Intro to Nervous System I Flashcards
(156 cards)
1
Q
Why is the brain difficult to study?
A
- Due to its complexity
- 86 Billion neurons
- 85 Billion Glial cells
2
Q
How many neurological disorders & syndromes are there?
A
- 445
3
Q
What is Absence of the Septum Pellucidum?
A
- The septum pellucidum (SP) is a thin membrane located at the midline of the brain
- Pituitary deficiencies
- Abnormal development of the optic disk
- Disorder known as septo-optic dysplasia
4
Q
Zellweger Syndrome?
A
- Congenital disorder affecting the Myelin sheath on axons
- Affects most organs of the body
- Neurological deficits
- Loss of muscle tone (hypotonia)
- Hearing loss
- Vision problems
- Liver dysfunction
- Kidney abnormalities
5
Q
Another name for the autonomic division of the PNS ?
A
- Visceral Nervous System
6
Q
CNS is composed of ?
A
- Brain
- Spinal cord
7
Q
Two main divisions of the Nervous system?
A
- PNS
- CNS
8
Q
The PNS is divided into two subdivisions ?
A
- Autonomic (Visceral Nervous System)
- Somatic
9
Q
What is the Autonomic Visceral Nervous system divided into ?
A
- Sympathetic
- Parasympathetic
10
Q
What are the two ways to control the enteric nervous system?
A
1) Autonomously
or
2) CNS through PNS autonomic visceral control
11
Q
What are the first three CNS development steps ?
A
1) Zygota
2) Morula
3) Blastocyte
12
Q
On day 5 of CNS development during gestation how many cell types are there and what is the name of the step?
A
Blastula
Two cell types
1) Trophoblast
2) Inner Mass cells = (Epiblast Cells & Hypoblast Cells)
13
Q
On day 7 through 9 of gestation, how many cells types ?
A
Three cell types
1) Hypoblast cells = (Endoderm)
2) Epiblast cells = (Ectoderm)
3) Trophobalst cells
14
Q
On day 15 the three cells types become what, and what is the step called?
A
Gastrula
- Ectoderm
- Mesoderm
- Endoderm
15
Q
What do hypoblast cells develop into?
A
- Endoderm
16
Q
What do Epiblast cells develop into?
A
- Ectoderm
17
Q
The inner cell mass (Body) develops into ?
A
- Epiblast Cells & Hypoblast Cells
18
Q
The Endoderm develops into?
A
1) GI
2) Liver
3) Pancreas
4) Lungs (inner layer)
19
Q
The Mesoderm develops into?
A
1) Circulatory System
2) Skeletal muscles
3) Muscular system
4) Lungs (outer layer)
20
Q
the ectoderm develops into?
A
1) Hair
2) Nails
3) Skin
4) Nervous System
21
Q
The neural plate cells migrate where?
A
- Midline
22
Q
The neural crest cells migrate with what cells?
A
- The neural plate cells
23
Q
On what day is the Neural Tube formation complete?
A
- Day 23
24
Q
The neural tube consist of?
A
- Neural Crest cells = PNS
- Neural Tube Cells = CNS
25
At 4 weeks, The Anterior end of the Neural Tube becomes three regions, what are they?
1) Forebrain
2) Midbrain
3) Hindbrain
26
At 6 weeks, the Hindbrain separates into three regions, what are they?
1) Medulla Oblongata
2) Cerebellum
3) Pons
27
At 6 weeks the Forebrain develops into two regions, what are they?
1) Diencephalon
| 2) Cerebrum
28
At 11 weeks, the cerebrum grows more rapidly than any other division?
T or F
- True
29
At birth 40 weeks the cerebrum covers most of the brain regions?
T or F
- True
30
What are the 7 major divisions of the CNS ?
1) Cerebrum
2) Dicencephalon
3) Mesencephalon
4) Pons
5) Cerebellum
6) Medulla Oblongata
7) Spinal cord
31
White matter consist of?
- Myelinated Axons
32
Grey matter consist of?
1) Unmyelinated nerve cell bodies
2) Dendrites
3) Axon Terminals
33
Clusters of cells bodies in the CNS is called what?
- Nuclei
34
Clusters of cells bodies in the PNS is called what?
- Ganglia
35
Bundles of Axons in the CNS is called what?
- Tracts
36
Bundles of Axons in the PNS is called what?
