Test 2: Nervous system Flashcards
Cerebrum
Conscious thought processes and intellectual functions. consists of 83% of brain’s volume. split into two halves.
Gyri
thick folds; ridges
Sulci
Shallow grooves
Longitudinal fissure
separates two hemispheres
Corpus collosum
at bottom of long. fissure, two hemispheres are connected to eachother by this bundle of nerve fibers
Cerebrum is made up of…
outer layer of gray matter and inner layer of white matter
Cerebellum
inferior to cerebrum. 2nd largest part of brain.
Separates the corpus collosum
Transverse cerebral fissure
Brainstem
life-support functions.
4 structures of brianstem
diencephalon, midbrain, pons, medulla oblongata
Gray matter
houses motor neuron and interneuron cell bodies, dendrites, telodendria, and unmyelinated axons
Cerebral nuclei
internal clusters formed by gray matter
White matter
Made up of myelinated axons
deep to gray matter of cortex
composed of tracts
Tracts
connect one part of brain to another or the spinal cord
Frontal lobe
voluntary motor fxn, decision making, concentration, planning
Frontal lobe posterior border
central sulcus
Frontal lobe inferior border
lateral sulcus
Precentral gyrus
mass of nervous tissue in frontal lobe immediately anterior to central sulcus
Parietal lobe
General sensory functions
Partietal lobe anterior boundary
Central sulcus
Partietal lobe lateral boundary
lateral sulcus
Parietal lobe posterior boundary
parieto-occipito sulcus
Post central gyrus
mass of nervous tissue in parietal lobe immediately posterior to central sulcus
Temporal lobe
Hearing and smelling
Temporal lobe superior border
lateral sulcus
Occipital lobe
stores visual memories, processes incoming visual information
Occipital lobe anterior border
Parieto-occipito sulcus
Insula
located deep in lateral sulcus; memory and interpretation of taste
Innermost meninge layer
Pia mater
Middle meninge layer
Arachnoid mater
Outermost meninge layer
Dura mater
Cranial dura septa
separate parts of the brain to provide stabilization and support
Dura septa that projects into longitudinal fissure and separates the left and right hemispheres
Falx cerebi
2 dural venous sinouses in falx cerebi
superior saggital sinous (in superior part) and inferior saggital sinous (in inferior part)
Dura septa that horizontally separates cerebrum from cerebellum
Tentorium cerebelli
Venous sinus in tentorium cerebelli
transverse sinus (in posterior part)
Dura septa that separates left and right cerebral hemispheres and is attached to internal aspect of occipital bone; lies inferior to tentorium cerebelli
falx cerebelli
Venous sinus in falx cerebelli
occipital sinus
Cerebral nuclei
paired masses of gray matter found deep within the central white matter
Caudate nucleus
Large nucleus; one of three that makes up basal ganglia
Amygdaloid body
Small bulb that lies at tail end of caudate nucleus
Lentiform nucleus
made up of putamen and globus palladus; along with caudate nucleus make up basal ganglia; large nucleus that lies at head end of caudate nucleus
Functions of meninges
- separate soft tissue of the brain from bones of the cranium
- enclose and protect blood vessels that supply the brain
- contain and circulate CSF
- form some of the veins that drain blood from the brain
Brain ventricles
cavity within the brain that contains CSF
name 4 ventricles in brain
2 lateral ventricles; one in each hemisphere
3rd ventricle in diencephalon; inferior to lateral ventricles
4th ventricle between pons and cerebellum; inferior to 3rd ventricle connected to 3rd ventricle by aqueduct
Diencephalon
contains epithalamus, thalamus, hypothalamus
Epithalamus
partially forms posterior roof of diencephalon and covers third ventricle. contains pineal gland and habenular nuclei
Thalamus
paired oval masses of gray matter. lie on each side of third ventricle between third ventricle and lateral ventricles
Hypothalamus
Anteroinferior region of diencephalon; on each side of third ventricle
Brainstem function
connects cerebrum to spinal cord. passage way for all tracts extending btwn cerebrum and spinal cord. contains autonomic centers and reflex centers for survival and houses nuclei for many of cranial nerves
Limbic system
structures of limbic system form ring around the diencephalon
Cingulate gyrus
Limbic system; recieves input from other limbic structures
Parahippocampal gyrus
Limbic system; cortical tissue associated with hippocampus
Hippocampus
Limbic system; nucleus shaped like seahorse, storing memories and forming longterm memory
Amygdaloid body
emotion; fear
Olfactory bulbs, tract and cortex
odors can provoke emotions/memory
Fornix
thin tract of white matter connecting hippocampus with other structures
Key function of Olfactory CN I
Smell
Key function of Optic CN II
