MT#8 Neurophysiolpgy Flashcards
Topic 98
A. Membrane Potential
B. Local response and Action Potential,
C. Propagation of AP
A. Membrane Potential…..
A: Membrane Potential Ion gradient Na+/K+ pump Equilibrium Potential Resting membrane Potential Electrogenic pump Goldman Hodkinz Katz equation MP occur in 2 ways
Topic 98
A. Membrane Potential
B. Local response and Action Potential,
C. Propagation of AP
B Local response and AP
B: Local response and AP
Local:
- Depolarization does not reach THRESHOLD
- Propagation - physical processes
- Depolarization: + charge -> IC space, red MP
- Hyperpolarization: oppsite -> Inc polarization
Depolarization - does reach THRESHOLD =AP
- All-or-none
Hyperpolarization - never AP
AP: Biltragedie dependent ION Channel Blocked by TTX and TEA ADaptation Summation Absolute refractory periode : drawing Relative refractory periode: drawing Phases : drawing
MS: Rheobase
MT: Chronaxia (2*Rheobase)
Topic 98
A. Membrane Potential
B. Local response and Action Potential,
C. Propagation of AP
C: prop of AP
In myelinated fibers
- nodes of ranvier
- salutary conduction
- fast prop of AP
NON myelinated fibers
- AP prop step-by-step
- conduction velocity (speed)= slow/proporsjonal squareroot of dm of axon
Topic 99: Axonal transport and synaptic transmission.
A: Axonal transport
B: Synaptic transmission
A. Axonal Transport
- AP Conducted - Synaptic nerveendings
- Neurotransmitters (smal:norepinephrine, acetylcholine. Large: peptides). .
- Axonal transport
- Anterograde transport - Kinesin
- Retrograde transport - Dynein
- Synthesis - neural soma.
- Bound to therir reseptor on the post Synaptic membrane
- Hyperpolarization- RMP inc
- Depolarization- RMP dec
Topic 99: Axonal transport and synaptic transmission.
A: Axonal transport
B: Synaptic transmission
C. Types of ion channels
B. Synaptic transmission
- Gap junctions(free diffusion) - hexamer - fast -conexion
- best known neural gap j= system of ❤️cells
- Rectification - one dominant direction
Gap j, leads to either: - EPSP
- IPSP
- Metabotropic transmitter - slow matabotropic response
- binding of ligandReceptor ->IC 2nd Messenger -> IC metabotropic effects -> long lasting de/hyperpolarization
Topic 99: Axonal transport and synaptic transmission.
A: Axonal transport
B: Synaptic transmission
C: types of ion channel
C ….
Function of NS- sensing stim from outer and inner environment.
Receptor potensial: amplitude/frequency
- inc/dec flow of cation/anion by inc/red PERMABILITIES
- classification: Na, K, Cl
Leak
Voltage drependent
Ligand dependent - nACh
- Glutamate
- Anion
- G-protein
Mechanoreceptive
Energy sensors - Ca2+ (drawing)
Ryanodine and DHP
IP-3 reseptorer
Voltage dependent: P, T and N
Topic 100: general characteristics of A: Spinal chord B: Neural networks C: Rexed zones D: Dermatomes
A….
- function of SC: reflex!! Fine coordinTed movements.
- brain and Spinal C- efferent(motor), afferent(sensor)
- upper CNS units
- segmental(habituation) and intersegmental level(hl->Inhib imp -> HL = schiff Sherringtonor scratch reflex)
- the Spinal chord : C, th,Abd, lum, sacral
- grey (nerve cells) and white matter(N.fibers)
Topic 100: general characteristics of A: Spinal chord B: Neural networks C: Rexed zones D: Dermatomes
B
GENERAL: Endoneurium - Perineurium - Epineurium - Afferent N: sensor N->CNS - Efferent N : CNS-> target cells/gl. -Mixed: Vagus N. - Neuron polarity: uni, bi, multi, pseudo - Neuronal network: Convergence: drawing 2->1 Divergence: drawing: 1-->2 Monosynaptic org reflex and Polysynaptic reflex Presynaptic inhibition and postsynaptic exitation *EPSP-> depol (excitat) *IPSP -> hyper (inhib). . Inhib of ex= DISFAcILiation Inhib of Inhib neuron =disinhib
Topic 100: general characteristics of A: Spinal chord B: Neural networks C: Rexed zones D: Dermatomes
C And D
Rexed zones and Dermatomes
The grey matter (Exept lateral horn) devided Into
Rexed fields:
Laminas I-VI belong to the upper, - VII-IX to the lower horn.
