Exam 1 Week 2 Flashcards
What is the structure of the body that is specialized for sound detection?
What are the parts of this structure
- *what parts conduct sound
- *what parts detect sound
EAR
3 PARTS
- OUTER EAR
- funnel shaped structure of cartilage and skin that leads to tympanic membrane
- DIRECTS SOUND (pressure waves in air) toward tympanic membrane
- helps to detect source of sound - MIDDLE EAR
- air filled chamber that contains bones (ossicles) that link tympanic membrane to cochlea
- also contains skeletal muscles that dampen sounds
- middle ear is linked to nasopharync by AUDITORY TUBE (allow for equilibrium of air pressure on inner side of tympanic membrane
- common middle ear infection is OTITIS MEDIA - INNER EAR
- fluid filled chamber in petrous part of temporal bone
- contains cochlea for hearing
- contains vestibular apparatus for gravity detection
* *both innervated by CN VIII - vestibulocochlea
- *Outer and middle ear CONDUCT SOUND
- *Inner ear DETECT SOUND (sensorineural part/cochlea - in petrous part of temporal bone)
1) How can the functioning of inner ear be tested independently
- what is test called?
2) Damage to inner ear called?
3) Damage to middle ear called?
- Clinical test; Inner ear detects transmitted vibrations and can be tested independently by VIBRATIONS TRANSMITTED DIRECTLY THROUGH BONE
- called WEBER TEST; tuning fork on cal various directly causes bone to vibrate, conducted to COCHLEA BY BONE and PERCEIVED AS SOUND by patient - SENSORINEURAL HEARING LOSS - damage to inner ear (independent of outer and middle ear)
- CONDUCTIVE HEARING LOSS - damage to middle ear (tympanic membrane, auditory ossicles/bones)
The ear is composed of 3 parts which are the outer, middle and inner ear. Identify the respective parts of the outer ear
- elastic cartilage covered with skin
- functions to REFLECT SOUND WAVES
- has 4 parts ? (Why can you safely pierce a part of this structure?)
- tube from auricle to the tympanic membrane
- posterior to parotid and TMJ
- anterior to mastoid process
- AURICLE (pinna)
- 4 parts: helix, antihelix, tragus and lobule
- can safely pierce and suspend decorative metal objects from LOBULE - because cartilage does not extend into lobule - EXTERNAL AUDITORY MEATUS
- Outer 1/3rd consist of elastic cartilage (contains hairs, sebaceous glands and ceruminous glands- produce cerumen/ear wax which is insect repellant) *PROTECT TYMPANIC MEMBRANE
- Inner 1/3rd is composed of bone lined with skin
- What is the curvature of the external auditory meatus (children vs adult)
- What is the innervation of the outer ear
* *patient with Bell’s palsy have what sensation
- External auditory meatus is STRAIGHT IN CHILDREN and CURVED AND CURVED ANTERIORLY in adults
**In adults, auricle is pulled up and back to insert otoscope
- Sensory innervation of outer ear is complex and derived from CN: V, VII, IX, X
* Patient with Bell’s palsy can have the sensation of ear ache (pain in outer ear) - somatic sensory (precise sensation)
Identify the part of the ear
- cavity in the petrous portion of the temporal bone that is hard to visualize
- lies below the middle cranial fossa
- *What makes up the boundaries of this part of the ear
1. Separate tympanic cavity from middle cranial fossa
2. Jugular foramen below
3. Opening of auditory tube
4. Leads to mastoid air cells
5. Has oval and round window
5. Tympanic membrane
MIDDLE EAR (Tympanic cavity)
BOUNDARIES
- ROOF - tegmen tympani; thin plate of petrous part of temporal bone that separates tympanic cavity from middle cranial fossa
- FLOOR - jugular foramen lies below cavity; rupture of internal jugular vein can result in hemorrhaging into the tympanic cavity
- ANTERIOR WALL - has opening of auditory tube (posterior 1/3rd of tube is in bony canal, anterior 2/3rd is cartilage)
- POSTERIOR WALL - leads to mastoid air cells in mastoid process (opening is called ADITUS); canal for facial nerve (CN VII) courses in posterior wall (after passing from medial wall)
- MEDIAL WALL - lateral wall of inner ear
* OVAL WINDOW (fenestra vestibuli) - attachment of stapes
* ROUND WINDOW (fenestra cochlea) - other end of coiled cochlea - LATERAL WALL - Tympanic Membrane e
Summarize the main points of otitis media
- Very common MIDDLE EAR INFECTION in children
- Middle ear is the dead space cavity that opens to NASOPHARYNX
- Infection can spread from upper respiratory system - Spread of infection from respiratory system can damage auditory ossicles which lead to HEARING LOSS
- Prolonged infection in Tympanic cavity can spread through tegmen tympani to brain
* *Tx is tympanostomy - tube through tympanic membrane
What happens to the occurrence of otitis media with age?
What 2 factors contribute to this?
