This presentation is about signal processing in the nervous system, pain control, ascending and descending pathways in spinal cord, cerebrum cerebellum, limbic system,....

1. The Nervous System
1
The central
processing unit

2. Parts of the Nervous System
• Central Nervous System (CNS): brain and spinal
cord
• Peripheral Nervous System (PNS): Craniospinal
nerves
• Autonomic Nervous System (ANS): nerves that
control vital organs: heart, lungs, GI, vessels,
glands, etc.
2

3. 3

4. Receptors
(eyes, ears, other sense organs)
change information from outside the
body ( for example, light waves) into
electrical impulses.
Digitalization
4

5. 5

6. Receptive field
6

7. Stimulus Receptor Location Receptive
field
Adaptation
mechanoreception
Touch, pressure Free nerve ending Hair root
Small
Variable
Texture, steady
pressure
Merkel receptor
Superficial
Slow
Flutter, stroking Meissner Rapid
Stretch Ruffini Deep Large Slow
Vibration Pacinian corpuscle Extremely rapid
Thermoreception
Cold Free nerve ending Superficial Small Rapid
Warm
Nociception
Thermal
Free nerve ending Superficial
Small Rapid
Mechanical Large Slow
Polymodal ( chemical) Large Slow
7

12. Somatosensory receptors
12

13. Glial cells
• 10 times than neurons
• 50% of volume
• Astrocytes in BBB
• O2A, in remyelination
• Microglia as
macrophage
13

14. Glymphatic System
14

15. Astrocytes
• Ions & NT regulation in ECF
• Buffering K+
• Beta amyloid protein removal
• Trophic support of neurons, nourish,
Neurotaxism
• Boundaries between adjacent
process(insulate)
• Capillaries & neurons
• Forming glial scar
• Removing debris
• CSF flow
15

16. 16

17. • (1) CSF flows into the brain parenchyma via
the periarterial space
• From this perivascular space CSF enters the
interstitium of the brain tissue via Aquaporin 4
(AQP4)-controlled water channels
• These are distributed in the end feet of
astrocytes in outer wall of the perivascular
space
• (2) CSF entering IF flows by convection, and
CSF-ISF exchange within the brain
parenchyma
• (3) After washing the waste proteins from the
tissue, it flows into the perivenous space in
deep-draining vein, and is subsequently
discharged outside the brain
17

18. 18

19. 19

20. 20

21. • If the cellular system became overloaded or
slowed down as we aged, metabolic garbage
would build up between the cells
• This garbage includes products such as beta-
amyloid, the protein associated with
Alzheimer's disease
21

22. Spaces between the meninges
22

23. The meninges: three membranes
envelop the entire CNS
(central nervous system)
dura mater The outer, hardest, toughest
arachnoid The middle, web like
pia mater The inner, thinner
23

24. Cerebrospinal fluid
• Cerebrospinal fluid: watery liquid
is found inside the brain, spinal cord, and
subarachnoid space
supports the brain’s weight
protects and cushions the brain and the spinal
cord
24

25. CSF
• Clear body fluid, produced by plexus choroid
• Nearly protein-free fluid
• Daily production: 500-600 ml
• Total: 100- 160 ml
• https://www.youtube.com/watch?v=JCf273U0ktc
25

26. CSF
26

27. 27

28. CSF vs Plasma
Substance CSF Plasma
Water Content (%) 99 93
Protein (mg/dL) 35 7000
Glucose (mg/dL) 60 90
Osmolarity (mOsm/L) 295 295
Sodium (mEq/L) 138 138
Potassium (mEq/L) 2.8 4.5
Calcium (mEq/L) 2.1 4.8
Magnesium (mEq/L) 0.3 1.7
Chloride (mEq/L) 119 102
pH 7.33 7.41
28

29. Increased intracranial pressure
• Behavior changes
• Decreased consciousness
• Headache
• Lethargy
• Neurological symptoms, including weakness,
numbness, eye movement problems, and double
vision
• Seizures
• Vomiting
• https://www.youtube.com/watch?v=kaOphkMv2pM
29

30. 30
The Central Nervous System includes
White matter: bundles of axons and dendrites
Gray matter: masses of nerve cell bodies
The brain: inside the cranium
The spinal cord: inside the vertebral column
(the “backbone”)

