What connects the lateral ventricle to the third ventricle?
Interventricular foramen of monro
What does the proencephalon develop into?
Telencephalon and Diencephalon
What does the mesenceophalon develop into?
What does the Rhombencephalon develop into?
Metencephalon and Myelencephalon
What is the forebrain?
What is the Midbrain?
What is the hindbrain?
List the ventricles in order.
Lateral ventricle, third, cerebral aqueduct (aqueduct of sylvius), forth, central canal
Where is the lateral ventricles?
Where is the third ventricle?
Where is the cerebral aqueduct of sylvius?
Where is the forth ventricle?
Metencephalon and myelencephalon
What are the lateral apertures? Where do they go? How many are there?
- Foramen of luschka
- Into subarachnoid space of the pontine cistern to the spinal canal
What are the median aperture? Where do they go? How many are there?
- Foramen of Magendie
- Into subarachonid space of the cisterna magna (cebebellomedulary cistern)
What CN's come from the Telencephalon?
What CN's come from the Diencephalon?
What CN's come from Mesencephalon?
What CN's come from Metencephalon?
What CN's come from Myelencephalon?
What structures come from the Telencephalon?
Cerebrum and higher function
What structures come from the Diencephalon?
Thalamus, hypophysis, mamillary body
What strucutres come from Mesencephalon?
Midbrain and everything else
What structures come from the Metencephalon?
pons and cerebellum
What structures come from the Myelencephalon?
What are the lateral ventricles?
1st and 2nd ventricles
What is the roof of the 4th ventricle? What is the floor of the 4th ventricle?
- roof - cerebellum
- floor - pons and medulla
What reabsorbs the CSF?
What separates the lateral ventricles?
What produces CSF?
Choroid plexus - Ependymal cells which line the ventricles
What does the nervous system develop from?
dorsal ectoderm, neural plate --> neural groove --> neural fold --> neural tube --> brain and spinal cord
What forms the neural crest?
Neuroectodermal cells not in the neural tube
What does the neural crest develop into?
- Schwann Cells
- Branchial arches
- Adrenal medulla
- Meisners plexus
- Auerbach plexus
- "SMSM BAD MA"
What neural tissue is the adenohypophysis derived from?
What is the Anterior Pituitary derived from?
Rathke's pouch (ectoderm)
What is the epithelial lining of the posterior 1/3rd of the tongue, floor of the mouth, soft palate, ducts of the sublingual glands and submandibular glands derived from?
What is the epithelial lining of the GI tract derived from?
What are Hepatocytes and the epithelial lining of the biliary tree derived from?
What are the kidneys, testes, ovaries, genital ducts and accessory sex glands derived from?
What are Epidermis, hair, sweat and cutaneous glands derived from?
What are acinar cells, islet cells and the epithelial lining pancreatic ducts derived from?
What are the skeletal muscles of the limbs derived from?
What are CNS derived from?
What is the neurohypophysis derived from?
What is the neural crest derived from?
Ectoderm gives rise to?
Nerves and Epidermis
Endoderm gives rise to?
Respiratory tract and gut
Mesoderm gives rise to?
Where do pharyngeal pouches develop?
In the lateral wall of foregut or pharynx
What does the 1st pharyngeal pouch give rise to?
Epithelial lining of the auditory tube and middle ear cavity
What does the 2nd pharyngeal pouch give rise to?
Epithelial lining of the palatine tonsil crypts
What does the 3rd pharyngeal pouch give rise to?
Inferior parathyroid gland and thymus
What does the 4th pharyngeal pouch give rise to?
Superior parathyroid gland, parafollicular cells of the thyroid
What pouch is CN 5 derived from?
What pouch is CN 7 derived from?
What pouch is CN 9 derived from?
What pouch is CN 10 derived from?
What does the foregut give rise to?
mouth, pharynx, lower respiratory tract, esophagus, stomach, liver, pancreas, duodenum
What does the midgut give rise to?
small intestine, appendix, cecum, ascending colon, transverse colon
What does the hindgut give rise to?
distal 1/3rd of the transverse colon, descending colon, sigmoid colon, rectum
What are the 4 types of support cells in the CNS? What do they do?
- Astrocyte - Blood brain barrier, repair, many functions
- Oligodendrocyte - makes myelin in CNS
- Microglia - macrophage of CNS (engulf foreign and dead particles)
- Ependymal - makes up choroid plexus (line the ventricles)
What type of cell forms myelin sheath around cells in the PNS?
From where are the extensors formed?
hypomere of myotome
What muscles do the epimere of the myotome form?
Those innervated by the dorsal ramus of the spinal nerves (back muscles)
What are the three parts of the mesoderm? What do they form?
- Dermatome --> Dermis
- Sclerotome --> Bone (vertebral column)
- Myotome --> muscle
What controls the skeletal muscles?
What controls the visceral organs?
What is hypomere?
What is the Falx cerebri?
crescent shaped extension of the dura mater, projects between the two cerebral hemispheres
What sinus runs along the Falx Cerebri?
superior sagittal sinus
What are the 4 lobes of the brain? What are their main functions?
- Frontal - motor
- Parietal - evaluation of emotion
- Temporal - hearing and smell
- Occipital - vision
What is the main function of the prefrontal area?
What three sulcus surround and divide the motor and sensory parts of the brain? Name them from ant. to post.
Precentral sulcus, central sulcus of rolando and postcentral sulcus
What is the primary function of the precentral gyrus?
What is the main function of the postcentral gyrus? What is another name for it?
- Anterior parietal lobe
What is Wernickes area? Where is it?
- Sensory speech - Comprehension of words
- Parietal lobe
Where does the blood supply for the brain originate?
- Anterior - Internal carotid artery
- Posterior - Vertebral artery
What is the lowest level that the vertebral that the vertebral artery passes through the transverse foramen?
What artery feeds broca's area?
Middle cerebral artery
What arteries are in the circle of Willis?
