Unit 4 Lecture Flashcards
1
Q
How is the nervous system organized? What are the CNS and PNS and how do they work together?
A
CNS - Brain and spinal cord
PNS - cranial and spinal nerves, sensory receptors
Sensory division sends afferent input into CNS
- CNS analyzes, stores info
CNS sends efferent signal to neurons
2
Q
What are the two cells that comprise nervous tissue?
A
Neurons - highly specialized, able to sense, think, remember, ctrl muscle activity and glandular secretions
- unable to undergo mitotic divisions
- electrical excitability
Neuroglia - support, nourish, protect neurons and maintain interstitial fluid
- smaller, but outnumber neurons
- ability to divide
3
Q
Which division of the peripheral nervous system only innervates the GI tract’s wall?
A
Enteric nervous system
4
Q
What are the parts of the neuron?
A
- Cell body (perikaryon/soma): contains nucleus and cytoplasm
- Dendrites - detect sensations
- Axon - where AP propagates down
5
Q
What are Nissl bodies?
A
cluster of rough ER, contain ribosomes and are the site of protein synthesis in neurons
proteins are used for:
- replacement of cellular components
- material for growth of neurons
- regenerate damaged axons in the PNS only
6
Q
What is lipofuscin?
A
orange/brown pigment that is found in the cytoplasm of aging neurons
- product of neuronal lysosome that accumulates as the neuron ages
- does not seem to harm neuron
7
Q
What is a nerve fiber? What are their functions?
A
general term for any neuronal process that emerges from the soma
- dendrites (multiple): receives input
- single axon: propagates nerve impulses toward another neuron, muscle fiber or gland cell
8
Q
What does an axon contain? What does it not contain that other neuronal structures do?
A
contains: mitochondria, microtubules, neurofibrils, axoplasm (cytoplasm), and axolema (plasma membrane)
does not have rough ER - no protein synthesis
9
Q
What are axon collaterals and axon terminals?
A
axon collaterals - side branches of an axon, typically at a right angle
axon terminal - many fine processes at the end of an axon and its collaterals
10
Q
Compare and contrast slow and fast axonal transport
A
slow - conveys axoplasm in one direction only: from soma to axon terminals
fast - moves materials in both directions: to and from the soma
- anterograde - organelles and synaptic vesicles move from soma to axon terminals
- retrograde - moves membrane vesicles from the axon terminals to cell body to be degraded or recycled
11
Q
Describe a multipolar neuron. How is this type classified? Where are they found?
A
Structural classification - depends on number of processes extending from soma
has many dendrites and an axon coming off of cell body
motor neurons are ONLY multipolar
found in the brain and spinal cord
12
Q
Describe a bipolar neuron. What kind of classification is this? Where are they found?
A
structural classification - based on number of processes coming off of cell body
one main dendrite and one axon
found in the 3 special senses - retina (vision), inner ear (hearing, olfactory (smell)
13
Q
Describe unipolar neurons. What type of classification is this? Were are they found?
A
structural classification - based on how many processes come out of cell body
AKA pseudounipolar - begin in embryo as bipolar
dendrites function as sensory neurons for touch, pressure, pain and thermal stimuli
cell bodies located in the GANGLIA OF SPINAL AND CRANIAL NERVES
14
Q
What are the other cells that are classified structurally?
A
Purkinje cells - cerebellum
pyramidal cells - cerebral cortex of the brain which have pyramid shaped soma
15
Q
What are afferent neurons? What kind of classification is this? What is their typical structural classification?
A
functionally - direction in which the AP is conveyed in respect to CNS
once stimulus activates receptor, sends AP into the CNS through the cranial or spinal nerves
most sensory neurons are unipolar in structure
16
Q
What are efferent neurons? What type of classification is this? What is their typical structural classification?
A
functional classification -
direction in which AP is conducted in relation to CNS
conveys APs away from the CNS to effectors - muscles or glands - in the PNS through cranial or spinal nerves
efferent neurons are multipolar in structure
17
Q
What are interneurons What type of classification is this? What is their typical structural classification?
