Neuroanatomy 2 Flashcards
Brainstem: Location
What is it continuous with rostrally and caudally?
Continuous rostrally with the diencephalon and caudally with the spinal cord
Brainstem: Location
Structural features
characterized by bumps and bulges formed by the underlying gray matter (nuclei) and white matter (tracts, fasciculi, and lemnisci
Brainstem: Location
What regions/structures does it include?
Midbrain, pons, and medulla oblongata. All of the regions share a basic organization.
Most of the cranial nerves attach to the brainstem except for CNI which attaches to the telencephalon and CNII which attaches to the diencephalon.
Brainstem: Internal Anatomy
What are the internal regions of the brainstem?
Tegmental area, basilar area
Brainstem: Internal Anatomy
Tegmental Area - Location and Contents
The tegmental area is the central core of the midbrain and pons, and is continuous with a comparable area of the medulla.
It is located dorsal to the basilar area
It contains nuclei and primarily sensory (ascending) tracts
Brainstem: Internal Anatomy
Basilar Area - Location and Contents
The basilar area is the ventral region of the midbrain and pons and is continuous with a comparable area of the medulla.
It is located ventral to the tegmental area.
It contains nuclei and primarily motor (descending) tracts
Brainstem: Cranial Nerve Nuclei
How are the cranial nerve nuclei in the brainstem classified?
They are classified according to the functional components of the entering or exiting cranial nerve neurons. A nucleus can only have axons that have the same functional component.
Brainstem: Cranial Nerve Nuclei
What is their medial-lateral organization?
Sensory (afferent) nuclei are located laterally and motor (efferent) nuclei are located medially.
Brainstem: Cranial Nerve Nuclei
What is their rostral-caudal organization?
Reflects the rostral caudal organization of the head and neck structures. Therefore, the cranial nerve nuclei associated with the lower number CNs will be higher, and with the higher number CNs will be lower based on where those nerves exit the brainstem.
Brainstem: Cranial Nerve Nuclei
What CN nuclei are in the midbrain and what functional components are they associated with?
GSE: Occulomotor nucleus, troclear nucleus
GVE: edinger Westphal Nucleus
GSA: Trigenimal sensory, mesencephalic
Brainstem: Cranial Nerve Nuclei
What CN nuclei are in the pons and what functional components are they associated with?
GSE: Abducens
GVE: Superior Salivatory, Inferior Salivatory
SVE: trigeminal motor, facial
GSA: trigeminal sensory principal nucleus
SSA: Vestibular, cochlear
GVA/SVA: Nucleus of the solitary Tract
Brainstem: Cranial Nerve Nuclei
What CN nuclei are in the medulla and what functional components are they associated with?
GSE: spinal accessory, hypoglossal
GVE: dorsal motor, nucleus ambiguus
SVE: Nucleus Ambiguus
GSA: Trigeminal sensory spinal nucleus
SSA: Vestibular, cochlear
GVA/SVA: Nucleus of the solitary tract
Brainstem: Additional Nuclei
What other types of nuclei are there in the brainstem?
Sensory, Motor, Modulatory
Brainstem: White Matter
Tracts - how are they named?
Tracts are usually named for where they originate and where they terminate.
Brainstem: White Matter
Tracts - What 3 types of tracts can be found in the brainstem?
Sensory, Motor, Modulatory
Brainstem: White Matter
Tracts - Sensory (ascending) tract
The sensory tracts are located more dorsally in the tegmental region.
Brainstem: White Matter
Tracts - Motor (descendin) tract
The motor tracts are located more ventrally in the basilar region
Brainstem: White Matter
Tracts - Modulatory
These tracts carry associational information and have information from many systems coming together.
Brainstem: Functions
1) The brainstem has a crucial relationship with the cranial nerves. It serves as a target or source for the cranial nerves that deal primarily with sensory and motor function in the head and neck.
