Neuro1 Flashcards
1
Q
Neurons are the basic building blocks of the nervous
System.
A
2
Q
Classification of the neurons
A
• Motor and Sensory
• Efferent and Afferent
• Golgi types
• Order neurons
• Upper and lower motor neurons
3
Q
What are nucleus in the CNS
A
clearly separated group of cell bodies of
neurons inside CNS
4
Q
____ is like a nucleus, but less clearly delineated
A
Sunstantia
5
Q
What’s Ganglion
A
collection of somata in the PNS & one group in
the CNS basal ganglia
6
Q
____ is bundle of CNS fibers (axons) with a common
origin and destination
A
Tract
7
Q
____ are CNS fibers that have more than one origin and
destination
A
Bundle
8
Q
What are Capsule
A
fibers connecting cerebrum with the brain
stem and other lower part of the brain
9
Q
• Commissure
– group of fibers crossing the midline
A
10
Q
Neuroglia Cells
A
11
Q
Astrocytes are involved in
A
in the supportive structural and metabolic
activities.
12
Q
Astrocytes are classified morphologicaly to ____ &____
A
Protoplasmic & Fibrous)–
13
Q
Protoplasmic astrocytes: These astrocytes have numerous short and branching processes that extend in all directions. They are primarily found in the gray matter of the CNS, particularly in the cerebral cortex and cerebellar cortex.
A
14
Q
Fibrous astrocytes: These astrocytes have fewer processes compared to protoplasmic astrocytes, and their processes tend to be longer and less branched. They are primarily found in the white matter of the CNS, where they form a network of processes around blood vessels and axon bundles.
A
15
Q
Oligodendrocytes functions
A
– Responsible for the
formation and maintenance of myelin sheath
16
Q
Microglia function
A
specialized macrophages
capable of phagocytosis that protect neurons
of the central nervous system.
17
Q
Ependymal cells are found in
And it’s functions
A
Also named ependymocytes,
line the cavities of the CNS and make up the
walls of the ventricles.
These cells create and secrete cerebrospinalfluid(CSF)
And beat their cilia to help circulate
that CSF.
18
Q
Dorsal & ventral surfaces of the brain & the spinal cord
A
For the brain, it means towards the upper part of the head, and for the spinal cord, it means towards the back part of the body.
19
Q
So, in summary, reflex actions involve a pathway that primarily goes to the spinal cord, but information about the reflex action is also transmitted to the brain for processing and coordination.
A
20
Q
Reflect action is Controlled by a pathway that goes only to the
spinal cord, not the brain.
A
21
Q
What are the components of the reflex arc
A
Receptor
– Sensory neuron
– Integration center
(CNS)
Motor neuron
– Effector
22
Q
The spinal cord runs from ___ to _____
A
Foramen magnum to L1/L2 & L3 in new born
23
Q
The spinal cord Occupies upper ___ of vertebral canal
A
⅔
24
Q
The spinal cord is Surrounded by 3 layers of meninges namely
A
dura mater
– arachnoid mater
– pia mater
25
CSF is located in ____
subarachnoid space
26
External features of the spinal cord
27
Enlargement of the spinal cord is located in
Cervical and lumber
28
What are the external features of the spinal cord
• Enlargements: cervical & lumbar
• Conus medullaris
• Filum termniale
• Anterior median fissure
• Posterior median sulcus
• 31 pairs of spinal nerves attached to it by the
anterior roots & posterior roots.
29
Features of the Dura mata
Dense, strong fibrous membrane.
• Encloses the spinal cord & cauda equina.
• Separated from wall of vertebral canal by the extradural space
Contains loose areolar tissue & internal vertebral
venous space.
30
The Dura mata is Continuous above with meningeal layer of dura
covering the brain.
31
The Dura mata Ends at the level of .
S2
32
Which meningeal layer is impregnable
Arachnoid layer
33
Features of the arachnoid matter
• Delicate impermeable membrane.
• Lies between pia and dura mater.
• Separated from pia mater by subarachnoid
space.
