Neurones Flashcards
(19 cards)
What are the different axonal morphology
Unipolar
Multipolar
Bipolar
Pseudo-unipolar
what are the different structures of multipolar neurones
Purkinje cell- GABA neurones in cerebellum
Pyramidal cell
Golgi cells- GABA neurones in ventricles
Differentiate between gray and white matter
Grey- unmyelinated cell bodies
White- myelinated axons
What are the features of a neurone?
Excitable cells
Non-dividing cells
Heterogenous morphology
What is the. Structure of a neurone
Dendrites- NOT myelinated; receive info
Soma
Axon- can branch off into collaterals; originate from hillock
What are the different cells that makes up a neuroglial
Astrocyte
Oligodendrocyte
Microglial
Ependymal
What are the features and functions of an Astrocyte
Features- can proliferate; most dominant in CNS. They have foot processes.
Functions
Blood brain barrier structure
Cell repair- make neurotrophic factors
Homeostasis- neurotransmitter reuptake and removal
What are the features and functions of an oligodendrocyte?
Features
Located only in CNS
Forms internodes of myelin that can myelinated many axons
What’s the difference between oligodendrocyte and Schwann cell?
One Schwann cell- myelinated one axon only in PNS
One oligodendrocyte myelinates many axons only in CNS
What is the function of a microglial cell
Similar to macrophages and perform immune functions in CNS
What is the function of an ependymal cell
Regulate production and movement of CSF
They are epithelial cells- lining the ventricles
What are the 4 ions involved in resting membrane potential
Na
K
Cl
Ca
Describe purpose and significance of sodium potassium pumps?
Used to restore RMP
3 sodium out/ 2 K+ in
Uses 40% of BMR
What are the 2 types of cell to cell communication in a synapse
Autocrine and paracrine.
Autocirne- maintain release of neurotransmitter
Paracrine- stimulates AP in post synaptic terminal
What are the 3 types of synaptic organisation
Axodendritic
Axoasomatic
Axoaxonic
What type of neurotransmitter is released in a NMJ
Ach
How is AP generated in Sarcolemma
Ach binds to nAchR, stimulate influx of Na+
In terminal
AP generated as threshold is reached
End plate potential is generated.
Each EPP is controlled by quantal ACh release.
How is muscle contraction generated
AP in sarcolemma continuous with T-tubule
T- tubule down to sarcoplasmic reticulum
Sarcoplasmic reticulum surrounds myofibrils
Sarcoplasmic reticulum releases Ca2+
Causes contraction.
What are the disorders of the NMJ
Botulism- toxin stops release of ACh from presynaptic terminal
Myasthenia Gravis- Autoimmune against nAChR- causes fatigue and weakness
LEMS- blocks VGCa2+, autoimmune