**Occurence DECLINES with age of child (rapidly after age 5)
- cranial growth is associated with a change in orientation of the auditory tube (from horizontal to angled inferiorly)
- increase in the size of the lumen
Identify the structure(s) of the middle ear
- link tympanic membrane to oval window and cochlea
- anchored by ligaments
- amplify effect of vibration
AUDITORY OSSICLES
From lateral to medial
- Malleus (hammer)
- Incus (anvil)
- Stapes (stirrup)
- ossicles amplify effect of vibration
- tympanic membrane has 15-20 tines greater area than footplate of stapes (area of oval window); this increases force per unit area and helps transmit sound vibrations from air to fluid in inner ear (impedance matching)
What is seen in otoscope view of tympanic membrane
What is a branch of VII that carry taste to anterior 2/3rd of tongue
- *In OTOSCOPE VIEW - there is a broad attachment of malleus to tympanic membrane
- handle/malleus is attached to upper half of tympanic membrane
- malleus is supported by ligaments linking it to wall of tympanic cavity
- part of tympanic membrane surrounding handle is tense (pars tense)
- upper end is less tense (pars flaccida)
**CHORDA TYMPANI - branch of VII (carry taste fibers to ANTERIOR 2/3rd of tongue)
Identify the muscles of the middle ear
-what is their role?
**paralysis of muscles result in what?
DAMPEN SOUND
1. TENSOR TYMPANI MUSCLE Origin - canal in anterior wall Insertion - handle of malleus Nerve - V3 Action - TENSES/TIGHTENS tympanic membrane (prevent damage to inner ear)
- STAPEDIUS MUSCLE
Origin - posterior wall (landmark is pyramid)
Insertion - neck of stapes
Nerve - VII (facial nerve)
**Both muscles act to DAMPEN MOVEMENTS OF OSSICLES (decrease intensity of sound)
- *Paralysis of muscles produces HYPERACOUSIA (sound seem too loud)
- damage to facial nerve
What is the SENSORY innervation of the MIDDLE EAR
_ what innervates mastoid air sinus and auditory tube (give rise to what?)
- *VISCERAL SENSORY (GVA) from tympanic plexus of CN IX (GLOSSOPHARYNGEAL)
- imprecise sensation, branch of IX that enter tympanic cavity (exit via jugular foramen)
- IX Nerve Forms
1. Tympanic plexus that also innervates (VISCERAL MOTOR) the mastoid air sinus and auditory tube which can give rise to
2. Lesser petrosal nerve; VISCERAL MOTOR (parasympathetic) to parotid gland
Identify the nerve
- leaves posterior cranial fossa via internal auditory meatus (enters facial canal))
- what are the 3 branches
FACIAL NERVE
- GREATER PETROSAL NERVE
- VISCERAL MOTOR parasympathetic to lacrimal gland, mucous glands of nose and palate (visceral sensory to nasopharynx) - STAPEDIAL NERVE
- BRANCHIOMOTOR to stapedius - CHORDA TYMPANI
- Taste to anterior 2/3 of tongue
- Parasympathetics to submandibular, sublingual salivary glands
Identify;
- branch of VII (facial nerve)
- no function in middle ear
- provides taste to anterior 2/3 of tongue
- Parasympathetics to submandibular ganglion - leaves facial canal and passes through tympanic cavity and crosses over upper end of handle of malleus before exiting via petrous panic fissure
**damage lead to what?
CHORDA TYMPANI
**If tympanic membrane is pierced - Damage CHORDA tympani and lose taste to anterior tongue on that side
The neck is compartmentalized into what 3 compartment
- VERTEBRAE AND MUSCLES which support and move head and neck
- VISCERA and rostral continuation GU and respiratory systems
- Blood vessels and nerve (CAROTID SHEATH)
- POSTERIOR compartment
- ANTERIOR compartment
- LATERAL compartment
The posterior compartment of the neck is composed of vertebrae and muscles that support and move head and neck respectively.
What are the types of muscles in the different orientation to vertebrae
- Posterior to vertebrae
- Lateral to vertebrae
- Anterior
- Posterior side
- muscles are continuations of muscles of back (deep muscles) and suboccipital region - Lateral side
- scalene muscles; flex neck LATERALLY - Anterior side
- Prevertebral muscles ; directly anterior to vertebrae; FLEX head and neck
What is the anterior compartment of the neck composed of (2)
- VISCERAL - in lower part of neck; trachea, thyroid gland and esophagus
- PHARYNX - in upper part of neck; pharynx. Pharynx is a tube composed of muscles and facia that is continuous anteriorly with the oral and nasal cavities; the esophagus and the larynx open into the pharynx
