Vol.3-Ch.3 "Neurology" Flashcards
What are the two main section of the peripheral nervous system?
The Autonomic (automatic or non voluntary) and the Somatic (voluntary)
What are the two sections of the Autonomic nervous system?
Sympathetic (fight or flight) and Parasympathetic (feed or breed)
What are the 3 sections of the nervous cell (neuron) body?
- Cell body (contains nucleas)
- Dendrites (transmit electrical impulses to the cell body)
- Axons (transmit electrical impulses away from the cell body)
How does the nervous system create electrical impulses?
Similarly to the heart
The neuron is positively charged on the outside and negative on the inside at a resting (polarized) state. When electrically stimulated the sodium outside rushes inside, pushing the potassium to the outside of the cell to make up for the imbalance of charge created (it depolarizes). This depolarization is transmitted down the neuron at a high right of speed.
What is the area where neurons come close to each other to send neurotransmitters across ____?
Synapses are where neurons come close to each other to send neurotransmitters (either acetylcholine or norepinephrine) across a synaptic cleft to the receiving neurons post synaptic membrane.
**(The giving neuron is using it’s synaptic terminals to get close to the receiving neuron)
What are the 3 layers of the meninges that cover the entire central nervous system to protect it?
- Duramatter (durable outer most layer)
- Arachnoid membrane (middle web like layer)
- Pia Mater
***The subarachnoid space is between the arachnoid and pia mater
***The subdural space is between the dura and the arachnoid
What are the 6 regions of the brain?
Which create the forebrain, midbrain, hindbrain, and brain stem?
Forebrain:
- Cerebrum - Diencephalon
Brainstem:
- Mesencephalon (also the called midbrain) - Pons - Medulla Oblongata
Hindbrain:
- Cerebellum - Brain Stem (all those under that category)
What controls the important areas of:
- personality
- motor
- speech
- sensory
- vision
- balance/coordination/fine motor
- reticular activating system
- personality = frontal lobe of cerebrum
- motor (broad movements) = frontal lobe of cerebrum
- speech = temporal lobe of cerebrum
- sensory = parietal lobes of cerebrum
- vision = occipital cortex of cerebrum
- balance/coordination/fine motor = cerebellum
- reticular activating system = lateral portion of the medulla, pons, and especially midbrain (the RAS sends impulses to and receives impulses from the Cerebral Cortex. It is responsible for maintaining consciousness and the ability to respond to stimuli)
How does the brain get it’s blood?
Through two systems that join at the Circle of Willis before entering structures of the brain,
- carotid system
- vertebrobasilar
Where does the spinal cord begin and end? How long is it in the average adult?
It begins at the medulla and goes through the foramen magnum and down the spinal canal to end around the 1st lumbar vertebra
How many pairs of nerve fibers exit the spinal cord?
31 pairs
Efferent VS Afferent VS Dermatomes?
Efferent (motor) fibers carry impulses FROM the CNS TO the body
Afferent (sensory) fibers carry impulses TO the CNS FROM the body
Dermatomes are areas of the skin that correspond to a nerve route and supply sensation to it
What are the 4 categories of peripheral nerves?
- Somatic Sensory
- Somatic Motor
- Visceral (autonomic) sensory
- Visceral (autonomic) motor
What are the 2 neurotransmitters for the CNS (what gets released by neurons over synaptic clefts) and to which system do they belong?
Neurons either transmit Acetylcholine for the Parasympathetic and Somatic (voluntary) nervous system
or
Norepinephrine for the sympathetic nervous system
The sympathetic and parasympathetic nervous system are the two components that make up the _____ nervous system.
Normally they are at balance but during time of stress the _____ takes over and during times of rest the _____ takes over
The Sympathetic and Parasympathetic nervous system are the two components that make up the Autonomic nervous system. (remember the Somatic NS is the opposite of autonomic but on the same level)
Normally they are at balance but during time of stress the Sympathetic nervous system takes over (using epinephrine & norepinephrine) and during times of rest the parasympathetic takes over (using acetylcholine)
What happens when the Sympathetic nervous system is activated? (5)
What neurotransmitters mediate these actions?
- increased heart rate
- increased blood pressure
- dilated pupils
- rise in blood sugar
- bronchodilation
Epinephrine and norepinephrine mediate these effects oppositely
What happens when the Parasympathetic nervous system is activated? (4)
What neurotransmitters mediate these actions?