A
functional classification - direction in which AP is conveyed in respect to the CNS
process incoming sensory info from sensory neurons, and elicit a motor response by activating appropriate motor neurons
- mainly located within CNS between motor and sensory neurons
most interneurons are multipolar in structure
18
Q
Describe neuroglia
A
make up about half the volume in the CNS
- smaller than neurons but more numerous
- in cases of injury or disease, neuroglia multiply to fill in the spaces formerly occupied by neurons
do not generate APs
19
Q
What are astrocytes? Describe their structure. What are the two types?
A
glia found in CNS
- star shaped with many processes
- largest and most numerous
protoplasmic - short, branches processes found in gray matter
fibrous - long, unbranched processes found in white matter
20
Q
What structures do astrocytes make contact with? What are their functions?
A
contact with: blood capillaries, neurons, pia matter
f(x)’s:
- support neurons - contains microfilaments for strength
- create the BLOOD BRAIN BARRIER - prohibits entrance of most substances btw blood and interstitial fluid
- in embryo, regulates growth, migration and interconnection among neurons
- helps maintain chemical environment required for AP
- may play role in learning in memory
21
Q
What are oligodendrocytes? What system are they found in?
A
glia in CNS - smaller and fewer processes than astrocytes
responsible for FORMING AND CONTAINING MYELIN SHEATH AROUND CNS AXONS
- can myelinate multiple axons
- contains less Nodes of Ranvier than myelinated PNS neurons
22
Q
What is the myelin sheath? What cells produce them?
A
multilayered lipid and protein covering around some axons
- insulates and increases the speed of APs
- protects axon
Nodes of Ranvier: areas on myelinated axon that do not contain myelin
CNS - oligodendrocytes
PNS - Schwann cells
Multiple sclerosis attacks myelin sheath
23
Q
What are microglia and what system are they part of?
A
glia in the CNS
small cells with slender processes with spine like projections
function as phagocytes - eat debris, foreign particles, invaders, damaged nervous tissue
24
Q
What are ependymal cells and where are they located?
A
glial cells in CNS
- cuboidal/columnar cells arranged in single layer, contain microvilli and cilia
lines the ventricles of the brain and central canal of spinal cord to produce/move CSF
also forms the BLOOD-CSF barrier - does not allow most chemicals into CSF
25
What are Schwann cells and what system are they part of?
glia of PNS
forms the myelin sheath around axons in PNS
- can only myelinate single axon
participates in AXON REGENERATION - slow process that occurs only in PNS
contains neurolemma - outer, nucleated cytoplasmic layer on Schwann cells
- encloses myelin sheath and aids in regeneration
26
What are satelite cells and what system are they found in?
glia in PNS
- flat cells t hat surround the cell bodies of neurons of PNS ganglia
provides structural support
regulates exchange of materials between neuronal cell bodies and interstitial fluid
27
Are neurolemma found in the CNS? Does this affect regrowth after injury?
No, bc oligodendrocyte cell bodies do not envelop the axon
- myelinated parts of several axons
CNS displays little regrowth after injury, possibly due to:
- absence of neurolemma
- inhibitory influence exerted by oligodendrocytes on axon regrowth
28
Define the following: cluster, ganglion, nucleus
cluster: neuronal cell bodes that are grouped together
ganglion: cluster of neuronal cell bodies in PNS
- closely associated with cranial and spinal nerves
nucleus: cluster of neuronal cell bodies located in CNS
29
Describe white matter. Where is it found in the brain and the spina cord?
white matter - composed primarily of myelinated axons, whitish color
brain - deep
spinal cord - superficial
30
Describe gray matter. Where do you find in the brain and the spinal cord?
gray matter contains neuronal cell bodies, dendrites, unmyelinated axons, axon terminals, and neuroglia
- contains little to no myelin in these areas
- appears gray due to Nissl bodies
center of spinal cord
surface of the brain
31
Describe leak ion channels and where you would find them.
gated channels that randomly open and close
- more K than Na leak ion channels
found in nearly all cells
32
Describe ligand gated channels and where they are found
gated ion channels that open in response to binding of a ligand stimulus
found in sensory neurons like pain receptors, dendrites and cell bodes of interneurons and motor neurons
33
Describe mechanically-gated ion channels and where they are found
gated ion channels that open in response to a mechanical stimulus like touch, pressure, vibration or tissue stretching
- ex. Pascinian corpuscles
found in dendrites of some sensory neurons such as touch, pressure and some pain receptors
34
Describe voltage gated ion channels and where they are found
gated ion channels that open in response to change in membrane potential
found in axons of all types of neurons
35
What is the typical resting membrane potential? What causes it?
