neuro Flashcards
1
Q
Neurons
A
functioning cells of the nervous system
2
Q
Neuroglial cells
A
protect the nervous system and supply metabolic support
3
Q
Afferent (sensory) neurons
A
transmit information to the CNS
4
Q
Efferent (motor) neurons
A
carry information away from the CNS
5
Q
Interneurons
A
efferent and afferent neurons communicate
6
Q
Neuron componenet
A
dendrites, axon, and cell body (soma)
7
Q
Neuroglial cells of the CNS
A
oligodendrocytes, astrocytes, microglia, and ependymal cells
8
Q
oligodendrocytes
A
form myelin in the CNS
9
Q
Schwann cells
A
form myelin in the PNS
10
Q
Astrocytes
A
Blood-brain barrier
11
Q
Ependymal cell
A
line ventricular system. involved in CSF production
12
Q
Microglia
A
phagocytic cells
13
Q
Satellite cells
A
protect cell body in the PNS
14
Q
Saltatory conduction (PNS)
A
conduction jumps from node to node
15
Q
Nodes of Ranvier (PNS)
A
schwann cells are separated by these gaps. voltage0gated sodium channels are concentrated here
16
Q
depolarization
A
inward flow of positive ions. Inflow of Na+ produces local positive current, causing Na+ channels to open. (+30mV)
17
Q
Action potential phases
A
resting state, depolarization, and repolarization
18
Q
resting state
A
(-70mV) is when the nerve is not transmitting impulses. membrane is polarized due to large separation of charge (K+ inside the cell and Na+ outside the cell)
19
Q
Repolarization
A
when the polarity of the resting membrane potential is reestablished. Accomplished via Na+ channel closure and K+ channel opening
20
Q
absolute refractory period
A
membranes remain refractory and cannot create a stimulus
21
Q
relative refractory period
A
membrane can be excited by a stronger than normal stimulus.
22
Q
Muscular dystrophy
A
genetic disorders that produces progressive deterioration of skeletal muscles because of mized muscle cell hypertrophy, atrophy, and necrosis.
23
Q
Muscular dystrophy
A
DMD is the most common. it is a recessive single-gene defect on the X chromosome transmitted from mother to male offspring.
24
Q
DMD etiology
A
mutation of dystrophin
25
Muscular dystrophy manifestations
muscle weakness with frequent falling at 2-3 years of age. Postural muscles of the hip and shoulders are usually the first to be affected. death from respiratory and cardiac muscle involvement occurs in young adulthood
26
Muscular dystrophy diagnosis
serum levels of creatine kinase
27
Multiple sclerosis
inflammation and destruction of myelin in the CNS (oligodendrocytes). onset is 20-30 years and frequently affects females of North European ancestry.
28
multiple sclerosis pathogenesis
immune response to CNS protein. consists of hard, sharp-edged, demyelinated patches in white matter. lesions=plaque (result of myelin breakdown)
29
multiple sclerosis manifestations
paresthesias, vision problems, weakness or fatigue, speech disturbance, abnormal gait.
psychological- mood swings, depression, euphoria, inattentiveness, apathy, forgetfulness, and loss of memory.
30
multiple sclerosis categories
relapsing-remitting: episodes of acute worsening with recovery and stable course between relapses
Secondary progressive disease: gradual neurologic deterioration with or without acute relapses
primary progressive disease: continuous neurologic deterioration from onset of symptoms.
progressive relapsing: gradual neurologic deterioration from onset of symptoms but with subsequent relapses.
31
Multiple sclerosis treatment
corticosteroids
32
SCI
most common SCI is motor vehicle crash, followed by falls, violence (gunshot wounds), and sports
33
SCI involves
motor and sensory function
34
Most SCI injuries
occur due to writhing movements and a compressive force.
35
Primary neurologic injury (SCI)
occurs at the time of injury and is irreversible.
