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BIOL 430 > Unit 4 Lecture > Flashcards

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

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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
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3
Q

Which division of the peripheral nervous system only innervates the GI tract’s wall?

A

Enteric nervous system

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4
Q

What are the parts of the neuron?

A
  1. Cell body (perikaryon/soma): contains nucleus and cytoplasm
  2. Dendrites - detect sensations
  3. Axon - where AP propagates down
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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

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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
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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
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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

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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

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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
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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

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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)

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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

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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

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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

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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

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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

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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

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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

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20
Q

What structures do astrocytes make contact with? What are their functions?

A

contact with: blood capillaries, neurons, pia matter

f(x)’s:

  1. support neurons - contains microfilaments for strength
  2. create the BLOOD BRAIN BARRIER - prohibits entrance of most substances btw blood and interstitial fluid
  3. in embryo, regulates growth, migration and interconnection among neurons
  4. helps maintain chemical environment required for AP
  5. may play role in learning in memory
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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
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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

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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

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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

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25
Q

What are Schwann cells and what system are they part of?

A

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

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26
Q

What are satelite cells and what system are they found in?

A

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

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27
Q

Are neurolemma found in the CNS? Does this affect regrowth after injury?

A

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
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28
Q

Define the following: cluster, ganglion, nucleus

A

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

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29
Q

Describe white matter. Where is it found in the brain and the spina cord?

A

white matter - composed primarily of myelinated axons, whitish color

brain - deep
spinal cord - superficial

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30
Q

Describe gray matter. Where do you find in the brain and the spinal cord?

A

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

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31
Q

Describe leak ion channels and where you would find them.

A

gated channels that randomly open and close
- more K than Na leak ion channels

found in nearly all cells

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32
Q

Describe ligand gated channels and where they are found

A

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

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33
Q

Describe mechanically-gated ion channels and where they are found

A

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

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34
Q

Describe voltage gated ion channels and where they are found

A

gated ion channels that open in response to change in membrane potential

found in axons of all types of neurons

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35
Q

What is the typical resting membrane potential? What causes it?

A

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
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36
Q

What is a graded potential? What can cause a graded potential? Where do they occur? What affects their size?

A

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

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37
Q

What is wave summation?

A

the addition of graded potentials

- if two depolarizing grade potentials summate, the net result is a larger depolarizing graded potential

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38
Q

What is a postsynaptic potential? What is a receptor potential? What is a generator potential?

A

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

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39
Q

What channels open first in an action potential? What opens second? What stays open longer?

A

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

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40
Q

What is the refractory period? Absolute refractory period? Relative refractory period?

A

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

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41
Q

Describe continuous conduction of an action potential

A

type of propagation

step-by-step depolarization and depolarization of each adjacent segment of the plasma membrane

occurs in unmyelinated axons and muscle fibers

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42
Q

Describe saltatory conduction of an action potential

A

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
Q

What are the three major factors that affect the speed of propagation?

A
  1. amount of myelination
  2. axon diameter - larger = faster AP
  3. temperature - APs propagate at lower speeds when cooled
44
Q

Describe A fibers

A

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
Q

Describe B fibers

A

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
Q

Describe C fibers

A

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
Q

What are factors that affect stimulus intensity?

A

more intense stimuli = higher frequency of action potentials

also depends on the number of sensory neurons recruited by the stimulus

48
Q

Describe an electrical synapse structurally and functionally

A

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
Q

Describe a chemical synapse structurally and functionally

A

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
Q

Compare and EPSP and IPSP

A

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
Q

Describe ionotropic and metabotropic receptors

A

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
Q

What are the three ways neurotransmitters removed from the synapse?

A
  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
Q

Describe spatial and temporal summation

A

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
Q

What small molecule neurotransmitters are inhibitory?

A

ACh, GABA, epinephrine, norepinephrine, dopamine, serotonin

55
Q

Describe the divergence and convergence neural circuit

A

divergence - single presynaptic neuron that synapses with several post synaptic neurons

convergence - several presynaptic neurons synapse with a single postsynaptic neuron

56
Q

Describe the reverberating and parallel after discharge neural circuit

A

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
Q

Describe the difference between plasticity and regeneration of nervous tissue

A

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
Q

What are the 3 reasons for no repair in the CNS?

A
  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
Q

What are the three steps of PNS repair? What does it require?

A

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
Q

What are the structures that protect the brain?