Posterior Cerebral, Posterior Communicating, Internal Carotid, Anterior Cerebral, Anterior Communicating
What is the circle of Willis?
where the anterior circulation of the brain meets the posterior circulation
What are the branches of the internal carotid artery?
Anterior cerebral artery, opthalmic artery and middle cerebral artery
Where is the anterior communicating artery?
Between the right and left anterior cerebral arteries
What are the branches of the middle cerebral artery?
Posterior communicating artery and anterior choroidal artery
What are the branches of the vertebral artery?
Posterior Inferior cerebellar artery, Anterior and posterior spinal arteries, basilar artery, posterior meningeal artery
What are the branches of the basilar artery?
- 10 medullary arteries including Anterior inferior cerebellar artery, labyrinthine artery, pontine arteries and superior cerebellar artery
- Also Posterior cerebral arteries
Where do Berry aneurysms occur?
Usually the circle of Willis
Where does the middle cerebral artery supply?
Lateral surface of the cortex
Where does the anterior cerebral artery supply?
Most of the medial surface of the neocortex
Where does the posterior cerebral artery supply?
What is the tentorum cerebelli? What sinus runs in the tentorum cerebelli?
- Dura extension separating the cerebellum from the occipital lobe
- Transverse sinus
What veins empty into the External jugular vein?
Posterior auricular vein and retromandibular vein
What veins empty into the straight sinus?
Inferior sagittal and great vein of Galen (great cerebral vein)
What veins empty into the Confluence of the sinuses?
Superior sagittal sinus, occipital sinus, straight sinus
Where does blood flow from the confluence of the sinuses?
to the transverse sinus then the sigmoid sinus
Where does blood go from the sup. and inf. petrosal sinuses?
- sigmoid sinus --> internal jugular vein --> subclavian vein
- "internal jugular vein drains the brain
What are the three types of fibers in the cerebrum and what do they do?
- Association fibers - connect regions of the same hemisphere
- Commissural fibers - connect the right and left cerebral hemispheres
- Projection fibers - send information to other parts of the brain and spinal cord
What lobe is the precentral gyrus in? What special cells does it have? What are the functions of this gyrus?
- Betz cells in 4th layer
- Voluntary motor, origin of corticospinal tract
What lobe is the postcentral gyrus in? What are the functions of this gyrus? What areas is it?
- Parietal (anterior)
- Primary somesthetic (sensory) area, receives fibers from the thalamus
What lobe is the prefrontal gyrus in? What are the functions of this gyrus? What areas is it?
- Social Interaction
What lobe is the Broca's area in? What are the functions of this gyrus? Where is it? What would a lesion here cause?
- Motor speech
- Left area 44 (interior frontal gyrus)
- Motor aphasia
What lobe is the Transverse temporal gyrus in? What are the functions of this gyrus?
What lobe is the Angular gyrus in?
What lobe is the uncus in? What are the functions of the uncus?
- "I smell a skuncus in the uncus"
What lobe is the Calcarine sulcus in? What are the functions of it?
- Vision (along with visual cortex)
What pathway brings information into the brain from the body?
What pathway brings info. from the spinal cord/brain to the body?
What part of the face covers the largest area of the sensory part of the neocortex?
What is the main function of the cerebellum?
unconscious coordination of muscle movements
Name the four cerebellar nuclei from medial to lateral.
- Dentate (the largest and most lateral)
- "Fat Guy's Eat Doughnuts"
What are the three layers of the cerebellum?
What are the three lobes of the cerebellum and their function?
- Flocculonodular - equilibrium
- Anterior - proprioception (unconscious, spinocerebellar tract)
- Posterior - fine motor skills
What are the three different types of fibers that enter the cerebellum and what is their function?
- Superior cerebellar peduncle - connects the cerebellum and cerebrum
- Pontocerebellar fibers (middle cerebellar peduncle) - connects the cerebellum and the pons
- Infereior cerebellar peduncle (climbing fibers) - come from the inferior olivary nucleus of the medulla
- "Climb the olive tree"
Name the 12 cranial nerves.
- 1. Olfactory
- 2. Optic
- 3. Oculomotor
- 4. Trochlear
- 5. Trigeminal
- 6. Abducens
- 7. Facial
- 8. Vestibulocochlear
- 9. Glossopharyngeal
- 10. Vagus
- 11. Accessory nerve (cranial root and spinal root)
- 12. Hypoglossal nerve
Where is the decussation of the pyramids?
What is another name for the corticospinal tract?
What is the lateral geniculate body involved in?
What is the medial geniculate body involved in?
What is the superior colliculus involved in?
What cranial nerve comes off dorsal to the brainstem?
Trochlear (CN IV)
What pathway does sight follow?
Rods and cones (layer 2) --> bipolar cells --> ganglion cells of the retina --> Optic nerve --> Optic chiasm --> optic tract --> lateral geniculate body --> Superior colliculus (visual motor functions) and calcarine cortex of occipital lobe (via the geniculocalcarine tract)
What pathway does hearing follow?
- Spiral organ of corti --> CN VIII (cochlear nucleus) --> Lateral lemniscus (through trapezoid body) --> Inferior colliculus --> medial geniculate body --> temporal lobe of the cortex
- LIME = Lateral, Inferior, Medial, Ear
Where are the Superior and inferior colliculi located?
What is the obex?
The fold at the bottom of the 4th ventricle
Where are the geniculate bodies located?
Lateral to the colliculi in the dorsal mesencephalon
What is the main function of the pons?
To relay fibers going to the cerebellum (pontocerebellar fibers via the Middle cerebellar peduncle)
Where is the pons located?
- Superior to the medulla oblongata
- Ventral to the cerebellum
- Inferior to the midbrain
Where is the medulla oblongata located?
Caudal to the pons
What two important structures does the medulla oblongata contain?
Olives and the pyramids
What is the main function of the basal ganglia?
Background muscle tone
What 4 structures are in the basal ganglia?
- Lentiform nucleus
- Caudate nucleus
- Substantia Nigra
What makes up the lentiform nucleus?
