Pgs 21-31

Question 1

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

Answer 1

Reticular formation

Question 2

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

Answer 2

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

Question 3

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

Answer 3

Coma

Question 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.

Answer 4

Horner’s

Question 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.

Answer 5

True

Question 6

Where is the primary motor cortex?

Answer 6

Area 4
Precentral gyrus (anterior portion) & paracentral lobule

Question 7

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

Answer 7

Primary motor cortex

Question 8

Where is the premotor cortex located?

Answer 8

Anterior to the precentral gyrus

Question 9

Where is the supplementary motor cortex located?

Answer 9

Anterior to the paracentral lobule

Question 10

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

Answer 10

Primary motor

Question 11

Where is the primary somatosensory cortex?

Answer 11

Areas 3,1,2

Postcentral gyrus & posterior portion of the paracentral lobule

Question 12

What artery supplies the blood to the precentral gyrus?

Answer 12

Middle cerebral artery

Question 13

What artery supplies the blood to the paracentral lobule?

Answer 13

Anterior cerebral artery

Question 14

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

Answer 14

Paralysis of the contralateral arm, hand, and lower face

Question 15

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

Answer 15

Paralysis of the contralateral leg and fot

Question 16

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

Answer 16

Internal carotid

Question 17

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

Answer 17

Corticospinal tract (of the pyramidal system)

Question 18

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

Answer 18

Corticospinal tract

Question 19

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

Answer 19

Lateral motor cell column

Question 20

Where does corticospinal tract cross?

Answer 20

Pyramid of the medulla

Question 21

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

Answer 21

Brainstem

Question 22

What LMN come from the corticobulbar tract?

Answer 22

V, VII, IX, X, and XII

Question 23

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

Answer 23

Facial - VII

Question 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.

Answer 24

TRUE

Question 25

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

Answer 25

No

Question 26

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

Answer 26

Contralateral paralysis of the lower face

Question 27

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

Answer 27

Ipsilateral paralysis of both upper and lower face

Question 28

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

Answer 28

Extrapyramidal system of UMNs

Question 29

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

Answer 29

True

Question 30

What is the extrapyramidal tracts primarily involved in?

Answer 30

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

Question 31

What are the 5 different extrapyramidal tracts?

Answer 31

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

Question 32

Which of the extrapyramidal UMNs crosses in the midbrain?

Answer 32

Rubrospinal tract

Question 33

Which of the extrapyramidal UMNs is bilateral?

Answer 33

Medial vestibulospinal tract

Question 34

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

Answer 34

Lateral corticospinal tract

Question 35

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

Answer 35

No, never

Question 36

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

Answer 36

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

Question 37

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

Answer 37

Contralateral paralysis of both the body and face

Question 38

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

Answer 38

Contralateral body paralysis

Question 39

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

Answer 39

Ipsilateral body paralysis