Section 6 Spinal Tracts Flashcards Preview

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Flashcards in Section 6 Spinal Tracts Deck (36):
1

Gray Matter is made of

cell bodies, axon terminals, dendrites

2

White matter is made of

myelinated axons

3

Gray Matter spinal part

Dorsal Horn
Ventral Horn
Lateral Horn

4

Dorsal Horn

somatic sensory nuclei visceral sensory nuclei

5

Ventral Horn

somatic motor nuclei

6

Lateral Horn

Visceral efferent (ANS)

7

White Matter spinal part

Ascending Tracts - sensory
Descending Tracts - motor

8

Ventral Median Sulcus

divides the anterior surface of the SC into two halves

9

Dorsal Median Sulcus

divides the posterior surface of the SC into two halves

10

Central canal

Contains CSF (cerebrospinal fluid)

11

Ventral White commissure

bundle of nerve fibers which cross the midline of the spinal cord just anterior to the gray commissure

12

anterolateral sulcus

exit point for anterior/ventral efferent root (motor)

13

Posterolateral sulcus

entry point for posterior/dorsal afferent root (sensory)

14

Nerve pathways, called _____, connect eh CNS and PNS

tracts

15

Sensory pathways include

1. The posterior column pathway
2. The spinothalamic pathway
3. The spinocerebellar pathway

16

The posterior column pathway contains

Dorsal columns - fine touch and proprioception
separated by the dorsal median sulcus
Nerve endings: meissner's corpuscles, pacinian corpuscles, ruffini ending, merkel endings

17

The Dorsal columns are split in 2 sections:

Cuneate Fasciculi - upper extremities (above T6)
Gracile Fasciculi - lower extremities (below T6)

18

The spinothalamic pathway is split in 2 sections

Lateral Spinothalamic tract - Pain and temperature
Anterior spinothalamic tract - Crude touch

19

The spinocerebellar pathway

proprioception from limbs to cerebellum
2 parts: posterior spinocerebellar tract and Anterior Spinocerebellar Tract

20

Sensory pathways usually contain _____ chain neurons

3
First-order, Second-order, and Third-order

21

First-order Neuron

to the CNS (delivers sensations to the CNS) the Cell body is in the dorsal or cranial root ganglion

22

Second-order Neuron

an interneuron with eh cell body located in either the spinal cord or the brain stem

23

Third-order Neuron

carries information from the thalamus to the cerebral cortex

24

Motor commands are delivered by the

1. Somatic Nervous system- directs contractions of skeletal muscles
2. Autonomic nervous system- directs the activity of glands, smooth muscles, and cardiac muscle

25

Flexor-extensor rule

motor neurons that innervate flexor muscles are located posteriorly to motor neurons that innervate extensor muscles

26

Proximal-distal rule

motor neurons that innervate distal muscles (ex. hand) are located lateral to motor neurons that innervate proximal muscles

27

descending motor pathways are organized into two major groups

1. lateral pathways
2. medial pathways

28

Lateral pathways

control both proximal and distal muscles and are responsible for most voluntary movements of arm and legs
Includes: a. Lateral corticospinal tract
b. rubruspinal tract

29

Medial pathways

control axial muscles and are responsible for posture, balance, and coarse control of axial and proximal muscles
Includes: a. vestibulospinal tracts
b. reticulospinal tracts
c. tectospinal tract
d. anterior corticospinal tract

30

corticospinal tracts

1. lateral corticospinal tracts- conscious control over skeletal muscles: motor to limbs
2. anterior/ventral corticospinal tracts- conscious control over skeletal muscles: axial motor

31

rubrospinal tracts

send information to the flexor and extensor muscles

32

corticobulbar tracts

conscious control over eye, jaw, and face muscles

33

Subconscious tracts:

1. Vestibulospinal tracts
2. Tectospinal tracts
3. Reticulospinal tracts

34

vestibulospinal tracts

send info from the inner ear to monitor position of the head

35

tectospinal tracts

send info to the head, neck, and upper limbs in response to bright and sudden movements and loud noises
Superior colliculi: visual info
Inferior colliculi: auditory info

36

motor pathways usually contain _____ neurons

2