Week 2 Flashcards
Central Nervous System (CNS)
- Brain
- Spinal cord
Peripheral Nervous System (PNS)
-All nervous tissue outside the CNS including sensory and motor neurons
Basic functions of the Nervous System
-Recognize, processing, and reacting to changes in the internal and external environment
Adrenergic response
- Activated under stress
- Fight or flight response
- Ready the body for an immediate response to a potential threat
Cholinergic response
- Activated under non-stressful conditions
- Rest-and-digest
- Digestive process promoted: heart rate and blood pressure decline
Autonomic Nervous System: Sympathetic and Parasympathetic Divisions
- Produce opposite effects
- Body tries to maintain proper balance of the two (homeostasis)
- Don’t always produce opposite effects
Synapse
- Juncture of neurons
- Includes a pre and post ganglionic neuron
5 Mechanisms by which drugs can affect synaptic transmission
- Affect the synthesis of the neurotransmitter in the pre-synaptic nerve
- Prevent storage of the neurotransmitter in the vesicles within the pre-synaptic nerve
- Influence release of the neurotransmitter from the pre-synaptic nerve
- Prevent the normal destruction or repute of the neurotransmitter
- Bind to the receptor site on the postsynaptic target tissue
Primary Neurotransmitters of the Autonomic Nervous System
- Norepinephrine
- Acetylcholine
Norepinephrine
- Released by most postganglionic nerves
- Class of agents called catecholamines
- Adrenergic receptors
Acetylcholine
- Released by cholinergic nerves
- 2 types: Muscarinic and Nicotinic receptors
Norepinephrine is synthesized…..
- In the nerve terminal
- Requires amino acid phenylalanine and tyrosine
- Can be renewed, recycled, and reused
Acetylcholine is synthesized…..
- In persynaptic nerve terminal from choline and coenzyme A
- In the synaptic cleft is rapidly destroyed by acetycholinesterase
Cholinergic receptors of Ach
- Nicotinic
- Muscarinic
Nicotinic
- In sympathetic and parasympathetic divisions
- -Stimulate smooth muscle and gland secretion
Muscarinic
- In parasympathetic target organs except the heart
- Stimulates smooth muscle and gland secretions
2 types of Adrenergic receptors
- Alpha
- Beta
Seizures
- Abnormal or uncontrolled neuronal discharges in the brain
- Affects consciousness, motor activity, sensation
- Treated with Anti Epileptic Drugs (AED)
Known causes of seizures
- Infectious disease
- trauma
- metabolic disorders
- vascular diseases
- pediatric disorders
- neoplastic disease
- medications
- high dose of local anesthetics
- eclampsia
- drug abuse
- withdrawal syndromes
- sedative-hypnotic drugs
Epilepsy
- Seizures occurring chronically
- Types: partial (focal), generalized, special epileptic syndromes
Simple Partial Seizures
- Olfactory, auditory, and visual hallucinations
- Intense emotions
- Twitching of arms, legs, and face
Complex Partial (psychomotor) seizures
- Aura (preceding)
- Brief period of confusion or sleepiness afterward with no memory of seizure (postictal confusion)
- Fumbling with or attempting to remove clothing
- No response to verbal commands
Absence seizures
- Lasting a few seconds
- Seen most often in children
- Misdiagnosed often (especially in children) as ADD or daydreaming
Tonic-Clonic seizures (Grand mal)
- Preceded by aura
- Intense muscle contraction (tonic phase) followed by alternating contraction and relaxation of muscles (clonic phase)
- Crying at beginning as air leaves lungs; loss of bowel and bladder control; shallow breathing with periods of apnea; usually lasting 1-2 min
- Disorientation and deep sleep after seizure (postictal state)
- May become cyanotic in the face
Febrile seizure
- Tonic-clonic activity lasting 1-2 min
- Rapid return to consciousness
- Occurs in children usually between 3 months and 5 yrs of age
- Usually benign
Myoclonic seizures
- Large jerking movements of a major muscle group, such as an arm
- Falling from a sitting position or dropping what is held
Status Epilepticus
- Considered a medical emergency
- Continuous seizure activity, which can lead to coma and death
The choice of a seizure drop depends upon
- Type of seizure
- Patient’s hx
- Associated pathologies
The main FDA warning with anti seizure medications is
-They double the risk of suicidal behavior and ideation
When taking phenytoin (Dilantin), what is a common teaching point with oral care
-Brush with a soft bristle toothbrush
Effective pharmacotherapy depends on
- Assessment of the degree of pain
- Determining the underlying disorders
Substance P
- Neurotransmitter
- Passes on pain message
Opioids
- A natural or synthetic morphine-like substance responsible for reducing moderate to severe pain
- Receptors: mu, kappa, sigma, delta, epsilon
- For pain management mu and kappa receptors are most important
What are important considerations when administering pain medication
-Degree of pain and underlying disorders
Malignant Hyperthermia
- Fast rise in temperature with severe muscle contractions when succinylcholine is administered
- Dantrolene Sodium is the preferred tx (muscle relaxant specific for malignant hyperthermia)
Alzheimer’s Disease
- Most common degenerative disease of CNS
- Progressive loss of brain function, memory loss, confusion, dementia
- Etiology unknown
- Acetylcholine function affected
Parkinson’s Disease
- 2nd most common CNS disease
- Progressive loss of dopamine, tremor, muscle rigidity, abnormal movement and posture
- Fall risk
Amyotrophic Lateral Sclerosis (Lou garricks) Disease
-Progressive weakness and wasting of muscles, destruction of motor neurons
Multiple Sclerosis
- Demyelination of neurons in the CNS
- Progressive weakness, visual disturbances, mood alterations, cognitive deficits
- No cure, tx aimed at providing relief from recurring symptoms
Huntington’s Chorea
-Autosomal dominant genetic disorder, progressive dementia, involuntary spasmodic movements, muscles of limbs and face affected
Tx for Parkinson’s
- Pharmacotherapy doesn’t cure the disorder, but attempts to reduce symptoms
- Drug action: restore dopamine function or stimulate dopamine receptors in the brain
- Types of drugs: Dopaminergic (Levodopa) & anticholinergics (Benadryl)
Tx for Alzheimer’s
- Supportive tx of symptoms
- Drugs
Tonic spasm
-single, prolonged contraction
Clonic spasm
-rapidly, repeated contraction
Spasticity
- muscle stays in continual state of contraction
- Usually due to CNS damage
Causes for muscle spasms
- Excess use or local injury to skeletal muscle
- Overmedication with antipsychotics
- Epilepsy
- Hypocalcemia pain
- Neurologic disorders
Pharmacological tx of muscle spasms
- Centrally acting skeletal muscle relaxant
- Direct-acting antispasmodics
- Neuromuscular blockers