Where do fibers from the globus pallidus terminate?
What does a lesion of the basal ganglia cause?
Parkinson's disease (Paralysis agitans)
What does a lesion in the basal ganglia result in?
No dopamine in substantia nigra
What are the symptoms of Parkinson's?
- Resting tremor
- Festinating gate
- Toe walk
- Mask face
What is another name for the anterior pituitary? What is it derived from?
- Rathke's Pouch (oral ectoderm)
What is the link between the CNS and the Adenohypophysis?
Hypophyseal Portal system (blood)
What is another name for the Posterior pituitary? What type of tissue is it?
- nerve tissue
Where are oxytocin and ADH (Vasopressin) formed? Where are they released?
- Formed in hypothalamus
- Released by posterior pituitary
What is the thalamus?
The major sensory integration center, it recives all senses except smell prior to the cortex
Sensory fibers ascend through the thalamus to where?
the sensory cortex via the Internal capsule
What part of the thalamus recieves input from the cerebellum?
What part of the thalamus is a synaptic region for ascending spinal sensory pathways?
What part of the thalamus projects to sensory areas of the parietal and temporal lobes?
What are the main functions of the thalamus?
Temperature regulation, thirst, hunger, defensive reactions
What hormones does the hypothalamus produce?
GHRH, GHIH (somatostatin), CRH, TRH, GnRH (LHRH), PRH, PIH
What does GHRH do?
Stimulates the anterior pituitary to release growth hormone which stimulates the liver to produce somatomedians
What does GHIH do?
Decrease the production of GH
What does CRH do?
Stimulates the anterior pituitary to release ACTH which stimulates the adrenal gland to produce Glucocorticoids, mineralcorticoids and androgens
What does TRH do?
Stimulates the anterior pituitary to release TSH which stimulates the follicular cells of the thyroid to produce thyroxine
What does GnRH (LHRH) do?
- Stimulates the anterior pituitary to release FSH and LH
- FSH in females stimulates the ovaries to produce estrogen
- FSH in males stimulates the production of sperm
- LH in females stimulates the production of progesterone and estrogen and stimulates the development of the ovum
- LH in males stimulates the production of testosterone
What does PRH do?
Stimulates the anterior pituitary to release Prolactin which stimulate the breast to produce milk (oxytocin stimulates the release of milk)
What does PIH do?
Decreases the production of Prolactin
What effect does osmolarity and Na+ have on the paraventricular and supraoptic nuclei?
- High osmolarity will stimulate the paraventricular and supraoptic nuclei
- High Na+ will only stimulate the paraventricular nucleus
- Both release ADH (vasopressin)
Which cranial nerves are parasympathetic?
CN III, VII, IX, X
The vagus nerve supplies parasympathetic to how much of the body?
Where does CN I exit the skull?
Ethmoid bone (cribiriform plate)
Where does CN II exit the skull?
What CN constricts the pupils?
Where does the trigeminal nerve exit the skull?
- Opthalmic division (I) - Superior orbital fissure
- Maxillary division (II) - Foramen rotundum
- Mandibular division (III) - Foramen ovale
What cranial nerves exit through the superior orbital fissure?
III, IV, V1, VI
What is the function of CN V?
General nose sensation, Senosry to face, Motor to muscles of mastication
What is the function of CN VII?
Taste to ant. 2/3 tongue, muscles of fascial expression
What CN's exit the skull through the internal auditory meatus?
What CN's exit through the jugular foramen?
IX, X, XI
What is the function of CN IX?
Stylopharyngeus muscle (motor), taste to post. 1/3 of tongue
What is the function of CN XI?
SCM, trapezius motor
Where does CN XII exit the skull?
What is the function of CN XII?
Motor to the tongue
Which CN's are sensory only?
I, II, VIII
Which CN's are motor only?
III, IV, VI, XI, XII
Which CN's are both motor and sensory?
V, VII, IX, X
What CN is the greater petrosal/intermediate nerve associated with?
What is the chorda tympani?
Branch of CN 7 which carries taste
Pathway of CN VII.
- Internal acoustic meatus --> lacrimal gland, stapedius, taste (ant. 2/3), submaxillary and submandibular glands
- --> Stylomastoid foramen --> facial muscles
What CN innervates the tounge muscles?
CN XII innervates all but palatoglossus which is innervated by CN X
What nerve innervates the Styloglossus? What does this muscle do?
- CN XII
- Retract and elevate tongue
What nerve innervates the Genioglossus? What does this muscle do?
What muscle closes the mouth? What muscle opens the mouth?
- Medial (internal) pterygoid closes
- Lateral (external) pterygoid opens
What are the muscles of the TMJ and what CN innervates them?
- Buccinator (VII), Internal Pterygoid (V), Temporalis (V), External Pterygoid (V), Masseter (V)
What part of the neuron conducts impulses toward the cell body?
What part of the neuron conducts impulses away from the cell body?
What is a nucleus?
A group of neuron cell bodies in the CNS
What is a ganglion?
A group of cell bodies in the PNS
What is the function of unipolar cells?
Sensory, cell bodies in DRG
What is the function of bipolar cells?
What is the function of multipolar cells?
Most neurons, motor and interneurons
What type of fibers are big and myelinated?
A Alpha fibers
What type of fibers are small and unmyelinated?
A Delta and C fibers
What are the 4 main types of sensory receptors?
Pain, temperature, touch, proprioception
What are pain receptors?
Nociceptors, free nerve endings, non-encapsulated
What are the two types of temperature receptors?
Krause (cold) and Ruffini (hot)
What are the 4 types of touch receptors?
- Merkel discs (non-encapsulated)
- Meissner corpuscles
- Pacinian corpuscles (pressure)
- Peritrichial nerve endings
What are the two main proprioception receptors?
- Muscle spindles (stretch --> triggers muscle to contract)
- Golgi tendon organs (protective, stretch --> triggers muscle to relax)
What are the two enlargements of the spinal cord?