typically -70 mV - indicating inside of cell more negative than outside
3 major factors for resting membrane potential:
1. unequal distribution of ions in the ECF and cytosol
- extracellular fluid is rich in Na and Cl
- cytosol has a lot of K but molecules with lots of phosphates
2. inability of most anions to leave the cell due to their size
3. electrogenic nature of Na/K ATPases
- expels 3 Na for 2 K imported
- electrogenic: contributes to negativity of resting membrane potential
36
What is a graded potential? What can cause a graded potential? Where do they occur? What affects their size?
small deviation from the membrane potential - can be more or less polarized
occurs in response to the opening a mechanically or ligand-gated ion channel
mainly occur in the dendrites or the cell body of a neuron
amplitude dependent on strength of stimulus
- affected by how many and how long ion channels stay open
37
What is wave summation?
the addition of graded potentials
| - if two depolarizing grade potentials summate, the net result is a larger depolarizing graded potential
38
What is a postsynaptic potential? What is a receptor potential? What is a generator potential?
postsynaptic potential - graded potential that occurs in the dendrites or cell body of a neuron
receptor potential - graded potential developed by a receptor cell as a response to stimuli
generator potential - graded potential developed in a receptor zone (dendritic zone) of a neuron in response to a stimuli
39
What channels open first in an action potential? What opens second? What stays open longer?
once it is depolarized to threshold (-55mV), vg Na channels open first and depolarize the cells
vg K open second, and allow K to flow out of the cell during the repolarizing phase
- remains open after the repolarizing phase for hyperpolarization
40
What is the refractory period? Absolute refractory period? Relative refractory period?
refractory period: period of time after an AP during which the cell cannot generate another AP in response to normal threshold
absolute - even very strong stimulus cannot initiate second AP
relative - second AP can be initiated but only with a larger-than-normal stimulus
- coincides with the period when the vg K channels are still open after inactivated Na channels return to rest
41
Describe continuous conduction of an action potential
type of propagation
step-by-step depolarization and depolarization of each adjacent segment of the plasma membrane
occurs in unmyelinated axons and muscle fibers
42
Describe saltatory conduction of an action potential
type of propagation
AP propagates along myelinated axons at Nodes of Ranvier
- axolemma contains many vg channels at Nodes of Ranvier
consequences:
1. AP appears to leap between nodes and travels much faster
2. opens smaller number of channels only on nodes
43
What are the three major factors that affect the speed of propagation?
1. amount of myelination
2. axon diameter - larger = faster AP
3. temperature - APs propagate at lower speeds when cooled
44
Describe A fibers
myelinated
largest diameter axons
long (but shortest) absolute refractory period
associated with touch, pressure, proprioception, and some thermal and pain sensations
axons of motor neurons that conduct impulses to skeletal muscles
45
Describe B fibers
myelinated
Intermediate rise
longer absolute refractory period than A
conduct sensory nerve impulses from the VISCERA to the brain and spinal cord
constitute all the axons of the autonomic motor neurons that extend from the brain and spinal cord to the autonomic ganglia
46
Describe C fibers
unmyelinated
smallest
longest absolute refractory period
pain, touch pressure, heat and cold from the skin
pain from the viscera
autonomic motor fibers that extend form autonomic ganglia to stimulate the heart, smooth muscle and glands
47
What are factors that affect stimulus intensity?
more intense stimuli = higher frequency of action potentials
also depends on the number of sensory neurons recruited by the stimulus
48
Describe an electrical synapse structurally and functionally
at an electrical synapse, AP's conduct directly between the plasma membrane of adjacent neurons throughout gap junctions
common in: visceral smooth muscle, cardiac muscle, developing embryo and brain
faster communication
synchronization - coordinates the activity of a group of neurons or muscle fibers
49
Describe a chemical synapse structurally and functionally
presynaptic and postsynaptic neurons do not touch - separated by the synaptic cleft
presynaptic neuron released neurotransmitter that diffuses through synaptic cleft to the plasma membrane of the postsynaptic neuron
postsynaptic neuron received chemical signal - produces postsynaptic potential (graded potential)
slower than electrical potentials
typically only one way information transfer can occur
50
Compare and EPSP and IPSP
Caused by a neurotransmitter - when bound to correct receptor, an ion channel opens
EPSP - excitatory postsynaptic potential
- depolarizing postsynaptic potential
- typically does not initiate nerve impulse, but cell does become more excitable
IPSP: inhibitory postsynaptic potential
- hyperpolarization of postsynaptic membrane
51
Describe ionotropic and metabotropic receptors
ionotropic: NT receptor that contains a NT binding site and an ion channel of the SAME protein
- ligand gated channel
metabotropic: NT receptor that contains NT binding site but lacks ion channel as part of structure
- couples to a separate ion channel
52
What are the three ways neurotransmitters removed from the synapse?