The lateral compartment of the neck is lateral and posterior to the pharynx
**what is contained here? (What is in this content? What is not?)
CAROTID SHEATH
Contents
- Carotid arteries (common and internal carotid arteries)
- Internal jugular veins
- Vagus nerve
Not in carotid sheath
1. Sympathetic chain (posterior to carotid sheath)
The muscles of neck and head are divided into:
- muscles not attached to hyoid (2)
- Infrahyoid muscle (4)
- Suprahyoid muscle (4)
- Muscles of pharynx (4)
**2 are not attached to hyoid bone
- STERNOCLEIDOMASTOID
Action
Nerve
- Sternocleidomastoid (2 heads)
Action
- On both sides; flex neck
- Singly; rotate head so face is directed to opposite side
Nerve Accessory nerve (XI)
The muscles of neck and head are divided into:
- muscles not attached to hyoid (2)
- Infrahyoid muscle (4)
- Suprahyoid muscle (4)
- Muscles of pharynx (4)
- 2 muscles are not attached to hyoid bone
2. Scalenus anterior and Scaleus mediums
Action
Flex neck and elevate rib 1
Nerve
Branches of ventral rami of cervical spinal nerves
The muscles of neck and head are divided into:
- muscles not attached to hyoid (2)
- Infrahyoid muscle (4)
- Suprahyoid muscle (4)
- Muscles of pharynx (4)
*There are 4 Infrahyoid muscles
- Omohyoid
(Muscle has 2 bellies connected by an intermediate tendon)
Action
Depresses hyoid bone
Nerve
Ansa cervicalis
The muscles of neck and head are divided into:
- muscles not attached to hyoid (2)
- Infrahyoid muscle (4)
- Suprahyoid muscle (4)
- Muscles of pharynx (4)
- There are 4 Infrahyoid muscles
2. Sternohyoid
Action
Depresses hyoid bone
Nerve
Ansa cervicalis
The muscles of neck and head are divided into:
- muscles not attached to hyoid (2)
- Infrahyoid muscle (4)
- Suprahyoid muscle (4)
- Muscles of pharynx (4)
- There are 4 Infrahyoid muscles
3. Sternothyroid
Action
- Depresses thyroid cartilage
- indirectly depresses hyoid bone, larynx
Nerve
Ansa cervicalis
The muscles of neck and head are divided into:
- muscles not attached to hyoid (2)
- Infrahyoid muscle (4)
- Suprahyoid muscle (4)
- Muscles of pharynx (4)
- There are 4 Infrahyoid muscles
4. Thyrohyoid
Action
- Depresses hyoid bone
- Elevates larynx
Nerve
C1 via branch hitch-hiking with hypoglossal nerve (XII)
The muscles of neck and head are divided into:
- muscles not attached to hyoid (2)
- Infrahyoid muscle (4)
- Suprahyoid muscle (4)
- Muscles of pharynx (4)
- There are 4 Suprahyoid muscles
1. Digastric (has two bellies)
Action
- Elevates hyoid bone
- Depresses mandible
Nerve
Posterior belly - facial nerve (VII)
Anterior belly - trigeminal nerve (V3)
The muscles of neck and head are divided into:
- muscles not attached to hyoid (2)
- Infrahyoid muscle (4)
- Suprahyoid muscle (4)
- Muscles of pharynx (4)
- There are 4 Suprahyoid muscles
2. Stylohyoid
Action
Elevates hyoid bone
Nerve Facial nerve (VII)
The muscles of neck and head are divided into:
- muscles not attached to hyoid (2)
- Infrahyoid muscle (4)
- Suprahyoid muscle (4)
- Muscles of pharynx (4)
- There are 4 Suprahyoid muscles
3. Mylohyoid
Action
- Elevates hyoid bone
- Raises floor of mouth during swallowing
Nerve Trigeminal nerve (V3)
The muscles of neck and head are divided into:
- muscles not attached to hyoid (2)
- Infrahyoid muscle (4)
- Suprahyoid muscle (4)
- Muscles of pharynx (4)
- There are 4 Suprahyoid muscles
4. Geniohyoid
Action
- Elevates hyoid bone
- Draws hyoid forward
Nerve
C1 via branch hitch-hiking with hypoglossal nerve (XII)
The muscles of neck and head are divided into:
- muscles not attached to hyoid (2)
- Infrahyoid muscle (4)
- Suprahyoid muscle (4)
- Muscles of pharynx (4)
*There are 4 muscles of pharynx. 3 are circular muscles. 1 is Longitudinal
Name all
CIRCULAR 1. Superior constrictor Action : constrict pharynx Nerve : X 2. Middle constrictor Action: constrict pharynx Nerve: X 3. Inferior constrictor Action: constrict pharynx Nerve: X
LONGITUDINAL
4. Stylopharyngeus
Action: Raises pharynx and pull wall laterally
Nerve: IX
What is the most important landmark in neck for diagnosis and procedures?
*what vessels is between 2 heads of this muscle and why is it important
- what is anterior to muscle?
- what are the lateral mass anterior to the muscle
**what is located deep to sternocleidomastoid
STERNOCLEIDOMASTOID
- important landmark in diagnosis and procedures in neck
**INTERNAL JUGULAR VEIN can be accessed and catheterized between sternal and clavicular heads of sternocleidomastoid (VENOUS CATHETERIZATION)
- *Thyroid gland and jugular chain of lymphatics are located ANTERIOR to sternocleidomastoid
- BRANCHIAL CLEFT CYSTS are lateral masses anterior to sternocleidomastoid
**Deep cervical chain of lymph nodes are located deep to sternocleidomastoid
What is used to diagnose neck masses?
- lateral neck mass
- midline mass
- Use STERNOCLEIDOMASTOID to diagnose neck masses
- BRANCHIAL CYST or (fistula = channel) are lateral neck masses located anterior to sternocleidomastoid
- *This is different form THYROGLOSSAL duct cysts
- this will be MIDLINE MASSES
- Cyst = pocket
- Fistula = channel
What is the SECOND most important landmark in neck? Why?
