Chapter 17: Alterations in Cognitive Systems, Cerebral Hemodynamics, and Motor Function

Chapter 17: Alterations in Cognitive Systems, Cerebral Hemodynamics, and Motor Function

 

Complete Chapter Questions With Answers

 

Sample Questions Are Posted Below

 

MULTIPLE CHOICE

 

1. Cognitive operations cannot occur without the effective functioning of the brain’s:

a.	Pons	c.	Reticular activating system
b.	Medulla oblongata	d.	Cingulate gyrus

 

 

ANS:  C

Cognitive cerebral functions require a functioning reticular activating system (RAS). Cognitive operations are not managed by any of the other options.

 

PTS:   1                    REF:   Page 528

 

2. Which intracerebral disease process is capable of producing diffuse dysfunction?

a.	Closed head trauma with bleeding	c.	Neoplasm
b.	Subdural pus collections	d.	Infarct emboli

 

 

ANS:  D

Disorders within the brain substance (intracerebral)—bleeding, infarcts emboli, and tumors—primarily functioning as masses may cause diffuse dysfunction. Such localized destructive processes directly impair functioning of the thalamic or hypothalamic activating systems. Disorders outside the brain but within the cranial vault (extracerebral), including neoplasms, closed-head trauma with subsequent bleeding, and subdural empyema (accumulation of pus), can cause similar dysfunction.

 

PTS:   1                    REF:   Page 528

 

3. What is the most common infratentorial brain disease process that results in the direct destruction of the reticulating activation system (RAS)?

a.	Cerebrovascular disease	c.	Neoplasms
b.	Demyelinating disease	d.	Abscesses

 

 

ANS:  A

Infratentorial disorders produce a decline in arousal through a direct destruction of the RAS and its pathways. The most common cause of direct destruction is cerebrovascular disease, but demyelinating diseases, neoplasms, granulomas, abscesses, and head injury also may cause brainstem destruction by tissue compression.

 

PTS:   1                    REF:   Page 528

 

4. What stimulus causes posthyperventilation apnea (PHVA)?

a.	Changes in PCO2 levels	c.	Damage to the forebrain
b.	Changes in PaCO2 levels	d.	Any arrhythmic breathing pattern

 

 

ANS:  B

With normal breathing, a neural center in the forebrain (cerebrum) produces a rhythmic breathing pattern. When consciousness decreases, lower brainstem centers regulate the breathing pattern by responding only to changes in PaCO₂ levels. This irregular breathing pattern is called PHVA. The other options are not responsible for PHVA.

 

PTS:   1                    REF:   Pages 529-530 | Table 17-4

 

5. Posthyperventilation apnea (PHVA) ceases and rhythmic breathing is resumed when levels of arterial:

a.	Carbon dioxide increase	c.	Oxygen increase
b.	Carbon dioxide become normal	d.	Oxygen decrease

 

 

ANS:  B

Rhythmic breathing returns when the PCO₂ level returns to normal. None of the remaining options would affect normal rhythmic breathing after PHVA.

 

PTS:   1                    REF:   Page 530 | Table 17-4