1. diffusion - some NT's diffuse away from the synaptic cleft
2. enzymatic degradation - only certain NTs have enzymes that break them down
3. uptake by cells - many NT's are actively transported back into the neuron that release them (reuptake)
53
Describe spatial and temporal summation
spatial - summation of post synaptic potentials in response to stimuli that occur in different locations of the postsynaptic membrane at the same time
- ex. NTs released simultaneously by several presynaptic end bulbs
temporal - summation os postsynaptic potentials in response to a stimuli that occur at the same location in the membrane but at different times
- NT released by a single presynaptic end bulb 2+ more times in rapid succession
54
What small molecule neurotransmitters are inhibitory?
ACh, GABA, epinephrine, norepinephrine, dopamine, serotonin
55
Describe the divergence and convergence neural circuit
divergence - single presynaptic neuron that synapses with several post synaptic neurons
convergence - several presynaptic neurons synapse with a single postsynaptic neuron
56
Describe the reverberating and parallel after discharge neural circuit
reverberating - incoming impulse stimulates the first nerve, that stimulates second, that stimulates third, so on
- branches of later neurons synapse at earlier synapse, sending impulses back through circuit again
parallel after-discharge - single presynaptic cell stimulates group of neurons, each of which synapses with a common post synaptic cell
57
Describe the difference between plasticity and regeneration of nervous tissue
plasticity - capability to change based on experience
regeneration - capability to replicate or repair
although nervous system exhibits plasticity, neurons have limited ability to regenerate themselves
58
What are the 3 reasons for no repair in the CNS?
1. inhibitory influences from neuroglia, particularly oligodendrocytes
2. absence of growth-stimulating cute that were present during fetal development
3. rapid formation of scar tissue - physical barrier to repair
59
What are the three steps of PNS repair? What does it require?
requires that the cell body is in tact, Schwann cells are functional, and scar tissue does not occur too rapidl y
1. chromatolysis: Nissl bodies break up into fine granular masses
2. Wallerian degeneration: distal part of axon and myelin sheath degenerate
3. Regeneration rube: Schwann cells near site of injury multiply to form regeneration tube
60
What are the structures that protect the brain?
cranial bones
cranial meninges: pia, arachnoid, and dura mater
- cranial dura matter has 2 layers: periosteal and meningeal
cerebrospinal fluid
No epidural space around brain
61
What are the extensions of dura matter that separates part of the brain?
1. falx cerebri - separates hemispheres of cerebrum
2. falx cerebelli - separates 2 hemispheres of the cerebellum
3. tentorium cerebelli: separates cerebellum from cerebrum
62
How does blood flow to the brain? Why is it important that the brain has blood supply?
blood flows to the brain via the vertebral and carotid arteries
- flows back to the heart via jugular veins
brain uses ~ 20% of body's oxygen, glucose supply
- interruption of O2 can result in weakening, permanent damage, or death of brain cells
- glucose deficiency produces mental confusion, dizziness, convulsions, and unconsciousness
63
What is the blood brain barrier and what is it made of?
selective barrier that protects brain cells from harmful substances/pathogens from blood into the brain
- can prevent entry of therapeutic drug
- injury to brain can breakdown barrier allowing passage of restricted substances
made mostly of:
- tight junctions - seal together endothelial cells of BB capillaries
- basement membrane - surrounds capillaries
- astrocytes - secrete chemicals that maintain permeability
64
What is CSF? Describe it physically. What are its functions?
