Chapter 5 Flashcards
what type of specialized cells is the nervous system made up of
neurons
about how many neurons are there in the human body
200 billion
how many neurons are there in the brain
about 100 billion, or half of the total neurons in the body
what are axons and dendrites responsible for
axons conduct impulses AWAY from the cell body and dendrites conduct them TOWARDS it
what are the junctions between neurons called and what chemicals pass the impulses from one neuron to another
synapses are the junctions and neurotransmitters pass the impulses from one neuron to another
brains require a huge supply of ____
oxygen
oxygen is brought to the brain via the _____
carotid arteries
what are the 3 regions of the brain
forebrain, midbrain, hindbrain
what area of the brain is the cerebral cortex in and name 2 of its functions
forebrain, nerve pulses are received and analyzed here, and memories are stored. also conscious thought process, reasoning, deliberation, judgement
what is the function of the midbrain
connects spinal cord with the forebrain and forms major part of the brainstem
where is the medulla oblongata and what is it responsible for
it is part of the hindbrain and controls vital functions (breathing, blood circulation, swallowing).
where is the cerebellum and what does it do
in hindbrain, coordinates movement, partially responsible for learning motor actions like riding a bike
what is the cauda equina
extends from the spinal cord and supplies nerves to the legs
what are the two separate parts of the peripheral nervous system
somatic and autonomic
what is the somatic nervous system made up of and what does it do
nerves that connect the brain and spinal cord with skeletal muscles that are under voluntary control, such as arm and leg muscles. also connects sensory organs with the brain, convey info about touch and pain
what is the autonomic nervous system made up of and what does it do
connects brain and spinal cord with internal organs and all processes within body that are not under voluntary control (HR, respiration, digestive process)
what is the sympathetic nervous system
part of the autonomic nervous system, prepares for fight or flight/emergency situations
what is the parasympathetic nervous system
part of the autonomic nervous system, maintains internal status quo in everyday scenarios, reduce HR and BP after response to an emergency
what is the most important diagnostic technique in diagnosing neurological disorders
history and physical exam, observation
what is the 3rd leading cause of death in most developed countries
stroke
what are the main two pathological types of stroke
primary ischemic stroke and primary intracerebral hemorrhage
what is the most common cause of stroke
ischemia
what are the causes of ischemic stroke
atherosclerosis, blood clot that form on the brain (thrombus), blood clot or piece of atheromatous plaque or other material that travels to the brain from another location
what is the most common cause of ischemic stroke (underlying disease)
atherosclerotic disease
strokes caused by embolism are most commonly due to what
cariogenic emboli, clots that develop secondary to heart disorders such as valve defects or arrhythmia
what are vertebrobasilar strokes and blockage or which arteries almost always result in severe disability or death
blockage of arterial vertebrobasilar systems that circulate blood within areas of brain such as medulla, cerebellum and midbrain. blockage of large arteries in this area almost always result in severe disability or death. those in smaller vessels are survivable.
what is cause of lacunar stroke
lacunar infarcts commonly occur as result of an occlusion to a large cerebral artery. most in subcortical white matter, basal ganglia or pons
what are the risk factors for intracerebral hemorrhage (comorbids)
similar to those for cardiovascular disease - HTN, heart disease, fib/flutter, smoking, hx of TIAs, generalized atherosclerotic disease, HLD, DM, use of OCPs
what are possible causes for primary intracerebral hemorrhage
HTN (50% of cases), when blood vessel affected by diseases bursts, when blood vessel blocked by an embolism bursts, when AVM or aneurysm ruptures.