36
Primary neurologic injury (SCI) characterized by
small hemorrhages in the gray matter followed by edematous changes in white matter that lead to necrosis and cell death.
37
Primary neurologic injury (SCI) results from
forces of compression, stretch, and shear associated with fracture or compression of the spinal vertebrae, dislocation of vertebrae, and contusions.
38
Secondary injuries (SCI)
follows the primary injury and promote the spread of injury
39
types of SCI
tetraplegia (quadriplegia), paraplegia, complete cord injuries, and incomplete cord injuries
40
tetraplegia (quadriplegia)
impairment of function in arms, trunk, legs, and pelvic organs.
41
paraplegia
impairment of thoracic, lumbar, or sacral segments. arm functioning is spared, but function of the trunk, pelvic, and legs are impaired.
42
complete cord injuries
severance of the cord. no motor or sensory function is preserved in segments S4 to S6.
43
incomplete cord injuries
imply residual motor or sensory function below the level of injury. prognosis is better for return of injury.
44
compression injury (SCI)
causes vertebral bones to shatter, squash, or even burst when there is loading from a blow to the top of the heard. diving injury
45
axial rotation (SCI)
occurs in the cervical region especially between C1 and C2 and at the lumbosacral joint.
46
CN I (olfactory) located in forebrain
olfaction (smell)
47
CN II (optic nerve) located in forebrain
carries visual impulses from eye to brain
48
CN III (oculomotor) located in midbrain
contracts eye muscles to control eye movements (inferior lateral, medial, and superior), constricts pupils, and elevates eyelids.
49
CN IV (trochlear) located in pons
contracts one eye muscle to control inferomedial eye movement
50
CN V (trigeminal) located in midbrain
carries sensory impulses of pain, touch, and temperature from the face to the brain. influences clenching and lateral jaw movements (biting, chewing).
51
CN VI (abducens) located in caudal pons
controls lateral eye movements
52
CN VII (facial)
contains sensory fibers for taste on anterior 2/3 of tongue, and stimulates secretions from salivary glands (submaxillary and sublingual) and tears from lacrimal glands. Supplies the facial muscles and affects facial expressions (smiling, frowning, and closing eyes)
53
CN VIII (vestibulocochlear)
contains sensory fibers for hearing and balance
54
CN IX (glossopharyngeal)
contains sensory fibers for taste on posterior third of tongue and sensory fibers of the pharynx that result in the gag reflex when stimulated. provided secretory fibers to the parotid salivary glands; promotes swallowing movements.
55
CN X (vagus)
carries sensations from the throat, larynx, heart, lungs, bronchi, GI tract, and abdominal viscera. promotes swallowing, talking, and production of digestive juices.
56
CN XI (spinal accessory)
innervates neck muscles (sternocleidomastoid and trapezius) that promote movement of the shoulders and head rotation. Also promotes some movement of the larynx.
57
CN XII (hypoglossal)
innervates tongue muscles that promote the movement of food and talking.
58
Frontal lobe
involved in anticipation and prediction of consequences of behavior; provides precise movement control for distal flexor muscles of the hands and feet and of the phonation apparatus for speech (Broca's area); planning complex learned movement patterns (damage- dyspraxia or apraxia)
59
Parietal lobe
Interprets tactile sensations, including touch, pain, temp, shapes, and 2-point discrimination; somesthetic perception- concerned with "where" the stimulus is in space and in relation to body parts (deficit- agnosia)
60
Occipital lobe
visual experience- color, motion, depth perception, pattern, form, and location in space; neocortical areas of parietal lobe relate texture and location of an object with its visual image; auditory and visual association areas (parieto-occipital region) relates meaningfulness of a sound and image to an object or person; influences ability to read and is the primary visual receptor center
61
Temporal lobe
receives and interprets impulses from the ear. contains wernicke area, which is responsible for interpreting auditory stimuli;
62
Autonomic NS is involved in
regulating, adjusting, and coordinating vital visceral functions such as blood pressure and blood flow, body temperature, respiration, digestion, metabolism, and elimination.