cerebrospinal fluid - clear, colorless liquid composed mostly of H2O
- 80-150 mL in adult
- continuously circulates through cavities in the brain and spinal cord and in subarachnoid space
functions:
1. mechanical protection - shock absorbing medium
2. homeostatic function: maintains pH of CSF
- serves as hormone transport
3. circulation - minor exchange of nutrients and waste products
- carries O2 , glucose, etc
65
What are the roles of the ventricle and the choroid plexus in regards to CSF? State the order in which the CSF flows.
ventricles of the brain contain CSF
- each ventricle has its own choroid plexus
choroid plexus produces CSF
- network of blood capillaries in the walls of ventricles
- selects substances from the blood plasma to be secreted into ependymal cells to make CSF
lateral ventricle - 3rd ventricle - 4th ventricle - subarachnoid space - arachnoid villa of dural venous sinuses - heart and lungs- back into blood for choroid plexus
66
Describe hydrocephalus
abnormalities in the brain (tumors, inflammation, etc) can interfere with the circulation of CSF from the ventricles into the sub arachnoid space
- excess CSF accumulation = increased CSF pressure
- can be due to obstruction of CSF flow or abnormal rate of CSF production/reabsorption
67
What is the brainstem composed of? Where is it located?
medulla oblongata
pons
midbrain
located between the spinal cord and diencephalon
68
Describe the medulla oblongata. What cranial nerves is it associated with?
What are its structural regions? What are its functions?
continuous with superior aspect of spinal cord, contains portion of motor and sensory tracts
Cranial nerves: vestibulocochlear, glossopharangeal, vagus, accessory and hypoglossal
structural regions:
- pyramids - formed by corticospinal tract, ctrl voluntary movement of limb and trunk
- inferior olivary nuclei: makes adjustments to muscle activity when learning new motor skills
functional regions:
- HR, RR, vasoconstriction, swallowing, coughing, vomiting, sneezing, hiccups
- nuclei associated with sensations of: touch, pressure, vibration, conscious proprioception
69
Describe the pons. What cranial nerves is it associated with? What are its functional regions?
superior to the medulla oblongata, links parts of brain to each other thru tracts
cranial nerves: trigeminal, abducens, facial, vestibular branch of vesibulocochlear
functional regions:
- relays nerve impulses related to voluntary skeletal muscle movements from cerebrum to cerebellum
- pneumotaxic and apneustic areas (control of respiration)
70
Describe the midbrain. What cranial nerves are associated with it? Describe its structural and functional regions.
AKA mesencephalon
superior to the medulla oblongata and extends from bonds to diencephalon
cranial nerves: oculomotor and trochlear
structural regions: cerebral peduncles, corpora quadrigemina, substantia nigra, red nuclei, medial lemniscus
functional regions: conveys motor impulses from the cerebrum to cerebellum and spinal cord
- sends sensory impulses from the spinal cord to the thalamus
- regulates auditory and visual reflexes
71
What are the cerebral peduncles and where are they located? Where do their axons go?
anterior part of the midbrain
consists of 3 types of axons:
1. corticospinal - motor cortex to the spinal cord
2. corticobulbar - motor cortex to the medulla
3. corticopontine - motor cortex to the pontine
72
What is the tectum? What does it consist of? Describe the two pairs.
posterior part of midbrain with 4 rounded elevations
superior colliculi: reflex center for certain visual activities
- govern movement of the head, eyes, and trunk response to visual stimuli
inferior colliculi: part of the auditory pathway
- center for startle reflex, sudden movements
- contains substantia nigra: produces DA that control subconscious muscle activities
73
What is the red nuclei? Why is it red? Where is it found?
red due to being rich in blood
located in the midbrain
axons from the cerebellum and cerebral cortex synapse in red nuclei - help control muscle movements
74
What are the main functions of the reticular formation? Where is it?
regulates muscle tone
alerts cortex to incoming sensory signals
responsible for maintaining consciousness and awakening from sleep
extends from superior part of spinal cord, throughout brainstem, and into the anterior part of the diencephalon
RF neurons have both ascending and descending functions
75
What is the RAS? What are its ascending portion functions? What happens if it is inactivated or damaged?
reticular activating system - consists of sensory axons that project to the cerebral cortex directly and through the thalamus
RAS important for:
- awareness of position of body parts
- consciousness
- active during arousal or awakening from sleep
- prevents sensory overload by filtering out insignificant info
```
inactivation = sleep
damage = coma
```
76
What are the descending portion functions of RAS?