Cervical enlargement (1-3cm) and lumbar enlargement (1-2cm)
What is the conus medullaris?
The end of the cord (at L1-2 level)
What is the lumbar cistern?
- Subarachnoid space from L2 to S2
- Contains the Cauda Equina (ends at S2)
List the meninges from inside to outside.
Pia, arachnoid, dura (PAD)
What is the Leptomeninx?
- Pia and arachnoid
- "Leprachaun peed on a spider"
What is Pachymeninx?
What are the three major projects of dura mater into brain fissure?
- Falx cerebri - between the cerebral hemispheres
- Tentorium cerebelli - between the cerebellum and cerebrum
- Falx cerebelli - between the cerebellar hemispheres
Where are arachnoid granulations?
In the subarachnoid space where CSF is located
What are the two many functions of the pia mater?
- Denticulate ligaments which hold the spinal cord in place (tooth-like projections)
- Filum terminale interna at a the end of the spinal cord is pia only
What are the three names for the posterior plate of a spinal cord?
Dorsal, alar, sensory plate
What are the three names for the anterior plate of the spinal cord?
Basal, Ventral, Motor plate
What do the dorsal primary rami innervate?
Postural muscles, back
What is the DRG?
Dorsal root ganglion - cell bodies of somatosensory neurons
What plexuses come from the ventral primary rami?
cervical, brachial, lumbar, sacral
What is the sulcus limitans?
separation between the sensory (alar) and the motor (basal) plate
What is the mantle layer of the spinal cord?
What is the marginal layer of the spinal cord?
What is gray matter made of?
lamina and nuclei
What lamina are in the posterior horn?
1 to 6
What is lamina 2?
What lamina are in the anterior horn?
8 and 9
Where are the cell bodies of the lower motor neurons?
Anterior horn of the spinal cord
Where do neurons to axial muscle originate?
What does lamina 7 contain?
Lateral horn or intermediaolateral cell column
Where do sympathetic fibers originate?
lateral horn of T1 to L2
Where do parasympathetic fibers originate?
Cranial nerves 3, 7, 9, 10 and S2,S3,S4
The sympathetic and parasympathetic are part of what nervous system?
What does the anterolateral tract contain?
Spinothalamic and spinoreticular tracts
Where is the lateral corticospinal tract?
Dorsolateral part of spinal cord
Where is the Ventral corticospinal tract?
Medial, ventral part of spinal cord
What makes up the dorsal columns?
Fasiculus Gracilis (legs) and Fasciculus cuneatus (arms)
What is the pathway for the dorsal columns? What is another name for it?
- Upper limb unconscious proprioception: DRG --> Fasiculus --> nuclei --> Accessory cuneate nucleus --> inf. cerebellar peduncle --> cerebellum
- Lower limb unconscious proprioception: DRG --> Dorsal nucleus of clark (lamina VII, C8 to L3) --> Dorsal spinocerebellar tract --> cerebellum
- All others: DRG --> Fasiculus --> nuclei --> Medial lemniscus --> Thalamus (VPL) --> postcentral gyrus (somatosensory)
- Medial leminiscal system
What parts of dorsal column/ML pathway are ipsilateral? Contralateral?
- Lower limb unconscious proprioception, whole limbs is ipsilateral (crosses over twice)
- Lower limb unconscious proprioception, individual muscles and all others are contralateral
What is the function of the dorsal columns?
Conscious and unconscous proprioception, vibration, 2 point discrimination
What is the function of the posterior spinocerebellar tract?
Unconscious proprioception to the cerebellum from lower limbs
What is the function of the anterior spinocerebellar?
stretch from spindle cells of lower limbs
What is the spinocerebellar pathway?
DRG --> nucleus of clark C8 to L3 --> inferior cerebellar peduncle --> cerebrum
What causes Fredeicks ataxia?
damage to the spinocerebellar pathway
What does the lateral spinothalamic pathway carry?
pain and temperature
What does the anterior spinothalamic pathway carry?
Light touch and pressure
What is the spinothalamic pathway?
First order neuron to DRG (2nd order synapse) --> crosses over --> 2nd order neuron to medulla then midbrain then thalamus (3rd order synapse) --> 3rd order neuron to somesthetic area of cortex (post central gyrus)
Where is the 2nd order synapse for the spinothalamic tract?
Lamina 4,5,6 (nucleus proprius)
What type of fibers are the anterior spinothalamic 1st order neurons?
A beta fibers
What type of fibers are the lateral spinothalamic 1st order neurons?
A delta and C fibers
What does the spinotectal pathway carry?
Tactile stimulation causing visual reflexes
What is the spinotectal pathway?
DRG --> crosses over --> tectum (superior colliculus)
What does the spinoreticular pathway carry?
What is the spinoreticular pathway? What is another name for it?
- Same as spinothalamic except it also synapses in the reticular formation and hypothalamus as well as the thalamus
- Paleospinothalmic tract
What are the pyramidal tracts?
Lateral and anterior corticospinal tracts
What is the function of the corticospinal tract?
Conscious, voluntary motor movements form the cerebral cortex of Giant cells (betz cells) especially fine movements of the hands
What will a lesion in the corticospinal tract cause?
What is the lateral corticospinal pathway?
Motor cortex --> contralateral pyramid (lower medulla - dexussation of pyramids) --> spinal cord anterior horn
What is the anterior corticospinal pathway?
Motor cortex --> ipsilateral medulla --> contralateral spinal cord anterior horn (crosses at level of muscle)
What % of the corticospinal tract is lateral? anterior?
What descending tracts are extra pyramidal tracts?
Rubrospinal, Reticulospinal, Vestibulospinal, Tectospinal
What does the rubrospinal tract do?
Facilitates flexors, inhibits extensors, coordinates movements
Where does the rubrospinal tract originate?
Red nucleus in tegmentum (floor of the midbrain)
What is unique about the rubrospinal tract?
Some fibers can cross at termination
What does the reticulospinal tract do?