63
ANS is strongly affected by
emotional influences: blushing, pallor, palpitations of the heart, clammy hands, and dry mouth
64
ANS is represented in
both the CNS and PNS
65
Efferent outflow of ANS
sympathetic and parasympathetic
66
SNS function
maintains body temperature and adjusts blood vessels and BP to meet changes in the body. Activated during critical threats- "fight-or-flight" response
67
Fight-or-flight response
HR accelerates; BP rises; blood sugar increases; bronchioles and pupils dilate; sphincters of the stomach and intestine and the internal sphincter of the urethra constrict; and rate of secretion of exocrine glands involved in digestion diminish.
68
Sympathetic function is described as
catabolic- actions predominate during periods of pronounced energy expenditure, such as when survival is threatened.
69
PNS function
concerned with conservation of energy, resource replenishment and storage, and maintenance of organ function- the "rest-digest" response
70
PNS functions to
slow the HR, stimulates GI function and related glandular secretion, promotes bowel and bladder elimination, and contracts the pupil (protects retina from too much light)
71
PNS and SNS are continually
active
72
Tone
PNS or SNS can alter the tone of an effector organ by increasing or decreasing function
73
Structure innervated by both PNS and SNS
SA node and AV node- PNS can brake HR and SNS increases HR. when one is active the other is suppressed
74
Pain classified by duration
acute or chronic
75
Acute pain characteristics
Recent onset; <6 month duration (short); consistent with sympathetic fight-or-flight responses; increased HR; increased stroke volume; increased BP; increased pupillary dilation; increased muscle tension; decreased gut motility; decreased salivary flow (dry mouth); associated anxiety
76
Chronic pain characteristics
continuous or intermittent duration; 6 months or more duration; absence of autonomic responses; increased irritability; associated depression; somatic preoccupation; withdrawal from outside interests; decreased strength of relationships; decreased sleep; decreased libido; appetite changes
77
Acute pain is elicited by
injury and activation of nociceptive stimuli at the site of local tissue damage.
78
Chronic pain may have
recurring episodes of acute pain. has characteristics of both acute and chronic pain
79
chronic pain includes:
peripheral, peripheral-central, and central mechanisms
80
Peripheral mechanisms (chronic pain)
results from persistent stimulation of nociceptors and are involved with chronic musculoskeletal, visceral, and vascular disorders. (migraine headaches, sickle cell crisis)
81
Peripheral-central mechanisms (chronic pain)
related to abnormal function of the peripheral and central portions of the somatosensory system, such as those resulting from partial or complete loss of descending inhibitory pathways or spontaneous firing of regenerates nerves fibers (phantom limb pain)
82
Central mechanisms (chronic pain)
associated with CNS disease or injury and characterized by burning, aching, and other abnormal sensations (spinal cord injury, MS)
83
Cutaneous pain
arises from superficial structures. it is a sharp pain with a burning quality that may be abrupt or slow in onset. it ca be localized and may be distributed along the dermatomes.
84
Deep somatic pain
originates in deep body structures. more diffuse than cutaneous pain. various stimuli, such as strong pressure on bone, muscle ischemia, and tissue damage. may radiate from the site of injury
85
Visceral pain
most common pains produced by disease. contractions, distention, or ischemia of visceral walls can induce severe pain
86
Referred pain
pain perceived at a site different from its point of origin but innervated by the same spinal segment
87
Phantom limb pain
neurologic pain that follows amputation of a limb or part of a limb.
