Create
Learn
Share

PHYSIOLOGY - Neuro PART 2

rename
tasnimjaisee's version from 2017-10-15 00:45

Lecture 6

Question Answer
How are large peptide neurotransmitters handled?Produced & packaged in vesicles at soma & transported (fast axonal transport)
How are small peptide neurotransmitters handled?Synthesized and packaged at axon terminal (empty vesicles transported from soma/recycled)
enzymes for synthesis brought to terminal using which axonal transport? (Fast or slow)Slow
Neurotransmitter release occurs via ___ mediated ___Ca2+ ○ Exocytosis
Pre-synaptic terminal contains a high concentration of voltage-gated ____ channelsCa2+
Neurotransmitter release stepsAction potential depolarizes axon terminal ○ Ca2+ channels opened ○ Ca triggers exocytosis - Neurotransmitters binds postsynaptic cell receptors - Initiates response
What does neurotransmitter binding depend on?Cleft concentration
Neural signaling is of short duration due to?Rapid removal/inactivation of neurotransmitter in the synaptic cleft
Neurotransmitter termination 3 waysRecycling - Inactivation - Diffuse out
A single AP releases a set amount of ___ in one neuronNeurotransmitter
A stronger stimuli releases ____ neurotransmitters. (more or less)More
Increased AP firing leads to? Greater influx Ca2+ ○ increased neurotransmitter release
Synaptic integration typesConvergence - Divergence
Spatial summationCurrents from multiple nearly simultaneous graded potentials combine - Suprathreshold signal - AP generated
Synaptic Inhibition1 IPSP sums with 2 EPSP summing to prevent AP (because below T)
Spatial summation can be ____ (inhibitory/excitatory)Inhibitory
Result of temporal summationNo summation - Summation causing AP
Temporal summation: No summation2 subT potentials will not initiate AP if they are far away
Temporal summation: Summation causing AP2 subT potentials at trigger zone within short amount of time; can create AP
Both temporal and spatial graded potentials are incorporated in a neuron: ____Postsynaptic integration
Axo-axonic synapseExcitatory/inhibitory neurons synapsing on synaptic terminals - Augment communication between pre and postsynaptic cells
Presynaptic inhibitioninhibits neurotransmitter release
presynaptic facilitationincreases neurotransmitter release
Synaptic activity can be altered by changing (3) ?The target's: Structure - Affinity - Number of receptors
memorize

Lecture 7

Question Answer
Brain: Gray matterUnmyelinated somas, dendrites and axons -
Brain: White matterMyelinated axons
Spinal Cords' 4 regionsCervical (8) ○ Thoracic (12) ○ Lumbar (5) ○ Sacral (5) ○ Coccygeal (1)
Each spinal segment gives rise to a ___ ___ of spinal nerves, each nerve splits into ___bilateral pair ○ Roots
Dorsal rootCarries sensory (afferent) information to CNS
Ventral rootCarries motor (efferent) information to muscles and glands
Spinal cord: Gray matterSensory and motor nuclei
Spinal cord: White matterTracts of axons carrying information to and rom brain
Spinal cord: White matter→Ascending tractsCarry sensory information to brain
Spinal cord: White matter→Descending tractsCarry commands to motor neurons
Spinal reflexInitiates response without brain input
How much does the brain weigh?1.4kg
How many neurons exist?85 billion; 1000s synapses
6 major divisions of the brainCerebrum ○ Cerebellum ○ Diencephalon ○ Medulla ○ Midbrain ○ Pons
Oldest and most primitive region of the brainBrainstem
Which tracts run through brainstem?ascending and descending
Brain stem contains how many cranial nerves11/12
Do brain stem contains nuclei?Yes
Brain stem is involved in basi processes, such as...Arousal, sleep, muscle tone, breathing, blood pressure, pain
Medulla white matterascending somatosensory tracts and descending corticospinal tracts
Which % of corticospinal tracts decussate (crossover) at the pyramids90%
Nuclei in the medulla controls involuntary functionsCardiovascular center and respiratory center
PonsNuclei and tracts ○ Communicates cerebellum & cerebrum ○ Assists the medulla in breathing coordination
Midbrain (mesencephalon)Stays between lower brainstem & diencephalon ○ Controls eye movement ○ Relays auditory and visual reflexes ○ Contains the substantia nigra
Reticular formationExtends throughout the brainstem ○ small clusters interspersed among tracts (ascending & descending)
____ inactivated during sleep, damage can induce comaRAS
Important in consciousness, arousal, attention and alertnessReticular formation
Second largest brain structureCerebellum
How many hemispheres are there in the cerebellum2
Cerebellum sends feedback signals to motor areas of the cerebral cortex, via?Thalamus helping correct errors & smooth movements
Which part of the brain regulates posture and balance?Cerebellum
Which brain part contains the vomiting center?Medulla
Which brain part contains the deglutition (swallowing) center?Medulla
Controls arousal, sleep, muscle tone, breathing, blood pressure and painBrainstem
Where does the Diencephalon stay?Between brain stem and cerebrum
Diencephalon - 2 primary structuresthalamus and hypothalamus
Diencephalon - 2 endocrine structurespineal gland and pituitary
ThalamusReceives sensory info from optic tract, ears, spinal cord ○ Motor info from cerebellum & projects info to cerebrum for processing
Pineal glandCyclically releases melatonin involved in sleep/wake
Hypothalamus (2)Center for homeostasis ○ influences autonomic and endocrine functions
PituitaryOutput of the hypothalamus
What type of tissues are in the posterior pituitaryNeural tissue
IndundibulumStalk connecting pituitary to brain
Posterior PituitaryExtension of neural tissue
Anterior PituitaryTrue endocrine gland of epithelial orgin
memorize

