Neuro F-notes Flashcards
Which Funiculus contains only Ascending Sensory fibers?
Posterior Funiculus
Fasciculus Proprius
Interphase between white and grey matter
Somatotopic Organization of Ascending & Descending Fibers in white matter
- Post. Funiculus: Long fibers deeper than short (due to invagination)
- Ant/Lat. Funiculi: Short fibers deeper than long
Dopamine Neuron and Pathway
- Ventral Tegmental Area & Substantia Nigra
- Nigrostriatal Pathway
- Parkinson’s & Schizophrenia
Norepinephrine Neuron and Pathway
- Locus Ceroleus
- Sympathetic Nervous system
- Low = ADHD
Serotonin Neuron and Pathway
- Raphe Nucleus
- Main monaminergic NT
- Low = Depression
Adrenaline Neuron and Pathway
- Dorsomedialis & Ventrolateralis Medulla
- FIght-or-flight response
Acetylcholine Neuron and Pathway
- Nucleus Basalis of Meynert
- Autonomic Systems
- Low = Alzheimer’s
Ascending Reticular Activating System (ARAS)
- Arousal Center in terms of Wakefulness
- Fibers ascend to excite cortex
- NE, Serotonin, ACh
- Spinoreticular Tract
Out of all input to CNS how much is Visceral info?
Only 10%
Sympathetic viscerosensory Afferent Limb
1) Central process carries info to ipsilat. spinal cord lamina I
2) Goes to CONTRALATERAL side of lateral spinothalamic tract T1-L2
3) Partially to VPM
4) Gives collateral branches to medulla in RF
5) Info projects to post. insular cortex
(internal body information)
Parasympathetic viscerosensory Afferent Limb SACRAL
1) Central process carries info to ipsilat. spinal cord lamina I
2) Goes to IPSILATERAL side of lateral spinothalamic tract in S2-S4
3) Partially to VPL
4) Gives collateral to medulla in RF
5) Info projects to post. insular cortex
(internal body information)
Parasympathetic viscerosensory Afferent Limb CRANIAL
1) Viscerosensory fibers from CN7, 9, 10.
2) Trigeminothalamic Tract
3) VPM
4) Post. Insular cortex
Spinoreticulothalamic tract
1) DRG to contralateral ascending in spinothalamic tract
2) Collaterals to RF, to Parabrachial and Periaquiductal Grey
3) Rest go to interlaminar, M/V/D thalamic nuclei
4) Thalamus to Post. insula, ant. cingulate, & secondary sensory cortex
Solitary Nucleus
Brainstem center for Viscerosensory afferentation
- Solitary tract nucleus (thalamic relay)
- Gustatory nucleus (CN7,9,10)
- Baroreceptor nucleus (CN9)
- Dorsal respiratory nucleus (insp.)
Prefrontal Cortices
- Most multimodal area of Brain
- Decision-making and Emotional regulation
- Dorsolateral PFC, attention & working-memory, even pain perception
Main types of Nociceptors
- A-delta Neurons
- C-Neurons
1st Neuron of Nociception regions
- Body: DRG
- Face: Trigeminal Sensory ggl.
2nd Neuron of Nociception regions
- Body: Dorsal Horn
- Face: Spinal Trigeminal Nucleus
(ventral trigeminothalamic tract)
A-delta Neurons
Nociceptor
- Thin myelin sheath
- Faster than C-fibers
- Sharp pain
C-Neurons
Nociceptor
- Non-myelinated
- Conducts with delay
- Prolonged burning/pain
What tract is similar to the spinothalamic but gives branches to RF?
Spinoreticular Tract
Spinohypothalamic Tract
- Highest autonomic center for homeostasis (hypothalamus)
- Nociceptive stim. reach here through RF
- Pain = more symp, less parasymp.
- CRH released, ACTH inc., Cortisol inc.
Visceral Motor Cortex
- Anterior part of Cingulate Gyrus
- Direct connection with visceral sensory cortex (post. insula)
- Projects to amygdala, hypothalamus, PAG, RF, Dorsal vagal N. (brainstem)
Micturition Control
- Anterior Cingulate Cortex
- Periaqueductal Grey (PAG)
- Pontine centers (storage & mict)
Continence & Innervation
Pontine Storage Center
- Sympathetic, Hypogastric Nerve, keeps detrussor m. relaxed and internal urethral sphincter closed.
