Week 2 - Severson Flashcards
What forms the laryngeal prominence?
Thyroid cartilage (a.k.a. Adam’s apple)
What artery bifurcates at the superior border of the thyroid cartilage?
Common carotid artery into external and internal branches.
What is the relationship of the hyoid bone to the thyroid cartilage?
It is located just above the thyroid cartilage.
What divisions of the neck are formed by the sternocleidomastoid muscle (SCM)?
Anterior/Posterior Triangle
What is the nerve supply of the SCM muscle?
Accessory Nerve (CN XI)
How does contraction of the SCM muscle affect head movement?
- Draws head toward shoulder and rotates it.
- Flex the head
What are the boundaries and contents of the neck triangles?
- Anterior triangle
- Boundaries: inferior border of the mandible, midline of neck, and anterior boder of SCM
- Contents: Submental/Submandibular glands, carotid arteries
- Posterior triangle
- Boundaries: clavicle, posterior aspect of SCM, and anterior border of trapezius
- Contents: CN XI, Subclavian artery, Brachial plexus
What muscle is found in the superficial fascia of the neck?
Platysma
What nerve innervates the Platysma?
Facial Nerve (CN VII)
What are the five components of the deep cervical fascia, and what are the contents of each component?
- Investing layer - encloses all neck structures
- Infrahyoid fascia - surrounds the strap muscles
- Pretracheal (visceral) fascia - surrounds chief cervical viscera
- Prevertebral - surrounds cervical vertebral column and associated musclulature
- Carotid sheath - encloses internal jugular vein, common carotid artery, Vagus Nerve (CN X)
Where is the retropharyngeal space, and what is its significance?
Where: Extends cranially to the base of the skull and inferiorly to the posterior mediastinum (behind the heart).
Significance: Potentially a pathway that pathogenic organisms can track along behind the viscer of the neck.
What are the names of the superficial nerves and their distribution?
Four superficial sensory branches of the cervical plexus (C2-C4) surface near the posteriomedial border of the SCM.
- Supraclavicular nerves
- Transverse cervical nerves
- Great auricular nerve
- Lesser occipital nerve
What superficial veins are found in the neck region?
- External jugular
- Anterior jugular
What muscles form the boundary of the carotid triangle?
- Posterior belly of the Digastric
- Anterior edge of SCM
- Superior belly of the Omohyoid
What are the contents of the carotid sheath?
- Internal Jugular Vein
- Common Carotid Artery
- Vagus Nerve (CN X)
What vessels join to form the brachiocephalic veins?
Internal jugular vein + Subclavian Vein
What is the thoracic duct and where does the thoracic duct empty into the venous system?
Largest lymphatic channel in the body.
Joins the region of confluence between the Internal Jugular Vein and the Subclavian Vein on the left side.
From what vessels do the left and right common carotid arteries originate?
Right: originates from Brachiocephalic Artery - direct branch of aortic arch
Left: originates directly from aortic arch
What anatomical landmark represents the site of bifurcation of the common carotid artery into the internal and external carotid arteries?
Near upper border of thyroid cartilage.
What are the carotid sinus and carotid body?
Sinus: slight dilation of the internal carotid that is an arterial blood pressure-regulating area (pressure receptor)
Body: chemoreceptor that responds to either increased CO2 tension or decreased O2 tension in the blood.
What is the nerve innervation of the carotid sinus and carotid body?
Glossopharyngeal Nerve (CN IX)
What are the branches of the vagus nerve in the neck?
- Superior laryngeal nerve
- Recurrent laryngeal nerve
- Small superior and inferior cardiac twigs
Where and how does the internal branch of the superior laryngeal nerve enter the larynx?
***
What muscle is innervated by the external branch of the superior laryngeal nerve?
Cricothyroid muscle
Where do the recurrent laryngeal nerves originate?
from the Vagus Nerve (CN X) at the level of the aortic arch
(hooks around the subclavian artery on the right and the arch of aorta on the left within the thorax as they head back toward the larynx on each side)
What spinal nerves innervate the “strap” muscles?
Anterior primary rami of C1-C3 (ansa cervicalis)
What spinal nerves form the superior and inferior roots of the cervical plexus?
C1-C4
How are the geniohyoid and thryohyoid muscles innervated?
