Pgs 21-31 Flashcards Preview

Neuroanatomy Final > Pgs 21-31 > Flashcards

Flashcards in Pgs 21-31 Deck (39):
1

The ________________________ consists of a diffuse collection of neurons that extend throught the central core of he brainstem, from the medulla to the midbrain.

Reticular formation

2

What does the nerve-net of the reticular formation control?

1) Levels of consciousness and alertness, sleep/arousal cycle
2) Awareness and spreading of pain (ARAS)
3) Control of lower motor neurons
4) Autonomic functions

3

Lesions in the ARAS or upper brainstem area can cause _______.

Coma

4

_____________ syndrome can be caused by damage to the descending reticulospinal fibers that synapse on the preganglionic sympathetic neurons that control the activity of the superior cervical ganglia.

Horner's

5

T/F - Coma can be caused by lesions in the reticular activating system of the brainstem, certain areas of the thalamus, or both hemispheres.

True

6

Where is the primary motor cortex?

Area 4
Precentral gyrus (anterior portion) & paracentral lobule

7

What is the area for final processing and execution of cortical motor commands?

Primary motor cortex

8

Where is the premotor cortex located?

Anterior to the precentral gyrus

9

Where is the supplementary motor cortex located?

Anterior to the paracentral lobule

10

Premotor and supplementary motor are more involved in motor planning and programming. They send many fiber to the ___________________ cortex.

Primary motor

11

Where is the primary somatosensory cortex?

Areas 3,1,2
Postcentral gyrus & posterior portion of the paracentral lobule

12

What artery supplies the blood to the precentral gyrus?

Middle cerebral artery

13

What artery supplies the blood to the paracentral lobule?

Anterior cerebral artery

14

What would happen if there was an occlusion to the middle cerebral artery?

Paralysis of the contralateral arm, hand, and lower face

15

What would happen if there was an occlusion to the anterior cerebral artery?

Paralysis of the contralateral leg and fot

16

What artery gives rise to the middle and anterior cerebral arteries?

Internal carotid

17

What is the tract that descends from the cerebral cortex that synapses on LMN in the spinal cord?

Corticospinal tract (of the pyramidal system)

18

What is the primary pathway responsible for fine, discrete, skilled movements of the hand and fingers?

Corticospinal tract

19

More than half of the corticospinal tract fibers end in the ______________________ cell column.

Lateral motor cell column

20

Where does corticospinal tract cross?

Pyramid of the medulla

21

Corticobulbar tract fiber run from the cerebral cortex to the __________________.

Brainstem

22

What LMN come from the corticobulbar tract?

V, VII, IX, X, and XII

23

All of the corticobulbar fibers mostly distribute bilaterally to the cranial nuclei on both sides of the brainstem except the _____________ nucleus.

Facial - VII

24

T/F - Corticobulbar fibers distribute bilaterally to LMN of the facial nucleus for the upper face but only contralaterally to the LMNs of of the facial nucleus for the lower face.

TRUE

25

Is the corticobulbar tract directly involved in the control of eye movements?

No

26

Damage to the corticobulbar tract on one side (cortex, internal capsule, crus cerebri, part of pons) will result in ______________ paralysis of the ________ face.

Contralateral paralysis of the lower face

27

Damage to the LMNs in the facial nucleus or facial nerve results in ________________ paralysis of ______________________ of the face.

Ipsilateral paralysis of both upper and lower face

28

What are the fibers from the cell bodies in the brainstem that descend and synapse near or on the lower motor neurons?

Extrapyramidal system of UMNs

29

T/F - The overall affect of most of the extrapyramidal tracts is bilateral.

True

30

What is the extrapyramidal tracts primarily involved in?

Movements of unskilled nature

Posture, tone, balance, and reflexes used to maintain an upright posture, orienting movements of the head and neck, and automatic gait-related movements

31

What are the 5 different extrapyramidal tracts?

1) Rubrospinal tract
2) Pontine reticulospinal tract
3) Medullary reticulospinal tract
4) Lateral vestibulospinal tract
5) Medial vestibulospinal tract

32

Which of the extrapyramidal UMNs crosses in the midbrain?

Rubrospinal tract

33

Which of the extrapyramidal UMNs is bilateral?

Medial vestibulospinal tract

34

Only the __________________ tract is responsible for fine hand movements (independent fingers) and precision grip.

Lateral corticospinal tract

35

Will fine hand movements ever recover if there is damage to the pyramidal system (lateral corticospinal tract)?

No, never

36

What are some signs/symptoms that there has been UMN damage?

1) Paralysis or weakness of voluntary movements
2) Babinski sign appears while superficial refelxes disappear (cremasteric, abdominal)
3) Increased deep tendon reflexes - loss of inhibitory effect of LMNs on reflexes
4) Increased muscle tone - claspknife and clonus
5) Spasticity - spastic paralysis - slow, disuse atrophy

37

What will happen if both the corticobulbar and corticospinal fibers are cut before they both cross?

Contralateral paralysis of both the body and face

38

What will happen if there is a cut just at the corticospinal tract before the cross?

Contralateral body paralysis

39

What will happen if the corticospinal tract is cut after crossing in the medulla?

Ipsilateral body paralysis