Control of respiration and heartbeat, faciliate muscles, inhibit antagonists (Involuntary) - unconscious focusing while maintaining balance
Where does the reticulospinal tract orginate?
What does the vestibulospinal tract do?
- Posture and balance
- Head and eye coordinated movement
- Extension of erector spinae
- Truns head toward sight and sound
Where does the vestibulospinal tract originate?
What does the tectospinal tract do?
Postrual reflexes to sight and sound
Where does the tectospinal pathway originate?
tectum of midbrain (superior colliculus)
What is an upper motor neuron lesion?
Lesion that involves any central neuron conveying impulses to the anterior horn (from brain to anterior horn but does NOT include the anterior horn cell)
What is a lower motor neuron lesion?
Involves the anterior horn cell, the anterior roots of the peripheral nerve
What are the symptoms of an UMNL?
Spastic paralysis, increased muscle tone, hyperreflexia, pathological reflexes
What are the symptoms of an LMNL?
Flaccid paralysis, decreased muscle tone, hyporeflexia, NO pathological reflexes
What is a preganglionic neuron?
- Visceral efferent neuron whose cell body is in the brain or spinal cord
- Terminates at an autonomic ganglion where it synapses with a postganglionic neuron
What is a postganlionic neuron?
- Lies entirely outside the CNS
- Cell body is located in an autonomic ganglion
- Unmyelinated axon, terminates in a visceral effector
What preganglionic neuron does not end on an autonomic ganglion?
Sympathetic innervation to the adrenal medulla (releases Norepinephrine and Epinephrine)
What does cholinergic mean?
That the neuron uses acetylcholine as a neurotransmitter
What does adrenergic mean?
That a neuron uses epinephrine and norepinephrine as a neurotransmitter
What nerves in the autonomic nervous system are cholinergic?
- All parasympathetic
- Preganglionic sympathetic
- Postganglionic sympathetic to sweat glands, erector pilae and blood vessels
What nerves in the autonomic nervous system are adrenergic?
Sympathetic postganglionic to smooth muscle, cardiac muscle and glands
What is the parasympathetic nervous system?
- Wine and Dine system - rest and digest
What is the pathway of CN 3 parasympathetic fibers?
- Preganglionic to ciliary ganglion
- Postganglionic to Intrinsic eye muscles (sphincter pupillae - consticts, ciliary muscle)
What is the pathway of CN 7 parasympathetic fibers?
- Preganglionic to Submandibular/Pterygopalatine ganglion
- Postganglionic to lacrimal and salivary glands (tears)
What is the pathway of CN 9 parasympathetic fibers?
- Preganglionic to otic ganglion
- Postganglionic to parotid gland (stensons duct - opposite second molar)
What is the pathway of CN 10 parasympathetic fibers?
- Preganglionic to myenteric and auerbach plexus
- Postganglionic to smooth muscle and glands of the thoracoabdominal cavity up to the left colic/splenic flexure
What is the pathway of S2,S3,S4 parasympathetic fibers?
- Preganglionic to pelvic plexus via pelvic splachnics of hypogastric plexus
- Postganglionic to colon below the splenic flexure (descending colon, sigmoid, rectum), sex organs, kidney, bladder
What are the main functions of the 4 parasympathetic cranial nerves?
- CN 3 - pupil and ciliary body constriction
- CN 7 - tearing and salivation
- CN 9 - salivation
- CN 10 - vagus
What nerves are needed to maintain an erection?
- Parasympathetic (S2, S3, S4)
- "S2,3,4, keep your penis off the floor
How does the parasympathetic system effect the body? (6)
- Constricts eye pupil
- Increases secretions of lacrimal gland (tears)
- Increases saliva in all salivary glands
- Bronchoconstriction of larynx, trachea, bronchii, lungs
- Decreases heart rate
- Increases digestive activity
What is the Sympathetic nervous system?
- "fight or flight" system
Fate of sympathetic fibers. (3)
- Fibers go to paravertebral sympathetic chains (pre --> post here) then out to organs
- Fibers leave the sympathetic chain without synapsing and leave via splanchnic nerves to synapse at a prevertebral splanchnic ganglion
- Innervate the adrenal medulla
What innervation do blood vessels have?
- Arteries and veins have sympathetic only, capillaries have no innervation
- Blood vessels have NO parasympathetic innervation
What are the splanchnic nerves and what levels do they come from?
- T5-T9 --> greater splanchnic nerve
- T10-T11 --> lesser splanchnic nerve
- T12 --> least splanchnic nerve
- L1-L3 --> Lumbar splanchnic nerve
What are the 4 splanchnic ganglion and what organs do they go to?
- Greater: celiac --> thoracoabdominal cavity through the small intestine
- Lesser: superior mesenteric --> ascending colon
- Least: superior mesenteric --> ascending colon
- Lumbar: inferior mesenteric --> descending colon, sigmoid, rectum, sex organs, bladder
What does the superior cervical ganglion do?
- Dilates eye
- Stimulates tear production
- Squeezes out saliva from glands then cuts off blood supply to salivary glands --> dry mouth
What does the malleus attach to?
What does the incus attach to?
malleus and stapes
What does the stapes attach to?
What are the main parts of the inner ear?
Cochlea and semicircular canals and vestibule
The auditory/eustachian tube is part of what?
What are the boundaries of the middle ear?
Tympanic membrane to the oval and round window of the inner ear
Name the ear bones from tympanic membrane to oval window.
- Malleus, Incus, Stapes
- "can't MIS the order of the bones"
What does the posterior wall of the middle ear communicate with?
Mastoid air cells
What does the anterior wall of the middle ear open to?
What is the vestibule of the ear?
The central part of the bony labyrinth, contains the utricle and saccule
What are the semicicular canals?
Canals (3) which open into the posterior part of the vestibule. Each canal has a swelling at one end called the christa ampullaris
What is the cochlea?
resembles a snail shell, opens into the anterior part of the vestibule, it consists of a central pillar called the modiolus which is perforated by the cochlear nerve
What does the basilar membrane of the ear do? What does it line?