SCALENUS ANTERIOR AND SCALENUS MEDIUS
- second muscle of neck not attached to hyoid
It contains:
- BRANCHIAL PLEXUS and subclavian artery pass between scalenus anterior and scalenus medius
- PHRENIC NERVE (nerve to diaphragm) passes anterior to scalenus anterior
* Phrenic nerve come from C3,C4,C5 and cause diaphragm to contract
Identify bone
- located in anterior part of neck
- free floating (no bony attachment)
- attached to skull and skeleton only by muscles and ligaments
What ligament;
- Like bone to styloid process
- Like bone to thyroid cartilage
- *What are the parts of the bone?
- *what attach to body of bone?
HYOID BONE (U shape)
- STYLOHYOID LIGAMENT: links hyoid to styloid process of temporal bone
- THYROHYOID MEMBRANE : links hyoid to thyroid cartilage
PARTS
- Body (central part)
- Greater and lesser horns (Cornu)
- *All INFRAHYOID and SUPRAHYOID muscles (except sternothyroid) attach to body of hyoid)
- *Greater horns can be palpated in neck above thyroid cartilage and used as landmarks to locate surrounding structures
What anchors tongue and floor of mouth and also support larynx
*Why is this important?
HYOID BONE
- muscles which move hyoid bone produce movements of larynx and tongue (as occur during swallowing and talking)
- contraction of muscles can stabilize position of hyoid bone (e.g in movement of tongue)
Identify the muscles
-all act to DEPRESS the hyoid bone
INFRAHYOID MUSCLES
4 muscles
- OMOHYOID (SUPRASCAPULAR notch to hyoid bone) -Greek for shoulder (2 bellies) - intermediate tendon linked to clavicle and rib 1
- STERNOHYOID - manibrium/sternum and clavicle to hyoid
- STERNOTHYROID - manubrium to thyroid cartilage
- THYROHYOID - thyroid cartilage to hyoid (ALSO ELEVATES LARYNX)
Identify the muscles
-all act to ELEVATE the hyoid bone
SUPRAHYOID MUSCLES
4 muscles
- DIGASTRIC - 2 bellies/2 cranial nerves ; insert to hyoid via INTERMEDIATE TENDON
* also OPENS MOUTH - STYLOHYOID - styloid process of temporal bone to hyoid; tendon splits to surround digastric tendon
- MYLOHYOID - forms muscular floor of mouth (ELEVATES floor of mouth in swallowing)
- GENIOHYOID - elevates and pulls hyoid forward
* *Important in swallowing
Identify the group of nerves of the neck
-formed from ventral primary rami of spinal nerves C2-C4, which emerge from posterior border of sternocleidomastoid (near its mid-point)
**Most branches are cutaneous
CERVICAL PLEXUS
- Lesser Occipital nerve (C2) -innervates skin behind ear and skin of upper lateral neck
- Great auricular nerve (C2,C3) - innervates skin over parotid gland and skin located inferior to ear
- Transverse Cervical nerve (C2,C3) - innervates skin of anterior neck
- Supraclavicular nerves (C3, C4) - innervates skin of lower lateral neck and shoulder
- Phrenic nerve - (C3,4,5) provides MOTOR innervation to the diaphragm, crosses anterior to scalenus anterior muscle
- Nerves emerge from posterior border of sternocleidomastoid
- Important for anesthesia for suturing neck
Identify the nerve of the neck
- fibers from C1 join Hypoglossal Nerve (XII)
- some leave and join fibers of C2 and C3 to form the nerve
- other fibers continue with XII to innervate thyrohyoid and geniohyoid
(Looks like XII innervates neck muscles; actually C1-C3 do)
*CN XII receives hitchhiking fibers
ANSA CERVICALIS
- fibers from anterior RAMUS of C1 join the hypoglossal nerve (CN XII) as “hitchhiking fibers”
- some fibers leave the XII in the neck and descend down and join other nerves of anterior rami of C2 and C3
- all of this form a loop called ANSA CERVACALIS
- some fibers leave the AC and innervate neck muscles
- other fibers of C1 travel further with the XII
- those fibers then leave the XII to innervate thyrohyoid and geniohyoid muscles
- the result is that XII has branches that look like they innervate neck muscles, but THEY DON’T
- only fibers from C1-C3 actually innervate those muscles
Identify the artery of the head and neck
- At root of neck; artery passes laterally toward arm, posterior to scalenus anterior
- becomes AXILLARY artery at rib 1
**Scalenus anterior muscle divides this artery into what 3 parts
SUBCLAVIAN ARTERY
PART 1 (medial to scalenus anterior)
1. Vertebral artery (ascends into neck and enters foramina transversaria of vertebrae C1-C6)
2. Internal thoracic artery (descends into thorax posterior to sternum)
3. Thyrocervical trunk - branches into;
A. Inferior thyroid
B. Transverse (or superficial) cervical artery
C. SUPRASCAPULAR arteries
PART 2 (posterior to scalenus anterior)
1. Costocervical trunk - branches;
A. Superior intercostal artery supply first two intercostal spaces with posterior intercostal arteries
B. Deep cervical artery - to deep neck muscles
PART 3 (Lateral to scalenus anterior) NO BRANCHES
Identify the arteries to neck and head
-arise from aorta on left, brachiocephalic artery on right; it ascends into neck and divides at level of upper border of thyroid cartilage (vertebral level C4) into internal and external arteries
CAROTID ARTERIES
- Internal carotid artery ascends to skull without branching
- External carotid branches supply face and scalp; branches are (from inferior to superior)
Identify the 8 branches of external carotid artery.