a stroke in the right hemisphere often causes paralysis in the _____ side of the body, and what are other possible symptoms
left (left hemiplegia). also can cause spatial and perceptual problems, diff with judgement, behavior, impose, memory
left hemisphere stroke can cause paralysis in the ______ side of the body, and what are other possible symptoms
right. also can cause aphasia
what are the underwriting considerations for TIA and stroke
age at time of episode, time elapsed since episode occurred, any persisting neuro deficit, underlying cause if known, if HTN adequacy of control, presence or absence of co-existing risk factors
what is subarachnoid hemorrhage and usual cause
presence of blood within the subarachnoid space, usually caused by rupture of intracranial aneurysm
what are other causes of subarachnoid hemorrhage
AVM, hematomas from trauma
what are surgical treatments for aneurysm
clipping and coiling
what are underwriting factors to consider when underwriting subarachnoid hemorrhage
severity of initial episode, results of all investigations and treatments, presence or absence of residual neurological symptoms including epilepsy, control of any co-existing risk factors particularly HTN.
what is the most common disabling neurological disorder in young adults
MS
what are subtypes of MS
relapsing-remitting, secondary progressive, and primary progressive
what eye disorder has close relationship with MS
optic neuritis
what are treatments for MS
symptomatic relief, disease modifying (injectables, infusions and oral therapies)
what are underwriting considerations for MS
whether there is definite dx, age at onset, which subtype, date of last attack, frequency of attacks, current level of disability
what are the major known causes of epilepsy
brain tumors, arteriovenous malformations, stroke
what factors can increase risk of epilepsy up to 10 times
1) head injury w/concussion and one or more of following: LOC for over 30 mins, some loss of memory after injury, neurological abnormalities, skull fx. 2) CNS infections such as meningitis 3) cerebral palsy with mental handicap 4) febrile seizures that are unusually long or frequent or involve only one side of the body 5) alcohol abuse
what are focal or partial seizures
confined to a localized area of the brain.
what are types of focal seizures
simple with no LOC, and complex partial including those that become generalized
what are generalized seizures
abnml electrical activity in brain. usually developmental in origin.
what are the types of generalized seizures
grand mal, absence seizures/petit mal, other (myoclonic)
are intracranial tumors generally considered benign or malignant? why? do they usually metastasize?
malignant, because of invasion of local tissue but rarely metastasize so don’t fit the usual definition of cancer. benign tumors do occur. `
what type of brain tumor is usually fatal within a year
glioblastoma
what brain tumors can be compatible with several years of survival
low grade gliomas
which brain tumors have more favorable prognosis
meningioma, acoustic neuroma, pinealoma
which brain tumors have less favorable prognosis
astrocytoma, glioma, medulloblastoma, neuroblastoma, sarcoma
what info should be obtained for underwriting brain tumors
precise histology, results of all investigations, treatment given, time since dx and completion of treatment, any residual neurological or psychological impairment
what is temporal arteritis
inflammation of arteries supplying the scalp
what are possible cause of encephalitis and what is it
viral, bacterial, parasitic, fungal. swelling of brain.
what are symptoms of encephalitis
severe headache, sudden onset of fever, photophobia, stiff neck, N&V, drowsiness and confusion, seizures.
what are common causes of encephalitis (specific infections)
herpes, common childhood illness (measles mumps rubella), insect borne viruses( west nile, EEE)
what is meningitis and what can it be caused by
inflammation of meninges, membranes that surround brain and spinal cord. caused by virus or bacteria
which has better prognosis, viral or bacterial meningitis
viral.
what are symptoms of meningitis
severe headache, high fever, photophobia stiff neck, N&V, drowsiness and confusion, rash, seizures
what are underwriting considerations for hydrocephaus
underlying cause if known, type of and respond to treatment, if shunt still in place then if there is hx of complications like blockages or infections, if any residuals
the intracranial tumor that has a high cure rate with surgery alone is
meningioma
the major known causes of epilepsy include all of the following except (thyroiditis, AVM, stroke, brain tumor? )
thyroiditis
all of the following can cause epilepsy except (migraine, brain tumor, head injury, stroke)
migraine
a stroke, as defined by The Who, includes which of the following: A) gradual onset of cerebral deficit, B) symptoms lasting more than 24 hrs, C) no apparent cause other than vascular
B and C are correct
MS would have unfavorable prognosis with presence of which of the following? A) older age at onset B) bowel or bladder involvement C) relapsing remitting form
A and B are correct