connections to the cerebellum and the spinal cord to regulate:
- muscle tone
- heart rate - blood pressure
- respiratory rate
received input from eyes, ears and other sensory receptors EXCEPT SMELL
- strong odors may fail to cause arousal
77
What is the function of the cerebellum?
coordinates skeletal muscle contractions and helps maintain normal muscle tone, posture and balance
evaluates how well movements ordered by the cerebrum are executed and sends feedback to correct errors
coordinates complex sequence of skeletal muscle contraction
78
What is the diencephalon composed of?
Thalamus
hypothalamus
epithalamus
79
What is the function of the thalamus?
superior to the midbrain and contains nuclei that serve as relay stations for all sensory impulses (besides smell) to cerebral cortex
- input from midbrain and spinal cord to primary somatosensory cortex
80
What are the three primary brain vesicles? What are the 5 secondary brain vesicles?
primary: prosencephalon, mesencephalon, and rhombencephalon
secondary:
telencephalon, diencephalon
mesencephalon
metencephalon, myelecephalon
81
What are the functions of the hypothalamus? What structure does it contain?
1. control the ANS
2. regulates circadian rhythms and states of consciousness
3. regulates emotional and behavioral patterns
4. controls body temperature
5. regulation of eating and drinking
6. produces hormones - contains important connections with pituitary glands
contains mammillary body - relay stations relating to scent
82
What are the functions of the epithalamus? What structure does it contain?
contains:
pineal gland - secretes melatonin
habenular nuclei - involved in olfaction, especially emotional response to odors
83
What are the CVO's of the diencephalon?
circumventricular organs
- part of the diencephalon that can monitor chemical changes in the blood bc it lacks a BBB
- includes portion of the hypothalamus, pineal and pituitary gland
- coordinate homeostatic activities in the endocrine and nervous systems like BP, thirst, hunger and fluid balance
84
In the cerebral white matter, describe the the 3 types of tracts.
1. association tracts: contains axons that conduct nerve impulses between gyri in SAME hemisphere.
2. commissural tracts: contains axons that conduct nerve impulses from gyri in one cerebral hemisphere to corresponding gyri in other cerebral hemisphere
- corpus callous, anterior and posterior commissure
3. projection tracts: contain axon that conduct nerve impulses from the lower parts of the CNS (thalamus, brain stem, spinal cord) to cerebrum or vice versa
- internal capsule
85
What structures make up the basal nuclei? What are its functions?What nearby structures are functionally linked to the basal nuclei?
Lentiform nucleus - globes pallidus and putamen
caudate nucleus
all three together = corpus striatum
functions:
- regulates initiation and termination of movements
- initiates and terminates some cognitive processes (attention, memory, planning)
- may act with the limbic system to regulate emotional behaviors
- control subconscious contractions of skeletal muscles
- globes pallidus: regulates muscle tone
functionally lines - substantia nigra, subthalamic nuclei, claustrum - may be involved in visual attention
86
What are some examples of brain injuries? Describe ischemia, hypoxia, a concussion, a brain contusion, and a laceration
hypoxia - low O2
ischemia - inadequate blood supply
concussion - temporary loss of consciousness, disturbances in vision, problems with equilbrium
brain contusion - bruising - results in immediate loss of consciousness, loss of reflexes, transient cessation of respiration and deceased BP
laceration - tear in the brain, results in rupture of large blood vessels - bleeding into brain and subarachnoid space
- cerebral hematoma - localized pool of blood
- edema - increased intracranial pressure
87
Where does the sensory areas receive input? Where are their association areas? What happens to someone with damage to their visual association area?
receive input form primary and other brain regions - integrates sensory experiences to generate meaningful patterns of recognition and awareness
association areas are adjacent to the primary areas
damage to visual association area - able to see but unable to recognize ordinary objects
88
What is Broca's area important for?
associated in L hemisphere of 97% of people
language area
damage can cause confluent aphasia - can form thoughts but not words
89
What is the Wernicke's area important for?
interprets the meaning of speech by recognizing spoken words
- activated when you translate words into thoughts
people who suffer strokes in the Wernicke's area can still speak, but cannot arrange words in coherent fashion
- fluent aphasia - word salad
90
What is the orbitofrontal cortex (association area) important for?
