MT#8 Neurophysiolpgy

Question 1

Topic 98
A. Membrane Potential
B. Local response and Action Potential,
C. Propagation of AP

A. Membrane Potential…..

Answer 1

A: Membrane Potential 
Ion gradient Na+/K+ pump 
Equilibrium Potential 
Resting membrane Potential
Electrogenic pump 
Goldman Hodkinz Katz equation
MP occur in 2 ways

Question 2

Topic 98
A. Membrane Potential
B. Local response and Action Potential,
C. Propagation of AP

B Local response and AP

Answer 2

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)

Question 3

Topic 98
A. Membrane Potential
B. Local response and Action Potential,
C. Propagation of AP

C: prop of AP

Answer 3

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

Question 4

Topic 99: Axonal transport and synaptic transmission.
A: Axonal transport
B: Synaptic transmission

A. Axonal Transport

Answer 4

• 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

Question 5

Topic 99: Axonal transport and synaptic transmission.
A: Axonal transport
B: Synaptic transmission
C. Types of ion channels

B. Synaptic transmission

Answer 5

• 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

Question 6

Topic 99: Axonal transport and synaptic transmission.
A: Axonal transport
B: Synaptic transmission
C: types of ion channel

C ….

Answer 6

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

Question 7

Topic 100: general characteristics of 
A: Spinal chord
B: Neural networks 
C: Rexed zones
D: Dermatomes

A….

Answer 7

• 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)

Question 8

Topic 100: general characteristics of 
A: Spinal chord
B: Neural networks 
C: Rexed zones
D: Dermatomes

B

Answer 8

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

Question 9

Topic 100: general characteristics of 
A: Spinal chord
B: Neural networks 
C: Rexed zones
D: Dermatomes

C And D

Answer 9

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

Question 10

Topic 101: The reflex and movement pattern

A Proprioceptive reflex
B Exteroceotive reflex

A…

Answer 10

• 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

1. 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
2. Inverse Myotactic reflex
   - passive stretch - m. Will contract=fusimotor
   - further stretching= sudden relaxation of m= Inverse myotactic reflex.
3. 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

Question 11

Topic 101: The reflex and movement pattern

A Proprioceptive reflex
B Exteroceotive reflex

B….

Answer 11

• 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

Question 12

Topic 102: The autonomic Nervous System (ANS)
A General
B ANS elements in the CNS

Answer 12

• 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

Question 13

Topic 102: The autonomic Nervous System (ANS)
A General
B ANS elements in the CNS
C sympathetc ANS

Answer 13

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

Question 14

Topic 102: The autonomic Nervous System (ANS)
A General
B ANS elements in the CNS
C sympathetc ANS and pheripheral symp. ANS

c…

Answer 14

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.

According to needs