2) Provides a throughway for all for all of the ascending sensory tracts, descending motor tracts, and local pathways
3) Involved in integrative (or modulatory) functions such as complex motor patterns, maintenance of homeostasis, and regulating the level of alertness.
Cranial Nerves: CNI
Name Brain Exit Foramen Functional Components Distribution Associated Nuclei
Name: Olfactory
Brain Exit: Telencephalon
Foramen: Cribiform plate
Functional Components: SVA
Distribution: Smell
Associated Nuclei: none
Cranial Nerves: CNII
Name Brain Exit Foramen Functional Components Distribution Associated Nuclei
Name: Optic
Brain Exit: Diencephalon
Foramen: Optic Canal
Functional Components: SSA
Distribution: Vision
Associated Nuclei: none
Cranial Nerves: CNIII
Name: Occulomotor
Brain Exit: Midbrain-pons junction
Foramen: Superior orbital fissure
Functional Components: GSE, GVE
Distribution:
GSE: Extraoccular muscles except SO4, LR6
GVE: Sphincter pupilae, cilliary muscles
Associated Nuclei:
GSE: Occulomotor
GVE: Edinger-Westphal
Cranial Nerves: CNIV
Name Brain Exit Foramen Functional Components Distribution Associated Nuclei
Name: Trochlear
Brain Exit: Midbrain-pons junction (DORSAL side)
Foramen: Superior orbital fissure
Functional Components: GSE
Distribution: Superior Oblique muscle of the orbit
Associated Nuclei: trochlear
Cranial Nerves: CNV
Name (3 parts) Brain Exit Foramen Functional Components Distribution Associated Nuclei
Name: Trigeminal Nerve - ophthalmic, maxillary, and mandibular divisions
Brain Exit: Basilar pons
Foramen:
1) Superior Orbital Fissure
2) Foramen Rotundum
3) Foramen Ovale
Functional Components: SVE, GSA
Distribution:
SVE: Muscles of mastication
GSA: Skin of the anterior Scalp and face
Associated Nuclei
SVE: Trigeminal: Motor Nucleus
GSA: Trigeminal: Sensory (Mesencephalic, Principle, and Spinal) Nucleus
Cranial Nerves: CNVI
Name Brain Exit Foramen Functional Components Distribution Associated Nuclei
Name: Abducens
Brain Exit: Pons-Medulla Junction
Foramen: Superior Orbital Fissure
Functional Components: GSE
Distribution: Lateral Rectus muscle of the orbit
Associated Nuclei: Abducens Nucleus
Cranial Nerves: CNVII
Name Brain Exit Foramen Functional Components Distribution Associated Nuclei
Name: Facial
Brain Exit: Pons-Medulla Junction
Foramen: Internal Acoustic Meatus, through the Facial Canal, and out the Stylomastoid foramen
Functional Components: SVE GVE GSA SVA
Distribution: SVE: Muscles of Facial Expression GVE: [parasympathetic] GSA: [skin external ear] SVA: taste in the anterior 2/3 of the tongue
Associated Nuclei: SVE: Facial Nucleus GVE: Superior Salivatory Nucleus GSA: Trigeminal: Sensory (Mesencephalic, Principle, and Spinal) Nucleus SVA: Nucleus of the Solitary Tract
Cranial Nerves: CNVIII
Name Brain Exit Foramen Functional Components Distribution Associated Nuclei
Name: Vestibulocochlear
Brain Exit: Pons-Medulla Junction
Foramen: Jugular Foramen
Functional Components:
SSA
Distribution: Hearing and balance
Associated Nuclei: Vestibular nuclei, cochlear nuclei
Cranial Nerves: CNIX
Name Brain Exit Foramen Functional Components Distribution Associated Nuclei
Name: Glossopharyngeal
Brain Exit:
Medulla - post-olivary sulcus
Foramen:
Jugular Foramen
Functional Components: SVE GVE GSA GVA SVA
Distribution:
SVE
GVE: [parasympathetic output]
GSA: sensation to the posterior 1/3 of the tongue and skin of the external ear
GVA: Carotid body and sinus**
SVA: Taste to the posterior 1/3 of the tongue