- Nerves
37
Nerves of the PNS enter and leave the spinal cord through notches between the stacked vertebrae, how many Vertebrae are they?
33 Total
- Cervical = 7
- Thoracic = 12
- Lumber = 5
- Sacral = 5
Coccxy = 4
38
The three layers of membrane collectively called Meninges lie between bone and the neuronal tissue, what is its function?
1) Stabilize
| 2) Protect (From Bruising)
39
What are the three layers of the Meninges?
1) Dura Matter
2) Arachnoid Membrane
3) Pia Matter
40
Another name for Dura matter?
- Durable Mother
41
Another name for Pia Matter ?
- Pious Mother
42
Dura matter has what type of blood vessels?
- Venous Blood Vessels
43
The Pia matter has what type of blood vessels?
- Arterial blood vessels
44
What space lies between the Pia matter and the Arachnoid membrane?
- Subarachnoid space
- Contains CSF fluid
- Secreted by Choroid Plexus in ventricles
45
T or F
Arachnoid Membrane is a fiber like membrane that connects to the Pia matter ?
- True
46
What secretes CSF fluid?
- The Choroid Plexus in ventricles
| - Chemical environment of the brain
47
Total cranium volume?
- 1.4 Liters
48
Cell volume in the cranium ?
- 1.0 Liters
49
Blood volume in the cranium?
- 0.125 Liters
50
CSF and Interstitial fluid volume?
- 0.275 Liters
51
T or F
The cranium holds twice as much CSF and interstitial fluid than blood?
- True
52
The CSF fluid is located where?
- Ventricles
- Subarachnoid space
Between Pia and Arachnoid membrane
53
The interstitial fluid is located where?
- Pia Matter (Fiber like)
54
What pumps Na2+ and other solutes from plasma into ventricles creating an osmotic gradient between the CSF and Plasma?
- Choroid Plexus
55
What solute are higher in plasma vs CSF?
- K+ (Potassium)
56
What solute is higher in CSF vs Plasma?
- H+ (Hydrogen Ion)
- More Acidic
CSF pH of 7.3
Plasma pH of 7.4
57
T or F
Na+ in Plasma and CSF are about equal ?
- True
58
What in CSF would be indicative of infection ?
- A lot of protein
| - A lot of Blood cells (WBC)
59
CSF fluid provides Buoyancy which provides what ?
- Decreases pressure (Reduces weight of brain 30 fold)
| - Increases protection (Against Trauma)
60
CSF provides what two types of protection?
- Chemical protection
| - Physical Protection
61
CSF exchanges solutes with ______ of the CNS including ________ ?
- Interstitial fluid in the Pia Matter
| - Wastes
62
What reabsorbs CSF into blood ?
- Arachnoid membrane Villi
63
What type of cells line the Choroid Plexus, and what is their function?
- Ependymal Cells
| - Transport Ions, Vitamins, Nutrients, Water
64
The lateral (Side) ventricles consist of?
- First and Second ventricles
65
What two ventricles extend through the brain stem and spinal cord?
- Third and Fourth Ventricles
66
What do the brain capillaries do for the BBB?
- Provide highly selective permeability
| - Provides protection
67
What does the BBB protect the brain from?
- Pathogens
- Toxic water soluble compounds
- Fluctuations in
Hormones
Ions
Neuroative substances in blood
68
T or F
The BBB is self made, contains 400 miles of capillaries?
- True
69
The selective permeability of the BBB arises from ?
- Transport properties of the endothelial cells lining the capillaries
70
What do the endothelial cells of the BBB express?
- Special channels
- Special transporters
- Move Nutrients and Waste products between Blood plasma and Interstitial fluid
71
What type of cell promotes tight junctions in the BBB?
- Astrocytes (Foot Processes)
- Secrete paracrine hormones
- Prevent solute movement
72
T or F
Water soluble substances can easily cross the BBB?
- False
73
What can easily cross the BBB?
- Small lipid soluble molecules
- L Dopa
- Antihistamine (Benadryl)
74
T or F
A functional BBB is missing leaky endothelial in the hypothalamus, the vomiting center of the medulla oblangata?
- True
| - Everywhere is the BBB is NOT LEAKY, protecting Neurons
75
What are the special metabolic needs of neural tissue?