31. More nerve terms
nerve fibers Dendrites and axons
nerve A bundle of dendrites and axons
nucleus
(plural: nucleii)
A group of neuron cell bodies INSIDE the
brain and spinal cord
ganglion
(plural: ganglia)
A group of neuron cell bodies OUTSIDE the
brain and spinal cord
synapse The space connecting one neuron to another
neurotransmitter A chemical which transmits an electrical
impulse from one neuron to the next
31

32. Types of Neurons
Type Connected to Carry impulses
from
Carry impulses
to
Sensory
(afferent)
receptors (eyes, ears,
other sense organs)
other neurons
sense organs spinal cord
and brain
Motor (efferent) effectors (muscles and
glands)
other neurons
spinal cord
and brain
muscles
and glands
Connector
(interneuron)
other neurons other neurons other neurons
32

33. 33

34. Spinal cord
34

35. Spinal Cord, Rexed Lamina Organization
• Lissauer: entrance of inputs
• Lamina I: pain & temperature inputs
• Lamina II: Substantia Gelatinosa Rolandi (SGR); in the control of
pain
• Lamina III & IV: similar to II but receive more senses of pain, temp
& touch
• Lamina V: T cells that transmit the pain sensation
• Lamina VI: present mainly in cervical & lumbosacral regions.
Receive proprioception of muscles
35

36. Spinal Cord, Rexed Lamina Organization(cont.)
• Lamina VII: intermediolateral (preganglionic of sympathetic &
intermediomedial nuclei; clark’s column, thoracic nucleus.
Neurons
• Lamina VIII: interneuron for flexor & extensor muscles
• Lamina IX: consists of IXm (medial) & IX (lateral, present in
cervical & lumbosacral); alpha & gamma motoneurons of
muscles
• In limbs motoneurons of axial muscles in medial & proximal and
distal laterally; flexors more internally & extensors more
externally
• Lamina X: interconnections between two sides of spinal cord
36

37. Spinal cord transection
37

38. Pain
• Dull pain; by C fiber
• Sharp pain; by Aδ
fiber
• Substantia Gelatinosa
Rolandi (SGR)
38

39. Pain Classification
Slow pain Fast pain
Dull pain Sharp pain
Transmitted by C fibers Transmitted by A fibers
Poorly localized Well localized
Body wants to be immobile to allow
healing (guarding, spasm, rigidity)
Immediate withdrawal of stimulation to
avoid further damage
Pain often radiates, or is referred Pain does not radiate
Effective relief from opioids Little relief from opioids
Examples: labour pain, pain starting after
fast pain from an injury, toothache,
internal organs
Examples: pain from a surgical incision
39

40. 40

41. 41

42. Classification of pain
42

43. Pain
• Pain receptors are free nerve endings
– Mechanical
– Thermal
– Chemical
• A mechanical stimulus would be, for example, high pressure or stretching,
• Thermal pain stimulus would be extreme heat or cold
• Chemical pain receptors can be stimulated by chemicals from the outside
(e.g. acids), but also by certain products present in the body and released
as a result of trauma, inflammation or other painful stimuli
– bradykinins, serotonin, potassium ions and acids (such as lactic acid, which
causes muscle pain after heavy exercise)
• Compounds called prostaglandins are released with painful stimuli, and
although they don’t directly stimulate pain receptors, they do increase their
sensitivity
• NSAIDs decrease the effect of prostaglandins
• Paracetamol operates in the central nervous system and the NSAIDs are
peripheral-acting substances
43

44. 44

45. Gate control theory
45

46. Gate control of pain
46

47. Control of pain
• Descending pathways;
– Periaquaductal gray matter (PAG)
– Prefrontal cortex
– Raphe nuclei
• Endorphins & enkephalines
47

48. 48
RostroVentral Medulla(RVM)

49. 49

50. 50

51. Spinal Cord, Motor & Sensory Paths
51

52. Sensory pathways of spinal cord
(afferents)
• Dorsal column:
• Gracilis: lower limbs
• Cuneatus: upper limbs
– Cuneocerebellar: inf peduncle, same side of
cerebellum
52