3 branches
- branches from anterior side of external carotid
- branches from posterior side of external carotid
- terminal branches of external carotid
Branches from anterior side of external carotid
- SUPERIOR THYROID ARTERY - descends to thyroid (gives off superior laryngeal a. Which courses to larynx)
- ASCENDING PHARYNGEAL ARTERY - ascends to pharynx
- LINGUAL ARTERY - tongue
- FACIAL ARTERY - below then on surface of mandible
Branches from posterior side
- OCCIPITAL ARTERY - supplies posterior scalp
- POSTERIOR AURICULAR ARTERY - supplies posterior ear and adjacent scalp
Terminal branches - external carotid ends when it divides to;
- SUPERFICIAL TEMPORAL ARTERY - arise opposite external auditory meatus; ascends to supply scalp and temporalis muscle
- MAXILLARY ARTERY - many/15 branches
What is the major cause of ischemic stroke of the brain
CAROTID ARTERY STENOSIS
-MRI and CT angiography are the principal diagnostic tools for diagnoses and surgical intervention (Carotid Endarterectomy)
Most arterial branches have accompanying veins (venue comitantes); branching pattern is variable
**What are the 6 branches
- SUPERFICIAL TEMPORAL and MAXILLARY VEINS - unite to form RETROMANDIBULAR vein (RM)
- RETROMANDIBULAR vein - divides at angle of mandible into anterior (AD) and posterior divisions (PD)
- Anterior division - joins facial vein to form COMMON FACIAL VEIN which drains to INTERNAL JUGULAR VEIN
- Posterior division - joins POSTERIOR AURICULAR VEIN to form EXTERNAL JUGULAR VEIN drains to SUBCLAVIAN VEIN
- Anterior jugular vein - forms from small veins below mandible; descends to join EXTERNAL JUGULAR VEIN above clavicle
The fascia of the neck are divided to 2 layers. Identify them
A.
- loose CT below dermis
- in neck generally thin and hard to demonstrate
- contains platysma and superficial veins
B.
- layers of CT
- one layer completely surrounds neck
- other layers form tubes contained within that layer
- SUPERFICIAL FASCIA
- DEEP CERVICAL FASCIA
- Investing layer of deep cervical fascia - surrounds neck, splits around sternocleidomastoid, trapezius, Supra and infrahyoid muscle
- Prevertebral layer - surround vertebral column, muscles of neck, (Prevertebral, lateral vertebral, suboccipital muscle)
- Pretracheal layer - surround trachea, esophagus and thyroid continues to thorax
- Carotid sheath - surrounds common and internal carotid, internal jugular and X vagus (Not sympathetic chain)
- *Retropharyngeal space - between pretracheal and pre vertebral layers - infection from head (tonsillitis) can spread to mediastinum
- *INFECTIONS TEND TO REMAIN LOCALIZED WITHIN THE CAROTID SHEATH
Identify the problem
- can be difficult to diagnose (no external swelling)
- life threatening because can block airway
RETROPHARYNGEAL ABSCESS
- Infection in Retropharyngeal space can spread unimpeded to thorax (mediastinum)
- George Washington may have died of this
The lymphatics of head and neck are described as 3 groups of lymphatics and nodes
Name all
2 are arranged as rings; drain to chain
- Superficial ring of nodes - drains areas adjacent to their location; consist of submental, submandibular, Buccal, parotid, retroauricular and occipital nodes
- Deep ring - consist of Retropharyngeal and Pretracheal nodes
- Deep cervical chain - chain of nodes along internal jugular vein; receive lymph vessels from all nodes of head and neck
- Jugular lymph trunk - efferent lymph vessels from deep cervical nodes drain into THORACIC DUCT (on left), RIGHT LYMPHATIC DUCT (on right); these drain into brachiocephalic veins (at junction of internal jugular and subclavian veins)
Neck Part 2
**The thyroid gland has 2 lobes inferior to and on sides of thyroid cartilage? What are they called
**WHAT is the laryngeal prominence of thyroid cartilage called?
**What is located below cricoid cartilage?
**When present, what is often attached to hyoid bone by fibrous strand?
**Left and right LATERAL LOBES (cover common carotid artery)
**Adam’s apple
**ISTHMUS - located below cricoid cartilage
**PYRAMIDAL LOBE - attached to hyoid bone by fibrous strand
Summary Thyroid gland composed of - 2 lateral lobes -central isthmus - pyramidal lobe (sometimes present above isthmus)
The thyroid gland is very vascular. Identify 2 branches from the external carotid artery and thyrocervical trunk
that supply the thyroid gland
1.
Come from external carotid that course with superior laryngeal n.
- Come from course with recurrent laryngeal n.
- SUPERIOR THYROID CAROTID ; courses with superior army gear nerve
- INFERIOR THYROID ARTERY come from thyrocervical trunk and course with recurrent laryngeal nerve (located in groove btw trachea and esophagus)
Why must care be taken during thyroid surgery
Why?