allows you to ID odors and to discriminate among different odors
- receives sensory information from primary olfactory area
91
What does the common integrative area (association area) do?
receives nerve impulses from primary gustatory area, primary olfactory area, thalamus and parts of the brain stem and allow formation of thoughts based on a variety of sensory inputs
92
What is the prefrontal cortex important for? What is the premotor area important for?
prefrontal cortex - concerned with the makeup of a person's personality, intellects, complex learning abilities, recall of information, judgement, mood, planning, development of abstract ideas
premotor area - deals with learned motor actives of a complex and sequential nature
- generates nerve impulses that cause specific groups of muscles to contracts in specific sequence
- ex writing your name
93
What is hemispheric lateralization? What are each of the hemispheres important for?
hemispheric lateralization - physiological and functional asymmetry in the different brain hemispheres
L brain: reasoning, numerical and scientific skills, spoken/written language, ability to understand sign language
R brain: musical and artistic awareness, spatial and pattern perception, recognition of faces, emotional content of faces and language, discrimination of different smells, generating mental images of sight, sound, touch, taste
94
Describe what brain waves are active during these different times:
Awake (eyes open)
Awake (eyes closed)
light sleep
deep sleep
deepest sleep
REM
Awake (eyes open) - Beta - nervous system is active
Awake (eyes closed) Alpha
light sleep - Theta - also emotional stress
deep sleep - sleep spindles
deepest sleep - Delta - also normal in awake babies
REM - beta
95
What is cranial nerve I and II?
I - Olfactory - special sensory - smell
| II - Optic - special sensory - vision
96
What is cranial nerve III, IV, and VI?
III - oculomotor - motor nerve
- somatic component: moves eyeball and upper eyelid
- motor (autonomic): adjusts lens for near vision (accommodation), and construction of pupil
IV - trochlear motor nerve
- movement of eyeballs
VI - abducens - motor nerve
- movement of eyeballs
97
What is cranial nerve V?
trigeminal - mixed nerve
sensory functions - touch, pain, thermal sensations from scalp, face and oral activity (teeth and anterior 2/3 tongue)
motor functions chewing, controls of middle ear muscle
98
What is cranial nerve VII?
facial - mixed nerve
sensory function: taste from anterior 2/3 tongue, tough, pain, thermal sensations from skin in external ear canal
motor (brachial): controls muscles of facial expressions and middle ear muscle
motor (autonomic): secretion of tears and saliva
99
What is cranial nerve VIII?
vestibulocochlear - special sensory
hearing and equilibrium
100
What is cranial nerve IX?
glossopharyngeal - mixed nerve
sensory function: taste from post 1/3 tongue, proprioception in some swallowing muscles
- monitors BP and {O2/CO2} in blood
- touch, pain and thermal sensation from skin and external ear and upper pharynx
motor (brachial): assists in swallowing
motor (autonomic): secretion of saliva
101
What is the cranial nerve X?
vagus nerve - mixed
sensory functions: taste from epiglottis
- proprioception from throat and voice box
- monitors BP, O2 and CO2 concentration in blood
- touch, pain and thermal sensation from skin of external ear
motor (brachial) function: swallowing, vocalization, and coughing
motor (autonomic) function: motility and secretion of GI organs
- construction of respiratory passage ways
- decreases heart rate
102
What is cranial nerve XI and XII?
XI - Accessory - motor nerve
brachial - movement of head and pectoral girdle
XII - hypoglossal - somatic - speech, manipulation of food and swallowing
103
Describe the following disorders: cerebrovascular accident, transient ischemic attack, and Alzheimers
CVA - Stroke
- abrupt, persisting neurological symptoms - paralysis or loss of sensation due to destruction of brain tissue
- cause: hemorrhage, blood cots, atherosclerosis
TIA - temporary cerebral dysfunction due to impaired blood flow to the brain
- dizziness, weakness, paralysis of limb on one half to ehe body
- no permanent neurological deficits
Alzheimer's
- senile dementia, inability to reason and care for one self
3 distinct abnormalities:
- loss of ACh neurons from nucleus basialis
- Beta amyloid plaques
- neurofibrillary tangles