- Continuous O2 (Diffuses Freely)
- 15% Blood from the heart
- 50% of body's total Glucose consuption (or Ketones) for ATP production
76
Dorsal root of each spinal nerve carries what?
- Afferent Sensory information to CNS
77
Where are the cell bodies of afferent nerves located?
- Dorsal Root ganglia (Swelling before entering Spinal cord)
78
Ventral roots carry ?
- Efferent CNS motor information to Muscles and Glands
79
What connects afferent neurons in the dorsal horn of the spinal cord?
- Interneurons
80
The butterfly core of the spinal cord consist of?
- Grey matter
1) Cell bodies of Interneurons
2) Efferent neurons
81
The white matter that surrounds the grey matter consist of ?
- Ascending tracts
| - Descending tracts
82
Where do sensory neurons from the DRG synapse ?
- Dorsal horn
- Interneurons
- Grey matter
83
The dorsal horn cell bodies are organized into?
- Somatic nuclei
| - Autonomic Visceral nuclei
84
The ventral horn of the grey matter consist of?
- Motor neurons
| - Efferent signals to muscles and glands
85
The ventral horns are organized into?
- Somatic Nuclei
| - Autonomic Visceral nuclei
86
Efferent motor fibers leave the Spinal cord via ?
- The ventral root
87
T or F
The interneuron in the grey matter has two synapses for somatic afferent sensory to somatic efferent motor?
- True
88
T or F
The autonomic efferent nuclei is in the lateral horn of the great matter?
- True
89
The white matter in the spinal cord is divided into columns composed of axon tracts? Transfer information up to the brain and back down the cord ?
T or F
- True
90
The tract and nuclei have set names, how are they arranged?
- Origin to Destination
Ex. Dorsal SpinoCerrebellar Tract
91
What are tracts know to do within the spinal cord and the brain?
- Desiccate (Cross over L to R or R to L)
92
Where does most desiccation occur?
- Medulla Oblongata
93
What are the only tracts that do not desiccate?
- Propriospinal Tract
| - Where internerons are located
94
What does the DCML (Dorsal Column Medial Lemniscal) pathway control?
Afferent Ascending
1) Fine Touch sensory
2) Vibration sensory
3) Proprioception sensory
95
DCML (Dorsal Column Medial Lemniscal) first order neurons from PNS carry info to _________ but take two different pathways?
- Medulla Oblangata
96
First order neuron signals from the upper limb (T6 and above) travel in the ?
- Fasciculus Cuneatus
- Lateral part of the dorsal column
- Synapse in the nucleus cuneatus of the medulla oblongata
97
First order neuron signals from the lower limb (below T6) travel in the
– Fasciculus Gracilis
- Medial part of the dorsal column
- Synapse in the nucleus Gracilis of the medulla oblongata
98
The second order neurons from the PNS begin in the Fasciculus Cuneate nucleus or Fasciculus Gracilis nucleus in the Medulla Oblongate, what happens next?
- First order neurons and Second order neurons synapse and decussate in the medulla oblongate
- Cross to the other side of the CNS
- Then travel in the contralateral medial lemniscus to reach the third order neurons in the thalamus
99
- Third order neurons transmit the sensory signals from the thalamus to the?
- Ipsilateral primary sensory cortex of the brain
- Ascend from the ventral posterolateral nucleus of the thalamus
- Travel through the internal capsule
- Terminate at the sensory cortex
100
The anterolateral system (ALS) consists of two separate tracts, what are they?
- Anterior spinothalamic tract
| - Lateral spinothalamic tract
101
The Anterior spinothalamic tract (AST) carries?
- Crude touch and pressure sensory
102
The Lateral spinothalamic tract (LST) carries?
- Pain and temperature sensory
103
Where do the first order sensory neurons of the anterolateral system (ALS) enter the spinal cord?
- 1 to 2 spinal levels above
- Synapse at the Dorsal horn
- Area known as Substantia gelatinosa
104
T or F
Before second order neurons from the ALS can carry the PNS sensory information from the Substantia gelatinosa to the thalamus the First and Second order neurons dessicute in the spinal cord?
- True
| - Travel up on the contralateral side
105
After the Anterolateral System (ALS) synapse with the first order neurons in the spinal cord, these fibers decussate within the spinal cord, and then form two distinct tracts on the contralateral side what are they?