Continuous above with arachnoid mater covering the brain
34
The arachnoid matter end @
Ends on filum terminale at level of S2
35
Which layer is a vascular membrane
Pia matter
36
Pia matter Thickenes on either side between nerve roots
to form the _____
ligamentum denticulatum
37
Is the ligamentum denticulatum paired or not
38
ligamentum denticulatum extends from ____to_____
pia mater to dura mater
39
ligamentum denticulatum function
It stabilize side-to-side movement
40
Each spinal nerve connects to the spinal cord
via
two medial roots
41
Ventral roots arise from the ____ and
contain ____ fibers
• Dorsal roots arise from ____ in
the dorsal root ganglion and contain ______fibers
anterior horn, motor (efferent) fibers
sensory neurons, sensory
(afferent) fibers
42
The short spinal nerves branch into three or
four distal rami
In summary, the text explains how spinal nerves connect to the spinal cord through ventral and dorsal roots. The spinal nerves then split into smaller branches called distal rami, which include the dorsal ramus (for the back), ventral ramus (for limbs and trunk), and meningeal branch (for the protective membranes of the brain and spinal cord).
43
The first type of distal ramus is the small dorsal ramus. This nerve goes towards the and supplies the muscles and skin on it
back of the body
44
The second type is the larger ventral ramus. This nerve connects to ____
It supplies the muscles and skin of the ___&____
networks of nerves called plexuses or intercostal nerves.
limbs and trunk.
45
The third type is the _____
tiny meningeal branch. This nerve goes to the meninges, which are the protective membranes surrounding the brain and spinal cord.
46
In the thoracic region (the middle part of the spine), there are additional nerves called ____
And it's located @
rami communicantes
at the base of the ventral rami and have a connection to the autonomic nervous system (ANS).
47
The rami communicantes allow communication between the spinal nerves and the ANS in the thoracic region.
48
Lateral gray column (horn) present in ___&_____segments
thoracic
& upper lumbar
49
Note: Amount of gray matter related to the amount of muscle
innervated.
50
Variations in grey matter
Long & slender pst horn & broad and massive ant. Horn is a xteristic of ______ region of grey matter
Cervical (large and oval)
51
Variations in grey matter
Massive and ovoid pst horn & massive and ovoid ant. Horn is a xteristic of ______ region of grey matter
Sacral ( small and circular or quadrilateral)
52
Variations in grey matte
slender pst horn , slender ant. Horn & lat. Horn is a xteristic of ______ region of grey matter
Thoracic ( small and circular)
53
Variations in grey matter
Bulbus and short pst horn & bulbus and short ant. Horn is a xteristic of ______ region of grey matter
Lumber( large and circular)
54
While the spinal cord does contain some elements of the reticular formation, its primary location is within the brainstem
55
Nerve cells of the pst. Grey horn
4
Substantia gelatinosa
• Nucleus proprius
• Nucleus dorsalis
• Visceral afferent nucleus
56
Features of Substantia gelatinosa
– situated at the apex
– throughout the length of spinal cord
57
Substantia gelatinosa composed mainly of ______ neuron
Golgi Type II neurons
58
Substantia gelatinosa receives afferent fibres concerning with ____, _____, &______ from?
Pain,temperature & touch from posterior root
59
_____ is Anterior to substantia gelatinosa
Nucleus propria
60
_____ makes the Main bulk of cells in posterior gray column
Nucleus propria
61
Nucleus propria is Present throughout the whole length of spinal cord
T or F
62
Nucleus propria Receives fibers from ____ that are assoc with ___, ___&____
posterior white column
proprioception, 2-point discrimination & vibration
63
The base of the pst. Column is occupied by
Nucleus dorsalis
64
Nucleus dorsalis is also called
(Clark’s column)
65
Nucleus dorsalis (Clark’s column) run from ___ part of the spinal cord to ____
C8--L3/L4
66
Nucleus dorsalis receives fibres associated with
associated with proprioceptive endings
(neuromuscular spindles & tendon spindles)
67
Visceral afferent nucleus runs from ___ to ___
T1 – L3
68
Location of the viseral afferent nucleus
And it receives _____
Lateral to nucleus dorsalis
– Receives visceral afferent info
69
Nerve cells in the lateral gray columns is formed by
• Formed by the intermediolateral group of cells
70
Nerve cells in the lateral gray columns runs from ____ to _____
T1 to L2/L3
71
Nerve cells in the lateral gray columns gives rise to ____ in ____, ___, &___ vertebrae
give rise to preganglionic sympathetic fibres
In S2, S3, S4; they give rise to preganglionic parasympathetic fibres
72
Central canal runs from the cervical (neck) region down to the sacral (lower back) region.