Anterior primary rami of C1 that run with and leave the hypoglossal nerve
Relate the origin and insertion of the Sternohyoid muscle to its function.
Superior attachment: Body of hyoid bone
Inferior attachment: Manubrium of sternum and medial end of clavicle
FXN: Depresses larynx and hyoid bone (steadies hyoid)
Relate the origin and insertion of the Sternothyroid muscle to its function.
Superior attachment: Oblique line of thyroid cartilage
Inferior attachment: Posterior suface of manubrium of sternum
FXN: Depresses larynx and thyroid cartilage
Relate the origin and insertion of the Thyrohyoid muscle to its function.
Superior attachment: Inferior border of body and greater horn of hyoid bone
Inferior attachment: Oblique line of thyroid cartilage
FXN: Depresses larynx and hyoid bone; elevates thyroid cartilage
Relate the origin and insertion of the Omohyoid muscle to its function.
Superior attachment: Inferior border of hyoid bone
Inferior attachment: Superior border of scapula near suprascapular notch
FXN: Steadies hyoid bone; depresses and retracts hyoid bone and larynx
Relate the origin and insertion of the Geniohyoid muscle to its function.
Superior attachment: Inferior mental spine of mandible
Inferior attachment: Body of hyoid bone
FXN: Elevates hyoid bone and tongue
Which arteries of the face originate from the internal carotid artery in the neck?
NONE.
The internal carotid artery does NOT give off branches in the neck (except for the brain and contents of the orbit).
What areas are supplied with blood from the internal and external carotid arteries, respectively?
Some Anatomists Like Freaking Out Poor Medical Students
S: superior thyroid artery
A: ascending pharyngeal artery
L: lingual artery
F: facial artery
O: occipital artery
P: posterior auricular artery
M: maxillary artery
S: superficial temporal artery
What is the usually the first branch off the external carotid artery?
Superior Thyroid Artery
What are the terminal branches of the carotid artery?
Superificial Temporal Artery & Maxillary Artery
What is the relationship of the thyroid gland to the thyroid cartilage?
Just below the thyroid cartilage
just anterior to the trachea
With what structure is the isthmus of the thyroid gland related?
Second and third tracheal rings
What two majory blood vessels supply the thyroid gland, and from what vessels do they originate?
- Superior thryoid artery (external carotid)
- Inferior thyroid artery (thyrocervical trunk - branch of subclavian artery)
What vessels are involved in the venous drainage of the thyroid gland, and where do they terminate?
- Superior/Middle thyroid vein –> internal jugular
- Inferior thyroid vein –> left brachiocephalic
What is the relationship of the parathyroid gland to the thyroid gland?
Small, oval glands situated on the posterior surfaces of the lateral lobes of the thyroid gland.
What is the relationship of the trachea and esophagus to one another?
Trachea is anterior to esophagus, start below larynx.
Esophagus is immediately posterior to the trachea, starts below pharynx.
What is tetany, and when does it occur?
A severe convulsive disorder that occurs due to decreased serum calcium levels after inadvertent removal of all parathyroid tissue after thyroidectomy.
What is a goiter?
pathological enlargement of the thyroid gland
In surgical removal of thyroid tissue, what nerve is in danger of injury?
Recurrent laryngeal nerves
What is the relationship of the scalene muscles to the brachial plexus?
Brachial plexus passes through the space between the Anterior & Middle Scalene muscles.
What is the relationship of the subclavian artery and vein to the scalene muscles?
Subclavian vein runs anterior to the Anterior Scalene Muscle.
Subclavian artery runs posterior to the Anterior Scalene Muscle (in between Anterior & Middle Scalene Muscles).
What important nerve lies on the anterior surface of the anterior scalene muscle?
Phrenic nerve
What are the four major branches of the subclavian artery in the posterior triangle?
- Internal thoracic
- Thyrocervical trunk
- Vertebral
- Costocervical trunk
Where are the lymph nodes located in the posterior triangle?
- Superficial cervical nodes: along the external jugular vein
- Deep cervical nodes: along the carotid sheath
What is the relationship of the sympathetic trunk to the carotid sheath?
Sympathetic trunk is directly posterior to carotid sheath.
Typically embedded/attached to the prevertebral fascia.