53. Sensory pathways of spinal cord (afferents)
• Spinocervical, from sensory hairs
• Dorsal spinocerebellar tract (DSCT), from Clark’s
column, same side, inf peduncle, same hemisphere,
second order neuron in Clark
• Ventral spinocerebellar tract (VSCT), opposite side,
sup peduncle, both hemispheres
• Rostral spinocerebellar tract, joints & muscle, same
side, sup peduncle, both hemispheres
• Anterolateral system: 1 or 2 segment upper
53

54. 54

55. 55

56. 56

57. Dorsal Column Medial Lemniscus
• Fine touch
• 2-point discrimination
• Vibration
• Proprioception
• Second neuron in lower
medulla( Gracile N.& Cuneate
N.)
• Cross in medulla
• 3rd order neuron in Thalamus,
goes toward PCG
57

58. 58

59. Motor pathway, Pyramidal tract
59

60. 60

61. 61

62. 62

63. 63

64. The Cerebrum
Is divided into two cerebral hemispheres
Has an outer surface,
or CORTEX,
made of “gray matter”
64

65. The Cerebral cortex
is divided into parts called lobes:
1. the frontal lobe
2. the parietal lobe
3. the temporal lobe
4. the occipital lobe
5. https://www.youtube.com/watch?v=owFnH01SD-s
65

66. 66

67. Cortex
• Columnar organization
• Parallel processing
67

68. 68

69. 69
Brodmann’s Areas

70. 70

71. 71

72. 72

73. 73

74. Cortex
• Prefrontal
• Frontal: motor cortex/ supplementary & premotor
cortex
• Somatosensory cortex ; for the sensation; it has huge
connections with other parts of cortex, such as
premotor cortex, temporal lobe & association cortex
74

75. The Frontal lobe
Is the center for voluntary movement
Is called the “motor area” (movement)
Includes the Prefrontal area,
for intelligence, creativity, memory, and
ideas, behavioral and pain control
75

76. Phineas Gage(1848)
1821-1860
76

77. 77

78. Edvardo(2012)
78

79. 2017
79

80. The parietal lobe
Collects, recognizes, and organizes sensations:
feelings of
Pain
Temperature
Touch
Position
Movement
80

81. The Temporal lobe
• Processes auditory information
• Stores auditory and visual memories
• Includes Wernicke’s speech area
81

82. The Occipital lobe
Is at the back of the cerebral hemisphere
Involves:
Vision
Visual memory
Eye movements
82

83. 83

84. Motor Areas of Cerebral Cortex

86. Association cortex
86

87. Strategy of movement
• Step 1: highest level; aim of movement,
specific for the most humans?!
• Step 2: how it can be performed, which
muscles should contract
• Step 3: how to do it; the lowest level,
present in all animals
87https://www.youtube.com/watch?v=tUBMSnHH7hc

88. • Termination:
directly on motor
neuron or on the
interneuron
• 55% end in cervical
region, 20% in
thoracic and 25%
in lumbosacral
region.

90. 90

91. 91

92. 92

93. 93

94. Neglect
• Spatial neglect is a behavioral syndrome
occurring after brain injury
• Spatial neglect involves the inability to report,
respond, or orient to stimuli, generally in the
contralesional space
94

95. Neglect Syndrome
• People with injury to either side of the brain
may experience spatial neglect, but neglect
occurs more commonly in persons with brain
injury affecting the right cortical hemisphere,
which often causes left hemiparesis
• Spatial neglect is more commonly associated
with lesions of the inferior parietal lobule or
temporoparietal region, superior temporal
cortex, or frontal lobe
95

96. Neglect Syndrome
• Association cortex defects
• Tests:
• Line bisection test
• Letter cancellation test
• Drawing and copying
• Reading and writing
96

97. Limb Neglect
• Somatoparaphrenia
97

98. 98

99. Apraxia(kinetic)
• Inability to perform certain learned
movements, motor memory
• Lesion in Premotor area
– Placing a letter in an envelop
– Buttoning-unbuttoning
– Licking lips
– Speech
– ..
99

100. 100

101. Apraxia(ideomotor)
• Acquired or Developmental
• Lesion in parietal lobe of dominant
hemisphere
• Bilateral effects
• Unable to perform
pantomim
101

102. 102

103. Corticobulbar tract
• From cortex to medulla
• Fibers terminate on Cranial Nerve nuclei
• Termination may be ipsilateral, contralateral,
or bilateral