A

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
Q

What are the extensions of dura matter that separates part of the brain?

A
  1. falx cerebri - separates hemispheres of cerebrum
  2. falx cerebelli - separates 2 hemispheres of the cerebellum
  3. tentorium cerebelli: separates cerebellum from cerebrum
62
Q

How does blood flow to the brain? Why is it important that the brain has blood supply?

A

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
Q

What is the blood brain barrier and what is it made of?

A

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
Q

What is CSF? Describe it physically. What are its functions?

A

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
Q

What are the roles of the ventricle and the choroid plexus in regards to CSF? State the order in which the CSF flows.

A

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
Q

Describe hydrocephalus

A

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
Q

What is the brainstem composed of? Where is it located?

A

medulla oblongata
pons
midbrain

located between the spinal cord and diencephalon

68
Q

Describe the medulla oblongata. What cranial nerves is it associated with?
What are its structural regions? What are its functions?

A

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
Q

Describe the pons. What cranial nerves is it associated with? What are its functional regions?

A

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
Q

Describe the midbrain. What cranial nerves are associated with it? Describe its structural and functional regions.

A

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
Q

What are the cerebral peduncles and where are they located? Where do their axons go?

A

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
Q

What is the tectum? What does it consist of? Describe the two pairs.

A

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
Q

What is the red nuclei? Why is it red? Where is it found?

A

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
Q

What are the main functions of the reticular formation? Where is it?

A

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
Q

What is the RAS? What are its ascending portion functions? What happens if it is inactivated or damaged?

A

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
Q

What are the descending portion functions of RAS?

A

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
Q

What is the function of the cerebellum?

A

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
Q

What is the diencephalon composed of?

A

Thalamus
hypothalamus
epithalamus

79
Q

What is the function of the thalamus?

A

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
Q

What are the three primary brain vesicles? What are the 5 secondary brain vesicles?

A

primary: prosencephalon, mesencephalon, and rhombencephalon

secondary:
telencephalon, diencephalon
mesencephalon
metencephalon, myelecephalon

81
Q

What are the functions of the hypothalamus? What structure does it contain?

A
  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
Q

What are the functions of the epithalamus? What structure does it contain?

A

contains:
pineal gland - secretes melatonin
habenular nuclei - involved in olfaction, especially emotional response to odors

83
Q

What are the CVO’s of the diencephalon?

A

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
Q

In the cerebral white matter, describe the the 3 types of tracts.

A
  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
Q

What structures make up the basal nuclei? What are its functions?What nearby structures are functionally linked to the basal nuclei?

A

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
Q

What are some examples of brain injuries? Describe ischemia, hypoxia, a concussion, a brain contusion, and a laceration

A

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
Q

Where does the sensory areas receive input? Where are their association areas? What happens to someone with damage to their visual association area?

A

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
Q

What is Broca’s area important for?

A

associated in L hemisphere of 97% of people
language area

damage can cause confluent aphasia - can form thoughts but not words

89
Q

What is the Wernicke’s area important for?

A

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
Q

What is the orbitofrontal cortex (association area) important for?

A

allows you to ID odors and to discriminate among different odors
- receives sensory information from primary olfactory area

91
Q

What does the common integrative area (association area) do?

A

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
Q

What is the prefrontal cortex important for? What is the premotor area important for?

A

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
Q

What is hemispheric lateralization? What are each of the hemispheres important for?

A

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
Q

Describe what brain waves are active during these different times:
Awake (eyes open)
Awake (eyes closed)

light sleep
deep sleep
deepest sleep

REM

A

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
Q

What is cranial nerve I and II?

A

I - Olfactory - special sensory - smell

II - Optic - special sensory - vision

96
Q

What is cranial nerve III, IV, and VI?

A

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
Q

What is cranial nerve V?

A

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
Q

What is cranial nerve VII?

A

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
Q

What is cranial nerve VIII?

A

vestibulocochlear - special sensory

hearing and equilibrium

100
Q

What is cranial nerve IX?

A

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
Q

What is the cranial nerve X?

A

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
Q

What is cranial nerve XI and XII?

A

XI - Accessory - motor nerve
brachial - movement of head and pectoral girdle

XII - hypoglossal - somatic - speech, manipulation of food and swallowing

103
Q

Describe the following disorders: cerebrovascular accident, transient ischemic attack, and Alzheimers

A

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

BIOL 430 (14 decks)

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