What is the origin of the nerve fibers in the cervical sympathetic trunk?
Lateral gray horn (intermediolateral cell column) of spinal segments T1-L5
What are the three sympthetic ganglia of the neck region?
- Superior cervical ganglion (near C1-C2)
- Middle cervical ganglion (C6)
- Interior/Stellate (cervicothoracic) ganglion
What type of comunicantes connect the cervical sympathetic chain with the cervical spinal nerves?
White rami communicantes found in spinal cord segments T1-L5 connect the ventral primary rami to the chain ganglia and the fibers ascend in the sympathetic trunk.
Do the nerve fibers of the internal carotid nerve contain pre- or post-ganglionic fibers?
POST-GANGLIONIC fibers
What are the boundaries of the submandibular triangle?
- Below: Anterior/posterior bellies of digastric muscle
- Above: lower border of mandible
Which of the salivary glands is found in the submandibular region?
Submandibular gland!
What major blood vessel is found in the submandibular triangle?
Facial Artery/Vein
What is the nerve supply of the muscles related to the triangle?
- Digastric:
- Anterior belly: Mylohyoid (V3)
- Posterior belly: Facial Nerve (CN VII)
- Stylohyoid: Facial Nerve (CN VII)
- Mylohyoid: Mylohyoid (V3)
- Geniohyoid: Anterior primary rami of C1
How does the origin and insertion of the Digastric muscle in the submandibular region relate to their function?
- Superior attachment:
- Anterior belly: digastric fossa of mandible
- Posterior belly: mastoid notch of temporal bone
- Inferior attachment: Intermediate tendon to body and greater horn of hyoid bone
- FXN:
- Raises hyoid bone and base of tongue;
- steadies hyoid bone;
- depresses mandible
How does the origin and insertion of the Stylohyoid muscle in the submandibular region relate to their function?
- Superior attachment:
- Styloid process of temporal bone
- Inferior attachment:
- Body of the hyoid bone
- FXN:
- Elevates hyoid bone and base of tongue
How does the origin and insertion of the Mylohyoid muscle in the submandibular region relate to their function?
- Superior attachment:
- Mylohyoid line of mandible
- Inferior attachment:
- Raphe and body of hyoid bone
- FXN:
- Elevates hyoid bone
- Raises floor of mouth
- Depresses mandible
How does the origin and insertion of the Genohyoid muscle in the submandibular region relate to their function?
- Superior attachment:
- Inferior mental spine of mandible
- Inferior attachment:
- Body of the hyoid bone
- FXN:
- Elevates hyoid bone and tongue
What is the relationship of the hypoglossal nerve to the submandibular triangle?
It courses superficial to the external carotid artery and then deep to stylohyoid and posterior digastric muscles, disappearing above the mylohyoid muscle.
How do parasympathetic pre- and post-ganglionic fibers reach the salivary glands?
- Submandibular
- Pre: CN VII –> chorda tympani –> lingual branch (V3) –> submandibular ganglion
- Post: Submandibular ganglion –> GLAND!
- Sublingual
- Pre: same as submandibular
- Post: Lingual nerve –> GLAND!
- Mucosal
- Pre: same as submandibular
- Post: Lingual nerve –> GLAND!
How do taste fibers from the anterior 2/3rds of the tongue reach the central nervous system?
Cell bodies in Geniculate Ganglion –> CN VII (via chorda tympani?)
What is torticollis or wryneck?
A cramping, or sometimes a spasmodic contraction of the SCM. May draw the head to one side with the chin pointing contralaterally.
Why may tumors in the neck produce hiccups?
The most common cause of long-term hiccups is damage to or irritation of the vagus nerves or phrenic nerves, which serve the diaphragm muscle.
How does the location of the ciliary glands and the tarsal glands differ?
- Tarsal glands are embedded in tarsal plates (seen as yellow streaks through the conjunctiva)
- Ciliary glands are associated with the eyelashes
Why does blood pool in the eyelid with injury to the area?
***
What is the function of the orbicularis oculi muscle?
Surrounds orbit as a sphincter and is a facial muscle under voluntary control (facial nerve VII)
What are the tarsal plates?
- Thin plates of fibrous connective tissue in each lid.
- Upper being larger
- Attached to palpebral ligaments laterally and medially, and to orbital septum
What is the orbital septum?