In the laminas II-III mostly interneurons are found (substantia gelatinosa Rolandii),
The lamina IX is the area of large (alpha) motor neurons and smaller motor neurons and of theRenshaw cells responsible for recurrent inhibition
Dermatomes:
Or head zones
Knowledge of these dermatomes is important in determination of the origin of skin
RETICULAR PERITONITIS in cattle
Topic 101: The reflex and movement pattern
A Proprioceptive reflex
B Exteroceotive reflex
A…
- Spinal reflexes
- receptors in same organ as the effector response.
- adequate
- Receptor in m.spindle
- afferent n - fast Ia fiber
- monosynaptic Reflex arch
- almost no latency
- immediatly response -no longer than stimulus
- reflex does not fatuige
- Myotactic Reflex
- Annulospinal receptors - Ia fibers
- Alpha motor neurons - large motor cells
- Gamma motor neurons - cerebral motor centers activate/inhib Fusimotor system - decending pathways.
- Reccurent inhibition - renshaw cells - Inverse Myotactic reflex
- passive stretch - m. Will contract=fusimotor
- further stretching= sudden relaxation of m= Inverse myotactic reflex. - Flexor-stretch reflex and extensor thrust
Fl. Stretch- light stretching - extention in both ext and fl. Muscles. TYPE II, afferent, FLOWER SpRay fusim. Receptors.
Ext. Thrust- footsoole - myotactic stretch ext of interosseous m = reliable support during stepping
Topic 101: The reflex and movement pattern
A Proprioceptive reflex
B Exteroceotive reflex
B….
- Receptor OUtSiDe effector organ
- Prevents NOCICEPTiVE (avoid pain)
- Receptor located in skin, and effector in M.
- tactile Receptor - pain Receptor of skin
- slow afferent -> conducting fibers in GR. 3&4
- very long latency
- Slow response, longer than stim.
- M. Easely fattigues.
- NOCICEPTiVE and thermorec. Of skin arrive grey matter via Spinal ganglia. GR 3&4 afferent
= moves Limb away from stimulus. - Afferent activation-
*inhibitory interneurons- relaxation. - excitatory interneurons - activation
- extero and interoceptive = usefull in case of injurier
Topic 102: The autonomic Nervous System (ANS)
A General
B ANS elements in the CNS
- Comprises the SYMPATHETIC and PARASYMPHATHETiC NS!
- regulates the involuntary functions & enteric NS (GI-system)
- Responsible for the automated Controll of METABOLIC processes and conections between organism and external environment.
- Controlling SM and exocrine and endocrine glands and the behaviour.
- Efferentation is particullary independent of the SOMaTIC motor system .
- Autonomic - Visceral - Vegitative
Topic 102: The autonomic Nervous System (ANS)
A General
B ANS elements in the CNS
C sympathetc ANS
ANS elements in the CNS - Cortex Frontal+pariettal association Prosessing of external stimuli Initiating behavioural response
- Limbic system (hippocampus - amygdala)
Behavioural and emotional responses
Processes emotions and learning
- Hypothalamus Main head ganglion of Autonomic function Integration of internal stimuli connected to the endocrine system * heat production * Osmotic homeostasis * endogenous rythms * Hunger * Thirst * species spesifikt behaviour
- Pons and medulla Visceral functions essential for life. * Respiration *Circulation * Digestion (Vomiting, belching, sneezing, rumination, salivation)
- Nuclei
Cranial nerves!!!!
Neurotransmission of ANS
- Transmitter = Acetylcholine
- Integrator = Postganglionic neuron
- Transmission in the postganglionic Sympathetic neuron happens by NOREPINEPHRINE in 95% of the cases
Topic 102: The autonomic Nervous System (ANS)
A General
B ANS elements in the CNS
C sympathetc ANS and pheripheral symp. ANS
c…
fIght or flight
Maintain homeostasis
Function: mobilization
Practical coordination: redistribution of blood in circulation
* icreased symph: dilates SM of skelletal m, vessels and Constricts the vessels in the gut wall.
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