73
Superiorly continuous with the
And inferiorly as
And terminates @
central canal of the medulla oblongata"
the central canal expands and enlarges to form the terminal ventricle. The terminal ventricle is a dilated portion at the end of the spinal cord, near the conus medullaris.
"Terminates within the root of the filum terminale
74
The axons of the large multipolar neurons in the anterior gray columns exit the spinal cord through the anterior nerve roots as
Alpha-efferent
75
The axons of the smaller multipolar neurons in the anterior gray columns exit the spinal cord through the anterior nerve roots as
ɣ-efferents
76
Four zones are evident within the gray matter which are____ from pst. To ant.
somatic sensory (SS),
Visceral sensory (VS),
Visceral motor (VM),
Somatic motor (SM)
77
White matter can be Divided into
• Consists of nerve fibres, neuroglia, blood
vessels
• White due to myelinated fibres
– anterior white column
– lateral white column
– posterior white column
78
Eg of short tracts id
Intersegmental
79
Examples of Sensory receptors include
Exteroceptors: external environment (e.g
pain temp., pressure etc)
Interoceptors: wall of viscera, gland, bld
vessels etc (e.g hunger,nausia etc)
Properioceptors: deeper tissue (e.g
contraction of muscle, movements etc)
Special sense receptors
; concerned withvision, hearing etc
80
Ascending pathway that reach consciousness consists of___ neurons:
Namely
1st-order neuron
– 2nd-order neuron
– 3rd-order neuron
81
The reticular formation is a network of interconnected nuclei located in the brainstem that is involved in regulating arousal, attention, and wakefulness.
82
The Lat. Spinothalamic tract second order neurons is located @ __ & crosses @ ____
Ant. Crossing
Substantia gelatinosa & nucleus propria
Crosses @ ventral white commisure within the same segment
Ant. Asends one segment b4 crossing
83
Lat.& Ant. Spinothalamic tract functions
Lat. Pain&temp
Ant. Crude touch & pressure
84
Lateral spinothalamic tract
1st-order neurons
• Pain conducted by δ A-type fibres & C-type fibres
2nd-order neurons
– decussate to the opposite side
& ends in _____
3rd-order neurons
– ends in ____
thalamus (ventral posterolateral nucleus
sensory area in postcentral gyrus
85
Spinothalamic tract involves 1,2&3 order neurons
86
Ant. Spinocerebral tract is located@ pst grey horn located below ____
It's function is ____
It involves what order neurons
Pst. Grey H,, below L3
Proprioceptive
1&2nd order
87
Ant. Spinocerebral tract crosses in ___ direction
How many times does it cross
&ends where
Counter laterally
Twice
Opposite side of the cerebellum
88
Pst spinocerebral tract involves___ neurons
And d neurons are located @____ @ ___to____
It's fibres crosses how? To supply___
1&2nd order
Clark column, C8-L3
Ipsilaterally to supply cerebral cortex via inferior cerebral peduncle
89
What are the pst. Column tracts
Fasciculus gracilis
Fasciculus cuneatus
90
The pst. column tract involves what neurons
They occupy ____
1,2&3rd neurons
Pst fasciculus
91
Fasciculus gracilis is located ____ in the pst funicular containing fibres from ___, ____, ____&____
While fasciculus cuneatus is located in ____ of pst fasciculus containing fibres from ___&___
Medially
Coccyx, sacral, lumber, lower thorax
Literally
Upper thorax &cervical
92
Function of the ant. And lat. Spinothalamic tract
Ant. Light(crude) touch and pressure pathways
Lat. Pain & temp
93
Pst. Column tract function
Discriminative touch, vibratory sense,conscious muscle joint sense (conscious proprioception)
94
Anterior spinocerebellar tract function
• Carries Info from trunk, upper & lower limbs
• Also carries info from skin & sub cut. tissue
95
Pst spinocerebral tract function
It carries muscle and joint sensory information to the cerebellum.