- Fibrous membrane attached to margins of bony orbit where it is continuous with periorbita (periosteum).
- Forms barrier between inside and outside contents of orbit.
Define palpebral and bulbar conjunctiva.
- Palpebral:
- thick, red, very vascular, lines inside of eyelids
- at margin of lid, continuous with skin
- Bulbar:
- thin, transparent, slightly vascular over sclera
- on the cornea only the epithelial part is present
What is the conjunctival sac?
When lids are closed, a space lined with conjunctiva lies in front of eye
Where does the levator palpebrae muscle originate and insert?
Originate: from the bone above the optic foramen
Insert: broad aponeurosis onto anterior surface of superior tarsus, with some fibers penetrating orbicularis oculi muscle to attach to skin of upper lid
What two types of muscle are associated with the levator palpebrae muscle?
- Skeletal muscle (levator palpebrae)
- Smooth muscle (Superior tarsal muscle, Muller’s muscle)
What is the innervation of the levator palpebrae?
Oculomotor Nerve - CN III
What is the innervation of the Superior tarsal muscle?
Postganglionic sympathetic nerve fibers from the superior cervical ganglion
What is Horner’s syndrome?
- Interruption of sympathetic nerves
- Induces:
- ptosis (drooping of lid)
- pupillary constriction
- flushing of the face
- anhidrosis (lack of sweating)
How does the sensory innervation of the upper and lower eyelids differ?
***
What is the major blood supply (arteries & veins) and lymphatics to the eyelids?
- Arteries: Palpebral branches of lacrimal and ophthalmic arteries
- Veins: similar to arteries
- Lymphatics:
- from upper lid drain to superficial parotid and superficial cervical nodes
- from lower lid tends to drain to submandibular nodes
What glands are infected with a sty?
Ciliary glands (sebaceous)
OR
Tarsal glands (meibomian)
What is conjunctivitis?
- Hyperemia of conjunctiva
- acute type pinkeye: inflammation of the bulbar and palpebral conjunctiva and may be caused by several organisms
- chronic type: may be caused by bacteria, irritating fumes, or allergies
Injury to what two nerves may produce ptosis?
Oculomotor nerve
OR
Sympathetic nerves innervating the smooth muscle of the superior tarsus muscle
What nerves are involved in the blink reflex?
Afferent: Trigeminal
Efferent: Facial
Where is the lacrimal gland located?
Lies in lacrimal fossa on superior lateral aspect of roof of orbit.
What sensory nerve fibers reach the gland?
Lacrimal nerve of Trigeminal V1
How do the autonomic (secremotor fibers) reach the gland?
Facial Nerve
- greater petrosal nerve carries preganglionic fibers to pterygopalatine ganglion
- postganglionic fibers from the pterygopalatine ganglion via zygomatic branch of maxillary (V2) to the communicating branch leading to the lacrimal nerve
(really F-ing complicated, huh!)
What are the lacrimal canaliculi?
Ducts at the medial end of each lid
Lead to lacrimal sac
Where is the lacrimal sac located?
Lacrimal groove formed by lacrimal bone and frontal process of maxillary bone
Where does the nasolacrimal duct begin and end?
Begin: Bony canal formed by maxilla, lacrimal bone, and inferior nasal concha
End: Inferior meatus of lateral nasal cavity
What nerves are involved in the tearing reflex?
Ophthalmic division of Trigeminal (V1)
Sensory root of trigeminal nerve
What is the shape of the orbit and how do the medial and lateral walls compare?
- Shape: pear-shaped with an apex posteriorly at the optic canal and a base anteriorly near the orbital margin
- Medial walls are parallel
- Lateral walls diverge 45° laterally from the medial wall
What sinus is located below the floor of the orbit?
Maxillary sinus
What is a “blow-out” fracture?
Floor of the orbit is fractured –> results in a descent of the orbital contents including the eyeball into the maxillary sinus
What cranial fossa is located above the roof of the orbit?
Anterior cranial fossa
What sinus is associated with the roof?
Frontal sinus
How is the orbital septum formed and what is its relationship to the tarsal plates?
- continuous with the periorbita (the periosteum of the bony orbit)
- attaches to tarsal plates in both lids
What is the vagina buli (Tenon’s capsule)?
