MD2001 Week 10-11 Flashcards
what type of neutrons enter the dorsal horn?
sensory neurons and interneurons enter this horn
interneuron
a neurone confined throughout its length to the CNS
motor unit
a motoneurons and all the muscle fibres it innervates
nerve trunk
a bundle of axons
spike-initiating zone
region of a neurone from which action potentials normally arise (action potential threshold of this region normally lower)
vestibular apparatus
fluid-filled canals closely associated w/ the cochlea (forming inner ear). Detects head motion
difference between a ventricular (cardiac) and neuronal action potential
this type of action potential plateaus b/c of Ca+ entering cell. Lasts much longer than the latter.
4 criteria for valid consent
- patient must have capacity
- patient must give consent voluntarily
- patient must be informed
- consent must be continuing
4 indications of adult capacity
- understand info
- retain info
- use or weight the info
- communicate their decision
3 types of proxy-decision makers
- lasting power of attorney (LPA)
- advance directive
- best interests test
root value
spinal segments that contribute to a named nerve
what is the only layer of the dura mater found around spinal cord?
inner meningeal layer
what does the dura mater become around the spinal cord?
dural sac
where does the dural sac fuse with filum terminale?
it fuses with the filum terminal at S2
where does the lumbar cistern end at?
this subarachnoid space ends at S2
what attach pia to arachnoid in the dural sac?
denticulate ligaments
what do the longitudinal spinal arteries branch from?
these arteries branch from the subclavian arteries
what do the cervical radicular arteries branch from?
these radicular arteries branch from the vertebral arteries
what do the thoracic radicular arteries branch from?
these radicular arteries branch from the intercostal arteries
what do the lumbar radicular arteries branch from?
these radicular arteries branch from the lumbar arteries
what do the internal vertebral venous plexuses pass through?
these veins pass through the extradural fat
what veins drain the medullary cavities of vertebral bodies?
external vertebral venous plexuses drain these structures
define global health
worldwide improvement of health, reduction of disparities, and protection against global threats that disregard national borders
justifications for breaking confidentiality (3)
- with patient’s consent
- unable to seek consent but in patient’s bets interest
- in the public interest
4 criteria justifying breaking confidentiality in the public interest
- risk must be real and serious
- risk must be of physical harm
- identifiable individual
- disclosure must be on need-to-know basis
5 metaphors applied to global health
- as foreign policy
- as security
- as charity
- as investment
- public health
define globalization
incorporation of national economies/societies into a world system through movements of goods, services, capita, technology, labour
globalisation challenges (3)
- fuel and food prices rise
- already challenged places struggle to cope
- tribal/ethnic/religious tensions may increase
“global flow” - influences of globalization on health (5)
- increased pathogen flows
- increased people flows
- increased info flows
- increased trade flows
- increased financial flows
major segmental artery that anastamoses
great anterior segmental medullary artery
what do somites differentiate into?
they differentiate into epaxial and hypaxial muscle and dermis
infection that lies dormant in a DRG, until it is reactivated and forms rash on its dermatome
shingles caused by varicella zoster virus infects this way
explain pathway from an anterior afferent signal
anterior ramus -> dorsal root ganglion -> dorsal root -> dorsal rootlets -> dorsal horn
types of nerves that travel through dorsal ramus
- sensory neurones from epaxial skin
- motor neurons to epaxial muscles
- sympathetic neurons to posterior blood vessels and sweat glands
paraesthesiae
pins and needles
recurrent acute pain
comes and go type of chronic pain
intractable-benign
benign but persistent chronic pain
progressive pain
continuing chronic pain that worsens over time; malignant
what is the gate control of pain influenced by? (3)
- amount of activity in pain fibres: A delta (fast) and C (slow)
- amount of activity in peripheral fibres: A-beta
- message descending from brain can open or close gate
examples of psychological pain management strategies
- biofeedback
- relaxation
- distraction
- cognitive methods ( changing perception of pain)
- behavioural therapy
- hypnosis
5 criteria to define a neurotransmitter
- synthesis
- storage
- release
- interaction
- inactivation
what type of receptor do biogenic amines bind to?
these type of NTs bind to metabotrophic receptors
proper name for ecstasy
methylenedioxymethampethamine (MDMA)
psychostimulants
group of drugs that release and inhibit reuptake of amines
where is epinephrine released?
this NT is released in the locus coeruleus
what does norepinephrine control?
this NT affects sleep, wakefulness, attention, and feeding behaviour
what NT is involved in bi-polar disorder?
norepinephrine is involved to this disorder
roles of dopamine
- control movement
- symptoms of psychiatric disease
- released by hypothalamus to control release of hormones in adenohypophysis
signs of Parkinson’s disease
- tremor
- muscle rigidity
- bradkinesia or akinesia
where does 5-HT (serotonin) originate from?
this NT originates from the Raphe nuclei
what disorders arise from a reduction of serotonin? (2)
a reduction of this NT can cause depression and OCD
treatment for decreased serotonin
fluoxetine (Prozac) is a reuptake inhibitor of this NT
co-agonists of 5-HT (3)
- LSD
- psilocybin
- mescaline
what chemical prevents the breakdown of serotonin?
MAOIs (monoamine oxidase inhibitors)
peptide NTs (7)
- dynorphin
- encephalin
- endorphin
- substance P
- neuropeptide Y
- neurotensin
- Cholecystokinin
what do peptide NTs affect?
these NTs affect pain transmission
examples of opiates
morphine, diamorphine (heroin) codeine, pethidine, methadone
nalaxone
an endorphin agonist given to heroin addicts
what is the principle peripheral excitatory NT?
acetylcholine
4 ways a channel can be opened
- voltage
- ligand
- stretch
- light
example of a stretch-activated ion channel
mechanosensative channel
example of a light-activated ion channel
channelrhodopsin
calculation for probability of channel gating
Popen = topen/ttotal
tetrodotoxin
Na+ channel inhibitor
tetraethylammonium
K+ channel inhibitor
RhR isoforms
RhR 2: cardiac isoform
RhR 1: skeletal isoform
RhR 3: neuronal isoform
autosomal dominant condition related to RhR 2
catecholaminergic polymorphic ventricular tachycardia (CPVT)
example of calcium-induced calcium coupling
cardiac muscle excitation-contraction coupling is an example of this type of coupling
disorder related to RhR 1
malignant hyperthermia
kyphosis
excessive concaving spine
listhesis
displacement of a vertebra
what factors affect the firing of an action potential? (3)
- inherent excitability of neurone
- amount of EPSPs
- amount of IPSPs
reciprocal inhibition
muscles on one side of a joint relaxing to accommodate contraction on the other side of that joint
functions of chemical synapses (3)
- compute summation of EPSP and IPSP input to fire/inhibit action potential
- impulses transfer in one direction, which allows information transmission
- plasticity of transmitter
2 examples of neuronal convergent neurons
- cortical pyramidal cell
2. cerebellar Purkinje cells
2 examples of neuronal divergence
- knee jerk reflex
2. golgi tendon organ reflex
where is dopamine secreted?
this NT is secreted in the substantia nigra and ventral tegmental area