105. Functions
• Execution of skilled voluntary movements
• Anterior corticospinal tract controls proximal
& axial muscles
• Form part of superficial reflex pathway

106. Rubrospinal Tract
• Originates in Red nucleus
• Cross over in midbrain and descend on
opposite side
• Terminate on motor neurons of distal muscles
• Has somatotopic map in red nucleus
• Concerned with skilled movements

107. Vestibulospinal tract
• Lateral vestibulospinal tract arise from Deiter’s
nucleus- receive input from utricle & saccule
• Medial vestibulospinal tract originates from
medial & descending vestibular nuclei- receive
signals from semicircular canals
• Concerned with muscle tone , posture &
equilibrium

108. Reticulospinal Tract
• Medullary reticulospinal tract decreases tone
of antigravity muscles
• Damage= rigidity
• Pontine reticulospinal tract increases tone of
antigravity muscle
• Under the influence of higher centers

109. Tectospinal tract
• Originate from superior colliculus
• Cross over to opposite side
• Concerned with muscles of head and neck
• Controls visually guided head movements

110. 110

111. Motor system
• The pyramidal system carries the signal for
muscle contraction
• The extrapyramidal system provides
regulatory influence on muscle contraction
111

112. Pyramidal Vs. Extrapyramidal system
Characters Pyramidal system Extrapyramidal
system
Phylogeny New Old
Myelination After birth Before birth
Functions Fine, skillful movements Gross postural movements
Damage Spastic paralysis
Even during sleep
Hypotonia + rigidity
paralysis
Hypotonic during sleep,
but hypertonic with
volitional movements
Speed of conduction Slow Fast

113. Extrapyramidal palsy
Dyskinetic
• Athetosis, wormlike slow
writing
• Chorea, quick, jerky
movements
• choreoathetosis
Ataxic
• Cerebellar, tremor and
drunken-like gait
113
https://www.youtube.com/watch?v=cOfUGUNxEqU

114. Internal capsule
• Mass of axons
• Laterally lenticular nucleus and medially thalamus & caudate
• Ascending sensory fibers occupy posterior 1/3rd of posterior
limb
• Corticospinal & Corticobulbar fibers occupy genu & anterior
2/3rds of posterior limb
• Frontopontine fibers & thalamocortical fibers in anterior limb
• Injury at this level causes hemiplegia
• Involvement of lenticulostriate artery

115. The Diencephalon
is located between the midbrain
and the cerebrum
has three parts:
the thalamus: receives sensory
information and sends it to the
cerebral cortex.
the epithalamus: contains the
pineal body and olfactory centers.
the hypothalamus: connects the
endocrine and nervous systems.
115
http://www.daviddarling.info/encyclopedia/A/anatomy_and_physiology.html

116. The Hypothalamus
Connects the endocrine and nervous systems.
Controls:
the autonomic nervous system
body temperature
carbohydrate and fat metabolism
appetite
emotions
116

117. The midbrain
Controls
vision
hearing
muscles
117

118. Parts of the brainstem
• Midbrain: contains auditory (hearing), visual (sight), and
muscle control centers
• Pons: connects the medulla oblongata, the cerebellum,
and cerebrum
• Medulla Oblongata: lowest and most posterior
(at the back of the brain)
The hindbrain includes the pons and the medulla.
118

119. The pons (the bridge)
Connects the medulla oblongata, cerebellum,
and cerebrum
Associates with sensory nerves: taste, hearing, and balance.
Controls muscles of the face
119

120. The medulla oblongata
Controls
alertness
heart action
respiration (breathing)
blood pressure
Connects the CEREBRUM with the SPINAL CORD
the RIGHT side of the brain controls the LEFT side of the body.
the LEFT side of the brain controls the RIGHT side of the body.
120

121. The Cerebellum
Coordinates muscle activity.
has three parts:
the vermis
the right cerebellar hemisphere
the left cerebellar hemisphere
121

122. The limbic system
controls emotions and memory
122
controls emotions and memory

123. Papez cicuit
123

124. 124

125. PNS: Peripheral Nervous System
• Includes all the nerves and ganglia outside the
brain and spinal cord
cranial nerves: 12 pairs of nerves connected
directly to the brain
spinal nerves: 31 pairs of nerves connected to
the spinal cord
125

