Flashcards in Anatomy - Block 2 Deck (81):
What innervates the platysma?
Cervical branch of the facial nerve
Where is the platysma?
In superficial fascia, from lower margin of the mandible to the upper regions of the thorax.
What does the investing layer of cervical fascia enclose?
Sternocleidomastoid muscle and trapezius muscle
What layer of cervical fascia surrounds the thyroid cartilage?
Pretracheal or visceral fascia
What does the accessory nerve leave the cranial cavity through?
What nerves supplies all strap muscles?
Ansa cervicalis (from ventral rami - motor nerves of C1-C3)
What is located outside the carotid sheath?
What is the carotid body and sinus?
The carotid sinus - pressure receptor
The carotid body - chemoreceptor (bicarb, etc. in blood)
-Both supplied with sensory fibers from the glossopharyngeal nerve (CN IX)
What are the main branches from bottom up of the external carotid artery?
1. Superior thyroid
2. Superior laryngeal
What does the internal branch of the superior larygneal nerve supply?
Its a branch of the vagus. It is sensory to that larynx above the vocal cords.
What does the external branch of the superior laryngeal nerve supply?
Inferior pharyngeal constrictor muscles and the cricothyroid muscles.
What can a cricothyrotomy do?
Cutting cricothyroid ligament. It can quickly relieve an acute respiratory obstruction.
What is the path of the accessory nerve (CN XI)?
It originates in upper spinal cord segments and passes through the foramen magnum. It continues through the jugular foramen and then innervates SCM and trapezius muscles.
What nerves supplies sensory to most of the pharynx?
Glossopharyngeal nerve (CN IX)
What is the vagus nerve nucleus?
What does the vagus nerve supply motor and sensory nerves to?
Motor - muscles of the pharynx (except stylopharyngeus) and larynx
Sensory - larynx and part of the pharynx
What motor nuclei are near the midline?
III, IV, VI and XII
What supplies the ciliary ganglion?
Oculomotor Nerve (CN III) - parasympathetic preganglionic fibers
What innervates the pterygopalatine ganglion?
***What is contained in the middle cerebellar peduncle?
Afferents to the cerebellum from pontine nuclei (pontocerebellar fibers!)
What is sensory to the posterior 1/3 of tongue (taste) and motor to the stylopharyngeus muscle?
Glossopharyngeal nerve (CN IX)
What is the superior colliculus?
It contains superior colliculus nucleus
-Involved in visual reflexes
What is the inferior colliculus?
Involved in auditory related relay nucleus.
What is in the cerebral peduncle (crus)? Where is it?
Location of corticospinal, corticobulbar and corticopontine tracts. It is on the sides (lateral) of the superior and inferior colliculi.
What does the superior cerebellar peduncle hold?
Efferent from cerebellum (cerebello-rubro-thalamic tract); ventral spinocerebellar tract afferents
What is the facial colliculi?
Bumps in the forth ventricle under the pons - where facial motor nerve fibers pass over abducens nucleus
What is the sulcus limitans?
Groove in fourth ventricle that separates the motor and sensory nerves!
Where is the vestibular area?
Under cut away pons in fourth ventricle - it holds vestibular nuclei
What is in the cuneate tubercle (fasciculus)?
Cuneate nucleus (touch/proprioception/two-point discrimination) for UPPER extremity - lateral spinal cord
What is the gracile tubercle (fasciculus)?
Touch/proprioception for LOWER extremity - medial spinal cord
What is the tectum above?
Cerebral aquaduct! It also contains the superior and inferior colliculi!
What does the tegmentum contain?
Dopaminergic fibers/cell bodies
What types of fibers does the pons contain?
Corticopontine, Corticospinal and Corticobulbar
What is created in the locus ceruleus?
What is the role of the anterior lobe of the cerebellum?
Regulation of muscle tone
What is the role of the posterior lobe of the cerebellum?
Regulate voluntary motor activity via the corticopontocerebellar fibers!
What is the role of the flocculonodular lobe?
It maintains posture and balance. Consists of nodulus (of vermis) and flocculus
What is in the lower tegmentum?
In what part of the brainstem is the locus ceruleus?
What is the lateral column (funiculus)?
It is the most lateral part of the spinal cord and contains the ascending sensory and descending motor tracts.
What do the ventral horns contain?
Alpha and gamma motor cell bodies that serve as the lower motor neurons.
What happens if you damage/puncture the prevertebral space (retrovisceral) behind the esophagus?
Injury to this pharyngeal wall may lead to infections spreading from the pharynx to the prevertebral space.
This space starts at the base of the skull and goes down into the thorax.
What pharyngeal pouch does the thymus gland develop from?
Where does the thoracic duct drain?
It starts down in the abdomen and drains into the left subclavian vein, near its junctions with the left internal jugular.
Where does the phrenic nerve run?
On top of the anterior scalene muscle - its from C3, C4 & C5
What muscle is behind the anterior scalene?
The middle scalene
What are the three branches of the thyrocervical trunk and what do they innervate?
1. Inferior thyroid - lower regions of thyroid gland
2. Transverse cervical - accompanies accessory nerve
3. Suprascapular artery - supplies the suprascapularis and infrascapularis muscles
What do the superior parathyroid glands originate from?
