- Rhombencephalon (hindbrain)
2
Q
which of the 3 primary brain besicles basically stays the same during the entire embryonic development?
- function?
A
mesencephalon –> becomes midbrain
- links forebrain and hindbrain
3
Q
what does prosencephalon develops into? (2) –> and then 5 parts ish + functions
A
prosencephalon –> telencephalon & diencephalon
- telencephalon –> cerebrum = biggest part of brain (L and R hemisphere) –> coordination, memory, emotions = highest integration part
- diencephalon –> eye cup + thalamus (somatosensory + special sensory), hypothalamus (ANS, endocrine), epithalamus (pineal gland = melatonin)
4
Q
what does rhombencephalon develops into?
A
rhombencephalon –> metencephalon + myelencephalon
- metencephalon –> pons (controls basic function of body: breathing, heartbeat, respiration) + cerebellum (behind the pons, kinda like 2nd brain)
- myelencephalon –> medulla oblongata
5
Q
what 3 parts form the brain stem?
A
pons, midbrain and medulla oblongata
6
Q
Gray matter (where + 3 charac) vs white matter (2 charac ish)
A
GRAY:
- cortex and nuclei in CNS
- unmyelinated nerve cell bodies
- dendrites
- axon terminals
WHITE:
- myelinated axons
- axon bundles connecting CNS regions are tracts (vs nerves in PNS) –> contain very few cell bodies
7
Q
what is gyri, sulci and fissure?
A
- gyri (gyrus) = folds of brain –> allows to increase surface area
- sulci (sulcus) = gaps
- fissure: large sulcus between gyri –> helps us separate brain into parts
8
Q
4 ways to protect the brain
A
- skull
- cranial meninges
- cerebrospinal fluid
- blood-brain barrier
9
Q
- brain is encased in bony ______ or ________
- spinal cord runs through __________ ___________
- meninges lie between _______ and _______ to stabilize neural tissue and protect from __________
A
- skull or cranium
- vertebral column
- bone and tissues, protect from bruising
10
Q
3 meninges + characteristics
A
- dura mater –> thick and tough, 2 layers ish merged together –> if open, forms cavity (venous sinus)
- arachnoid membrane –> spider web type membrane –> sits on 1 layer of connective tissue + blocks water
*Sub arachnoid space (btw arachnoid and pia mater) contains the cerebral spinal fluid in ventricules - pia mater: collé au brain tissue
11
Q
how do the meninges protect brain (3)
A
- prevents brain from touching skull
- holds cerebrospinal fluid in
- stabilizes blood supply to and from brain
12
Q
CSF:
- what is it?
- produced by what? (2)
- material selectively moves form _______ to _________
- water follows due to ______ ________
A
- salty solution similar to plasm
- produced by choroid plexus in ventricules
- moves from plasma to ventricules
- due to osmotic gradient
13
Q
- CSF surrounds entire ________
- contained within ______A________ space
- flows from ________ to _____A_____ space to return to _______ by ______
A
- brain
- subarachnoid space
- ventricles to subarachnoid space to return to plasma by villi
14
Q
Cerebrospinal fluid function in ______ and ______ protection
A
physical and chemical
15
Q
how many main ventricles in brains?
- in which part of the brain are they in?
A
- lateral ventricles (2) in cerebrum
- third ventricle in diencephalon
(cerebral aqueduct in midbrain) - 4th ventricle in hindbrain
16
Q
- what is choroid plexus?
- how is CSF produced in the choroid plexus? (3 ish)
A
- network of blood vessels in each ventricles in the brain
- ependymal cells (type of glial cells) produce CSF using the liquid from capillaries –> secretes liquid into ventricles which becomes CSF
- CSF goes down canal and around the meninges
17
Q
how is CSF reabsorbed in the blood?