- seperates the cochlea into two canals: the scala vestibuli (above) and the scala tympani (below)
- spiral organ of corti
What is the bony labyrinth?
cavities within the bone, they each contain fluid called perilymph (between membranous and bony labyrinth)
What is the membranous labyrinth?
- Within the boney, consists of utricle, saccule and three semicircular ducts (inside the canals) and the duct of the cochlea
- filled with endolymph
How is sound heard?
- Vibration of the ossicles in the middle ear push the oval window and cause waves of in the fluid of the cochlea
- These waves move the hair cells on the spiral organ of corti and stimulate nerve impulases via CN VIII to the cochlea nucleus
What is the purpose of the saccule?
- static equilibrium and linear acceleration
- lying down or horizontal
What is the purpose of the utricle?
- Static equilibrium and linear acceleration
- standing or vertical
What is the macula?
thickening on the saccule and utricle walls
What are sterocilia and kinocilium?
- Ends of hair cells in the macula which extend through an otolithic membrane
- When you move your head the otolithic membrane slides and stimulates the hair cells which are connected to CN VIII
What do semicircular canals detect?
- rotational movement in three planes (rotational, circular and angular) - dynamic equilibrium
- Anterior and posterior canal - vertical
- Lateral canal - horizontal
What is the ampulla?
- Dilated portion of each duct, contains crista (hair cells covered with gel called cupula)
- As you rotate your head hair cells move in the gel and stimulate the vestibular part of CN VIII
What is chemoreceptor sense?
smell (chemicals stimulate the sense)
Where does smell go?
- NOT through the thalamus
- Olfactory bulb, limbic system
Where is the emotional part of smell?
Uncus of the anterior parahippocampus
Pathway of smell
Fila olfactoria (Olfactory neurosensory neuron, CN I) --> cribiform plate of ethmoid bone --> olfactory bulb (mitral cells) --> uncus
What are the three nasal meatuses and what drains into them?
- Superior (olfactory epithelium) - posterior ethmoidal air cells
- Middle - Maxillary and frontal
- Inferior - Nasolacrimal
What are the nasal meatuses and concha?
- Nasal meatuses - spaces found between the nasal concha
- Superior and middle concha - on ethmoid bone
- Inferior concha - own process (not part of ethmoid bone)
What is the olfactory bulb an extension of?
What are the functional cells of smell?
Mitral and tufted cells
What type of neurons project through the cribiform plate?
What type of cells make up the olfactory bulb and tract?
What are the two types of interneurons?
- periglomerular cells - spread the impulse around
- granule cells - have only dendrites (no axons) (dendrodendritic synapses)
Layers of the eye out to inner
- sclera (continuation of the conjunctiva)
- choroid (vascular layer)
- Uvea (choroid, ciliary body and iris - all pigmented)
- Retina (rods = black and white vision, peripheral vision; cones = color vision, concentrated in the macula)
What happens when ciliary muscles contract?
suspensory ligaments relax and the lens becomes convex (spherical)
What are the three chambers of the eye?
- Anterior - cornea to iris (CIA)
- Posterior - Iris to lens
- Vitreous - lens to retina
What does the posterior chamber contain?
Ciliary body which produces aqueous humor
What is the flow of aqueous humor? What will a blockage cause?
Posterior chamber to anterior chamber and out Canal of Schlemm to venous system (blockage at Canal of Schlemm --> Glaucoma)
Where are cones the most concentrated?
Macula lutea and fovea centralis (center of the macula)
What is the optic disc?
Blind spot which allows the passage of vessels and optic nerve out of eye, the retina develops from here
What artery supplies the eye?
What reaction does the pupillary light reflex cause?
- CN II sees the light
- Parasympathetic from Edinger Westphal nucleus send signals through CN III to constrict the pupil
- CN III causes the reaction
How will Argyll-Robertson pupil present?
Pupil accomodates but does not react
What type of cells is the retina made of?
Extraocular muscles are supplied by?
SO4 LR6, the rest are CN III
What occurs in accomodation?
- Convergence of eyes
- Constriction of pupil
- Contraction of the lens
Which CN opens the eye? Which closes?
- CN III opens
- CN VII closes
What are the four types of partial vision loss? What part of the vision is lost in each?
- Anopsia of one eye - vision is lost completely in one eye and remains normal in the other
- Right nasal hemianopsia - vision is lost in the nasal half of the vision field in right eye
- Bitemporal hemianopsia - vision lost in the temporal half of the vision field in both eyes
- Left homonymous hemianopsia - Loss of the left half of the vision field in both eyes
Where does vision from the superior retina go?
Parietal lobe optic radiation to the area above the calcarine fissure
Where does vision from the inferior retina go?
Temporal lob optic radiation to the area below the calcarine fissure
Where does vision from the left half of each retina go?
To the left side of the brain
Where do objects in right visual field go?
Left side of the brain
Damage to the optic chiasm will cause vision loss where?
In the temporal fields of vision (nasal part of retina)
Damage to the left optic nerve will cause vision loss where?
Damage to the left optic tract will cause vision loss where?
Right visual field in both eyes
Damage to the left temporal lobe optic radiation will cause vision loss where?
Superior half of right visual field in both eyes
What does the endoneurium do?
surrounds individual nerve fibers
What does the perineurium do?
Surrounds small bundles or fascicles of fibers
What does epineurium do?
Surrounds the entire nerve
What nerves innervate the diaphragm?
C3,4,5 (phrenic nerve) - "C3,4,5 keeps the diaphragm alive"
What nerves innervate the SCM and trapezius?
CN XI and C1-5
What nerves are in the cervical plexus?
Where cutaneous (sensory) nerves does the cervical plexus supply?
- Small/lesser occipital nerve from C2
- Great auricular nerve
- Transverse cervical (anterior cutaneous) nerve
- Supraclavicular nerve (top of shoulders)
What nerves make up the brachial plexus?