Epithelium of 4th pharyngeal pouch
What do the inferior parathyroid glands originate from?
Epithelium of the 3rd pharyngeal pouch
What pharyngeal arch does the mylohyoid muscle originate from?
First pharyngeal arch!
What is contained in the spiral ganglion?
It contains bipolar neurons. The peripheral processes of the neurons innervate the sensory hair cells located in the cochlear duct, while the central processes extend into the brain stem to synapse in the cochlear nuclei!
How does the vestibular ganglion work?
It conducts impulses related to balance. The sensory receptors are located in the semicircular cancels, the utricle and saccule.
What ganglia are associated with the vestibulocochlear nerve?
Spiral ganglia - cochlea, hearing
Vestibular ganglia - balance
What is the pathway of innervation to the pharynx and larynx from the nucleus ambiguus?
1. Nucleus ambiguus
2. Vagal ganglia (sensory ganglia)
3. Vagus Nerve & recurrent laryngeal nerve
What is controlled by parasympathetic innervation (CN III)?
Sphincter pupillae muscle & ciliary muscle (controls curvation of the lens)
What eye muscles are controlled by sympathetic innervation?
1. Dilator pupillae muscle
2. Superior tarsal muscle
What are the three branches of V1 (ophthalmic) nerve within the eye?
1. Frontal nerve (divides into supratrochlear and supraorbital (lateral) nerve)
2. Nasocillary Nerve
3. Lacrimal Nerve
What can the superior rectus do?
Turn the eyeball upward
What innervates the superior tarsal muscle?
-It is smooth muscle
-Innervated by post-ganglionic sympathetic nerve fibers whose cell bodies are located in the superior cervical ganglion
What supplies extra nerves to the eyeball?
Long ciliary nerve branch of nasociliary nerve
What is the ophthalmic artery a branch off of?
Internal Carotid Artery
Where are the nerve cell bodies of the optic nerve?
Retina of the eye
What is the pathway from the oculomotor nerve to the eyeball?
1. Pre-ganglionic parasympathetic fibers (oculomotor) travel to
2. Ciliary ganglion
3. Post-ganglionic neurons travel via the short ciliary nerve to innervate the ciliary muscle and the constrictor of the pupil
What can cause swelling of the optic disc?
Dura & Arachnoid are continuous with the optic cancel --> so changes in CSF pressure are transmitted to the space around the optic nerve. This increase in pressure can compress the optic nerve and central vein draining the retina resulting in a swollen disc.
What causes Horner's Syndrome?
Interruption of sympathetic pathways on the ipsilateral side - either:
1. Cervical sympathetic trunk (pre-ganglionic fibers)
2. Sympathetic fibers in the brain stem and spinal cord
What are the symptoms of Horner's syndrome?
1. Ptosis - drooping eyelid (superior tarsal muscle)
2. Miosis - pupillary constriction
3. Anhidrosis - absence of sweating
4. Flushing of the face (redness/vasodilation)
Trace Parasympathetic innervation of the CN VII:
1. Superior salvatory nucleus (facial nerve)
2. Facial Nerve
3. Greater petrosal nerve
4. Nerve of the ptergoid canal
4. Ptergopalatine ganglion --> then VII travels with branches of the maxillary nerve (V2)
What happens with the sympathetic nervous system when you eye is in real pain?
Dilation of the pupil
What supplies secretomotor fibers to the lacrimal gland?
What is the sympathetic and parasympathetic innervation to the lacrimal gland?
-Parasympathetic innervation from facial nerve
-Post-ganglionic sympathetic neurons cell bodies supplying the gland are in the superior cervical ganglion
-Pre-ganglionic parasympathetic neurons are located in the superior salivatory nucleus of the facial nerve
What does parasympathetic innervation to the eye?
Oculomotor nerve (CN III)
What does sympathetic innervation to the eye?
Sympathetic trunk - Superior Cervical Ganglion
What does sensory innervation to the eye?
Trigeminal ganglion (V1)
What is the substantia gelatinosa?
-Area where the first and second order pain/temp neurons synapse at entry of dorsal horn
What can syringomyelia cause?
May cause bilateral loss of pain and temperature regulation
Where does the main sensory trigeminal nucleus project?
Ventral Posteromedial Thalamus
What is unique about the spinal trigeminal nucleus?
It is similar to the substantia gelatinosa of the spinal cord. It is a long nucleus extending all the way from the pons to the spinal cord.
What is the mesencephalic nucleus?
It carries proprioceptive information about the gums & jaw. It has one process that extends peripherally to innervate the gums and jaw and a central process that terminates in the motor nucleus of the trigeminal nerve.
What are ALL the functions of the facial nerve?
1. Efferent to ipsilateral muscle of facial expression & stapedius
2. Preganglionic parasympathetics to lacrimal gland, submandibular and sublingual glands
3. Afferent to ipsilateral part of outer ear, nasal cavity and soft palate
4. Ipsilateral afferent supply for taste to anterior 2/3 of tongue
What is contained in the nucleus ambiguous?
Motor nucleus of glossopharyngeal and vagus nerves