126. 126

127. 127

128. 128

129. Nerve Pathways
Somatic (body) motor pathways carry impulses
from the CNS (central nervous system) to
skeletal muscles
• pyramidal pathways carry impulses that
control voluntary actions that involve thought
• extrapyramidal pathways carry impulses that
control automatic movements, such as
walking
129

130. Reflexes
• A reflex is an action that:
occurs below the brain, within in the spinal cord
is an automatic reaction
is not conscious (voluntary)
can be inborn (a baby has it at birth, such as
sucking, swallowing, urinating)
can be learned (such as talking,walking, driving)
130

131. More reflexes
• INBORN
knee jerk reflex
pupillary reflex
Babinski
swallowing
coughing
blinking
• LEARNED
reading
typing
swimming
dancing
skating
playing football
131

132. The Autonomic Nervous System
controls
• involuntary, smooth, and cardiac (heart)
muscles and glands.
• systems that work automatically: digestive,
circulatory, respiratory, urinary, and
endocrine.
132

133. ANS
• The ANS is the part of the nervous system responsible for
involuntary bodily functions such as:
• blood pressure
• heart and breathing rates
• body temperature
• digestion
• metabolism
• balance of water and electrolytes
• production of body fluids
• urination
• defecation
• sexual response
133

134. The Autonomic Nervous System
has two parts
• the sympathetic system
• the parasympathetic system
These parts work together to maintain
homeostasis: normal balance of the systems
in the body
134

135. 135

136. 136

137. Sympathetic Nervous System
• Transmit visceral pain
137

138. 138

139. Autonomic Dysreflexia(AD)
• A condition in which the involuntary nervous
system overreacts to external or bodily stimuli
• It’s also known as autonomic hyperreflexia
• This reaction causes a dangerous spike in
blood pressure, rapid heartbeat, constriction
of the peripheral blood vessels, and other
changes in autonomic functions
139

140. AD
• The condition is most commonly seen in
people with spinal cord injuries above the
sixth thoracic vertebra, or T6
• It may also affect people who have multiple
sclerosis, Guillain-Barre syndrome, and some
head or brain injuries
• AD can also be a side effect of medication or
drug use
140

141. • AD is potentially life-threatening and can
result in:
• stroke
• retinal hemorrhage
• cardiac arrest
• pulmonary edema
• AD is a very serious condition, and it’s a
medical emergency
141

142. AD
• AD interrupts both the sympathetic and the
parasympathetic nervous systems
• This means that the body’s SANS overreacts to
stimuli such as a full bladder, and the PANS
can’t effectively stop that reaction and may
actually make it worse
142

143. Mechanism of AD
• Lower body still generates a lot of nerve signals after a
spinal cord injury
• These signals communicate the status of the bladder,
bowels, digestion, and other bodily functions
• The signals can’t get past the spinal injury to the brain
• However, they are still being sent to the parts of the
sympathetic and parasympathetic autonomic nervous
systems that operate below the spinal cord injury
• Signals from bodily functions can trigger the SANS and
PANS, but the brain can’t appropriately respond to
them
• They can no longer work effectively as a team, so SANS
and PANS can get out of control
143

144. Triggers in AD
• a distended bladder
• a blocked catheter
• urinary retention
• a urinary tract infection
• bladder stones
• constipation
• a bowel impaction
• hemorrhoids
• skin irritations
• pressure sores
• tight clothing
144

145. Symptoms of AD
• anxiety and apprehension
• irregular or racing heartbeat
• nasal congestion
• high blood pressure with systolic readings often
over 200 mm Hg
• a pounding headache
• flushing of the skin
• profuse sweating, particularly on the forehead
• lightheadedness
• dizziness
• confusion
• dilated pupils
145

146. Emergency consideration
• Moving into sitting position to cause the blood to
flow to the feet
• Removing tight clothes and socks
• Checking for a blocked catheter
• Draining a distended bladder with a catheter
• Removing any other potential triggers, such as
drafts of air blowing the skin
• Treating for fecal impaction
• Administering vasodilators or other drugs to bring
the blood pressure under control
146

