Nervous system states revison Flashcards
What are the functions of the frontal lobe?
Voluntary movement, planning, attention, decision making, personality, production of speech
What are the functions of the parietal lobe?
Body sensation, language, comprehensive, audiovisual intergration
What are the functions of the occipital lobe?
Visual processing
What are the functions of the cerebellum?
Motor coordination, timing
What are the functions of the temporal lobe?
Auditory processing
What does the basal ganglia control?
Movement, reward
What does the thalamus do?
Sensory gateway
What does the hippocampus do?
Memories
What is the brainstem responsible for?
relay pathways, visual and auditory reflexes, breathing, heart rate, vasomotor centre, vomiting, coughing, arousal
What is the amygdala responsible for?
Emotion
What is the hypothalamus responsible for?
Regulating body function
What are the possible causes of impaired body function?
Failure of development or damage/loss of neurons; genetic- fragile X, downs; environmental insults- alcohol, kernicterus (high bilirubin newborns), infection; oxygen deprevation, degenerative changes, physical trauma.
Interference with normal nerve impulse conduction down axon- auto-immune destruction of myelin sheeth- MS, electrolyte imbalance, neurotransmitter function.
Interference with production of neurotransmitters- B group deficiency
Impacts on lipoprotein cell membranes- alcohol, GA
What is the most common type of stroke?
Ischemic (87%) vs Hemorrhagic (13%)
What are the causes of hemorrhagic stroke?
Trauma, aneurysm, problems clotting- imaging to determine cause
What are the causes of ischemic stroke?
atheroma, thrombus, embolus
What is the acute management of a hemorrhagic stroke?
Check for signs of increased ICP; stop bleed
What is the acute management of ischemic stroke?
clotbusting (mechanical/tPA).
Head trauma is a broad term that can relate to what?
the skull, meninges, blood vessels/neural tissue
What the most likely causes of meningitis? (organisms)
Bacteria: N.meningitidis, s.pneumoniae, H.influenzae; viruses and fungi
If the lesion is above C8 the patient is?
Quadriplegic
If the lesion is T1-L1 the patient is?
Paraplegic
What are some consequences of spinal injuries?
Exaggerated reflexes, loss of bladder and bowel control, sexual dysfunction, poor temperature regulation, decreased breathing capacity, impaired cough reflex etc
Why are herniated discs an issue?
They can push onto spinal nerves, compress spinal arteries, reducing blood flow directly damaging the spinal cord etc causing spinal cord injury
What is spina bifida?
Incomplete formation of vertebral arches. Increased neurological structures contained within sac=increased impairment. Linked with maternal folic acid intake.
What receptors does acetylcholine bind to?
Cholinergic- 2 subgroups of nicotinic and muscarinic, which are found in various locations in the brain
What is the neurotransmitter ACH associated with?
Memory facilitation- low levels are associated with Alzheimer’s and the normal ageing process
What is dopamine associated with?
Brain’s reward system; the pleasure centre of the brain. May play a role in addictive behaviour, low levels in basal ganglia in Parkinson’s. Dopamine high schizophrenia. High levels associated with vomiting, sex drive or sexual behaviour
What receptors do noradrenaline neurotransmitters bind to?
Adrenergic
What is the neurotransmitter ACH associated with?
Elevated levels with arousal and excitement; memory facilitation; low levels depression
What is the neurotransmitter serotonin associated with?
Low levels in depression.
Slow-wave sleep inducer
What is the neurotransmitter GABA associated with?
Inhibitory neurotransmitter. Low levels associated with convulsions and epilepsy and huntingtons.
Elevated levels: decrease anxiety and aggressive behaviour.
What is the impact of alzheimer’s disease?
Progressive, degenerative. Diffuse atrophy of the cortex. Widespread loss of cholinergic neurons.
Impact: Hippocampus- impaired memory, learning
Amygdala- inappropriate emotions, anxiety
Frontal lobe: impaired ADL, speech, reasoning, personality.
What is Parkinson’s Disease?
Progressive, degeneration of dopaminergic neurons in substantia nigra, Leads to reduction in dopamine activity in basal ganglia; functions affected: learned, automatic movement; monitoring and smoothing of voluntary movements initiated by motor cortex; inhibition of antagonistic or unnecessary movements.
What is the pharmacotherapy for Parkinson’s disease?
Levodopa + carbidopa (increased levels of dopamine in the brain); Ropinirole (dopamine agonist); Benztropine (anticholinergic)
What is huntington’s disease?
Autosomal dominant disease resulting in progressive loss of neurons in the basal ganglia. Get increased motor ouput- choreiform movements, dystonia, spasms
What are the positive symptoms of Schizophrenia?
Delusions, hallucinations, bizzare behaviour, paranoia
What are the negative symptoms of schizophrenia?
Social withdrawal, low motivation, loss of affect, loss of speech
What are the different types of epilepsy?
Tonic/clonic seizures; grand mal; petit mal; temporal lobe
What are the common features of the different type of epilepsy?
uncontrolled firing of a group of neurons; symptoms/presentation depend on location and extent of spread
Neurons- lowered seizure threshold or hypersensitive to hypoglycemia, hypernatremia, repeated sensory stimulation, fatigue etc
What are the drugs used to treat epilepsy?
CNS depressants, suppress spread of el-impulses (enhance GABA or inhibit sodium channels) eg valproate.
What is a tonic/clonic seizure?
Person loses consciousness, muscles stiffen and jerking movements are seen. Usually last 1-3 minutes and take much longer for a person to recover.
Tonic phase: all muscles stiffen, air being forced past the vocal cords causes a groan, the person loses consciousness and falls to the floor, the tongue or cheek may be bitten (bloody saliva may come from mouth), person may turn a bit blue in the face.
After the tonic phase comes the clonic phase: the arms and usually legs being to jerk rapidly and rhythmically, bending and relaxing at the elbows, hips and knees. Consciousness returns slowly, person may be confused, agitated or depressed. Seizures usually last 1-3 mins.
What are petit mal seizures?
Absence seizure, causing a short period of blacking out or staring into space.
What is MS?
Autoimmune, progressive demyelination. 20-40Y
What are the symptoms of MS?
Motor (limb weakness, loss of bladder/bowel control, speech); Sensory (numbness, pain); Visual (double vision, loss of vision); cognitive
What are the three types of pain?
Nociceptive pain- when tissue in the body is damaged. The pain signal starts in the pain receptors, which are located in the skin and internal organs, which register pain.
Inflammatory pain- leads to secretion of substances that lower the pain threshold and amplify pain. Occurs temporarily when tissue is damaged, can be chronic in illnesses such as rheumatism
Neuropathic- caused by injury or disease in the NS. Both direct damage to the nerve and pressure on the nerve can lead to pain. Can develop as a result of slipped disc, stroke, diabetes
Why do we get referred pain?
Viceral and somatic pathways converge on the same spinal dorsal horn neurons. Difficult for the brain to identify the original source of pain.