1) Anterior Spinothalamic Tract (AST)
Crude touch and pressure fibers
2) Lateral Spinothalamic Tract (LST)
Pain and Temperature fibers
106
T or F
The third order neurons from the (ALS) Anterolateral system carry the sensory signals from the thalamus (ventral posterolateral nucleus) to the ipsilateral primary sensory cortex of the brain.
- True
107
T or F
90% of the desiccations happen in the Medulla Oblongata?
- True
- 90% DCML (Dorsal Column Medial Lemniscal)
Medulla Oblongata
- 10% ALS (Anterolateral System)
Spinal cord
108
What does EPT stand for?
- Extrapyramidal tracts
109
What is the function of the Extrapyramidal tracts?
- Part of the motor system network
- Involuntary and Autonomic controls of all
1) Musculature
2) Muscle tone
3) Balance
3) Posture Locomotion
Traveling through the pyramids of the medulla
110
Dyskinesia would point to issues in the ?
- Extrapyramidal tracts
111
T or F
There are no synapses in the descending motor neuron tracts from the Brain ?
- True
112
Pyramidal motor tracts can be divided into two tracts?
1) Lateral corticospinal tract
| 2) Anterior corticospinal tract
113
Extrapyramidal motor tracts can be divided into four tracts?
1) Rubrospinal tract
2) Reticulospinal tract
3) Olivospinal tract
4) Vestibulospinal tract
114
Brown-Séquard syndrome is caused by ?
- Damage to one half of the spinal cord (Hemisection)
- Usually Cervical damage
- DCML = Paralysis and Loss of Proprioception
Ipsilateral side as the injury or lesion
- ALS = Loss of pain and temperature sensation
Contralateral side as the lesion or injury
115
Cardinal signs of UML (Upper Motor Neuron) Lesion or injury includes?
1) Hypertonia = Increased muscle tone
2) Hyperflexia = Increased muscle reflexes
3) Clonus = Involuntary muscle contractions
4) Babinski Sign = Hallux extension with sole stimulation
5) Muscle Weakness
116
T or F
The SCT helps our brain coordinate and refine motor movements
- True
| - No Dessication
117
A self contained integrating center for simple spinal reflexes?
- Spinal Cord
118
Definition of a spinal reflex?
- Sensory input enters Spinal cord and is acted on without input from the brain
- Response WITHOUT brain input
- Ex. Plantar reflex (Babinski Sign)
119
What plays a critical role in coordination of body movements?
- Spinal reflexes
120
T or F
In a spinal reflex, Sensory stimulus input is still sent to brain via
1) Interneurons
2) Ascending tracks
- True
121
Steps in a spinal reflex, Two motor neurons involved?
Ach stimulates
1) Stimulus on tendon
2) Receptor on muscle fires
3) Afferent sensory info sent to Dorsal Root Ganglia
4) Integrating Center (Spinal Cord)
5) Efferent motor somatic response
6) Muscle contracts
7) Swings leg forward
&
GABA Deactivates
5) Interneuron inhibits somatic motor neuron
6) Muscle relaxes
8) Leg swings back
122
The patellar tendon knee jerk reflex involves ?
1) Monosynaptic Stretch reflex
&
2) Reciprocal Inhibition of antagonist muscle
123
What is the oldest most primitive region of the brain?
Brain Stem which includes
1) Medulla Oblongata
2) Pons
3) Midbrain
4) (Cerebellum) sometimes
124
T or F
Ascending tracts of the Spinal cord synapse in the medulla or pass through?
- True
125
T or F
Descending tracts from the higher brain centers travel through the brain stem on the way to the spinal cord?
- True
126
How many cranial nerves originate in the brain stem and what fibers cross through it?
- 2 through 12
- Sensory Afferent fibers
- Motor Efferent fibers
- Mixed fibers
127
CN1 the Olfactory nerve travels through the brain stem?
T or F
- False
| - Enters forebrain directly
128
The brain stem contains many discrete groups of nuclei associated with basic processes, what are theses processes?
1) Arousal
2) Sleep
3) Muscle Tone
4) Stretch reflexes
5) Breathing
6) BP regulation
7) Pain modulation
129
The Midbrain Nuclei functions to control?
- Eye movement
130
The Pons Nuclei functions to control?
1) Relay station between
Cerebrum & Cerebellum
&
2) Breathing coordination
131
The Medulla Oblongata Nuclei functions to control?
