test 1: lecture 7 Flashcards
1
Q
where does spinal cord end?
A
conus medullaris
2
Q
lumbar and sacral nerves that travel past the conus medullaris are ___
A
cauda equina
3
Q
dorsal root has what kind of nerves?
A
sensory (afferent)
4
Q
ventral root have what kind of nerves?
A
motor (efferent)
5
Q
___ is made of nerve cell bodies, dendrites and axons
A
gray matter
H shaped
6
Q
another name for tracts?
A
fasciculi (pathways)
7
Q
three funiculus of white matter in the spinal cord
A
dorsal funiculus
lateral funiculus
ventral funiculus
8
Q
A
9
Q
A
cervical spinal cord
10
Q
A
Thoracic spinal cord
11
Q
A
lumbar spinal cord
12
Q
what part of the spinal cord has more grey matter then white matter?
A
lumbar
13
Q
A
dorsal horn
intermediate gray
ventral horn
14
Q
___ part of the spinal cord contains mainly neurons responding to sensory input
A
dorsal horn
15
Q
___ part of the spinal cord contains some sensory neurons, some motor neurons, interneurons
A
intermediate gray
16
Q
__ part of the spinal cord has mainly motor neurons whose axons exit the spinal cord
A
ventral horn
(blue)
17
Q
3 divisions of the spinal gray matter
A
dorsal horn
intermediate gray
ventral horn
18
Q
where is lateral horn found?
A
T1-L2
19
Q
lateral horn
A
(T1-L2)
- cell bodies of preganglionic sympathetic neurons
- send axons out ventral root to innervate smooth muscle, cardiac muscle and glands
20
Q
lower motor neurons are ___
A
alpha and gamma motor neurons that leave the ventral horn to innervate skeletal muscle
21
Q
___ is one alpha motor neuron and all the muscle fibers it innervates
A
motor unit
22
Q
___ is the collection of alpha motor neurons that innervates a single muscle, e.g., biceps brachii
A
motor neuron pool
23
Q
Motor neuron pool – the collection of alpha motor neurons that innervates ____
A
a single muscle, e.g., biceps brachii
24
Q
where do you find preganglionic sympathetic neurons?
A
lateral horn (T1-L2)
25
where are preganglionic parasympathetics found?
sacral level
on lateral edge of the intermediate grey
26
what type of muscle does each part of the ventral horn innervate?
27
pathway for motor innervation of skeletal muscle
upper motor neuron → lower (alpha) motor neuron → muscle
(2 neurons)
lower motor neuron leaves through the ventral horn and travels through spinal nerves
28
\_\_\_ controls voluntary muscle contraction of the distal extremities
corticospinal tract (pyramidal tract)
29
corticospinal tract
upper motor neuron in cerebral cortex
**switched sides** in the brain stem at the pyramidal decussation
travels down spinal cord in **lateral funiculus**
synapses with lower motor neuron in **ventral horn**
lower motor neuron (alpha) leaves spinal cord through **ventral root**
travels to skeletal muscle
gamma motor neurons travel from muscle spindles (reflex contraction) through **dorsal root** synapses on LMN and cause reflex
30
is the UMN contralateral or ipsilateral to the LMN for the corticospinal tract
voluntary muscle control
(**contralateral** - switches sides at the pyramidal decussation)
31
the corticospinal tract will travel down the ___ part of the spinal cord
lateral funiculus
32
\_\_\_ cross the midline
decussation
33
corticospinal tract
(descending pathway from motor cortex→ cross sides in pyramid → down through the lateral funiculus →voluntary muscle control)
34
**Descending** spinal pathways from brain
## Footnote
* modulate spinal reflexes or directly drive \_\_\_output
* Clinically referred to as “\_\_\_Neurons”
\_\_\_ is a common descending tract
motor
Upper Motor
corticospinal tract
35
lateral pathways in the spinal cord usually control ___ and is under direct ___ control.
voluntary movement of the distal musculature
cortical
(corticospinal tract and rubrospinal tract)
36
ventromedial pathways control \_\_\_
posture, locomotion orienting and balance
37
what are some ventromedial pathways of the spinal cord?
pontine and medullary reticulospinal tracts for posture and locomotion
38
ventromedial pathways are under ___ control and innervate ___ and proximal musculature
brainstem
axial
39
\_\_\_ are the lateral pathways of the spinal cord
corticospinal tract
rubrospinal tract
40
what pathway controls detailed finger movements
what pathway controls basic extension of hands
corticospinal tract
rubrospinal tract
41
what pathways control posture, locomotion and balance
ventromedial pathway
42
general sensory pathway
**3 neurons**
sensory afferent enter spinal cord by **dorsal root**
synapse on **second orde**r neuron
second order **changes sides**
2nd order synapses on 3rd order **in the thalamus**
3rd order travels to the **somato-sensory cortex**
43
in sensory pathway which neuron will change sides?
