Copy of CNS LECTURE FLASHCARDS
The afferent pathway refers to sensory or motor pathways?
Sensory-coming into the brain (A=arriving)
The efferent pathways deal with:
Effector/motor pathways-leaving the brain (E=exiting)
T or F: the CNS includes the brain and spinal cord.
TRUE
T or F: The PNS includes the brain, spinal cord, and peripheral nerves.
FALSE-peripheral nerves only.
The Monro-Kellie doctrine refers to:
The three components (brain tissue, IV blood, CSF) are equal within the vault (brain)
CPP stands for:
Cerebral perfusion pressure
T or F: CPP can’t be knocked out of balance
FALSE- increases or decreases in blood flow or CSF can alter the CPP.
T or F: The skull can expand to accommodate changes in pressure/fluid
FALSE. The skull is a rigid vault that does not expand
What are 6 possible etiologies of brain injuries?
Trauma Tumors Strokes Metabolic derangements Degenerative disorders Infections, inflammatory disease
Where does CSF flow in the brain?
Between the ARACHNOID layer and pia matter
CAD, HTN, PVD
Clotting disorders
Diabetes, Glucose, fluid and electrolyte
disorders are all:
Underlying conditions that are risk factors for brain injury
What are two examples of a degenerative disorder that can cause brain injuries?
Systemic lupis, Alzheimer’s
What are 3 mechanisms of brain injury?
- Ischemia/hypoxia
- Cerebral edema and Cerebral
Pressure - Increased Intracranial Pressure
(IICP)
Define hypoxia:
Low cellular oxygen with or without blood flow
Define ischemia
interrupted, reduced blood flow causing hypoxia
Decreased ATP, severe anemia, and CO2 toxicity are all pathological effects of:
hypoxia and ischemia
If a patient is hypoxic or ischemic in the brain neurons are:
compensating with anaerobic metabolism, creating lactic acidosis
List 8 clinical signs/symptoms of ischemia/hypoxia
Euphoria, drowsiness Level of consciousness Seizures Concentration, attention, problem solving Cerebral necrosis- coma and death
What is a treatment for ischemia in the brain?
Reperfuse brain tissue
How can one reperfuse the brain without a blood transfusion?
Give pt oxygen and fluids-to expand concentrated hemoglobin
If a patient has an increase work of breathing what should you do?
Decrease their metabolic needs through rest or sedation if necessary
Why would you give a pt glucose who is suffering from hypoxia/ischemia?
To increase their energy production and raise their metabolic functions
_________________is defined as increased tissue volume r/t abnormal accumulations
Cerebral edema
Interstitial edema is caused by:
Increased Na and H2O (white matter)
Vasogenic edema is due to:
Increased ECF
Cytoxic edema is due to
Actual swelling of cells
Cerebral Perfusion is dependent on:
Blood flow and ICP
The volume of the brain is made up by:
Tissue, CSF, blood
Define mean arterial pressure (MAP):
average arterial pressure during cardiac cycle
What is a normal MAP range?
70-100 mm Hg
For perfusion of vital organs we must maintain a pressure of:
> 60 mm Hg
What is the most valuable number for determining the cerebral pressure?
CPP
CPP=
MAP- ICP
CPP >
60mmHg
ICP =
0-15 mmHg
Why do we put brain injury patients in an induced coma?
To decrease O2 needs, metabolic needs so that brain can recover more quickly
T or F: The newest research shows HOB, Diuretics, and Steroids are the best form of treatment for a brain injury
FALSE. This is the classic mindset, new research shows that oxygenation of tissue is more important than immediately reducing ICP/edema
Define intracranial pressure:
is the pressure exerted by brain tissue, blood volume & cerebral spinal fluid (CSF) within the skull.
ICV =
Vbrain + Vblood + Vcsf
In cerebral edema, what is displaced first?
CSF
What is altered second in cerebral edema?
Cerebral blood flow
In an attempt to increase MAP and offset IICP ______________________ occurs first followed by _________________ to decrease the ICP (compensation)
Venous Vasoconstriction; arterial Vasoconstriction
T or F: An increased ICP results from an increased volume of brain tissue, blood, and / or CSF.
TRUE
What are the three main life threatening effects of IICP?
- obstructs blood flow, 2. Destroys brain cells, 3. Displaces brain tissue- herniation
List the 5 most common clinical presentations of increased intracranial pressure:
Decreased level of consciousness, Bradycardia, Headache, Increased systolic blood pressure, Seizures
Decreased level of consciousness relates to an increase in ICP because:
Usually, the greater the decrease in LOC, the more serious the injury is.
Two clinical symptoms of ICP that show the body is attempting to compensate are:
Bradycardia and Increased systolic blood pressure
A person who can t think rapidly and clearly is:
Confused
A person who begins to loose consciousness and awareness to Time, place, and self is:
Disoriented
Define lethargy:
spontaneous speech and movement limited
Define obtundation:
arousal (awakeness) is reduced
A person in a deep sleep or unresponsive, but opens eyes to vigorous or repeated stimuli is in a:
Stupor
A person who responds to noxious stimuli only is in a:
Coma
A person who demonstrates Unresponsive coma, No reflexes (pupils, gag, corneal, cough), No spontaneous respiration, Dilated fixed pupils is most likely in:
Brain death
Acute CNS catastrophe, Exclusion of complicating medical condition, No drug intoxication or poisoning, Core temp >90F are all prerequisites for a diagnosis of:
Brain death
Define Acute Confusional States:
Acquired mental disorder characterized by deficits in attention and coherence of thoughts and action
T or F: delirium is defined as irreversible Decreased cognitive functions, while Dementia is defined as an Acute Confusional state.
FALSE. Delirium is an acute confusional state, vs dementia which is an irreversible alteration in cognitive function.