What is affected?
Care taken not to damage RECURRENT LARYNGEAL NERVES (when lighting inferior thyroid artery)
- paralyze all muscles of larynx on one side (except cricothyroid muscle)
- patient has only HOARSE VOICE OR WHISPER
The thyroid glands have lots of veins. Name 3 veins that supply the thyroid glands
- *What is the large vein that can be in front of (anterior to) the trachea that can cause bleeding in tracheotomy.
- how can bleeding be avoided?
- SUPERIOR THYROID VEIN - vein follows superior thyroid artery
- MIDDLE THYROID VEIN - veins drain into internal jugular vein
- INFERIOR THYROID VEIN - left and right veins can join together and enter LEFT BRANCHIOCEPHALIC vein
- *INFERIOR THYROID VEINS course anterior to trachea, if large can cause extensive bleeding in tracheotomy
- *emergency access to trachea, bleeding avoided by CRICOTHYROTOMY
Identify the glands
- 4 very small bodies (2 on each side) located posterior to thyroid gland or within gland;
- position is very variable
PARATHYROID GLANDS
- superior parathyroid gland
- Inferior parathyroid gland
Identify
- there are three (3) cervical ganglia (superior, middle, inferior)
- all 3 ganglia send gray rami to cervical spinal nerves
- Most of head and neck is supplied by superior cervical ganglion
- Superior cervical ganglion sends postganglionic fibers via unnamed branches to form a plexus on carotid arteries and their arterial branches
SYMPATHETIC TRUNK
- *Sympathetic chain;
- directly anterior to vertebrae
- Not to be confused with Vagus X nerve
- deep to (not in) carotid sheath
**Sympathetics to most of head are form superior cervical ganglion
Identify
- Follows left margin of esophagus, enters left brachiocephalic vein (at junction of internal jugular and subclavian veins)
- Right recurrent laryngeal nerve courses under subclavian artery; left recurrent laryngeal under aorta; both ascend in groove between trachea and esophagus
- Thoracic duct at root of neck
2. Recurrent laryngeal nerve
What are the triangles of the neck?
**what muscle divides the neck into the 2 triangles?
STERNOCLEIDOMASTOID muscle divides the neck into 2 triangles :
- ANTERIOR TRIANGLE - (anterior to muscle) containing structures related to carotid arteries
- POSTERIOR TRIANGLE - (posterior to muscle), containing structures related to subclavian artery, cervical and brachial plexus
The sternocleidomastoid muscle divides the neck to anterior and posterior triangle.
- *Identify the boundaries of the posterior triangle
- anterior
- posterior
- inferior
- superficial
- deep
*what nerve divide the posterior triangle into inferior/careful and superior/carefree zone
- ANTERIOR - Sternocleidomastoid
- POSTERIOR - Trapezius
- Inferior - Clavicle
- SUPERFICIAL cover - superficial fascia, platysma and investing layer
- DEEP - (floor) covered by Prevertebral layer of fascia
- **The ACCESSORY NERVE is considered to divide the posterior triangle into clinically ‘careful’ zone (inferior) and ‘carefree’ zone (superior)
- *BRACHIAL plexus is the careful zone
NOTE
Subclavian vein is not within posterior triangle
The sternocleidomastoid muscle divides the neck to anterior and posterior triangle.
**Identify the boundaries of the anterior triangle
ANTERIOR - midline of neck
POSTERIOR - Sternocleidomastoid
SUPERIOR - lower margin of mandible
**Subdivided to smaller triangles
CONTENTS
- carotid sheath; common carotid dividing into internal and external carotid arteries
- numerous branches of external carotid
- Veins; Internal jugular vein
- Nerves; Hypoglossal nerve and descending branch of ansa cervicalis, Accessory and vagus nerves
- Lymphatics =; Deep cervical chain of lymph nodes
In cervical vertebra; articular facets are angles superiorly and medially to permit for what movements?