It is responsible for transmitting unconscious proprioceptive information.
96
The posterior spinocerebellar tract is crucial for the coordination and stability of the body.
97
The info from the spinocerebral tract is relayed to ____
This information is used by the cerebellum to coordinate movements and maintain posture.
98
From a functional point of view the ant. &pst spinocerebral tract is concerned with
Lower limb and trunk
Also carries info from skin & sub cut. tissue
99
Features of upper & lower motor neuron lesions based on
Paralysis
Muscle tone
Deep tendon reflex
Plantar response
Muscle atrophy
Fascilulation & fibrillation
Upper
Group of muscle
Spasmic paralysis
Exaggerated
Extensor( babinski sign +ve)
May occur late
Don not occur
Lower
Individual muscle paralysis
Flaccid
Absent
No response
Early & severe due to denservation
Are common
100
Fasciculations (visible twitching of muscle fibers) and fibrillations (small, spontaneous muscle contractions)
101
Arteries of the spinal cord includes
• Anterior spinal artery
• Posterior spinal artery
• Segmental spinal arteries
102
The anterior spinal artery is responsible for supplying the _____ (anterior) of the spinal cord.
front two-thirds
103
Ant. Spinal artery is formed by the union of two arteries and originates from the vertebral artery, which is a major blood vessel in the neck.
Those two spinal arteries are
The anterior radicular arteries
104
The posterior spinal arteries are responsible for supplying the _____ of the spinal cord.
one-third (posterior)
105
The pst. Spinal artery can arise from _____ or the ____ which are also branches of the vertebral artery.
either the vertebral artery or posterior inferior cerebellar arteries (PICA),
106
In lumber puncture the needle is incerted in between ___&___ into ___
L3$ L4
Subarachnoid
Space
107
Spinal shock
Follows acute severe damage to the spinal
cord.
• All cord functions below the level of the lesion
become depressed or lost.
• Sensory impairment and flaccid paralysis
occur.
108
What's Brown Sequard syndrome
And it's popular presentation
neurological condition that occurs due to a spinal cord injury or lesion affecting one side of the spinal cord
Ipsilateral (Same Side) Motor Weakness:(same side)
Ipsilateral Loss of Proprioception and Vibratory Sensation (same side)
Contralateral (Opposite Side) Loss of Pain and Temperature Sensation
Preservation of Light Touch and Discriminative Touch
109
What's Cauda equina syndrome
occurs due to pressure or damage to the nerve roots in the cauda equina region. This compression or damage can be caused by conditions such as a herniated disc, spinal stenosis, tumor, infection, or trauma.
110
Symptoms of Cauda equina
severe lower back pain
sciatica (pain radiating down the legs)
numbness or weakness in the legs, difficulty or loss of bowel and bladder control, and sexual dysfunction
111
Whats conus medullaris syndrome
Conus medullaris syndrome typically involves injury or damage to the spinal cord at the level of the conus medullaris, which is located at the lower end of the spinal cord around the L1-L2 vertebral level
112
Causes of conus medullaris
spinal tumors, trauma, infections, inflammatory conditions, vascular disorders, or congenital abnormalities.
113
Bladder and Bowel Dysfunction
Sexual Dysfunction
Reflex Abnormalities
Motor Weakness: Weakness or paralysis of the lower extremities,
114
Conus Medullaris Syndrome: Presents with a combination of motor, sensory, and autonomic dysfunctions, including lower extremity weakness, altered sensation in the saddle area and legs, bladder and bowel dysfunction, and sexual dysfunction.