147. 147

148. 148

149. Dermatomes
149

150. Ear
https://www.youtube.com/watch?v=qgdqp-oPb1Q

151. Lymphatic drainage
151

152. Cochlea2

153. Cochlea

154. Basilar/Tectorial Membrane

155. Human hearing
• human hearing is 20 Hz to 20 kHz
155
https://www.youtube.com/watch?v=fIAjJogJ0cs

156. Saccule/Utricle

157. Vestibular apparatus

158. Macula with Otoliths

159. Cupula of
semicircular
canal

160. Meniere’s disease
• A condition where the membranes and structures
within the inner ear contain too much fluid and become
distended
• Meniere's disease is a disorder of the inner ear that
causes episodes of vertigo, and fluctuating hearing loss
with a progressive, ultimately permanent loss of
hearing, tinnitus, and sometimes a feeling of fullness or
pressure in the ear
• In most cases, Meniere's disease affects only one ear
• Meniere's disease can occur at any age, but it usually
starts between the ages of 20 and 50
• It's considered a chronic condition, but various
treatments can help relieve symptoms and minimize
the long-term impact on life 160

161. Sign & symptoms
• Dizziness
• Nausea
• Vertigo
• Hearing loss
• Tinnitus
• Nystagmus
• Cold sweats
• Migraine
• Mood changes
• Diarrhea
161https://www.youtube.com/watch?v=qrk7OyAB_ss

162. Meniere’s disease
• Most episodes of vertigo with Meniere’s
disease are not related to head position as
with BPPV
• The attacks can occur without warning any
time and can last more than 20 minutes each
time
162

163. Triggers
• Factors that affect the fluid, which might contribute to
Meniere's disease, include:
• Improper fluid drainage, perhaps because of a blockage or
anatomic abnormality
• Abnormal immune response
• Allergies
• Viral infection
• Genetic predisposition
• Head trauma
• Migraines
• Because no single cause has been identified, it's likely that
Meniere's disease results from a combination of factors 163

164. Preventive care & Treatment
• Reduced-sodium diet, salted snacks…
• Drink adequate amounts of water
• Use more fresh fruits and whole grains
• Avoid dehydrating foods
• Avoid caffeine-containing fluids and foods
• Limit alcohol intake
• Avoid foods containing MSG (monosodium
glutamate)
164

165. Benign Paroxysmal Positional Vertigo
(BPPV)
• Common type of vertigo associated with the ears
• Associated with balance in the inner ear which
contain tiny crystals
• Crystals can become dislodged and, with certain
head movements, find their way into the semicircular
canals
• This causes intense dizziness that’s usually
characterized by a spinning sensation
• Lasts less than 5 min
• Epley Maneuver
165
https://www.youtube.com/watch?v=qw1QciZWfP0

166. Start sitting on
a bed and turn
your head 45°
to the right.
Place a pillow
behind you so
that on lying
back it will be
under your
shoulders.
Lie back
quickly with
shoulders on
the pillow and
head reclined
onto the bed.
Wait for 30
seconds.
Turn your
head 90° to
the left
(without
raising it) and
wait again for
30 seconds.
Turn your
body and
head another
90° to the left
and wait for
another 30
seconds.
Sit up on
the left
side.
This maneuver should be carried out three times a day. Repeat this daily until you are free from
positional vertigo for 24 hours. 166
https://www.youtube.com/watch?v=9SLm76jQg3g

167. 167

168. PTSD
• Role of amygdala & cortex on PTSD
• Role of prefrontal cortex
168

169. Depression
• Lack or decrease in serotonin secretion in
prefrontal cortex
• Prozac, stimulates 5-HT secretion in prefrontal
cortex, in order to improve depression
• Prozac has dependency
169

170. Laboratory tests
• brain scan: using a scanner to diagnose defects of
the brain
• cerebrospinal fluid tests: check for blood,
infection,and other abnormalities
• echoencephalogram: using ultrasound to check
the brain for abnormalities
• electroencephalogram (EEG) using a machine to
check for abnormal electrical activity in the brain
• myelography: x-ray of the spinal cord
170

171. Psychiatric (or Mental) Disorders
These diseases of the mind generally are not
caused by physical abnormalities.
• alcoholic intoxication: confusion and amnesia
caused by drinking alcohol (being “drunk”)
• delirium tremens: mental disturbance caused
by drinking alcohol, with trembling,
excitement, anxiety, hallucinations,and
convulsions
171