- FLEXION-extension
- In C1, superior articular facets about occipital condyles- joint permit FLEXION and extension and no rotation - Rotation
- Right of atlas rotates on dense of C2
- C1-C2 joints permit rotational movement of head ‘no’
- Does not permit flex-extend
Identify 3 ligaments of vertebrae
- strong band on anterior side
- weaker, narrower band
- yellow elastic bands connecting laminae
- ANTERIOR LONGITUDINAL LIGAMENT - strong band on anterior side
- POSTERIOR LONGITUDINAL LIGAMENT - weaker, narrower band
- LIGAMENTA FLAVA - yellow elastic bands connecting laminae
The craniovertertebral joints are specialization of joints between vertebrae
- Identify joint between atlas (vertebra C1) and occipital bone
- movements are FLEXION-extension of the neck (nodding the head in ‘yes movement) - Joint between atlas (C1) and axis (C2)
- movement is rotation of atlas on axis (shaking head in ‘no’ movement)
- ATLANTO-OCCIPITAL JOINT
2. ATLANTO-AXIAL JOINT
IDENTIFY
- stabilize joints and protect medulla and spinal cord
- some prevent excessive movement
- some are extensions of ligaments of spinal column
**Identify the 4 types
**What fuse to DURA
LIGAMENTS of Craniovertebral joint
- Anterior Atlanta-occipital membrane (C1 - Occipital) = anterior longitudinal ligament
- Membrane tectoria (C2-Occipital) = posterior longitudinal ligament
- Post Atlanto-occipital membrane (C1 - Occipital) = LIGAMENTUM flava
- Cruciate ligament
**Posterior Atlano-occipital Membrane and membrane tectoria fuse to DURA
The ligaments of craniovertebral joints help stabilize and protect medulla. Identify the 4 ligaments
1- extension of anterior longitudinal ligament
2 - extension of posterior longitudinal ligament
3 - extension of LIGAMENTA flava
4 - composed of 3 parts
5. -From dens to occipital bone
- Anterior Atlanta-Occipital membrane = extension of anterior longitudinal ligament - extends from atlas (C1) to occipital bone
- Membrana Tectoria = extension of posterior longitudinal ligament of spinal column - extends from axis to occipital bone, posterior to cruciate ligament
- Posterior Atlanto-Occipital membrane = extension of LIGAMENTA flava - extends from atlas (C1) to occipital bone
- Cruciate (cruciform or cross) ligament - composed of;
- Transverse ligament of atlas
- Superior band to occipital bone
- Inferior band to body of C2 - Atlas “check” ligaments - extending laterally from dens to occipital bone
- prevents excessive rotation of head
There are 4 ligaments of cranial-vertebral joints. The cruciate ligament is one of them and include 3 parts
*Identify
- Transverse band within vertebral canal which is attached to INNER SIDE OF ATLAS (C1)
- holds dens of axis (C2) against inner aspect of anterior arch of atlas - Upper extensions from transverse ligament of atlas to occipital bone superiorly
- Lower extensions from transverse ligament of atlas to body of the axis inferiorly
**A tear in the cruciate ligament lead to what?
- Transverse ligament of atlas
- Superior band to occipital bone
- Inferior band to body of C2
**Tear of cruciate ligament of atlas Can allow dens to be driven into spinal cord (result in QUADRIPLEGIA) or medulla (resulting in DEATH)
Describe the process of hanging someone
- most cervical vertebrae have articular facets that permit extension-FLEXION and rotational movements
- the joint between the atlas and axis is specialized and permit ONLY ROTATIONAL MOEVEMENT (Joint C1-C2)
- IN ACCURATE HANGING; a large knot is placed posterior to the joint btw C1 and C2 and weight of body forcibly flexes the joint (TYPICALLY FRACTURING C2- result in instantaneous death)
- IN INNACURATE HANGING; knot is placed behind other cervical joints resulting in FLEXION of neck, prolonged agony and death by strangulation. Similar fractures occur after trauma (e.g automobile accidents)
The suboccipital region in the suboccipital triangle are bounded by muscles.
- what are the boundaries
- Inferior
- medially
- laterally
- Inferiorly - Obliquus capitis inferior
- Medially - Restuc capitis posterior major
- Laterally - Obliquus capitis superior
There are 4 muscles that make up the suboccipital muscles
- RECTUS Capitis Posterior Major
Attachments
Action
Nerve
Attachment
C2 - occipital bone
Action
- extends head
- rotates skull in unilateral action
Nerve
Suboccipital n. (Dorsal ramus of C1)
There are 4 muscles that make up the suboccipital muscles
- RECTUS Capitis Posterior Minor
Attachments
Action
Nerve
Attachment
C1 - occipital bone; Dura mater
Action
Extends head
Nerve
Suboccipital n. (Dorsal ramus of C1)
There are 4 muscles that make up the suboccipital muscles
- Obliquus Capitis Inferior
Attachments
Action
Nerve
Attachments
C2 - C1
Action
Rotates head
Nerve
Suboccipital n. (Dorsal ramus of C1)
There are 4 muscles that make up the suboccipital muscles
- Obliquus Capitis Superior
Attachments
Action
Nerve
Attachment
C1 - Occipital bone
Action
Extends head
Nerve
Suboccipital n. (Dorsal ramus of C1)
Identify the nerves of suboccipital region
- dorsal ramus of C1 spinal nerve
- MOTOR to suboccipital region
- dorsal ramus of C2 spinal nerve
- SENSORY to skin of back of head and neck
- Suboccipital nerve
2. Greater Occipital nerve
Identify the arteries of the suboccipital region
- Branch of external carotid artery; pierces fascia of trapezius muscle to supply back of head and suboccipital region
- Ascends neck through foramina transversaria of vertebrae C1-C6 and enters skull through foramen magnum
- passes through suboccipital triangle
- OCCIPITAL ARTERY
2. VERTEBRAL ARTERY
The insertion of what muscle to DURA may form anatomical basis for relief of tension headaches by neck massage
Insertion of RECTUS CAPITIS POSTERIOR MINOR
Identify
- sound generator
- consist of cartilage that are connected by membranes and ligaments and moved by muscles