A
CSF reabsorbed at fingerlike projections of arachnoid membrane called villi
- 2 layers of dura mater –> space in between called veinous sinus (2) where arachnoid membrane protrudes out and forms a villus
18
Q
flow of CSF from lateral ventricle to subarachnoid space (3 steps)
A
- lateral ventricle –> third ventricle (passes a foramen/hole)
- third ventricle –> fourth ventricle (passes through cerebral aqueduct)
- fourth ventricle –> subarachnoid space of brain and spinal cord (passes 2 foramen)
19
Q
3 roles of CSF
A
- cushions and insulates delicate nervous tissue (ie put tofu in water so it won’t break)
- gives buoyancy to the brain (floats in CSF) –> apparent weight of 0.5kg instead of 1.5kg
- exchange of gases (O2 and CO2), nutrients and wastes (with interstitial fluid)
20
Q
Blood-brain barrier
- highly __________ permeability of brain _________
- __________ foot processes promote ______ junctions between __________ cells
- protects brain from __________ water soluble compounds and __________
- small __________-soluble molecules cross BBB
A
- selective permeability of brain capillaries
- astrocytes –> tight junctions between endothelial cells (IMPORTANT! vs usually there is space btw endothelial cells –> pressure difference and bulk flow)
- toxic and pathogens
- lipid-soluble
21
Q
3 types of cells super important for BBB + explain
A
- astrocyte endfoot (type of glial cells) –> send signals for endothelial cells to make tight junctions
- pericyte (not a glial cell) –> kinda like endfoot: sends signal for endothelial cells to make tight junctions
- endothelial cells make tight junction
(cells sit on basement membrane)
22
Q
neural tissues has special metabolic requirements:
- neurons need a constant supply of ______A____ and _________
- brain receives ___% of blood pumped by heart
- ____A_____ passes freely/doesn’t pass across BBB
A
- oxygen and glucose!
- 15%
- oxygen passes freely
23
Q
Glucose in brain:
- what moves it from plasma into brain interstitial fluid?
- brain responsible for how much of body’s glucose consumption?
- progressive hypoglycemia leads to (3)
A
- membrane transporters (glucose transporter 3)
- half!
- confusion, unconsciousness and death
24
Q
spinal nerve branches into which 2 roots? + characteristics
A
- dorsal root
- contain afferent/sensory nuclei
- afferent neuron connect with interneurons into dorsal horns - ventral roots
- carry motor information from CNS to muscles and glands
25
how many pairs of spinal vs cranial nerves?
- 31 pairs of spinal nerves
- 12 pairs of cranial nerves
*Nerves = axons in PNS
26
Gray matter in spinal cord:
- dorsal vs lateral vs ventral horns contain what type of of nuclei?
- dorsal (back): visceral and somatic sensory nuclei
- lateral: visceral motor nuclei (sends signal to internal organs)
- ventral (front): somatic motor nuclei (to motor neurons)
27
white matter in spinal cord:
- divided into columns of ____A____
- ascending ___A_____ take ________ info to the brain
- descending ____A____ carry ________ signals from the brain
- ________ ____A____ stay in the cord (vs spinothalamic ____A____ go from spine to thalamus)
- tracts!
- ascending tracts take sensory info to brain
- descending tracts carry motor signals from brain
- propriospinal tracts
28
white/grey matter outside/inside for cerebrum vs spinal cord?
Cerebrum:
- cortex/outside = grey
- inside = white
Spinal cord:
- outside = white
- inside = grey
29
which region in brain is associated with body part (Dr. Penfield's work on homunculus)?
primary somatic sensory cortex
30
brain stem is the ________ part of brain
- contains (3)
oldest
- contains pons, midbrain and medulla
31
cranial nerves can include ________ fibres, ________ fibres or both (________ nerve)
- many nuclei are associated with ________ formation (control 4)
- sensory fibres, efferent fibres or both (mixed nerves)
- reticular formation (in brain stem)--> controls wakefulness, sleep, muscle tone, pain modulation
32
2 things to remember for cranial nerves
1. most start from where?
2. which one do we have to remember?