Lecture 8

Question Answer
Largest and most distinctive part of the brainCerebrum
Cerebrum gray matterCerebral cortex, basal ganglia & limbic system
Cerebrum: 2 ___ divided into 4 ___, connected by ___ ___Hemispheres ○ Lobes ○ Corpus Callosum
3 nuclei collectively termed the basal gangliaGlobus pallidus ○ Putamen ○ Caudate nucleus
Basal ganglia's major job is?regulating the initiation and termination of movement
Basal ganglia: Receives input from ________ and provides output to motor portions of the cortexcerebral cortex ○ motor portions of the cortex
“emotional brain”Limbic system
Cingulate gyrusRole in emotions
HippocampusLearning and memory
AmygdalaEmotion and memory
3 major components of limbic systemCingulate gyrus ○ Amygdala ○ Hippocampus
Outermost layer of the cerebrumCerebral cortex
Cerebral cortex 3 specialization areasSensory ○ Motor ○ Association
Association areas of cerebral cortexIntegrate information from sensory & motor areas; direct volunteering behaviours
Olfactory cortexSmell
Gustatory cortexTaste
Simple receptors in sensory systemsFree nerve endings ○ Myelinated/Unmyelinated axons
Complex receptors in sensory systemsClosed nerve endings in connective tissue capsules
Pacinian corpuscleSenses touch
Special receptors in sensory systemsRelease neurotransmitter onto sensory neurons ○ Initiate AP ○ Non-neuronal cell transduces (except olfactory)
Physical stimuli are transduced into which type of potentials?Graded
Receptive fields: ConvergenceCreates large receptive fields
Receptive fields: Small receptive fieldsFound in sensitive areas
Visceral sensoryinfo is integrated in brainstem and spinal cord
Almost all special and somatic sensory information are routed through?Thalamus
Olfactory ___ from nose project through olfactory ___ to the olfactory ___Pathways - Bulb - Cortex
Special senses have a set of?dedicated cortical regions
Somatic senses are integrated in?the primary somatosensory cortex
______ have dedicated cortical regionsSpecial senses
Somatic sensesIntegrated in primary somatosensory cortex
Most of the sensory pathways project to?Thalamus
Cerebellum needs the aid of which pathwaysEquilibrium pathways
CNS distinguishes four properties of a stimulusModality - Location - intensiry - Duration
Properties of stimulus: Modality (4)Sensed physical stimuli - Activates with sensory recepors - temperature vs touch receptor - Pathways terminate in the brain
Properties of stimulus: LocationCoded according to activated receptive fields
Body part sensitivity is determined by?Space on somatosensory cortex devoted to each
Sound localizationTiming in which sound reaches the auditory cortex from each ear
What can lateral inhibition increase?Accuracy of localization
Lateral inhibitionIndentation is weakly activa
Lateral inhibationInhibition at secondary neuron, only tertiary single neuron activated
Primary neuron response is proportional to?Stimulus strength
Can intensity be determined by amplitude? Why or why not?No, because AP amplitude is constant
Properties of stimulus: IntensityDetermined by number of receptors acitvated ○ frequency of incoming action potentials
Intensity is determined by....Population coding and frequency coding
Population codingnumber of receptors being activated
Frequency codingfrequency of incoming action potentials
Duration of stimulusDetermined by how long AP’s are being activated for
Types of receptor adaptationTonic and Phasic
Tonic receptorsSlowly adapting receptors responding for stimulus duration - Monitored parameteres (couple lines close and next are further appart)
Phasic receptorsRapidly adapting stimulus and turn off - Stops once stimulus constant (3 close lines & still)
Each receptor are most sensitive to which signal ?Particular types of stimulus
A stimulus above threshold initiates?AP’s in a sensory neuron that project to the CNS
Stimulus intensity and duration are coded in?The pattern of AP’s reaching the CNS
Stimulus location and modality are coded according to?Which receptors are activated or by the timing of activation
memorize

Lecture 9

Question Answer
Autonomic Nervous system subdivides into which categoriesSympathetic and parasympathetic
ParasympatheticRest-and-Digest
SympatheticFight-or-flight
What do Autonomic nervous systems control?smooth muscle, cardiac muscle, glands and adipose tissue
Which Autonomic Nervous system parts help homeostasisHypothalamus, Pons and Medulla
What kind of control difference do sympathetic and parasympathetic have?Antagonistic controls
How many efferent neurons in series do autonomic pathways have?2
Autonomic pathways consists of ___ that synapse in an ____ ganglion2 neurons - autonomic
Divergence is common in which pathways?Autonomic
___ preganglionic will synapse with ___ or ___ postganglionic neuron1 - 8 - 9
Self contained neurons within ganglia can act as ___ centersmini-integrating
Sympathetic: Where are ganglia found?In 2 ganglion chains running along side vertebral column
Sympathetic: Preganglionic neurons originationThoracic and lumbar regions
Sympathetic: Preganglionic neurons exit viacranial nerves or sacral region of the spinal cord
Sympathetic: ___ preganglionic, ___ post ganglionic neuronsShort - Long
Parasympathetic: Preganglionic neurons originate in the ___ and exit via ___ or ___brainstem - cranial nerves - sacral region of the spinal cord
Parasympathetic: Ganglia are mainly located on/near..target organs
Parasympathetic: ___ preganglionic, ___ post ganglionic neuronsLong - Short
Cranial nerve X (vagus) contains 75% of all ____parasympathetic neurons
memorize

Lecture 10

Question Answer
Adrenal medullaneuroendocrine structure associated with sympathetic nervous system - Modified sympathetic ganglion - contain chromaffin
Chromaffin cellsmodified postganglionic neurons
Autonomic pathwaysTarget smooth and cardiac muscle, exocrine glands, few endocrine glands, lymphoid tissue and adipose tissue
memorize