Vision
Key function of Oculomotor CN III
innervates superior, inferior and medial recti muscles of the eye, inferior oblique, levator palpebrae; moves eyelid and eyeball and adjusts pupil and lens of the eye
Key function of Trochlear CN IV
Innervates superior oblique muscle of the eye; moves eyeball
Key function of Trigeminal CN V
Facial muscles including mastication; facial sensation
Key function of Abducins CN VI
Innervates lateral rectus muscle of the eye; moves eyeball
Key function of Facial CN VII
Facial movement and expressions(smile, eye lid); taste sensation; tears, saliva
Key function of Vestibulocochlear CN VIII
Hearing and balance (equilibrium)
Key function of Glossopharyngeal CN IX
Salivation, swallowing, taste; cardiopulminary function
Key function of Vagus CN X
Gut motility, swallow, cardiopulmonary function; Control of PNS and smooth muscles of GI tract
Key function of Accessory CN XI
moving head and shoulders, swallowing
Key function of Hypoglossal CN XII
Tongue muscles: speech and swallowing
Cranial nerves with nuclei in midbrain
Motor nuclei: Oculomotor (III), Trochlear (IV)
Cranial nerves with nuclei in the pons
Motor nuclei: Trigeminal (V), Abducins (VI), Facial (VII)
Sensory nuclei: Vestibulocochlear (VIII) [on border of pons and medulla)
Cranial nerves with nuclei in the medulla oblongata
Motor nuclei: Glossopharyngeal (IX), Vagus (X), Hypoglossal (XII)
Sensory nuclei: [Facial (VII), Glossopharyngeal (IX), Vagus (X)] is one nucleus and half of nucleus that is innervated by Vestibulocochlear (VIII).
Cranial nerves with nuclei in Cervical spinal cord
Motor nuclei: Accessory (XI)
Which nerve has a nucleus that spans the length of all 4 parts of the diencephalon (sensory)?
Trigeminal (V); At caudal end Facial (VII), Glossopharyngeal (IX) and Vagus (X) innervate it too in cervical spinal cord
Which nerves innervate the muscles of the eye?
Oculomotor (III), Trochlear (IV), Abducens (VI)
Which nerves aid in mastication and swallowing?
swallowing: Glossopharyngeal (IX), Accessory (XI), Hypoglossal (XII)
Chewing: All three branches of the Trigeminal (V)
Which nerves aid in facial expression?
Facial (VII)
Which nerves aid in salivation?
Facial (VII), Glossopharyngeal (IX),
Which nerves sense facial sensations?
Trigeminal (V)
Which nerves sense taste?
Facial (VII), Glossopharyngeal (IX)
Which nerves monitor blood pressure?
Glossopharyngeal (IX), Vagus (X)
Pathway of Olfactory I
Nerve axons extend through cribiform foramina of ethmoid bone and synapse in olfactory bulbs in anterior cranial fossa; go down olfactory tract and to the cerebral cortex
Pathway of Optic II
Enters cranium via OPTIC CANAL of spenoid bone
left and right optic nerves unite at optic chiasm
optic tract travels to lateral geniculate nucleus of thalamus
information forwarded to occipital lobe
Origin of Optic II
Retina of eye
Origin of Oculomotor III
Oculomotor nucleus in midbrain
Pathway of Oculomotor III
leaves cranium via SUPERIOR ORBITAL FISSURE and innervates eye and eyelid
Origin of Trochlear IV
trochlear nucleus within midbrain
Pathway of Trochlear IV
Leaves cranium via SUPERIOR ORBITAL FISSURE and innervates superior oblique muscle of the eye
Origin of Trigeminal V
Motor and sensory nuclei in pons
Function of Trigeminal V (opthalmic V1)
Sensory impulses from cornea, nose, forehead
Pathway of Trigeminal V (opthalmic V1)
enters through SUPERIOR ORBITAL FISSURE, goes through trigeminal ganglia to the pons
Function of Trigeminal V (Maxillary V2)
Sensory impulses from mucosa, palate, cheek, meninges
Pathway of Trigeminal V (Maxillary V2)
Enters through FORAMEN ROTUNDUM, goes through trigeminal ganglia to the pons
Function of Trigeminal V (Mandibular V3)
Sensory impulses from anterior 2/3 of tongue, skin of chin, lower jaw, lower teeth, 1/3 from sensory axons from auricle of the ear
Motor innervation of muscles of mastication, mylohyoid, anterior belly of digastric, tensor tympani muscle, tensor pali palatini
Sensory pathway of Trigeminal V (Mandubular V3)
Enters through FORAMEN OVALE, goes through trigeminal ganglia to the pons
Motor pathway of Trigeminal V (Mandibular V3)
Exits through FORAMEN OVALE, innervates muscles of mastication, mylohyoid, anterior belly of digastric, tensor tympani muscle, tensor pali palatini
Origin of Abducins VI
Pontine (abducins) nucleus in pons
Pathway of Abducins VI
Exits through SUPERIOR ORBITAL FISSURE and goes to lateral rectus muscle of the eye
Origin of Facial VII
Motor Nucleus in pons; sensory nucleus in medulla
Somatic motor pathway Facial VII
Axons leave pons through INTERNAL ACOUSTIC MEATUS and enter the temporal bone (middle ear). Project through the temporal bone and then through STYLOMASTOID FORAMEN of the temporal bone.