- decrease in heart rate
- increase in digestive activity
- pupillary constriction
- reduced blood glucose
Acetylcholine mediates these effects
What are the 12 cranial nerves?
CN-I = Olfactory (smell) CN-II = Optic CN-III = Oculomotor CN-IV = Trochlear (keep eyes moving together) CN-V = Trigeminal (facial senses and chewing) CN-VI = Abducens (downward eye movement) CN-VII = Facial CN-VIII = Acoustic (Vestibulocochlear) CN-IX = Glossopharyngeal (swallowing, baroreceptors) CN-X = Vagus (PNS, heart, respiration) CN-XI = Spinal Accessory (neck,swallowing,vocal chords) CN-XII = Hypoglossal (voluntary control of tongue)
“Ooo, Ooo, Ooo, To Touch And Feel Very Good Velvet, Such Heaven”
The ability to respond to stimuli depends on an intact _____.
Cognition and the ability to respond to stimuli received from the environment depends on an intact _____.
The ability to respond to stimuli depends on an intact Reticular Activating System (RAS).
Cognition and the ability to respond to stimuli received from the environment depends on an intact Cerebral Cortex.
The two work together to receive, process, and respond to environmental stimuli
What are the main 2 categories of mechanisms that are able to cause an altered mental status?
- Structural Lesions (tumors, degenerative diseases, Intracranial hemorrhages, parasites, or trauma)
- Toxic Metabolic States (anoxia or lack of O2, diabetic ketoacidosis, hepatic failure, hypercapnia, hypoglycemia, renal failure, etc)
What is Peripheral Neuropathy?
Mononeuropathy VS Polyneuropathy
The malfunction or damage of the peripheral nerves.
Mononeuropathy = involves a single nerve and is usually caused by localized conditions like trauma, compression, or infection
Polyneuropathy = involves multiple nerve and is usually caused by the demyelination or degeneration of peripheral nerves leading to sensory, motor, or both deficits.
What is the normal PaCO2 in the blood?
When testing for this, the ETCO2 should be within what range?
What happens to vasculature if the mmHg of CO2 in the blood goes up or down? How can that effect ICP?
Normal PaCO2 is 40mmHg so the ETCO2 should range from 35-40mmHg.
If the mmHg of CO2 goes above 40 it can cause vasodilation or if it goes below 35 it can cause vasoconstriction.
Therefore, if CO2 goes up (as it does with poor ventilation) it will cause vasodilation and a subsequent rise in ICP
What are Cheyne-Stokes Respirations?
A period of apnea lasting 10-60 seconds followed by gradually increasing depth and frequency of respiration before another period of apnea
What are Kussmaul’s Respirations?
Rapid, deep respirations caused by severe metabolic and CNS problems
What is Central Neurogenic Hyperventilation?
Hyperventilation caused by a lesion in the CNS, often rapid, deep, noisy respirations
What are Ataxic (Biot’s) Respirations?
Poor respirations caused by CNS damage, causing ineffective thoracic muscular coordination
What are Apneustic Respirations?
Prolonged inspiration unrelieved by expiration attempts
seen in pts with damage to the upper part of the pons
What are the 6 steps for sensorimotor evaluation?
- Determine AVPU
- Evaluate spine for pain and or tenderness
- Observe for bruises on the spine
- Observe for deformity of the spine
- Note any incontinence (suggest period of unconsciousness)
- Check circulation, motor, and sensory function of extremities (compare and contract bilaterally)
What are the 5 steps in checking motor system function
- Muscle tone (rigid or atrophied)
- Strength
- Flexion/Extension
- Coordination
- Balance
Adult Glasgow Coma Scale
EYE OPENING: (4)
- Spontaneous
- To Voice
- To Pain
- None
BEST VERBAL RESPONSE:(5)
- Oriented
- Confused
- Inappropriate Words
- Incomprehensible Words
- None
BEST MOTOR RESPONSE: (6)
- Obeys Commands
- Localizes Pain
- Withdrawals to Pain
- Flexion to Pain (Decorticate posturing)
- Extension to Pain (Decerebrate posturing)
- None
What do different GSC score ranges indicate?
13-15 = possible head injury
9-12 = moderate head injury
8 or less = severe head injury
What is the classic sign combination of increased ICP?
What is the name for the combo?
Cushing’s Triad:
- Increased BP
- Decreased Pulse
- Irregular Respiration (overall decrease)
(Opposite of shock findings)