- Onuf’s Nucleus, Ventral horn S2-S4, controls ext. urethral sphincter (voluntary)
Micturition & Innervation
Pontine Micturition Center
- Sensed by stretch sent to PAG
- Inhibited sympathetic path
- Inhibited Onuf’s nucleus
- Activated parasympathetic path
Schultze’s Comma tract spinal region
Cervical
Flechsig’s oval field spinal region
Lumbar
Philippe-Gombault’s trigone spinal region
Sacral
Execution of speech
1) Auditory pathway to Wernicke’s sensory speech center (Br.22)
2) Then to Brocca’s speech area (br.44/45)
3) Motor cortex (Br4) for muscles involved in production of speech (larynx)
Kinetic receptors in Vestibule
In Ampullary Crest for detecting angular acceleration
Static receptors in Vestibbule
In Macula for linear acceleration and gravity
Info transmitted from Vestibular nerve
- Lat. Vestibulospinal tract to motor neurons
- Vestibulocerebellar tract to Flocculonodular lobe of cerebellum
- Medial longitudinal fasciculus Ipsi/Contra Occulomotor nuclei
What Nucleus controls Horizontal Vestibulocular movements
- Abducens Nucleus
- Oculomotor Nucleus
(med/lat rectus)
What Nucleus controls Vertical Vestibulocular movements
- Trochlear Nucleus
(sup. oblique)
Visual tracts outside of LGB
- Retinothalamic tract (circadian)
- Tectum
- Superior colliculus
Neuroanatomy of Reading and Understanding
1) Primary visual cortex
2) Decoding in post/inf temporal
3) Storage in angular gyrus
4) Making sense, prefrontal
Hippocampus main role
Converts recent memories to long term memories
Amygdala
- Almond shaped nucleus
- Major Emotional processing
- Corticomedial & Basolateral Nuclei
Parts of Limbic system
- Limbic lobe (CG / PHCG)
- Dentate gyrus (afferent)
- Subiculum
- Hipocamp. Propper
- Amygdala
- Hypothalamus
- Thalamus
- Septal Area & Habenula
Fornix
Connect Hippocampus to:
- Hypothalamus
- Septal Area
(memory)
Stria Medularis Thalami
Connects:
- Septal Area
- Habenula
Mamillothalamic Tract
Connects:
- Mamillary Bodies
- Anterior Nuc. of Thalamus
Limbic System Olfaction
1) Olfactory Bulb to Tract
2) Lat. Olfactory Stria
3) PHCG & Amygdala
Limbic System Memory & Learning
Hippocampus, Fronix, Mamillary Bodies, Mamillothalamic Tract, Ant. Nucleus of Thalamus, Cingulate Gyrus, finally Parahippocampal Gyrus to Dentate Gyrus via Entorhinal cortex (and repeats)
Limbic System Feeding
Amygdala signals Hypothalamus:
- Ventromedial Nuc: Satiety
- Lat. Hypoth. Nuc: Hunger
How does Light Effect Circadian Rhythm?
- Suprachiasmatic Nucleus
- Retinohypothalamic Tract
- Melanopsin Pigment and Glutamate signal
- SCN signals PVN for ACTH for Cortisol & Intermediolateral symp.
- Pineal Gland: Melatonin
REM Sleep
- EEG low amplitude & high freq. looks like awake
- HR, BP, breathing increase
- Inh. of Trunk muscles
What controls REM sleep?
aCh Neurons in:
- Peduncolopontine Tegmental Nuc.
- Laterodorsal Tegmental Neurons
Resting State
Brain is active but not focused on any specific task (daydreaming / resting)
3 Major brain Networks in Resting state
- Default Mode Network (thinking about yourself, memories)
- Central Executive Network (problem-solving)
- Salience Network (stimuli response)
Motivation amygdala connections
- Septal Area (stria terminalis)
- Hypothalamus (Vent. amygdalofugal pathyway)
Motivation Dopamine
Septal Area & Hypoth. communicate with Ventral Tegmental Area for DOPAMINE
- Nucleus Accumbens
- Prefrontal Cortex
REWARD
Motivation Mesolimbic Path
VTA dopamine to Nucleus Accumbens
Motivation Mesocortical Path
VTA dopamine to Prefrontal Cortex
Fear Pathway
Amygdala signals 2 Hypothalamic Nuclei
- Post. Hypoth. Nucleus
- Paraventricular Nucleus
Fear Pathway Posterior Hypothalamic Nucleus
- Hypothalamospinal Tract
- Preganglionic Neurons in thoracic/lumbar sympathtic
- HR, BP, Breathing (auto)
Fear Pathway PVN
- Corticotropin Releasing Hormone (PVN)
- Adrenocorticotropic Hormone (Pituitary)
- Cortisol (adrenal gland)
Otic Ganglion (CN IX)
1) From Inf. Salivatory Nucleus
2) Pre-ggl Parasymp: Lesser Petrosal
Pre-ggl Symp: External Carotid Plexus
3) Post-ggl: Auriculotemporal nerve
(e.g. parotid gland)
Submandibular Ganglion (CN VII)
1) From Sup. Salivatory Nucleus
2) Pre-ggl Parasymp: Chorda Tympani
Pre-ggl Symp: External Carotid Plexus
3) Post-ggl: Lingual n.
(e.g. submandibular/sublingual glands)
Pterygopalatine Ganglion (CN VII)
1) From Sup. Salivatory Nucleus
2) Pre-ggl Parasymp: Greater Petrosal
Pre-ggl Symp: Deep Petrosal n.
3) Post-ggl: Maxillary n.
(e.g. lacrimal gland)