1. most start from the brain stem (2nd to 12th)
2. Cranial nerve X (10) --> vagus, type mixed --> primary function = sensory and efferents to many internal organs, muscles and glands)
33
function of medulla oblongata?
medulla also includes (3)
controls involuntary functions: blood pressure, breathing, swallowing, vomiting
- somatosensory and corticospinal tracts + pyramids
34
what are pyramids?
- fibre carrying voluntary motor message from cerebrum to spinal cord
- where signals switch from L brain to R side of body and vice versa!
35
funtions of pons and midbrain
Pons:
- relay station
- coordinates control of breathing
Midbrain:
- eye movement
- relay signals for hearing and seeing reflex
36
Reticular formation contains lots of __________ --> which sends signals to different parts of upper brain
- reticular formation = group of _______ sending signal from _______ to _________
- nuclei
- neuron sending signal from inside to outside (?) not sure
37
2nd largest structure in brain?
- also called ?
- functions (5)
- sensitive to __________
- cerebellum
- little brain
1. process sensory information
2. coordinate execution of movement
3. equilibrium and balance (sensory) from somatic receptors
4. motor input from cerebrum
5. related to proprioception
- sensitive to alcohol
38
diencephalon contains (3 ish) + functions
1. (2 fcts)
2. (3 fcts)
3. (2 parts)
1. thalamus:
- relay station integrating center
- coordinates all sensory except smelling
2. hypothalamus
- control of homeostasis
- center of behavioural drives (hunger, thirst)
- influences autonomic function and endocrine function
3. endocrine structures
- pituitary gland: anterior vs posterior
- pineal gland --> produces melatonin
39
How can hypothalamus control well homeostasis?
no blood-brain barrier --> more sensitive to what's going on outside!
40
Functions of hypothalamus (5 ish)
- control homeostasis
- activates sympathetic nervous system
- maintains body temp + osmolarity
- controls food intake
- interacts with limbic system
- ...
41
Cerebrum (cerebroooom)
- is the site of ________ brain functions
- consists of (what? (2)) connected by what
- 2 types of matters --> inside (what consists?) or outside?
- outside matter contains (2)
- higher brain functions
- 2 hemispheres connected by corpus callosum
- grey (cortex = outside) and white matter --> mostly found on interior
- white: bundles of fibers connecting different regions of brain
GREY:
- basal ganglia: control of movement
- Limbic system: link btw cognitive functions and emotions --> actually under the cerebral cortex
42
3 parts of the limbic system + what do they regulate?
- cingulate gyrus: emotion
- hippocampus: learning and memory
- amygdala: emotion and memory
43
basal ganglia
- 1 region?
- newer name?
- what does it do?
- 3 parts in each hemisphere
- basal nuclei (bc cell bodies in central nervous system VS ganglion)
- fine tune motor movement --> decides if initial signal coming from cortex is good --> if yes, sends to thalamus (?)
44
does the gray matter in cerebral cortex contain different layers?
yes!
45
what are the 4 lobes in cerebral cortex? + areas in each lobe
1. Frontal lobe: controls movement
- primary motor cortex (skeletal muscle mvt)
- motor association area (skeletal muscle mvt)
- prefrontal association area
2. Parietal lobe:
- Primary somatic sensory cortex
- sensory association area
3. Occipital lobe:
- Visual cortex
- Visual association area
4. Temporal lobe:
- Olfactory cortex (smell)
- Auditory cortex (Hearing)
- auditory association area (hearing)
* gustatory cortex (taste) underneath cerebral cortex
46
difference between primary (smtg) cortex and its association area? vs prefrontal association area
- if you stimulate specific region in primary cortex, makes specific mvt/sensory = lower level
- association area: higher level --> can integrate more
*prefrontal association area: highest level of integration --> can integrate action from different lobes
47
Brain function:
1. sensory system (2)
2. cognitive system (1)
3. behavioral state system (1)
1. monitors internal and external environments + initiates reflex response
2. initiates voluntary responses --> planning, preparation and production of our own actions (ie can walk even if there's no stimulus)
3. governs sleep-wake cycles and other intrinnsic behaviors (breeding during seasons for animals)
48
3 functional areas in cerebral cortex
1. sensory areas (1)
2. motor areas (1)
3. association areas (2)
1. sensory input translated into perception (awareness)
2. direct skeletal muscle movement
3. integrate information from sensory and motor areas + can direct voluntary behaviors
49
what is cerebral lateralization?
each hemisphere has its specialties ish (writing, math, language on L --> controls the right ish VS artistic, touch on R --> controls the L ish)
- corpus callosum links between the 2 hemispheres
50
what are the 3 major types of outputs from motor system of CNS?
