Chapter 11-12-13 Neuronal microenvironment, Physiology of Neurons and Synaptic transmission (2019) - Evals #6 by Keim Flashcards
EPSP arriving rapidly arriving in succession while first EPSP has not yet been completed. A subsequent EPSP tends to add its amplitude to the preceding EPSP
Temporal summation
Neurons resting membrane potential
-70 mV
Most often neuron’s threshold potential
-55 mV
Inhibitory neurotransmitters
GABA
Glycine
Excitatory neurotransmitters
Aspartate
Receptor that has a direct mechanical response to a neurotransmitter binding to it is:
Ionotropic
Higher permeability to Ca ions
NMDA
Voltage dependent in addition to being ligand-gated
NMDA
What mediates the large majority of synaptic inhibition in the CNS?
GABA
The larger diameter of axon, the faster its conduction velocity.
True
Synaptic transmission at chemical synapses occurs in seven steps:
1st – Neurotransmitter molecules are packaged into vesicles and vesicles are concentrated in the presynaptic terminal
2nd – the presynaptic membrane depolarizes, usually as the result of action potential
3rd – depolarization causes voltage-gated Ca channels to open and allow Ca ions to enter the cell
4th – the resulting increase in intracellular Ca triggers fusion of vesicles with the presynaptic membrance
5th – the transmitter is released into the extracellulr space in quantile amounts and diffuses passively across the synaptic cleft and some bind to the receptors in the post synaptic membrane
Serotonin
Raphe nuclei
Dopamine
Substantia nigra and ventral tegmental area
Norepinephrine
Locus coeruleus
Acetylcholine
Septal nuclei and nucleus basali
Organization of nervous system, portion where axons can regenerate
PNS
Organization of nervous system, portion where axons cannot regenerate
CNS
Cranial nerve not included in the PNS
CN II
Part of nervous system that has a functionally distinct system that regulates and controls visceral functions
ANS
True of neuronal axon:
A. Initial segment is unmyelinated and is the spike origination zone
B. Axon is thin with 1000x as much cytoplasm
C. Action potential travels by continuous propagation without myelin
Paki screenshot then ask Lloyd hahaha.
CNS glial cells
Oligodendrocytes
Astrocytes
Glial Cells
Saltatory axoplasmic transport movement along microtubules by motor molecules through dynein
Fast retrograde
True of glial cels
They have much more numerous diversity
Most neurons of the brains are:
Multipolar
Predominant electrolyte permeable to astrocyte is:
Potassium
True
A. Basic physiological properties of all astrocytes are similar
B. Neurotransmitter receptor among astrocytes are different in the brain region
C. Astrocytes store all glycogen and provide neuronal lactate demand
No answer. Please edit and answer if you know.
As glucose enters the brain from the blood, it initially encounters the:
Astrocytic endfoot
Development of fully excitatory synapses in the brain rquires the presence of:
Astrocytes
60 yr old farmer fell down from an 8ft coconut tree, head down resulting to fatal brain injury. The following physiologic changes are sustained:
A. High concentration of neurotransmitter glutamate is released to the brain ECF
B. There is activation of ionotropic glutamate receptors
C. Glial cells swell due to neuronal entry of sodium, water and chloride ions
No answer. Please edit and answer if you know.
Cerebral edema
A. Brain fluid that accumulates comes from vascular compartment
B. Small increases in intracranial volume have little effect on pressure
C. Additional increases in volume involving potentially life threatening increases in pressure
No answer. Please edit and answer if you know.
EPSP reaching the soma in combination with EPSP arising from other dendrites on the cell, leads to epsp’s substantially larger than those generated by a single synapse
Spatial summation
EPSPs arrive in rapid succession, adding more amplitude to the residual of the preceding EPSP
Temporal summation
Cable theory:
A. Dendritic sattenuation of synapticpotential
B. Predicts how much current flows through the dendritic cytoplasm and its leakage across its membrane
C. Action potential in a thinner dendrite creates no signal as it reaches the axon hillock as compared to the response in the thicker dendrite
No answer. Please edit and answer if you know.
Density of sodium channels are high only at:
Initial segment and node of Ranvier
Functions of myelin sheath:
Insulator to the axon
Serves to decrease the resistance between axoplasm and the ECF
Characteristic of demyelinated axon:
Source of spontaneous action potential
Induce crosstalking among other demyelinated fibers
Increase conduction velocity
Purkinje cell, large output neuron of cerebellum is best described as:
Generating large, sharp action potential if stimulated strongly
Amplifies signal along the entire dendritic length
Has Na channels and rich voltage gated Ca channels
40 yr old female executive complained of decreased visual acuity, poor extraocular muscle and eye movement. Positive Lei sign. Electrical sensation felt form back to legs and neck flexion. She diagnosed of multiple sclerosis. True pertaining to disease:
An autoimmune disease against myelin, oligodendrocytes and white matter tracts
Most common demyelinating PNS disease:
Guillain-Barre
On 35th embryologic development of the brain, diencephalon seperates into the following neural tissue:
A. Neuropituitary
B. Hypothalamus
C. Thalamus
Idk
True to the development of nervouse tissue
A. After birth, neurons do notdivide and when lost, is usually not retrieved
B. Main cells that proliferate at injury are microglial cells
C. Neurons have specific locations in the brain and are lost through apoptosis
Idk
Conducts a spike initiation zone:
Initial segment
False:
Axon hillock is an untampered region.
Saltatory movement along microtubules via motor molecule brain dynein:
Fast retrograde
Synapses undergo long-term changes based on certain patterns of prior activit:
Long term potentiation
Cholinergic causes alzheimer’s:
Acetylcholine
Cause of Parkinson’s:
Dopamine
Purkinje cells:
Ca channel
Involved in excitatory synapse:
Astrocytes
Hippocampus:
Long term memory
Resistance and loss of sensory:
Inversely proportional
Branching of dendrites:
Increase attenuation
Found mainly in gray matter:
Protoplasmic astrocytes
Astrocytic endfoot:
Glucose
Attack oligodendrocytes and myelin sheath:
Multiple sclerosis
High density of sodium channels
Node of Ranvier and initial segment
Demyleination two adjacent axons:
Crosstalk
High recovery rater:
Guillain Barre
Most common disease for demyelination:
Guillain Barre
Decrease capacitance:
Myelination
The thinner the axon, the signal will attenuate prior to arriving at the initial segment that would result to: _________.
no action potential