Ventral rami of C5-T1
Where does the axillary nerve come from? What does it supply?
- Off of the posterior cord of the brachial plexus
- Motor: Teres Minor, Deltoid
- Sensory: Anterior shoulder
Where does the musculocutaneous nerve come from? What does it supply?
- Off of the lateral cord, accompanies the radial artery
- Motor: Coracobrachialis, biceps, brachialis (forearm flexors)
- Sensory: Anterior forearm
Where does the Median nerve come from? What does it supply?
- Off medial and lateral cord, accompanies brachial artery
- Motor: Wrist flexors and pronators, thenar muscles
- Sensory: First 3.5 digits and palm
What does a lesion of the median nerve cause? Ulnar nerve? Radial nerve?
- Median --> Ape hand
- Ulnar --> Claw hand
- Radial --> wrist Drop
- "Dr. Cu Ma"
Where does the Ulnar nerve come from? What does it supply?
- Off medial cord
- Motor: Hand interossei and lumbricals, hypothenar muscles, thumb adduction
- Sensory: Pinky and 1/2 of ring finger
Where does the Radial nerve come from? What does it supply?
- Off posterior cord
- Largest branch
- Motor: Forearm and wrist extensors and supinators, tumb extension
- Sensory: Posterior arm and hand
What is another name for the long thoracic nerve? What does it supply?
- External respiratory nerve of bell
- Motor: serratus anterior
What does the suprascapular nerve supply?
Supra and infra spinatus
What does the medial and lateral pectoral supply?
- Medial --> Pec major and minor
- Lateral --> Pec major only
Where does the Thoracodorsal nerve come from? What does it supply?
- Off posterior cord
- Also called Middle subscapularis
- Motor: Latissimus dorsi
Summary of which nerves come from which cord.
- PART: Posterior --> Axillary, Radial, Thoracodorsal
- MUM: Middle --> Ulnar, 1/2 of Median
- LMM: Lateral --> 1/2 of Median, Musculocutaneous
Summary of thumb movements.
- Radial --> Extension
- Ulnar --> Adduction
- Median --> Flexion (opposition)
What nerves are part of the lumbar plexus?
T12 to L4
What supplies the ilioinguinal nerve?
What supplies the genitofemoral nerve?
What supplies the Lateral femoral cutaneous nerve?
- "She's 23 and too CUTe for me"
What supplies the Femoral nerve?
What supplies the obturator nerve?
What nerves make up the sacral plexus?
L4 to S3
What nerves are in the lumbosacral trunk?
What supplies the superior gluteal nerve?
What supplies the Inferior gluteal nerve?
L5 to S2
What supplies the posterior femoral cutaneous nerve?
What makes up the sciatic nerve?
Common peroneal and tibial nerves, L4 to S3
What bones are in the axial skeleton?
Skull, vertebral column, ribs, sternum and hyoid
Which skull bones are paired?
Temporal, parietal, maxilla, nasal, lacrimal, inferior concha, zygomatic
Which skull bones are not paired?
Frontal, occipital, mandible, sphenoid, ethmoid (includes cribiform plate and superior and middle concha)
What bones are part of the eye?
Zygomatic, frontal, lacrimal, ethmoid, maxilla, sphenoid
What type of joint are sutures?
What does the coronal suture separate?
frontal from parietal bones
What does the sagittal suture separate?
2 parietal bones
What does the squamous suture separate?
temporal from parietal bones
What does the lambdoidal suture separate?
occipital from parietal
What does the internasal suture separate?
2 nasal bones
What does the intermaxillary suture separate?
2 maxillary bones
What does the frontonasal suture separate?
Frontal and nasal bones
What does the occipitomastoid suture separate?
occiput from the mastoid
What does the parietomastoid suture separate?
parietal from the mastoid
What is the bregma?
Intersection of the coronal and sagittal sutures
What is the glabella?
flattened triangular area of the forehead
What is the nasion?
Intersection of frontal and nasal sutures
What is the pterion?
Intersection of the frontal, sphenoid, temporal and parietal bones
What is the asterion?
Intersection of squamous and lambdoid sutures and the mastoid sutures
What is lambda?
Intersection of lambdoid and sagittal sutures
How many vertebrae are there?
- 24 moveable (7 cervical, 12 thoracic, 5 lumbar)
- Sacrum, coccyx
How many spinal and cranial nerves are there? Where do they exit?
- 31 pairs of spinal nerves
- 12 cranial nerves
- Cervical nerves 1-7 exit above the corresponding veretebra, all others exit below, Cervical nerve 8 exits between C7 and T1
What part of the spine is made up of IVDs?
Which vertebra are typical?
C3-6, T2-8, L1-4
Typical cervical vertebra.
- Oval body
- Triangular spinal canal
- Joint plane coronal 45 degrees
- Superior facet direction is posterosuperior, slightly medial
Typical thoracic vertebra.
- heart-shaped body
- oval spinal canal
- joint plane coronal 65 degrees
- Superior facet direction is posterosuperior, slightly lateral
Typical lumbar vertebra.
- kidney-shaped body
- triangular spinal canal
- Joint plane is sagittal 90 degrees
- Superior facet direction is posteromedial
Which cervicals have a bifurcated Spinous?
What are joints of luschka? Where are they found?
- Uncovertebral joints
- C2/3 to C6/7
Which joints of the spine have the most mechanoreceptors?
Zygaphophyseal joints of cervicals
Which TP has the carotid tubercle?
Which vertebra have transverse foramen?
C1-7 but vertebral artery does not always pass through C7 foramen, usually starts at C6
What forms the IVF?
- Posterior border: articular pillars (facet)
- Roof and floor: pedicles (inferior vertebral notch of the vertebra above and the superior vertebral notch of the vertebra below)
- Anterior: uncinate processes (body and IVD)
Which veretebra are atypical?