88
Phantom limb pain described as
tingling, squeezing, or heaviness, followed by burning, cramping, or shooting pain
89
core body temp is a reflection of
the balance between heat gain and heat loss by the body. metabolic process produce heat which must be dissipated
90
hypothalamus is the
thermal control center for the body and receives info from peripheral and central thermoreceptors and compare that info with its set point
91
an increase in core temp results from
vasoconstriction and shivering
92
a decrease in temp results from
vasodilation and sweating
93
fever describes
an elevation in body temp that is caused by an upward displacement of thermostatic set point of the hypothalamic thermoregulatory center
94
fever results from
cytokine-induced increase
95
fever is a nonspecific response mediated by
endogenous pyrogens from host cells in response to infectious or noninfectious disorders
96
what causes the release of pyrogenic cytokines into the bloodstream?
when bacteria is present in blood or tissue and phagocytic cells engulf them
97
what do cytokines induce?
prostaglandin E2 (PGE2)
98
what does PGE2 bind to?
receptors in the hypothalamus to induce increases in thermostatic set point. hypothalamus then initiates shivering and vasoconstriction
99
what is hyperthermia?
increase in body temp that occurs without a change in the set point of the hypothalamic thermoregulatory center
100
when does hyperthermia occur?
when the thermoregulatory mechanisms are overwhelmed by heat production, excessive environmental heat, or impaired dissipation of heat.
101
hyperthermia includes
heat cramps, heat exhaustion, and heatstroke (worst). may also result from a drug reaction
102
malignant hyperthermia is an
autosomal dominant disorder in which an abnormal release of intracellular stores of calcium causes uncontrolled skeletal contractions which result in rapid increase in core body temp.
103
malignant hyperthermia is a response to an
anesthetic
104
initial sign of malignant hyperthermia is
skeletal muscle rigidity followed by cardiac arrhythmias and a hypermetabolic state
105
heat cramps are
slow, painful, skeletal muscle cramps and spasms lasting 1-3 min. results from salt depletion from heavy sweating
106
heat exhaustion is
a gradual loss of salt and water after prolonged exertion in a hot environment
107
heatstroke is a failure of thermoregulatory mechanisms resulting in
excessive increases in body temp- a core temp >104; hot, dry skin; absence of sweating; and delirium, convulsions, and loss of consciousness.
108
muscle tone is maintained by
spinal cord stretch reflex and UMN and LMN
109
hypotonia or flaccidity is a
condition of less than normal muscle tone
110
hypertonia or spasticity is a
condition of excessive tone
111
paresis (weakness) and paralysis (loss of muscle mvmt) reflect
a loss of muscle strength
112
manifestations of brain injury
changes in level of consciousness and alterations in cognitive, motor, and sensory function
113
most susceptible to damage in brain injury?
cerebral hemisphere
114
signs of injury to diencephalon, midbrain, pons, and medulla are related to
pupillary and eye movement reflexes, motor function, and respiration
115
key clinical signs of brain injury in diencephalon
impaired consciousness and Cheyne-Stokes respirations
116
key clinical signs of brain injury in midbrain, pons, and medulla
coma
117
levels of consciousness
full consciousness, confusion, lethargy, obtundation, stupor, coma
118
confusion characteristics
disoriented to time, place, person
memory difficulty
difficulty following commands
119
lethargy characteristics
oriented to time, place, and person
slow mental processes, motor activity, and speech
responds to pain approp.
120
obtundation characteristics
```
responds verbally with a word
arousable with stimulation
responds approp. to painful stimulation
follows simple commands
very drowsy
```
121
stupor characteristics
unresponsive except to vigorous and repeated stimuli
responds approp. to painful stimuli
minimal spontaneous mvmt and quiet
incomprehensible sounds and eye opening
122
coma characteristics
does not respond approp to stimuli
sleeplike state with eyes closed
does not make verbal sounds
123
hypoxia is
deprivation of oxygen with maintained blood flow and interferes with the delivery of oxygen. may be due to atmospheric pressure, carbon monoxide poisoning, severe anemia, and failure to oxygenate the blood. produces a generalized depressant effect on the brain.
124
ischemia is
reduced or interrupted blood flow and interferes with oxygen and glucose delivery and metabolic waste removal. can be focal (stroke) or global (cardiac arrest). global is when the entire brain is compromised and focal is when only a region is underperfused