172. Psychiatric (or Mental) Disorders
• anorexia nervosa: an eating disorder
sometimes resulting in the patient starving to
death; most patients are young females.
• antisocial personality disorder: patient
behaves in a way that is not acceptable to
society; for example, criminal or violent
behavior
172

173. Psychiatric (or Mental) Disorders
• attention deficit/hyperactivity disorder (ADHD): a
child or adolescent does poorly in school, is restless,
has a short attention span, and is very active
physically
• bulimia: deliberately vomiting after eating, to control
weight
• dissociative disorder: a personality disease
• down syndrome: congenital mental retardation with
physical symptoms
173

174. Psychiatric (or Mental) Disorders
• mania: extreme excitement
• mental retardation: below average intelligence
• paranoia: patient believes that people are
trying to harm him
• posttraumatic stress disorder: emotional
problems following a traumatic (harmful)
event, such as war, rape, or crime
174

175. Psychiatric (or Mental) Disorders
• personality disorder: patient blames problems
in relationships on other people. common
types:
paranoid
schizoid
antisocial
passive-aggressive
obsessive-compulsive
175

176. Psychiatric (or Mental) Disorders
• phobia: an unreasonable fear
• acrophobia: fear of heights
• agoraphobia: fear of open or crowded places
• claustrophobia: fear of closed-in places
• xenophobia: fear of strangers
• zoophobia: fear of a animal, or of animals in
general
176

177. Psychiatric (or Mental) Disorders
• posttraumatic stress disorder: severe anxiety
following a traumatic (frightening or harmful)
event
• psychotic disorder: patient is out of touch with
reality, confused, and cannot think properly
• substance abuse: patients are dependent on
alcohol and/or drugs, and this interferes with
their work or social lives
177

178. Other Psychiatric Terms
• Amnesia: loss of memory
• Analgesia: not being able to feel pain
• Anesthesia: not feeling anything in a body part
• Apathy: not feeling emotions
• Asthenia: weakness
• Autism: personality disorder that affects
children
178

179. Other Psychiatric Terms
• Catalepsy: muscles are rigid
• Cyclothymic: switching between being very
happy and very sad
• Delusion: false belief or idea
• Disorientation: confusion about time,
place, and/or identity
• Drug dependency: being addicted to or
used to using drugs
179

180. Other Psychiatric Terms
• Dyslexia: being unable to read well
• Dysphoria: sadness or depression
• Egocentric: self-centered
• Empathy: the ability to understand how other
people feel
• Euphoria: feeling too happy, the opposite of
dysphoria
180

181. Other Psychiatric Terms
• Gay: homosexual (slang)
• Hallucination: seeing, hearing, smelling,
feeling, or tasting something that does not
exist
• Homosexuality: romantic attraction to people
of the same sex
• Hypnosis: induced condition of altered
consciousness
181

182. Other Psychiatric Terms
• Incest: sexual relations among close relatives
• Inertia: not active
• Insomnia: not able to sleep
• Introverted: a person thinks about himself and
doesn’t communicate much with other people
182

183. Other Psychiatric Terms
• Malingering: pretending to be sick
• Neurosis: mild psychiatric (mental) problem
• pre-menstrual syndrome (PMS): emotional distress
before the start of menstruation
• Psychogenic: illness came from psychological, rather
than physical, disease
• Psychosis: sever mental disorder; patient is out of
touch with reality
• Sadism: taking pleasure in hurting other people
183

184. Psychiatric Treatment
• electroconvulsive therapy (ECT): electric shocks used
to treat depression
• antianxiety drugs: tranquilizers, medicine that makes
a person feel calmer
• psychotherapy: treatment for psychiatric disorders
• psychiatry: medical treatment for diseases of the
mind and emotions
• tranquilizer: medicine that makes a person feel
calmer
184

185. Nerve Structures and Related Terms
• Myelinated nerves: nerves covered with
white fatty material called myelin
• Neuron: single nerve cell; has a cell body,
axon, and dendrites
• Neurotransmitters: chemicals that
stimulate (start) or prohibit (prevent) the
transmission of nervous impulses
185