second neuron
44
\_\_\_ carries **proprioception** (limb position sense) fine touch, pressure and vibratory sense to the cortex.
dorsal column medial leminiscal tract
45
the 1st neuron for the dorsal column medial lemniscal system goes where?
touch and proprioception
heavily myelinated
comes from body through **dorsal root** and some will trigger reflexes axon collateral will travel up spinal cord through the **dorsal column** will synapse on 2nd order neuron **in the medulla**
46
pathway for vibration, touch and proprioception
dorsal column- medial lemniscal tract
sensory from body through **dorsal root** into dorsal columns
will synapse on 2nd neuron at **the medulla** at the dorsal column nuclei
2nd neuron **crosses sides** (now called medial lemnicus)
2nd will synapse with 3rd **in the thalamus** (ventropostero-lateral nucleus VPL)
3rd will travel into the **cerebral cortex**
47
what is this pathway called
dorsal column-medial lemniscal tract
48
what pathway carries info about vibration, light touch, pressure, proprioception
dorsal column- medial lemniscal pathway
49
parts of the dorsal column
**Fasiculus gracilis** – hindlimb (sacal, lumbar)
**Fasiculus cuneatus** – forelimb (thoracic, cervical)
(organized from medial to lateral from bottom of spinal cord to top: sacral→ cervical)
50
\_\_\_ is a body map
somatotopy
areas are divided based on where from the body they came from
dorsal column (organized from medial to lateral from bottom of spinal cord to top: sacral→ cervical)
51
two parts of the dorsal column
**Fasiculus gracilis** – hindlimb (sacral and lumbar)
**Fasiculus cuneatus** – forelimb (throacic and cervical)
52
what pathway
**Dorsal Column – Medial Lemniscal Tract**
Vibration, Light touch, Pressure, Proprioception
(3 neurons- dorsal root to dorsal column → medulla, change sides → 3rd at thalamus → primary somatosensory cortex
53
pain and temperature tract
spinothalamic tract
(unmyelinated and lightly myelinated tracts)
54
for the spinothalamic tract the f**irst neurons are s**mall diameter axons of dorsal roots that carry pain and temperature modalities into the cord. They all synapse with sensory neurons in the \_\_\_
dorsal horn!
(black and grey)
55
spinothalamic tract
pain and temperature
unmyelinated or lightly myelinated
1st from body through **dorsal root** will synapse in **dorsal horn**
2nd from dorsal horn **crosses sides** goes up through the **anteriolateral tract**
2nd synapses at **3rd in the thalamus** (ventroposterolateral nucleus VPL)
**up to cerebral cortex**
56
**spinothalamic tract**
(pain and temperature)
1st → 2nd at dorsal horn
2 crosses
2→3 at thalamus up to the cerebral cortex
57
spinothalamic tract
58
compare the dorsal column-medial leminiscal pathway and the spinothalamic pathway
59
\_\_\_ convey ***unconscious*** proprioception to IPSILATERAL cerebellum.
**spinocerebellar system**
dorsal spinocerebellar
cuneocerebellar
60
what controls lower limb unconscious proprioception to the cerebellum?
dorsal spinocerebellar tract
61
what controls upper limb unconscious proprioception to the cerebellum?
cuneocerebellar tract
62
dorsal spinocerebellar tract
**lower limb unconscious proprioception to ipsilateral cerebellum**
**2 nerve pathway**
sensory from muscle spindles through dorsal root ganglion
synapses on 2nd neurons at **clark's nucleus**
2nd neuron up through the **inferior cerebellar peduncle** to the **cerebellar cortex**
63
cuneocerebellar tract
**upper limb unconscious proprioception to ipsilateral cerebellum**
**2 nerve pathway**
sensory from muscle spindles through dorsal root ganglion
synapses on 2nd neurons at **accessory cuneate nucleus in the brain stem**
2nd neuron up through the **inferior cerebellar peduncle** to the **cerebellar cortex**
64
two ascending pathways for conscious proprioception
**•****Dorsal Column - Medial Lemniscal Tract** (proprioception/touch/vibration/ pressure)
•**Spinothalamic Tract** (pain/temperature)
65
two ascending tracts for unconscious proprioception
* Dorsal Spinocerebellar Tract (lower limb)
* Cuneocerebellar Tract (upper limb)
66
•somatosensory input is split into separate ___ and carried up to brain on separate paths
submodalities
67
what tract goes through here?
dorsal spinocerebellar tract
(unconscious proprioception of the lower limb to the cerebellum)
68
what tract goes through here?
•Dorsal Column - Medial Lemniscal Tract (proprioception/touch/vibration/ pressure)
69
what tract goes through here?
**spinothalamic tract**
ascending pain and temperature to the cortex
70
these are showing ___ tracts
ascending
71
these are ___ tracts
descending
72
what tract
corticospinal tract (voluntary control of distal muscles ex. finger movement)