Split into 5 branches to supply to musculature (temporal, zygomatic, buccal, mandibular, cervical)
Sensory pathway for Facial VII
Exit tongue through tiny foramin and synapse on genuclate ganglion.
Origin of Vestibulocochlear VIII
Vestibular branch: hair cells in vestibule of inner ear
Cochlear branch: Cochlea of inner ear
Pathway of Vestibulocochlear VIII
Each branch extends from origin and they merge together, going through INTERNAL ACOUSTIC MEATUS and to nucleus in jxn of pons and medulla
Origin of Glossopharyngeal (IX)
Sensory: taste buds on posterior 1/3 of tongue and mucosa of posterior 1/3 of tongue and carotid bodies
Motor: in nuclei in medulla oblongata
Sensory function of Glossopharyngeal (IX)
general sensation and taste to posterior 1/3 of tongue; general sensation to most of pharynx; chemoreceptor axons to carotid bodies to monitor O2 and CO2 levels in blood
Sensory pathway of Glossopharyngeal (IX)
from posterior 1/3 of tongue and carotid bodies along nerve through inferior or superior ganglion into the JUGULAR FORAMEN, and travel to pons
Somatic motor function of Glossopharyngeal (IX)
Innervates stylopharyngeus (pharynx muscle)
Somatic motor pathway for Glossopharyngeal (IX)
leave cranium through JUGULAR FORAMEN and travel to stylopharyngeus
Parasympathetic function of Glossopharyngeal (IX)
Increase secretion of parotid salivary gland
Parasympathetic pathway of Glossopharyngeal (IX)
Travel to otic ganglion and to parotid gland
Origin of Vagus X
motor in medulla oblongata; sensory information from heart, lungs, and most abdominal organs, acoustic meatus, eardrum, laryngopharynx and larynx
Somatic motor pathway of Vagus X
leave cranium via JUGULAR FORAMEN before traveling and branching in neck, thorax and abdomen
Sensory pathway of Vagus X
cell bodies are located in superior and inferior ganglia associated with the nerve
Origin of Accessory XI
Cranial root: motor nuclei in medulla
Spinal root: motor nuclei in spinal cord
Pathway of Accessory XI Cranial root
Meets up with spinal root in skull and leave through JUGULAR FORAMEN; cranial root splits to meet up with CN X to innervate pharynx muscles
Origin of Hypoglossal XII
Hypoglossal nucleus in medulla oblongata
Pathway of Hypoglossal XII
leaves cranium via HYPOGLOSSAL CANAL; travels inferior to mandible to inferior surface of the tongue
Nerves that pass through the superior orbital fissure?
Oculomotor III, Trochlear IV, Trigeminal V1, Abducens VI
Nerves that pass through Foramen Rotundem
Trigeminal V2
Nerves that pass through Foramen Ovale
Trigeminal V3
Nerves that pass through Internal acoustic meatus
Facial VII, Vestibulocochlear VIII
Nerves that pass through jugular foramen?
Glossopharyngeal IX, Vagus X, Accessory XI
Nerves that pass through Hypoglossal canal
Hypoglossal XII