Facial sheath of eyeball
How are the medial and lateral check ligaments and the suspecnsory ligament of the eyeball formed?
- Fascia extends to lacrimal and zygomatic bones
- Blending of the check ligaments and the fascia coverings of inferior oblique and inferior rectus –> form a sling = suspensory ligament of the eyeball
What is the periorbita?
Special lining of the orbit that is actually periosteum.
Acts as a hammock for the eyeball!
Where do the extraocular eye muscles originate?
6/7 originate from bone or a ring of fibrous tissue, called the Common Tendinous Ring, around the optic nerve.
The inferior oblique arises from the medial edge of the orbital floor (maxilla).
What is the nerve supply to each of the extraocular muscles?
- Levator palpebrae - Oculomotor Nerve (CN III)
- Superior rectus - Oculomotor Nerve (CN III)
- Inferior rectus - Oculomotor Nerve (CN III)
- Medial rectus - Oculomotor Nerve (CN III)
- Lateral rectus - Abducens Nerve (CN VI)
- Superior Oblique - Trochlear Nerve (CN IV)
- Inferior Oblique - Oculomotor Nerve (CN III)
Through which foramen does the optic nerve enter the orbit?
Optic Foramen, obviously
Through which opening does the Ophthalmic Nerve enter the orbit?
Superior orbital fissure
What are the three branches of the Ophthalmic Nerve?
- Lacrimal (smallest branch)
- Frontal (largest branch)
- Nasociliary
What areas are supplied by the three branches of the Ophthalmic Nerve?
- Lacrimal
- Rostral to conjunctiva and skin of upper eyelid
- Frontal
- Supraorbital: upper eyelid, forehead, and scalp
- Supratrochlear: conjunctiva of upper lid and forehead
- Nasociliary
- Communication to ciliary ganglion (sensory root)
- Long ciliary: sensory to eyeball (slera/cornea)
- Infratrochlear: sensory to medial angle of eye for conjunctiva, lacrimal sac, skin of lid, and side of nose
- Anterior/Posterior Ethmoidales: sensory to frontal, ethmoid, and sphenoid sinuses as well as nasal cavity
What is the function of the Long Ciliary Nerve?
Sensory to eyeball, especially the sclera and cornea
Why is the “sympathetic” root of the ciliary ganglion derived from the nasociliary nerve?
It is communication to ciliary ganglion that carries sensory roots
THAT’S JUST THE WAY IT FREAKIN’ IS!
Where are each of the motor nerves in the cavernous sinus, and where do the nerves enter the orbit?
- Oculomotor (CN III) - lies in lateral wall
- Trochlear (CN IV) - runs in lateral wall between CN III and Ophthalmic branch of CN V
- Abducens (CN VI) - passes through b/t the internal carotid artery and Ophthalmic (V1)
ALL ENTER ORBIT THROUGH
SUPERIOR ORBITAL FISSURE!
How do the parasympathetic and sympathetic nerve reach the lacrimal gland?
- Parasympathetic:
- Pre- nervus intermedius (part of facial nerve) –> greater petrosal nerve –> pterygopalatine ganglion
- Post- pterygopalating ganglion –> maxillary nerve (CN V2) –> zygomatic nerve –> Ophthalmic nerve (CN V1)
- Sympathetic:
- Pre- superior cervical ganglion
- Post- deep petrosal nerve –> Vidian nerve –> run with lacrimal artery
How do the parasympathetic and sympathetic nerves reach the iris and ciliary muscles?
- Parasympathetic:
- Pre- oculomotor nerve –> ciliary glanglion
- Post- short ciliary nerve –> constrictor pupillae muscle of the iris
- Sympathetic:
- Pre- superior cervical ganglion
- Post- ophthalmic nerve –> nasociliary branch/short ciliary nerves/ophthalmic artery
How is an increase in intracranial pressure transmitted along the optic nerve?
Swelling of the optic disc (papilledema)
How does the Ophthalmic Artery enter the orbit?
Optic foramen
How do the superior and inferior ophthalmic veins connect the face with the cavernous sinus?
They usually drain posteriorly into cavernous sinus
What is the blind spot?
The area of retina where the optic nerve fibers leave the eyeball and the retinal vessels enter.
What is a choked disk?
Papilledema
