Chapter 5 Flashcards
The nervous system is comprised of which two basic systems? What organs are included in both?
- CNS- brain and spinal cord
2. PNS- nerves that connest CNS with sensory receptors, muscles
What is the typical anatomy of a neuron?
cell body, which dendrites spead off of, a long spine called axons, moves down to synapses which are specialized junctions that connect to other neurons.
What is myelin?
a white fatty substance that is wrapped around thee axon of the nerve cell to protect it and help with the conduction of nerve impulses.
What is the difference between axons with white matter and grey matter?
White matter is axons that have myelin protection, and those that are not covered in myelin are called grey matter.
The brain can be divided into what 3 regions?
- forebrain: cerebral cortext
- midbrain: connects spinal cords with the forebrain and forms the major part of brainstem
- hindbrain: medulla oblongata, cerebellum.
What is the responsibility of the sensory roots and motor roots in the spinal cord?
- convey messages from the body to the brain,
2. covey messages from the brain to the rest of the body, (skeletal muscles)
Define the difference between gray and white matter in the spinal cord?
inner core of spinal cord is the gray matter, outer layer is the white matter.
The white matter carries columns of sensory fibres and motor fibres
Define the physiology of the PNS (ie. what nerve categories are there)
PNS- are nerves outside the brain or spinal cord.
- comprised of 12 cranial nerves
- 31 pairs of spinal nerves,
The PNS is split into two main separate sxs. Name and define them.
- Somatic Nervous system: the nerves that connect the brain and spinal cord with skeletal muscles under voluntary control. Also connect sensory organs with the brain, including skin receptors
- Autonomic Nervous system:
connecta brain and spinal cord with internal organs that process within the body not under voluntary control .
There are two parts of the autonomic nervous system of the PNS. Name and define them
- sympathetic nervous system: prepares body for flight/fright
- parasympathetic nervous system: maintains internal status quo
Name different diagnostic investigations methods for neurological disorders. (13)
- observation
- history (personal/Fx)
- physical examination
- MRI
- CT
- MRA
- CTA
- Cerebral angiography
9, PET - lumbar puncture
- Evoked response test
- EEG
- Nerve conduction studies
If a neurological disorder is suspected a physical examination will be conducted. Which tests are preformed on the pt at this time?
reflexes, sensation, motor movement, coordination, gait, and stance as well as for the internal body system regulated by ANS.
They will also question the cpt’s mental status by asking basic questions.
What are the most common neurological sxs and signs?
- pain- headache/neck pain
- muscle problems-
- sensory problems
- altered consciousness - seizures/faiting/dizziness/confussion
What imaging test is best used for diagnosing MS, brain tumors and strokes? why?
MRI, - d/t ability to provide detailed images of body parts surrounded by bone.
What is fMRI?
functional MRI, (new), measured metabolic changes in the brain. Helps identify areas of the brain for specific processes.
for which neurological disorder would you use a CT imaging scan?
Hydrocephalus to brain tumors.
Clearer images of skull and spin than MRI, and detects bleeding.
Which imaging technique is best used to look at blood vessels withint the body, such as in the brain, head and heart and lungs?
Hint: it can also be used to identify atherosclerosis wihtin the carotid arteries, small aneurysms and arteriovenous malformations.
MRA-
What is a CTA and what would a CT angiography be used for?
like a CT but with contract material
blood vessels in the body, and images of calcium deposits in blood vesles.
CTA exposes pt to radiation but has clearer imaging than MRA
What imaging does a cerebral angiography provide ?
image of blood vessels and circulation in the brain
- contrast is used, and highlights these ares
- picture is VERY details.
What is a PET?
produces 3D images.
Metabolic imaging procedure that uses radioactive substance (tracer) in the body which is absorbed at different rates for different types of tissues. Hotspots are tumors and they’re brighter than normal tissue.
What is a Lumbar puncture?
A needle is inserted into the spinal canal to extract CSF from the subarachnoid space.
- detects: tumors, infection, injury, bleeding within brain/spinal. It can also measure the pressure of the fluid which can indicate tumors, bleeding and venous thrombosis
What is an Evoked response test?
measures electrical activity in the brain in response to stimulation by sound, sight or touch. the electric activity is measured by EEG
There are 3 types of Evoked response tests. Name them
- BAER- meausures hearing ability.
- VER- dx optic nerve problems
- SSER- dx problems with the spinal cord, as well as numbness or weakness of extremities.
What is an EEG, and when is it used?
Measured abN acitvities in the brain
dx seizures and evaluating brain damage caused by stroke or brain injury
When would you want to preform an EMG? (electromyography)
assess and record the electrical activity of muscles, both at rest and during contraction.
- usually used in conjunction wiht nerve conduction study to dx disorders of muscles, peripheral nerves or neuromuscular junctions.
What is a Nerve conduction study?
measures the speed of conduction of nerve impulses in both sensory and motor nerves.
Dx muscle weakness as a result of nerve disorder ie. CTS (carpal tunnel syndrome)
carotoid stenosis arises as a result of what?
generalize atherosclerotic disease and sig causes TIAs and stokes.
How is carotid artery stenosis dx’ed?
Asxs: dx with detection of a carotid bruit on physical examination
dx confirmed by non-invasive techniques such as carotid duplex u/w, MRA, or CTA
How is carotid artery stenosis tx’ed
reducing co-existing cardiovascular risk factors, or by the use of anti-platelet drug, or by carotid endaterectomy, if severe
What are the most common sxs for a cerebrovascular accident and TIA
changes in vision/speech
decreased movement or senstion, or changes in the level of consciousness
What is the definition of a stroke?
the clinic syndrome of rapid onset of focal cerebral deficit, lasting more than 24 hours or leading to death with no apparent cause other than a vascular one.
What are the two main pathological types of stokes?
- primary ischemic stroke
2. primary intracerebral hemorrhage
What are the 3 causes of an ischemic stroke?
- atherosclerosis
- blood clot that forms in the brain (thrombus)
- blood clot or piece of athromatous plaque or other material that travels to the brain from another location.
Does occlusion of the artery develop quickly or slowly?
slowly, arteries in the brain are large in diameter and can be blocked up to 75% and still provide adequate blood supply.
Ischemic strokes usually develop in the presence of atherosclerosis when what happens?
a small thrombus, often from disease in teh carotid arteries develops and becomes lodged in one of the smaller cerebral vesels.
Stokes caused by embolism are most common due to what?
cardiogenic emboli, ie clots that develop secondary to heart disorders such as valve defects or arrhythmia. On set is sudden severe neurological deficit. ITs worse if the blood vessel ruptures and blood leaks out
What areas of the brain are included in the vertebrobasilar system?
medulla, cerebellum, midbrain
20% of ischemic stokes occur in this system
What are the sxs of Vertebrobasilar strokes?
- cerebella signs
- dysarthria and dysphagia
- Vertigo, nausea, and vomiting.