**How are sounds extensively modified?
LARYNX - sit above trachea
2 functions
-sound production
-prevent objects from entering respiratory system (closes off respiratory system - allows increase in abdominal pressure)
** sounds are extensively modified in speech and singing by RESONANCE of PHARYNX, NASAL CAVITY and ORAL CAVITY
The larynx consists of cartilages that are connected by membranes and ligaments and moved by muscles
*Identify the 6 cartilage in larynx
- Thyroid cartilage
- Cricoid cartilage
- Arytenoid cartilage
- Corniculate cartilage
- Cuneiform cartilage
- Epiglottis cartilage
There are 6 cartilage that make up the larynx in part
Identify first 3
- Shield shaped cartilage; has horns (cornua) projecting from upper and lower edges; have SYNOVIAL HINGE JOINTS with cricoid cartilage
- Complete ring of cartilage resting on first tracheal cartilage; has narrow arch (anterior part) and broad lamina (posterior part)
- Two pyramidal shaped cartilages that rest above lamina of cricoid; have SYNOVIAL JOINT with cricoid cartilage that allow for SWIVEL AND SLIDING movements
- THYROID CARTILAGE
- CRICOID CARTILAGE
- ARYTENOID CARTILAGE
There are 6 cartilage that make up the larynx in part
Identify LAST 3
- Two small nodule shaped cartilages that articulate with spices of the arytenoid cartilages, give attachment to aryepiglottic folds
- Two small rod shaped cartilages in aryepiglottic folds
- Left shaped cartilage posterior to root of tongue; connected to body of hyoid bone and back of thyroid cartilage
- COMICULATE CARTILAGE
- CUNEIFORM CARTILAGE
- EPIGLOTTIC CARTILAGE
There are structural and functional ligaments of larynx
How many structural ligaments of larynx are there. Name them and what is the overall function ?
- Links THYROID CARTILAGE to HYOID BONE;
- Links CRICOID TO THYROID CARTIAGLE
- Links CRICOID TO FIRST TRACHEAL CARTILAGE
- Links ARYTHNOID TO EPIGLOTTIS
- Links EPIGLOTTIS TO THYROID CARTILAGE
There are 5 structural ligaments of larynx that hold larynx, hyoid and trachea together
- Thyrohyoid membrane (thickened medial part called median thyrohyoid ligament)
- Cricothyroid membrane (thickened medial and anterior part called median cricothyroid ligament)
- Cricotracheal ligament
- Quadrangular membrane (lower free edge is called vestibular ligament)
- Thyroepiglottic ligament
Identify the functional ligament of larynx
- elastic membrane forming vibrating lips
- arises from entire upper edge of arch of cricoid
- attaches anteriorly to thyroid cartilage
- POSTERIORLY to vocal processes of arytenoid cartilages
- upper free edges are thickened to form vocal ligaments
*8What is the opening between vocal ligaments called?
CONUS ELASTICUS
*opening between vocal ligaments is called RIMA GLOTTIDIS
What are the 2 functions of the CONUS ELASTICUS
- SOUND PRODUCTION - when the vocal ligaments are brought close together, air forced through rima glottidis causes ligaments to vibrate producing sound
- CLOSING RIMA GLOTTIDIS - when vocal ligaments are pressed tightly together the rima glottidis is closed
- this regents upward movement of the diaphragm when the abdominal muscles contract
- contraction of the abdominal muscles increases pressure in the abdominal-pelvic cavity (this is useful in childbirth, micturition, defecation etc)
The muscles of the larynx are divided into extrinsic and intrinsic muscles.
- Extrinsic muscles of larynx
- move entire larynx
- active during swallowing
- SUPRAHYOID muscles elevate larynx
- INFRAHYOID muscles depress larynx - Intrinsic muscles of larynx
- mostly well named for their origins and insertions
- change pitch by changing tension in vocal ligament; increase tension raises pitch, decreased tension lowers pitch
- open and close rima glottidis
There are 6 muscles of the larynx
- CRICOTHYROID
Attachment
Action
Nerve
Attachment
Cricoid cartilage to thyroid cartilage
Action
- Tenses vocal fold
- Raises pitch of sound
Nerve
External Laryngeal n. (X)
There are 6 muscles of the larynx
- THYROARYTENOID
Attachments
Thyroid cartilage to arytenoid cartilage
Action
- Relaxes vocal fold
- Decreases pitch of sound
Nerve
Recurrent Laryngeal n. (X)
There are 6 muscles of the larynx
- POSTERIOR CRICOARYTENOID
Attachments
Cricoid cartilage to Arytenoid cartilage
Action
- Abducts vocal folds
- Opens rima glottidis
Nerve
Recurrent laryngeal n (X)
There are 6 muscles of the larynx
- Lateral CRICOARYTENOID
Attachments
Cricoid cartilage to arytenoid cartilage
Action
- ADducts vocal folds
- Closes rima glottidis
Nerve
Recurrent Laryngeal n. (X)
There are 6 muscles of the larynx
- Arytenoid (transverse arytenoid)
Attachment
Arytenoid cartilage to Arytenoid cartilage of opposite side
Action
- Adducts vocal folds
- Closes rima glottidis
Nerve
Recurrent laryngeal n. (X)
There are 6 muscles of the larynx
- Aryepiglottic muscle
Attachment
Arytenoid cartilage to epiglottic cartilage
Action
- Pulls down epiglottis during swallowing
Nerve
Recurrent laryngeal n. (X)