115
Cauda Equina Syndrome: Usually characterized by severe lower back pain, bilateral leg pain or weakness, numbness in the buttocks or saddle area, bowel and bladder dysfunction, and possible loss of sensation in the lower body
116
Conus Medullaris Syndrome: Can have a sudden or gradual onset, depending on the underlying cause.
Cauda Equina Syndrome: Typically has a rapid or sudden onset, often due to a traumatic event or acute disc herniation.
117
Conus Medullaris Syndrome: Symptoms are often bilateral, affecting both sides of the body.
Cauda Equina Syndrome: Symptoms are often asymmetric, meaning they may affect one side of the body more than the other.
118
Conus Medullaris Syndrome: Anesthesia or loss of sensation may be present in the perineum (area between anus and genitals) and can extend to the lower extremities.
Cauda Equina Syndrome: Numbness or loss of sensation can occur in the buttocks, perineal region, inner thighs, and the backs of the legs.
119
Paralysis:
Conus Medullaris Syndrome: May cause weakness or paralysis of the
While Cauda equina can lead to
lower extremities, affecting the legs and possibly the bladder and bowel muscles.
Can lead to varying degrees of lower extremity weakness or paralysis
120
Conus Medullaris Syndrome: Results in bladder and bowel dysfunction, such as urinary retention, incontinence, or difficulty with bowel movements. EARLY
Cauda Equina Syndrome: Often presents with significant bladder and bowel dysfunction, including urinary retention, loss of bladder sensation, fecal incontinence, or constipation. LATE
121
Sexual Dysfunction
Conus Medullaris Syndrome: more frequent
Cauda equina: leads frequent
122
Anterior cord syndrome leafs to loss of
Movement, pain & temperature
You still have vibration, position & touch
123
Whats Syringomyelia
Syringomyelia occurs when a syrinx, which is a fluid-filled cavity, develops inside the spinal cord. The syrinx typically expands over time, elongating and enlarging the spinal cord.
124
Syringomyelia can be congenital (present at birth) or acquired.
125
The most common symptom of syringomyelia is the loss of
sensation or altered sensation, particularly affecting the hands and arms. This can include bilateral loss of pain and temperature sensation, as well as a decrease in sensitivity to touch or pressure.
126
Depending on the location and extent of the syrinx, muscle weakness or atrophy may occur, primarily affecting the hands and arms.
127
Syringomyelia produces dissociates anesthesia
128
What's Tabes dorsalis
is a neurological condition caused by untreated syphilis infection that specifically affects the dorsal nerve roots and the posterior white column of the spinal cord
129
Tabes dorsalis affects
Dorsal nerve root
Pst. Column tract
130
Syringomyelia affects what tracts
Spinothalamic tract
131
Brown sequard syndrome affects what tracts
Causing
Spinothalamic tract causing counter lateral loss of pain & temp.
Pst. Column tract causing ipsilateral loss of fine touch, two point discrimination, joint position, vibration sense
Corticospinal tract causing ipsilateral upper motor neuron types paralysis
132
Lesions of the dorsal columns result in a loss of
There is loss of the ability to identify the
characteristics of an object, called
astereognosis (e.g., size, consistency, form,
shape), using only the sense of touch.
joint position sensation, vibratory and pressure sensations, and two-point discrimination.
133
The pain and temperature information crosses
almost as soon as it enters the spinal cord, any
unilateral lesion of the spinothalamic tract in
the spinal cord or brain stem will result in a
contralateral loss of pain and temperature.
134
Lesions of the
Corticospinal Tract causes
If lesions of the corticospinal tract occur above
the pyramidal decussation, a weakness is seen
in muscles on the contralateral side of the
body;
Lesions below this level produce an ipsilateral muscle weakness.
135
Types of Paralysis
1. Hemiplegia: one side of the body.
2. Monoplegia: one limb only.
3. Diplegia: two corresponding limbs. Mainly the lower limb with a possibility of the upper limb
4. Paraplegia: two lower limbs.
5. Quadriplegia: all four limbs.
