Week 1 Neuro Fundamentals of the Nervous System Flashcards
What are the names for these parts of a neuron?
What are the two types of cells that form myelin in the CNS and PNS respectively?
What are the five glia?
Functions of microglia?
Phagocytosis of damaged cells
Comunication with astrocytes to coodininate response
Regulation of development of other CNS cells
Synaptic pruning
What neurological disease is ascociated with dissfunctional microglia?
Schizophrenia
3 Functions of astrocytes
Roll of ependymal cells
Production, circulation and reabsorption of CSF
What might you be looking for in a lumber puncture that indicates MS?
Signs of inflamation in the CSF sample due to de-myelination
Describe the structure of the blood brain barrier
What are three function of the blood-brain barrier?
To let in nutrients
To let in lipophilic chemicals
To prent the entry of environmental toxins
What is the resting potential?
-70mV
What is the threshold potential?
-55mV
What happens when the sodium channels open?
Depolarisation
What happens when the potassium channels open?
Repolarisation
What is saltatory conduction?
This is the effect where signals are propagated by jumping to each node of ranvier through myelination.
Myelin is insulateing therefore a change in current is felt further down and without every single cell having to depolarise
When myelinating why bother with nodes of ranvier at all? Why not insulate the whole thing?
Because shwann cells likely also play a role in regulation
What are the two common diseases charicterised by a loss of myelination and where does this loss occur?
Multiple Sclerosis - CNS
Guillian Barre Syndrome - PNS
Hint: Guillian got barred, she is now on the perifery
Describe the process of chemical transmission at a synapse thinking of vesticles etc.
How would an ion channel with receptors for an inhibitory neurotransmitter affect the membrane potential in the postsynaptic dendrite?
It would make the membrane potential more negative
How would an ion channel with receptors for an excitatory neurotransmitter affect the membrane potential in the postsynaptic dendrite?
It would make the membrane potential more positive
How do the parasympathetic and sympathetic nervous systems differ in terms of where they originate?
Sympathetic – thoracic and lumbar regions, also called the thoracolumbar division
Parasympathetic – cranial and sacral regions, also called the cranio-sacral division
In the ANS where is acetylcholine used and where is noradrenaline used?
Which cranial nerves are part of the pre-ganglionic para-sympathetic nervous system?
Oculomotor nerve (III)
Facial nerve (VII)
Glossopharyngeal nerve (IX)
Vagus nerve (X)
Which sacral nerves are part of the pre-ganglionic parasympathetic nervous system?
S2,S3,S4
At 24 you mostly just shit, piss and fuck
Which spinal nerves form the sympathetic nervous system?
T1-L2
Where are the sympathetic ganglia?
The form the sympathetic chain (or trunk) which runs on the outside of the vertebra
What structure do the sympathetic pre-ganglionic fibres form?
The lateral grey horn of the spinal chord
Where are the various sympathetic receptors located and what do they do
Alpha 1 located most smooth muscle in arterioles causing vasoconstriction
Alpha 2 located on coronary arteries causing vasodilatation
Beta 1 located on cardiac muscle causing increased contractility
Beta 2 smooth muscle of bronchi causing bronchodilation
Some functions are missing but these are the most important ones
Functionality wise What is the main difference between adrenaline and noradrenaline?
Noradrenaline is used as a post-ganglionic sympathetic neruotransmiter and induces sympathetic responses directly by the SNS which act locally.
Adrenaline is released by the adrenal medulla of the adrenal gland when stimulated by the sympathetic nervous system. This enters the blood and further induces systemic sympathetic responses.
What are the main manifestations of autonomic nerve disease?
Fainting
Vasovagal syncope: simple faint. This is where you get sudden vasoconstriction following strong emotion but the heart rate fails to increase to equalise pressure resulting in hypotension and fainting.
Orthostatic hypotension: same as Vasovagal syncope but when people sit up or stand up suddenly
Test for abnormality of ANS
Pupil reactions
Postural blood pressure response.
By bedside -a fall >30mmhg systolic and >15mmhg diastolic is abnormal.
Variation of HR with deep breathing (sinus arrhythmia).
Lacrimal function
Which cranial nerves are have parasympathetic function?
III,VII,IX,X
Memonic: 1973 1(0)973
III - occularmotor, pupil contraction
VII - facial specifically the opthalmic branch, lacrimation
IX - glossopharyngeal, salivation
X - vagus, bare parasympathetic shit
When it goes to penile function which is a parasympathetic and which is a sympathetic function?
Erection - Parasympathetic
Ejaculation - Sympathetic
Hint:
Point (p for parasympathetic) and Shoot (s for sympathetic)
What are Arachnoid granulations?
Arachnoid granulations (AGs) are small, lymphatic structures that drain cerebrospinal fluid (CSF) from the brain into the venous sinuses
Upper motor neuron symtoms?
Brisk reflexs
Bibinski (upgoing plantars)
Hypertonia
Pyrimidal weakness (proximal affected first, arm flexors and leg extensors spared, can still build a pyramid)
Lower motor neuron symtoms
Loss of reflexs
No tone
Fasiculations
Wasteing