C1, C2, C7, T1, T9-12, L5, sacrum, coccyx (11 total)
Where does the longus coli muscle insert?
anterior tubercle of atlas
Where is the groove for the suboccipital nerve and vertebral artery?
Superior aspect of the posterior arch of atlas
What is the fovea denatalis?
groove on the posterior surface of the anterior arch, dens fits in it
What is tropism? Where is it most common?
assymetrical facets, most common at L5/S1 (one coronal, one sagittal)
What is sacralization? lumbarization?
- sacralization - incomplete separation of L5 and sacrum
- lumbarization - S1 separates from sacrum
What are the major parts of the sacrum? What are they analogous to?
- Median crest - SPs
- Intermediate crest - articular pillars
- Lateral crest - TPs
- Sacral promentory - anterior portion of the most superior aspect
- Cornu - horn
Which ribs are typical? what do they articulate with?
- Ribs 2-9
- superior demifacet of corresponding vertebra
- inferior demifacet of vertebra above
- full costal facet on the TP articulates with rib tubercle
Which ribs are true ribs?
Which ribs are false ribs?
Which ribs are floating?
11 and 12
Which ribs articulate with one rib?
1, 10, 11, 12 (all have a 1 in them)
What type of joints do the ribs participate in?
- costovertebral and costotransverse - gliding
- costochondral - cartilaginous
What is the pars interarticularis?
region of bone between the superior articular process and the inferior articular process
What is a good rule of thumb for determining how superficial a back muslce is?
Loner muscles are more superficial
What are the actions of rhomboideus major and minor?
- major - adduct scapula
- minor - retracts scapula
What are the three erector spinae (layer IV) muscles?
- Iliocostalis - most lateral, attaches to ribs, no attachement to vertebra
- Spinalis - most medial
- "I Love Spinal!"
What muscles are in layer 1 of the back muscles?
Trapezius, latissimus dorsi
What muscles are in layer 2 of back muscles?
Rhomboideus major and minor, levator scapulae
What muscles are in layer III of the back muscles?
Splenius capitis and cervicis, serratus posterior superior and inferior
What muslces are in layer V of the back muscles?
All other back muscles not mentioned for layers I to IV (transverse spinal, sub-occipital, anterior vertebral, lateral vertebral)
Where does the rectus capitis anterior originate?
lateral mass of occiput
Where does the psoas major insert?
Where does the iliacus originate and insert?
- origin - iliac crest and sacrum
- insertion - psoas major
What layer is the levator costorum in?
layer 5 (lateral vertebral)
What nerve supplies the suboccipital triangle?
Posterior primary divison of C1
What runs through the suboccipital triangle?
vertebral artery and 1st cervical nerve (suboccipital)
What is another name for the lumbar triangle? What are its boundaries?
- Lateral: external oblique
- Medial: latissimus dorsi
- Inferior: iliac crest
- Floor: Internal oblique
What are the boundaries of the triangle of auscultation?
- Medial: traps
- Inferior: lats
- Lateral: medial scapula
At what level is the PSIS? Iliac crest?
- PSIS - S2
- Iliac crest - L4
What are the 9 common ligaments of the spine?
IVD, ALL (anterior longitudinal), PLL (posterior longitudinal), Capsular, Interspinous, Supraspinous, Ligamentum nuchae, Intertransverse, Ligamentum flavum
What is the IVD made of? Where do its parts originate from? What is its function?
- fibrocartilage (symphysis joint)
- Annulus fibrosis - from sclerotome
- nucleus pulposis - from notochord
- resists flexion and extension and all motions of the spine
What is the tectoral membrane a continuation of?
What is the function of the PLL? Where is it located?
- prevent the disc from herniating into the vertebral canal
- posterior to the body, on the anterior part of the vertebral canal
Where is the interspinous ligmament?
between the spinous processes
Where is the supraspinous ligament? What does it become?
- lays over the spinous processes
- above C7 it is the nuchal ligament
What si the function of the intertransverse ligament?
resist lateral flexion (runs TP to TP)
Hypertrophy of what ligament will cause canal stenosis?
ligamentum flavum (yellow ligament)
Where is the yellow ligament? What is its function? What is unique about it?
- runs from lamina to lamina in posterior portion of vertebral canal (it is inside the canal)
- strengthens the medial aspect of the zygapophyseal joint and resists flexion
- only elastic ligament in the body
Where does the tectoral membrane attach?
C2 to foramen magnum, superior continuation of PLL
What is another name for the alar ligament? Where does it attach?
check ligament, attaches the occipital condyles to dens, limits rotation of axis
What is another name for the apical ligament? Where does it attach?
suspensory ligament, attaches the dens to the foramen magnum
What is the purpose of the transverse ligament?
Holds the odontoid (dens) to atlas in the fovea dentalis
What membrane has the greatest tendency to ossify?
posterior atlantooccipital membrane
What is the denticulate ligament?
extension of pia
What does the sacrotuberous ligament do? Where does it attach?
resists flexion, attaches the sacrum to the ischial tuberosities
What does the iliolumbar ligament do?
becomes taut during hip extension
Where does the inguinal ligament attach? What is it formed by?
ASIS to pubic tubercle, formed by the aponeurosis of the external oblique abdominal muscle
What is the cremasteric muscle formed by?
aponeurosis fo the internal abdominal oblique muscle
What ligaments make up the cruciate ligament?
Transverse, superior longitudinal and the inferior longitudinal
What passes around the sacrospinous ligament?
The pudental nerve and vessels pass around this ligament to the ischiorectal fossa
What structures are in the greater sciatic foramen?
- Piriformis muscle
- Superior and inferior gluteal vessels
- Superior and inferior gluteal nerves
- Internal pudendal vessels
- Pudendal nerve
- Sciatic nerve
- Posterior femoral cutaneous nerve
- Nerves to the obturator internus and quadratus femoris muscles
What structures are in the lesser sciatic foramen?
- Tendon of the obturator internus
- Nerve to the obturator internus
- Internal pudental vessels
- Pudendal nerve