- Most involved brain stem area
| - Controls Involuntary functions
132
The Reticular formation (Crisscrossed axons in an up down orientation) Nuclei functions to control?
1) Arousal
2) Sleep
3) Muscle Tone
4) Pain Modulation
133
Mixed Cranial Nerves ?
CN 5 Trigeminal Nerve
CN 7 Facial Nerve
CN 9 Glossopharyngeal
CN 10 Vagus
134
Motor Cranial nerves ?
CN 3 Oculomotor
CN 4 Trochlear
CN 6 Abducens
CN 11 Spinal Accessory
CN 12 Hypoglossal
135
Sensory Cranial Nerves ?
CN 1 Olfactory
CN 2 Optic
CN 8 Vestibulocochlear
136
What is the Medulla Oblongata ?
Transition from the Spinal cord to the Brain proper
137
The Medulla Oblongata white matter includes?
1) Ascending Somatosensory tracts to the brain
| 2) Descending Corticospinal tracts from the Cerebrum to Spinal cord
138
Descending Corticospinal tracts from the Cerebrum to Spinal cord cross the midline in the medulla in a region called?
- Pyramids site of Decussation
| - Reason why each side of the brain controls the opposite side
139
What does the grey matter in the medulla control?
Involuntary functions
1) Breathing
2) Blood Pressure
3) Swallowing
4) Vomiting
140
The superior olivary complex nucleus (or SOC or superior olive) is a collection of brainstem nuclei that functions in ?
- Multiple aspects of hearing (Sound)
| - Important component of the ascending and descending auditory pathways of the auditory system.
141
The inferior olivary nucleus (ION), is a structure found in the medulla oblongata underneath the superior olivary nucleus that functions in?
- Coordinating signals from the spinal cord to the cerebellum
- Regulates motor coordination and learning
142
The Pons functions as a ?
- Relay station
- Transfers info from Cerebellum and the Cerebrum
- Helps in controlling breathing with the medulla
143
Another name for the Midbrain, what does it control ?
- Mesencephalon
| - Eye movement
144
The Cerebral Crus (Crus Cerebri) location and functions?
- Anterior portion of the cerebral peduncal
- Holds the Cerebrum
- Contains Motor Efferent tracts
- Traveling from the Thalamus to the pons then to the spinal cord
145
The Substantia nigra (SN) is a basal ganglia structure located in the midbrain that plays an important role in ?
- Reward and Movement
- Substantia nigra is Latin for "black substance"
- Appears darker than neighboring areas due to high levels of neuromelanin in dopaminergic neurons
146
The two parts of the Substantia nigra (SN) are the?
1) Pars compacta (SNpc) = Dopamine main source
| 2) Pars reticulata (SNpr) = GABA main source
147
T or F
A lesion of the DCML pathway causes a loss of proprioception and fine touch?
- True
148
A lesion of the DCML pathway causes a loss of proprioception and fine touch However, a small number of tactile fibres travel within the anterolateral system
T or F
Patient is still able to perform tasks requiring tactile information processing ?
- True
149
If the lesion occurs in the spinal cord (which is most common), the sensory loss will be
- Ipsilateral
| - Decussation occurs in the medulla oblongata
150
T or F
DCML lesions can be seen in vitamin B12 deficiency and tabes dorsalis (a complication of syphilis)
- True
151
Injury to the anterolateral system will produce an impairment of ?
- Pain and Temperature sensation
- Sensory loss will be contralateral
(Spinothalamic tracts decussate within the spinal cord).
152
Brown-Séquard syndrome refers to ?
- A hemisection (one sided lesion) of the spinal cord
- Most often due to traumatic injury
- Involves both the Anterolateral system and the DCML pathway
153
What deficets will a pt with Brown-Séquard syndrome show in the DCML pathway?
- Ipsilateral loss of touch, vibration and proprioception
154
What deficets will a pt with Brown-Séquard syndrome show in the ALS pathway?
- Contralateral loss of pain and temperature sensation
155
T or F
Brown-Séquard syndrome pt will also have involvement of the descending motor tracts, causing an ipsilateral hemiparesis?
- True
156
Lesions of the spinocerebellar tracts present with ?
- Ipsilateral loss of muscle co-ordination
- Likely to be additional injury to the descending motor tracts
- Causing muscle weakness or paralysis
- Usually masks the loss of muscle co-ordination