Associated Nuclei: SVE: Nucleus Ambiguus GVE: Inferior Salivatory Nucleus GSA: Trigeminal: Sensory (Mesencephalic, Principle, and Spinal) Nucleus GVA: Nucleus of the Solitary Tract SVA: Nucleus of the Solitary Tract
Cranial Nerves: CNX
Name Brain Exit Foramen Functional Components Distribution Associated Nuclei
Name: Vagus
Brain Exit: Medulla - Post-olivary sulcus
Foramen: Jugular Foramen
Functional Components: SVE GVE GSA GVA SVA
Distribution
SVE: Muscles of the larynx
GVE: Parasympathetic innervation of everything down to the L colic flexure
GSA: posterior 1/3 of the tongue, skin of the external ear
GVA: aortic chemo and baro receptors
SVA: Taste:
Associated Nuclei
SVE: Nucleus Ambiguus
GVE: Dorsal Motor Nucleus, Nucleus Ambiguus
GSA: Trigeminal: Sensory (Mesencephalic, Principle, and Spinal) Nucleus
GVA: Nucleus of the Solitary Tract
SVA: Nucleus of the Solitary Tract
Cranial Nerves: CNXI
Name Brain Exit Foramen Functional Components Distribution Associated Nuclei
Name: Spinal Accessory
Brain Exit: Medulla- Post-olivary sulcus
Foramen: Jugular foramen
Functional Components: GSE
Distribution: SCM and Traps
Associated Nuclei: Spinal accessory nuclei
Cranial Nerves: CNXII
Name Brain Exit Foramen Functional Components Distribution Associated Nuclei
Name: Hypoglossal Nerve
Brain Exit: Medulla - pre-olivary Sulcus
Foramen: Hypoglossal canal
Functional Components: GSE
Distribution: Muscles of the tongue except palatoglossus
Associated Nuclei: hypoglossal nucleus
Cerebellum: Location, components
Dorsal to the pons and inferior to the occipital lobe, filling most of the posterior cranial fossa.
Similar to the cerebrum, it includes the cerebellar cortex, white matter, and deep nuclei
Cerebellum: External Structure
Cerebellar cortex
This is the outer surface, composed of horizontal layers of neuronal cell bodies.
It is characterized by ridges and valleys of cortical tissue called folia.
Cerebellum: External Structure
Fissures
Primary fissure - seen superiorly, divides andterior and posterior lobes
Posterolateral - seen inferiorly; divides posterior and flocculonodular lobes
Cerebellum: External Structure
What are the three lobes?
Anterior, Posterior, Flocculonodular
Cerebellum: External Structure
Peduncles - names, function
Names: Superior, middle, and inferior peduncles
These three pairs of tracts attach the cerebellum to the brain stem.
superior - primarily carries output form the cerebellum
middle - exclusively carries input to the cerebellum
inferior - primarily carries input to the cerebellum
Cerebellum: Internal Structure
Cerebellar nuclei - where are they located? what are the composed of?
They are located in the white matter core of each hemisphere.
They are composed of aggregations of neuron cell bodies
Cerebellum: Internal Structure
Name the cerebellar nuclei
Fastigial - most medial
Interposed: includes globose and emboliform - these are intermediate
Dentate - most lateral
Cerebellum: Function
How many functional divisions are there in the cerebellum?
Three
Cerebellum: Function
Vestibulocerebellum - Location and function
Location: Flocculonodular lobe
function: regulation of balance and eye movements
Cerebellum: Function
Spinocerebellum - Location and function
Location: Vermis and intermediate region
Function: regulation of body and limb movement
Cerebellum: Function
Cerebrocerebellum - Location and function
Location: Lateral region
Function: evaluating sensory information and planning movement