186. Nerve Structures and Related Terms
• plexus: network of spinal nerves
• reflex: an action done without a person’s
control, such as blinking
• sensory neurons: nerves that carry
information from the sense organs to the
spinal cord
• synapse: space between two neurons, across
which an impulse is transmitted (passed)
186

187. Related Terms: Cranial Nerves
There are 12 pairs of cranial nerves. Here are a
few of them:
• acoustic (also called auditory): hearing
• facial: facial muscles and taste
• olfactory: sense of smell
187

188. Related Terms: Infections
encephalitis: inflammation of the brain
herpes zoster: infection caused by herpes virus;
characterized by small blisters on the skin;
also called “shingles”
meningitis: inflammation of the brain and
meninges
myelitis: inflammation of the spinal cord
neuritis: inflammation of a nerve
188

189. Related Terms: Infections
• Poliomyelitis (“polio”): virus infection of the spinal
cord, caused by a polio virus
• Polyneuritis: inflammation of a large number of
spinal nerves at the same time
• Rabies: infection of the CNS and salivary glands,
transmitted by animal bite
• Tetanus: acute bacterial infection caused by a
bacterium found in soil, dust, or animal or human
wastes
189

190. Hereditary and Congenital Disorders
• hereditary: inherited from a parent
• congenital: a disorder a child has at birth
• developmental: a disorder that appears as a
child grows
190

191. Related Terms: Hereditary and Congenital
Disorders
• epilepsy
nervous system disorder
inherited or the result of trauma (injury)
patient may have convulsions of four types:
grand mal
petit mal
psychomotor
focal
191

192. Related Terms: Circulatory Disturbances
• cerebral hemorrhage: bleeding into the
cerebrum
• CVA (cerebrovascular accident)
also called stroke or apoplexy
bleeding in the brain due to ruptured artery
symptoms: headache, nausea, vomiting,
confusion
192

193. Related Terms: Circulatory Disturbances
• epidural hematoma: collection of blood
outside the dura mater
• intracranial hemorrhage: bleeding inside the
cranium
• subdural hemorrhage or hematoma: bleeding
between the dura mater and the arachnoid
membrane
193

194. Related Terms: Other Organic Abnormalities
• Alzheimer’s disease: progressive brain
disease, mainly of the elderly (people over 65)
• ALS (amytrophic lateral sclerosis): progressive
nervous system disease of the spinal cord with
muscle weakness and twitching.
• Aphasia: loss of the ability to speak or write
• Ataxia: loss of muscle coordination
194

195. Related Terms: Other Organic Abnormalities
• Alzheimer’s disease: progressive brain
disease, mainly of the elderly (people over 65)
• ALS (amytrophic lateral sclerosis): progressive
nervous system disease of the spinal cord with
muscle weakness and twitching.
• aphasia: loss of the ability to speak or write
• ataxia: loss of muscle coordination
195

196. Related Terms: Other Organic Abnormalities,
• aura: before an epileptic seizure, a patient
sees, smells, hears, or feels something
unusual.
• Bell’s palsy: weakness on one side of the face
• cerebral palsy: brain damage affecting control
of muscles
• chorea: nervous disease with involuntary jerky
movements.
196

197. Related Terms: Other Organic Abnormalities
• coma: patient is unconscious, can’t be
awakened
• Delirium: patient has hallucinations, is excited,
restless, and incoherent ( talking in an illogical
way)
• Dementia: brain deteriorates because of disease
• dyskinesia: patient’s movements are incomplete
or uncontrolled, because of disease
197

198. Related Terms: Other Organic Abnormalities
• dysphasia: patient doesn’t speak clearly
• hemiplegia: one side of the body is paralyzed
• Jacksonian seizures: seizures that start in a distant
part of the body, such as the fingers, and spread
towards the center of the body
• multiple sclerosis: progressive disorder of brain and
spinal cord, starting early in life, resulting in tremors,
lack of coordination, speech problems, etc.
198

199. Related Terms: Other Organic Abnormalities
• narcolepsy: patient suddenly falls asleep
• neuralgia: pain in a nerve
• palsy: paralysis
• paralysis: loss of ability to move a part of the
body
• paraplegia: paralysis of lower body and legs
• paresis: a form of paralysis
199

200. Related Terms: Other Organic Abnormalities
• Parkinson’s disease: nervous system disease
of late life
• amnesia: loss of memory
• syncope: fainting
200