1. skeletal muscle movement (somatic motor division)
2. neuroendocrine signals
3. visceral responses (autonomic division --> heart, lung, stomach)
* 2 and 3 are involuntary + coordinated in the hypothalamus and adrenal medulla (brain stem)
51
what state system MODULATES motor output? explain
- behavioral state system!
- modulator (increase or decrease sensation) of sensory and cognitive processes
- neurons collectively known as diffuse modulatory systems (originate from reticular formation in brain stem --> projects axons to large areas of brain)
52
what measures brain activity?
electroencephalography (EEG)
53
Why do we sleep? (4)
- store memory
- remove waste from what happens during the day
- repair brain tissues
- growth hormones produced during night
54
what are the 4 states of sleep? which 2 are major ones?
1. N1
2. N2
3. Slow wave sleep (N3): adjusts body without conscious commands
4. rapid eye movement (REM) sleep:
- brain activity inhibits motor neurons to skeletal muscle, paralyzing them
- dreaming takes place
- knowledge consolidation for memory
- brain uses as much or more glucose than awake state
* N3 and REM are the major ones
55
EEG: compare amplitude and frequency
- stage W (awake, eyes closed)
- N1
- N2
- N3
- REM
- stage W similar to N1
- N2: amplitude increases, frequency decreases
- N3: decreased frequency + highest amplitude
- REM shortest frequency, amplitude btw N1/W and N2
amplitude: W = N1 < REM < N2 < N3
frequency: REM < N3 < N2 < N1 = W
56
order of sleep cycles?
- deepest sleep occurs in the first _____ hours
- N1 N2 N3 N2 N1 R N1 N2 N3 N2 N1 R
- N3 is the lowest, R is the highest
- 3 hours!
57
what is circadian rhythm?
- what control primary "clock?
- alternating daily patterns of rest and activity
- suprachiasmatic nucleus of hypothalamus --> sens axon to pineal gland --> releases melatonin
58
learning is the acquisition of knowledge
- associative learning vs non-associative learning
- associative learning --> links smtg to another event --> makes you learn faster
- non-associative learning --> memorize a term/textbook --> can develop habituation or sensitization
59
- habituation vs sensitization?
- habituation: same stimulus --> becomes less responsive (ie turn on TV while studying) --> decreased perception through inhibitory modulation (falls below perceivable threshold)
- sensitization: same stimulus: becomes more sensitive to it (ie keep doing mvt --> responds faster to it)
60
- where are memories stored?
- anterograde vs retrograde amnesia?
- short vs working vs long-term memory
- reflexive (implicit) vs declarative (explicit) memory
- in memory traces (in different places in brain) --> hippocampus is involved
- anterograde --> can't remember new info VS retrograde --> can't recall old memories
- short = few secs VS working = executing functions VS long term = store info for a long time (with consolidation)
- reflexive = how to do it + can't really describe (riding bike) VS declarative = knowing a fact + can report verbally (Ottawa is capital)
61
new information goes into _____-______ memory but is lost unless _________ and stored in _____-_____ memory
- short-term
- unless processed (consolidation)
- stored in long-term memory
62
2 areas for integration of spoken language
- damage?
- where are the areas found in the brain?
1. Wernicke's area
- understanding language
- damage: unable to understand sensory input
- towards parietal lobe (more sensory ish)
2. Broca's area
- produces speech
- damage: difficulty speaking or writing normal syntax + don't understand complicated sentences + possible deficit in short-term memory
- towards frontal lobe (more motor ish)
