Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Neuro > Descending Systems > Flashcards

Descending Systems Flashcards

0
Q

recent tracks utilize

A

older systems, which have more general effects and often influence reflex responses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
1
Q

3 functions of descending tracts

A

control motor neurons
other motor functions (autonomic)
modify sensory transmission

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

older systems directed as

A

postures

tone and proximal limb or trunk motions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

lateral funiculus

A

distal extremities

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

anterior funiculus

A

movement of trunk

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

ventrolateral funiculus

A

interneuron pools to axial and proximal limb muscles-bilateral effect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

descending tracts taht run mostly in MLF and what do they effect

A

tectospinal, medial vestibulospinal, pontine reticulospinal

trunk/neck movement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what do medial motor tracts have in common?

A

terminate bilaterally
axial muscle control (control of neck and trunk)
located in anterior funiculus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

located in the MLF

A

medial vestibulospinal

pontine reticulospinal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

located immediately adjacnet to MLF

A

tectospinal tract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

4 things all MLF tracts have in common

A

enter anterior funiculus of cord (part of medial motor system)
only affect axial muscles
terminate only in cervical and upper thoracic spinal cord (only affect neck movement)
terminate bilaterally

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

superior colliculus receives input from

A

cortex, visual systems, auditory systems, and somatic sensory systems (multisensory)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

two lateral motor systems

A

rubrospinal tract

lateral cortcospinal tract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

where are lateral motor systems located?

A

lateral funiculus and mostly involved in limb movement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

reticulospinal tract can function as..

A

indirect corticospinal projection pathway

–>indirect way for cerebral cortex to regulate activity in spinal motor neurons and interneurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what does reticulospinal tract control?

A

generalized, gross movements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what does reticulospinal tract regulate?

A

gama motor neuron activity

sensory transmission

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what does RSP contain?

A

descending autonomic fibers and respiratory control fibers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

highest level of motor control in humans

A

cerebral cortex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

coricospinal functions

A
  • voluntary command for movement

- can regulate sensory transmission through dorsal horn

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

corticobulbar means

A

cortex to brainstem

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

functions of corticobulbar

A

affect cranial nerve nuclei (voluntary movement of head and face)
-affect sensory transmission of nuclei
-activate brainstem nuclei involved in movement (indirect corticospinal projections)
project to pons (pontine nuclei) for relay to cerebellum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

brainstem projections to spinal cord (indirect pathway from cerebral cortex to spinal cord)

A

superior colliculus

corcioreticular projections

23
Q

precentral gyrus homunculus

A

feet on medial aspect, head on lateral

more motor cortex devoted to things with finer movements

24
Q

cortical motor neurons do NOT

A

control the activity of single muslces
–>instead, encode particular directions of movement (activate motor neurons that control the several muscles involved in a particular movement and inhibit muscles that would antagonize movement)

25
Q

cortical neuron activity___movement

A

precedes

26
Q

premotor cortex (including supplementary motor areas)

A

active during preparations for movements or during rehearsal of movements

27
Q

primary motor cortex does not become active until

A

movement is actually initiated

28
Q

internal capsule contaisn

A

corticofugal axons that connect cerebral cortex with the brain stem and spinal cord
Head, Arm, Leg

29
Q

corticobulbar fibers

A

control voluntary head movements–genu

control arm and leg–posterior limb

30
Q

small percentage of cerbral peduncles are occupied by fibers controlling

A

head and limb movements

31
Q

targets of corticobulbar tracts

A 
pontine nuclei (relay to cerebellum)
cranial nerve nuclei (esp facial)
eye movement control
indirect corticospinal tracts
sensory nuclei (regulate transmission)
visceral centers (respiration)
32
Q

hypermimia

A

some upper motor neurons in anterior cingulate cortex control emotional movements of face–do not project to facial nucleus, so sometimes severe paralysis of voluntary facial movements can lead to increased movement of face to emotional stimuli

dont go through the internal capsule

33
Q

supranuclear facial weakness

A

lesion is above the level of facial nuclei therefore producing lower face weakness

CNS lesions rostral to level of facial nucleus

34
Q

damage to facial nerve/nerve

A

entire face becomes weak

35
Q

cerebral cortex can influence

A

motor neurons

36
Q

activity in many supporting and stabilizing muscles produced by

A

indirect corticospinal projections

37
Q

descending motor tract functions

A

direct: directly influence alpha motor neurons via corticospinal tract
indirect: reflex excitation via interneurons, gama loop (reflex contraction to new set point)

38
Q

lateral vs medial motor systems

A

lateral- precise, limb

medial- course, axial and proximal limb

39
Q

tectospinal tract

A

superior colliculus (midbrain)–>dorsal tegmental decussation–>MIF–>anterior funiculus–>upper thoracic levels–medial part of intermediate grey bilaterally

40
Q

job of tectospinal

A

reflex head and arm movement to visual and auditory stimuli

41
Q

medial vestibulo tract

A

medial vestibulonuclears–>MIF–>anterior funiculus

42
Q

job of medial vestibulotract

A

adjust of head to vestibular stimuli (stabilizes head when body moving)

43
Q

pontine reticulospinal tract

A

reticularformation of pons (paramedian pontine reticular formation)–>MLF

44
Q

job of pontine reticulospinal tracts

A

head turning with horizontal eye movements

45
Q

corticobulbar–>brainstem (superior colliclus, corticoreticular projections)

A

–>spinal cord

indirect pathway from cerebral cortex to spinal cord

46
Q

corticobulbar–>pontine nucleus

A

–>cerebellum

47
Q

corticospinal tract

A

motorcortex (precentral gyrus)–>internal capsule–>cerebral peduncle–>pass through pons–>medullary pyramids–>

90% decussate right at pyramidal decussation–>lateral funiculus–>lateral corticospinalt ract–>mostly interneurons but few motor neurons

  • ->10% go to anterior funiculus to move axial muscles and some go to dorsal horn for sensory transmissiona nd reflexes
  • ->
48
Q

cerebrocortical motor neurons

A
  • ->motor neurons in spinal cord–>muscle

* *time lag**

49
Q

initaition of movement

A

movement that requires a decision

premotor cortex (supplementary motor area)–>primary motor cortex

50
Q

latearl vestibulospinal

A

lateral vestibular nucleus–>in lateral VSTract–>anterior part of lateral funiculus–>all spinal levels

51
Q

fx lateral vestibulospinal

A

extensors!

vestibulo-righting reflex–increased activity in extensors in right side of body when head tips to right

52
Q

medullary reticulospinal/lateral reticulospinal

A

medulla–>courses bilaterally in anterior part of lateral funiculus to all spinal ells

*mostly inhibitory interneurons in spinal cord–gross control via gama motor neurons and activity regulated by corticobulbar tract

53
Q

reticulospinal tracts

A

red nucleus (inputs from cortex & cerebellum)–>ventral tegmental decussation (midbrain)–>lateral funiculus->all spinal levels except cervical–>intermediate gray matter interneurons and in dorsal horn

54
Q

job of reticulospinal tract

A

proximal limb flexor muslces (crawling)

55
Q

cortico-reticulo-spinal

A

most important corticospinal pathway

premotor & supplementary motor cortex (rostal to primary motor cortex)–>medullary reticulospinal pathway

**inhibits spinal reflexes, so damage=increas inactivation

Neuro (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions