LAB 5: The Neck Flashcards Preview

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Flashcards in LAB 5: The Neck Deck (129)
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1
Q

Cervical vertebrae

A
  • 7
  • C1-C7
  • foramen transversarium
  • bifid spinous process
  • atlas- C1 -> no spinous process
  • axis- C2 -> dens
2
Q

hyoid bone

A
  • a small U-shaped bone
  • suspended by ligaments and muscles below the mandible and above the thyroid cartilage
  • lies at the level C3
  • midline of body is extended posterolaterally by long, slander greater horns
  • greater horn project posteriorly
  • lesser horns project superiorly at the junction of the body and the greater horns
  • *suspended from the bottom of the skull (styloid process of the temporal bone) by the stylohyoid ligament
  • hyoid provides attachment for 10 muscles that connect it to mandible, the pharynx, the larynx, and the sternum
3
Q

cartilage of the neck

A
  • tracheal cartilage
  • larynx
  • unpaired laryngeal cartilage
  • paired laryngeal cartilage
4
Q

tracheal cartilage

A
  • trachea runs down the front of the neck from the larynx into the throat
  • wall of tube is comprised of 16-20 C-shaped rings of hyaline cartilage
  • joined together by fibroelastic connective tissue
  • cartilage rings keep the tube open despite pressure changes during breathing
  • rings are open posteriorly where the trachea lies against the esophagus (to smooth muscle)
  • tracheal wall is made up of a smooth muscle (trachealis) that permits the esophagus to expand anteriorly as food passes through it and that can decrease the diameter of the tracheal lumen
5
Q

larynx

A
  • voice box
  • leads to trachea (larynx to lungs)
  • intricate arrangement of cartilages connected by ligaments and membranes
  • lies at level of C4-C6
  • part of it serves to keep the airway open by routing food and drink into the esophagus
  • plays an important role in voice production
  • 3 unpaired and 3 paired laryngeal cartilages:
  • unpaired: thyroid, cricoid, epiglottis
  • paired: arytenoids, corniculates, cuneiforms
6
Q

thyroid cartilage

A
  • unpaired
  • largest laryngeal cartilage
  • lies at the level C4-C5
  • composed of 2 rectangular laminae that meet in the midline at an acute angle (thyroid angle) to form the laryngeal prominence (adam’s apple)
  • posterior edge of each lamina is prolonged upward as a long superior horn and downward as a shorter inferior horn
  • change the sound of the mechanical vibrations -> voice
7
Q

cricoid cartilage

A
  • unpaired
  • shaped like a signet ring
  • lies at the level of C6, directly below and partly overlapped by the thyroid cartilage
  • the narrow part of the ring is anterior
  • back of the ring is expanded upward
  • the paired arytenoid cartilages articulate with the posterolateral corners of the cricoid cartilage along its upper margin
8
Q

epiglottis

A
  • unpaired
  • leaf-shaped
  • attached by its narrow stem by a strong ligament to the back of the angle of the thyroid cartilage
  • projects upward behind and beyond the hyoid bone
  • its free upper edge sits behind the tongue
  • blocks trachea
  • pulled down when swallowing
9
Q

arytenoids

A
  • paired
  • roughly pyramidal in shape
  • each articulates inferiorly with the posterolateral corners of the cricoid cartilage
  • arytenoids are capable of sliding across and rotating on the cricoid at their articulation -> synovial joint
  • the base of the pyramid projects anteriorly as the vocal process -> serves as an attachment for the vocal ligament
  • apex of the arytenoid cartilage supports the corniculate cartilage
10
Q

corniculates

A
  • paired
  • each small cartilage sits atop the arytenoid
  • serves as an attachment for the upper free margin (aryepiglottic fold) of the quadrangular membrane that extends anteriorly to the epiglottis
11
Q

cuneiforms

A
  • paired

- tiny, trivial cartilages lie in the aryepiglottic folds

12
Q

laryngeal membranes

A
  • connects laryngeal cartilages to one another by elastic membranes that permit a certain degree of movement while maintaining overall anatomical integrity
  • free margin of the membrane is slightly thickened -> referred to as a ligament
  • membranes are covered by squamous epithelium which lines the interior of the larynx -> the covering + ligament is called a fold or cord
  • principle membranes, ligaments, folds:
  • thyrohyoid membrane
  • quadrangular membrane
  • aryepiglottic fold
  • vestibular fold
  • conus elasticus
  • vocal fold
13
Q

thyrohyoid membrane

A
  • runs from the superior border of the thyroid cartilage to the bottom of the hyoid bone
  • laryngeal membrane
14
Q

quadrangular membrane

A
  • runs posteriorly from the lateral sides of the epiglottis to the corniculate and arytenoid cartilages
  • laryngeal membrane
15
Q

aryepiglottic fold

A
  • upper fold of the quadrangular membrane
  • superior border of the quadrangular membrane -> forms the aryepiglottic fold
  • two folds form an oval opening to the larynx
  • as food passes from the tongue into the throat -> the epiglottis is pushed posterior, partially blocking this opening
  • prevents food and drink from entering the respiratory tract
  • prevents food from getting in the trachea
16
Q

vestibular fold

A
  • inferior border of the quadrangular membrane is thickened to form the vestibular fold
  • fold are also known as the false vocal cords
17
Q

conus elasticus

A
  • triangular membrane that runs from the internal surface of the back of the thyroid cartilage angle to the superior border of the cricoid and arytenoid cartilages
  • certainly the most important of the laryngeal membranes because of its role in speech
18
Q

vocal fold

A
  • upper fold of the conus elasticus
  • superior free margin of the conus elasticus is thickened to form the vocal fold
  • folds are known as the true vocal cords
  • space between the vocal cords is known as the rima glottidis
19
Q

nerves of the neck

A
  • muscles of the neck are supplied by spinal or cranial nerves
  • thyroid and parathyroid glands are supplied by autonomic fibers
  • autonomic fibers- parasympathetic from the cranial nerves and sympathetic from the cervical sympathetic ganglia
20
Q

spinal nerves of the neck

A
  • spinal nerves from C1-C4 supply muscles in the neck directly or via the cervical plexus
  • cutaneous branches from the plexus innervates the skin over the neck, part of the head, the shoulder, and part of the chest
  • side note: ventral rami of the lower cervical spinal nerves (C5-C8, together with T1) from the brachial plexus
21
Q

cervical plexus

A
  • 4 roots of the cervical plexus are the ventral rami of C1-C4
  • each root gives off a branch that joins with one from its immediate neighbor creating a loop between them
  • there are loops between C1-C2, C2-C3 and C3-C4
  • plexus is deep to the internal jugular vein
  • nerves from C1 and the C2-C3 loop join together around the internal jugular vein in along loop known as the ansa cervicalis
  • provides somatic sensory innervation for cutaneous nerves below
  • emerge behind posterior of the sternocleidomastoid
22
Q

cutaneous nerves

A
  • 3 nerves supply the neck and head from the loop between C2-C3 -> *lesser occipital nerve, *great auricular nerve and *transverse cervical nerve
  • *supraclavicular nerve- supplies the shoulder and chest from the loop between C3-C4
  • these 4 nerves emerge behind the posterior margin of the sternocleidomastoid muscle
  • sensory innervation of skin on neck
  • OATS
23
Q

muscular nerves

A
  • small, unnamed branches come directly from the ventral rami of C1-C4 to supply muscles nearby
  • two motor nerves:
  • ansa cervicalis
  • phrenic nerve
24
Q

ansa cervicalis: muscular nerves

A
  • provides branches to the infrahyoid muscles (innervates)
  • fibers from C1 run with the hypoglossal nerve (CN XII) for a short distance and then descend between the internal jugular vein and internal carotid artery into the beck
  • this is where they join fibers from the C2-C3 loop that descend along the back of the internal jugular vein
25
Q

*phrenic nerve: muscular nerves

A
  • derives from the ventral rami of C3-C5
  • supplies motor innervation to the diaphragm
  • runs across scalenes muscle
  • provides the only motor nerve supply to the abdominal diaphragm
  • runs across the scalenus anterior muscle to enter the thorax between the subclavian artery and brachiocephalic vein
  • C3, C4, C5 -> keeps the diaphragm alive
26
Q

cranial nerves in the neck

A
  • 12
  • peripheral nerves of the brain
  • 6 supply structures in the neck
  • trigeminal nerve (V) -> mandibular division -> lingual nerve and mylohyoid nerve
  • Facial nerve (VII)
  • Glossopharyngeal Nerve (IX)
  • Vagus Nerve (X) -> pharyngeal branch, superior laryngeal nerve, internal laryngeal nerve, external laryngeal nerve, recurrent laryngeal nerve
  • Accessory Nerve (XI)
  • Hypoglossal Nerve (XII)
27
Q

trigeminal nerve (V)

A
  • cranial nerve of neck
  • 3 main divisions
    1. Mandibular division- 2 branches that enter the neck
  • one of these branches if the *lingual nerve- runs across the lateral surface of the hyoglosssus muscle to relay sensation from the anterior two-thirds of the tongue
  • the other branch is the *mylohyoid nerve- runs across the hyoglossus and mylohyoid muscles, supplying the latter, and the anterior belly of the digastric muscle
28
Q

facial nerve (VII)

A
  • cranial nerves in the neck
  • runs from beneath the ear to enter the parotid gland in the cheek, where it divides into several branches
  • one of these supplies the posterior belly of the digastric muscles and the stylohyoid muscle
  • another runs along the lower border of the mandible to innervate the platysma muscle
29
Q

glossopharyngeal nerve (IX)

A
  • cranial nerves in the neck
  • runs from between the internal carotid artery and the internal jugular vein onto the back of the pharynx, relaying sensation from the pharyngeal constrictor muscles
  • a branch continues on to supply the posterior one-third of the tongue
  • relays taste and sensation
30
Q

vagus nerve (X)

A
  • cranial nerves in neck
  • runs between the internal carotid artery and internal jugular vein throughout the length of the neck
  • gives off *pharyngeal branch to a plexus on the back of the pharynx that supplies the pharyngeal constrictors- provides 2 branches to the larynx
  • 1st branch- *superior laryngeal nerve- divides into *internal laryngeal nerve- relays sensation from the larynx above the vocal cords (cough, itchy throat) and the *external laryngeal nerve- innervates the cricothyroid
  • 2nd branch- *recurrent laryngeal nerve- comes off the the vagus in the thorax on the left curving around under the arch of the aorta to run back up into the neck between the trachea and esophagus (supplies intrinsic laryngeal muscles)
  • on the right side it comes off the vagus at the level of the subclavian artery curving around under it to run back up along the trachea
  • recurrent laryngeal nerves supply all but one the intrinsic laryngeal muscles
31
Q

accessory nerves (XI)

A
  • cranial nerves in neck
  • runs below the posterior belly of the digastric muscle to supply the sternocleidomastoid
  • descends within this muscle for about half its length
  • turns to innervated the trapezius
32
Q

hypoglossal nerve (XII)

A
  • cranial nerves in neck
  • runs into the neck with the vagus for a short distance
  • runs anteriorly across the external carotid artery and medial to the digastric and onto the hypoglossus muscle -> which it innervates
  • also supplies all but one of the tongue muscles
33
Q

autonomic nerves in the neck

A
  • concerned with the control and/or modificaiton of involuntary activities such as smooth and cardiac muscle contraction and glandular secretion
  • 2 divisions:
  • parasympathetic
  • sympathetic
  • both involve 2 neurons in transmission of motor impulses to a target organ
34
Q

preganglionic neuron

A
  • cell body in the CNS

- synapses with postganglionic neuron

35
Q

postganglionic neuron

A

-cell body in autonomic ganglion close to either the spinal cord (sympathetic) or the target organ (parasympathetic)

36
Q

sympathetic stimulation

A
  • come about via mass activation
  • fight or flight
  • signals come from T1-L2 vertebral levels
  • bc it only runs from T1-L2 -> the sympathetic chain ganglion- highway that extends the signals
  • intermediolateral (IML) column, or lateral horn between dorsal and ventral horns
37
Q

parasympathetic fibers

A
  • may involve individual nerve activation
  • rest and digest
  • signals come from cranial nerves and S2-S4
  • innervation of structures in neck derives from cranial nerves
  • only one cranial nerve supplies glands that are in the neck
  • Facial nerve (VII)- provides parasympathetic fibers to the submandibular and sublingual salivary glands via a branch (the chorda tympani) that runs along the lingual nerve
  • chorda tympani synapses with submandibular ganglion
  • parasympathetic preganglionic neurons are so long that the postganglionic is so short its in the body wall
38
Q

sympathetic chain

A
  • innervates glands in the neck
  • conducted largely through a chain of fibers and ganglia located on either side of vertebral column
  • preganglionic neurons of the thoracic and lumbar region of the spinal cord send their axons out into the ventral rami of spinal nerves
  • some of the axons enter the chain of sympathetic ganglia via myelinated white rami communicantes
  • other axons turn up or down the chain to synapse in higher or lower ganglia
  • the chain enters the neck deep to subclavian artery and runs upward through the length of the neck on the front of the longus colli and longus capitis muscles -> it runs adjacent to the common carotid and internal carotid arteries, which it supplies
  • these postganglionic fibers follow the internal carotid artery into the skull
  • there is no sympathetic outflow form the cervical spinal nerves, but sympathetic chain extends into the neck
  • from sympathetic ganglia of the neck some postganglionic neurons run to a target organ in the neck or back in the thorax (usually)
  • others jump back onto ventral rami of the cervical spinal nerves for distribution to targets in body wall and limbs
  • postganglionic neurons travel to the spinal nerves via unmyelinated gray rami communicantes
39
Q

sympathetic trunk

A
  • usually has 3 ganglia
  • fuse at the neck
  • contribute to innervation of thyroid gland, arrector pili in body wall, heart etc.
  • lowest is the *inferior cervical ganglion- located at or just below the level of C7
  • it is commonly fused with the uppermost thoracic ganglion to form the *stellate ganglion
  • *middle cervical ganglion lies somewhere between the levels of C4 and C6
  • long *superior cervical ganglion stretches from C1 to C2
  • at the level of the subclavian artery the sympathetic chain sends out a branch that courses around the artery and upward to region the chain -> this loop is the *ansa subclavia
  • chain communicates with the ventral rami of the cervical spinal nerves by thin gray rami communicantes that extend from the ganglia
40
Q

postganglionic sympathetic axons

A
  • two bundles of postganglionic sympathetic axons that travel back down the neck and into the thorax to innervate the heart ->cervical sympathetic cardiac nerves
  • some of these axons arise from the middle cervical ganglion to form the superior cervical cardiac nerve
  • most of the axons arise from the stellate ganglion to form the inferior cervical cardiac nerve
  • the chain provides innervation to the thyroid gland
  • nerves to thyroid gland travel to it from the superior and middle cervical ganglia in company with the superior and inferior thyroid arteries
41
Q

muscles of the neck

A
  • may attach to one or more of the bony or cartilaginous elements in it or simply pass by on their way between the head and trunk
  • some participate in movements of the shoulder (scapula)
  • others move the head, the spinal column, or larynx and pharynx
42
Q

muscles in the neck that that move the scapula

A
  • trapezius

- levator scapulae

43
Q

muscle in the neck that move the head

A
  • 7
  • insert onto the skull
  • splenius capitis
  • longissimus capitis (part of the erector spinae)
  • semispinalis capitis
  • rectus capitis anterior
  • rectus capitis lateralis
  • Longus capitis
  • rectus capitis lateralis
44
Q

spinal nerves

A
  • branch from the spinal cord

- C1-C8, T1-T12, L1-L5, S1-S5

45
Q

cranial nerves (CN)

A
  • branch directly from brain, not spinal cord
  • 12
  • CN 1 -CN X11
46
Q

cricoarytenoid joint

A
  • abduction -> swivels and pull folds open -> forced respiration
  • posterior circoarytenoid (abductor)
  • adduction -> closes vocal folds -> phonation
  • all other intrinsic laryngeal muscles (adductor)
  • allows for speech production
  • synovial
  • adduct and abduct vocal ligaments
  • arytenoids and cricoid articulate
  • always a little open for breathing
47
Q

glottis =

A

rima glottidis (space) + vocal folds (structures)

48
Q

longus capitis

A
  • origin- transverse processes C3-C6
  • insertion- runs upward and medially inserts on occipital bone anterior to the foramen magnum
  • flexes neck(head), rotates head to the same side (ipsolaterally)
  • innervated by cervical ventral rami of C1-C6
49
Q

muscles that move the neck: longus colli

A
  • origin- superior oblique- transverse processes C3-C5; inferior arch- bodies of T1-T3
  • insertion- superior oblique- anterior arch of atlas (C1); inferior arch- transverse processes of C5-Cs
  • action- flexes the neck forward or lateral
  • innervated by cervical ventral rami of C1-C7
50
Q

sternocleidomastoid

A
  • origin- arises from clavicle and by a tendon on from the manubrium of the sternum
  • insertion- on mastoid process (by temporal bone) and superior nuchal line of skull
  • action- laterally flexes the neck (when both sides are contracted)
  • rotates head to the opposite side (contralaterally- contraction of right rotates left) (when one side is contracted)
  • innervation- accessory nerve (CN XI) which communicates with spinal nerves C2-C4
  • bilaterally- flexes the neck, pulls chin to sternum (if you didnt flex this during sit-ups ur head would fling back)
  • unilaterally- laterally flexes neck to same side
  • unilaterally- rotates head to opposite side
51
Q

scalene muscles

A
  • anterior scalenes
  • middle scalenes
  • posterior scalenes
  • flex the neck laterally and raise either the 1st or 2nd rib during forced inspiration
  • innervation- cervical ventral rami
52
Q

anterior scalenes

A

-origin- arise from transverse processes of C3-C6

53
Q

middle scalenes

A

-arise from transverse processes of C2-C6

54
Q

posterior scalenes

A
  • arise from transverse processes C4-C6

- inserts on 2nd rib

55
Q

intrinsic laryngeal muscles…

A
  • 5

- run between larnygeal cartilages to change vocal

56
Q

suprahyoid muscles

A
  • stylohyoid
  • digastric (posterior belly and anterior belly)
  • mylohyoid
  • geniogyoid
57
Q

intrinsic laryngeal muscles

A
  • 5

- run between larnygeal cartilages to change vocal tension for voice production

58
Q

suprahyoid muscles

A
  • stylohyoid
  • digastric (posterior belly and anterior belly)
  • mylohyoid
  • geniohyoid
59
Q

digastric

A
  • posterior belly:
  • action- elevates hyoid when closing mouth
  • innervation- posterior auricular nerve (branch of facial- CNVII)
  • anterior belly:
  • action- elevates hyoid during swallowing and opening the mouth
  • innervation- mylohyoid nerve (V3)
60
Q

digastric

A
  • posterior belly:
  • action- elevates hyoid when closing mouth
  • innervation- posterior auricular nerve (branch of facial- CNVII)
  • anterior belly:
  • action- elevates hyoid during swallowing and opening the mouth
  • innervation- mylohyoid nerve (CN V3)
61
Q

stylohyoid

A
  • straddles the posterior belly

- both innervated by facial nerve

62
Q

geniohyoid

A
  • action- elevates the hyoid during swallowing
  • innervation- first cervical nerve C1
  • on top of stylohyoid
63
Q

infrahyoid muscles

A
  • omohyoid
  • sternohyoid
  • thyrohyoid
  • sternothyroid
  • innervated by ansa cervicalis
64
Q

sternohyoid

A
  • origin- arises from manubrium and clavicle
  • insertion- hyoid
  • action- depresses the hyoid
  • innervation…..
65
Q

sternohyoid

A
  • origin- arises from manubrium and clavicle
  • insertion- hyoid
  • action- depresses the hyoid
  • innervation- ventral rami C1-C3 (ansa cervicalis)
66
Q

posterior cricoarytenoid

A
  • abductor muscle for cricoarytenoid joint

- opens vocal folds

67
Q

cricothyroid

A
  • tenses the vocal cords

- not really in the larynx

68
Q

pharynx

A
  • muscular tube
  • covered in mucosa
  • 3 constrictor muscles:
  • superior constrictor
  • middle constrictor
  • inferior constrictor
  • all insert onto the medial pharyngeal raphe
  • move food down
  • sensory innervation- glossopharyngeal 9
69
Q

superior constrictor

A

-origin- medial pterygoid plate

70
Q

middle constrictor

A

-origin- greater horn of the hyoid bone

71
Q

inferior constrictor

A

-origin- thyroid and cricoid cartilages

72
Q

inferior constrictor

A

-origin- thyroid and cricoid cartilages

73
Q

somatic nerves

A
  • skin, skeletal muscles, joints, tendons, bones
  • voluntary motor control
  • sharp, localized pain -> caused by cutting, burning as well as inflammation, distention, ischemia
74
Q

visceral (autonomic) nervous system

A
  • smooth muscle, cardiac muscle, glands
  • parasympathetic and sympathetic
  • unconscious motor control
  • non-location, duller pain
  • caused by distension, ischemia, inflammation
  • visceral motor also called autonomic nervous system
  • ex. heart burn (feels like in ur heart and u cant even pinpoint it)
  • also has two neurons -> preganglionic (in lateral horn) and postganglionic
  • sympathetic chain ganglion -> from preganglionic to synapse with postganglionic
75
Q

neural pathway

A
  • preganglionic neuron in the lateral horn
  • goes out to ventral root
  • goes through spinal nerve proper
  • go through ventral rami
  • goes on the white ramus communicates
  • sympathetic chain ganglion
  • synapse on appropriate ganglion level at postganglionic neuron
  • gray ramus communicantes
  • ventral ramus or dorsal ramus
76
Q

arteries

A
  • left common cartoid branches off arch of the aorta
  • right common carotid branches off brachiocephalic trunk
  • upper margin of thyroid cartilage: common carotids divide into internal and external carotid arteries (ICA and ECA)
  • ICA -> brain
  • ECA branches in the neck
  • branches of subclavian artery also supply structures in the neck
77
Q

external carotid artery*

A
  • gives off 7 branches and then terminates as the superficial temporal artery
  • superior thyroid
  • ascending pharyngeal
  • lingual
  • facial
  • occipital
  • posterior auricular
  • maxillary
  • (superficial temporal)
  • Some Anatomists Like Freaking Out Poor Medical Students
78
Q

subclavian artery branches

A
  • vertebral artery (to brain)- runs through cervical transverse foramina
  • internal thoracic artery (to thorax)
  • thyrocervical trunk-> suprascapular artery, inferior thyroid artery, transverse cervical artery
  • costocervical trunks
  • branches into these 3 before crossing over the 1st rib to become axillary artery
79
Q

internal jugular (IJV) + subclavian =

A

= brachiocephalic vein

80
Q

retromandibular vein

A
  • behind mandible
  • joint up with facial vein -> forms common facial vein
  • common facial vein drains into internal jugular vein
81
Q

muscles that move the neck

A
  • 6
  • splenius (cervicis)
  • semispinalis (cervicis)
  • longus colli
  • scalenus anterior
  • scalenus medius
  • scalenus posterior
82
Q

muscles that move the neck: scalenus anterior

A

arises from the transverse processes of C3-C6

  • inserts on a bump called the scalene tubercle onto the superior surface of the first rib
  • flexes the neck forward or laterally
  • assists in raising the first rib during forced inspiration
  • innervated by ventral rami C5-C6
83
Q

muscles that move the neck: scalenus medius

A
  • arises from transverse processes of C2-C6
  • insert onto the superior surface of the first rib toward its posterior margin
  • flexes the neck laterally
  • assists in raising the first rib during forced inspiration
  • innervated by ventral rami C3-C8
84
Q

muscles that move the neck: scalenus posterior

A
  • little muscle that may blend with the fibers of scalenus medius or that may be absent
  • arises from the transverse process of C4-C6
  • insert onto the outer surface of the 2nd rib
  • flexes the neck laterally
  • assists in raising the 2nd rib during forced inspiration
  • innervated by ventral rami of C4-C7
85
Q

a muscle of facial expression: platysma

A
  • pulls on skin
  • almost entirely in the neck
  • no effect on skeleton
  • supplied by the facial nerve (CN VII)
  • platysma- flat, thin muscular sheet that covers the anterolateral surface of the neck
  • arises inferiorly from the fascia over the clavicle
  • inserts into the fascia below the mouth
  • uppermost medial fibers decussate with (cross over) those of the muscle from the opposite side
  • draws the corners of the mouth downward (as in terror)
  • when it contracts its lateral margins define clear ridges in the skin on the side of the neck
86
Q

muscle that move the hyoid and larynx

A
  • hyolaryngeal muscles -> suprahyoid hyolaryngeal muscle, infrahyoid hyolaryngeal muscle
  • intrinsic muscles
87
Q

muscle that move the hyoid and larynx: hyolaryngeal muscles

A
  • 8
  • 6 of these muscles attach to the hyoid either from above or from below -> move it up and down during swallowing
  • bc the hyoid bone is attached to the larynx by the thyrohyoid membrane -> movement of the hyoid translates into movement of larynx during swallowing
  • 2 groups:
  • suprahyoid hyolaryngeal muscle-4- originates above the hyoid bone (skull)
  • infrahyoid hyolaryngeal muscle-4- originate below the hyoid bone (thoracic skeleton or thyroid cartilage)
88
Q

muscle that move the hyoid and larynx: intrinsic laryngeal muscles

A
  • 5
  • run between the laryngeal cartilages to change vocal cord tension
  • integral part of voice production
89
Q

suprahyoid hyolaryngeal muscles

A
  • stylohyoid
  • digastric -> posterior and anterior belly
  • mylohyoid
  • geniohyoid
90
Q

suprahyoid hyolaryngeal muscles: stylohyoid

A
  • arises from the styloid process of the skull and runs along the stylohyoid ligament
  • inserts onto the hyoid greater horn
  • elevates the hyoid during swallowing
  • innervated by posterior auricular nerve = branch of facial nerve (CN VII)
91
Q

suprahyoid hyolaryngeal muscles: digastrci

A
  • two bellies connected by an intermediate tendon that is attached to the hyoid by a loop of fascia
  • posterior belly arises from the bottom of the skull medial to the mastoid process
  • anterior belly inserts onto the lower border of the mandible near its midline
  • posterior belly- elevates the hyoid during closing of mouth -> innervated by posterior auricular nerve = branch of facial nerve (CN VII)
  • anterior belly- elevates the hyoid during swallowing and opening of the mouth and depresses the mandible -> innervated by mylohyoid nerve = branch of trigeminal nerve (CN V3)
92
Q

suprahyoid hyolaryngeal muscles: mylohyoid

A
  • arises form a line on the inside of the mandible mandibular body
  • some of its fibers meet in the midline along a fibrous band ( a raphe) forming a semirigid floor to the mouth -> important for swallowing
  • other fibers insert on the hyoid and elevate it
  • innervated by mylohyoid nerve= branch of trigeminal nerve (CN V3)
93
Q

suprahyoid hyolaryngeal muscles: geniohyoid

A
  • runs from a small spine on the back of the mandibular symphysis to the hyoid
  • elevates the hyoid during swallowing
  • innervated by the first nerve C1 -> travels with the hypoglossal nerve (CN XII)
94
Q

infrahyoid hyolaryngeal muscles

A
  • omohyoid
  • sternohyoid
  • thyrohyoid
  • sternothyroid
95
Q

infrahyoid hyolaryngeal muscles: omohyoid

A
  • 2 bellies connected by an intermediate tendon that is bound to the medial end of the clavicle by a fascial sling
  • superior belly arises form the lower margin of the hyoid
  • inferior belly arises form the superior border of the scapula medial to the suprascapular notch
  • depresses the hyoid during vocalization and at the end of swallowing
  • innervated by ventral rami of C2-C3 (via ansa cervicalis)
96
Q

intrinsic laryngeal muscles

A
  • 5 -> change the tension of the vocal cords by moving the cricothyroid joint or the cricoarytenoid joint
  • 4 adduct (bring together) the cords
  • 1 abduct the cord
  • innervated by the vagus nerve (CN X)
97
Q

intrinsic laryngeal muscles: Cricothyroid

A
  • runs from the front of the cricoid cartilage to the inferior border and horn of the thyroid cartilage
  • rotates the thyroid forward and downward at the cricothyroid joint
  • causes the vocal cords to tighten and adduct
  • innervated by external laryngeal nerve (vagus)
98
Q

intrinsic laryngeal muscles: lateral cricoarytenoid

A
  • runs up and back from the upper rim of the cricoid
  • inserts onto the lateral side of the base of arytenoid cartilage
  • rotates the arytenoid medially
  • causes the vocal cords to adduct
  • innervate by the recurrent laryngeal nerve (vagus)
99
Q

intrinsic laryngeal muscles: thyroarytenoid

A
  • arises from the back of the thyroid angle
  • inserts onto the anterolateral aspect of the arytenoid
  • most medial fibers are considered to comprise of the vocalis muscle
  • uppermost fibers pass upward into the aryepiglottic fold to reach the epiglottis -> referred to as the thyroepiglottic muscle
  • thyroepiglottic muscle- rotates the arytenoid medially -> adducts the vocal cords and causes them to slacken
  • inverts the sensitive aryepiglottic folds during swallowing
  • avoids the cough reflex (otherwise would by elicited by the passage of food over the laryngeal opening)
  • innervated by recurrent laryngeal nerve (vagus)
100
Q

intrinsic laryngeal muscles: arytenoideus

A
  • composed of transverse and oblique fibers that run between the arytenoid cartilages
  • causes the arytenoid cartilages to approximate one another
  • adducts and tightens the vocal cords
  • innervated by recurrent laryngeal nerve (vagus)
101
Q

*intrinsic laryngeal muscles: posterior cricoarytenoid

A
  • runs from the back of the cricoid
  • inserts onto the posterolateral side of the arytenoid cartilage
  • laterally rotates the arytenoid cartilages
  • causes the vocal cords to abduct
  • only vocal cord that abducts
  • holds the glottis open during heavy breathing
  • innervated by recurrent laryngeal nerve (vagus)
102
Q

pharynx

A
  • muscular tube that extends from the base of the skull to the level of the lower border of the larynx
  • becomes continuous with the esophagus
  • upper half is open anteriorly into the nasal and oral cavities
  • 3 parts:
  • nasopharynx- open into the nasal canal of the skull
  • oropharynx
  • laryngopharynx- continuous with the esophagus
103
Q

oropharynx

A
  • lies below the palate and above the epiglottis
  • opens into the oral cavity
  • bounded around this opening by the uvula, palatine tonsils, and tongue
104
Q

pharyngeal muscles

A
  • superior constrictor
  • middle constrictor
  • inferior constrictor
  • supplied by the plexus of nerves that lies on the back of the middle constrictor
  • plexus is made up of branches from glossopharyngeal nerve (CN IX) (sensory) and the vagus nerve (CN X) (motor)
  • also receives sympathetic innervation via branches from the superior cervical ganglion
105
Q

pharyngeal muscles: superior constrictor

A
  • arises from the medial pterygoid plate of the skull and a narrow band of connective tissue (pteryhomandibular raphe)
  • has a tiny attachment to the base of the skull in the midline in front of the foramen magnum
  • region between the muscle and the skull is filled by a sheet of tissue, the pharyngobasilar fascia
  • fibers from each side curve around posteriorly to meet in the midline along a thin band of connective tissue (median raphe)
106
Q

pharyngeal muscles: middle constrictor

A
  • arises from the upper margin of the greater horn of the hyoid bone, deep to the hyoglossus muscle
  • fibers from each side curve around to meet at the median raphe
107
Q

pharyngeal muscles: inferior constrictor

A
  • arises from the thyroid cartilage, the fascia over the cricothyroid muscle, and the side of the cricoid cartilage
  • lowermost fibers intertwine with muscle fibers of the esophagus
  • fibers from each side curve around to meet along a thing median raphe
108
Q

arteries

A
  • right side- brachiocephalic trunk comes off aorta -> common carotid artery -> subclavian artery
  • left side- subclavian artery and common carotid artery arise directly from the aorta
  • both sides- common carotid artery runs upward next to the trachea and esophagus
  • at the upper margin of the thyroid cartilage, common carotid artery divides into the internal carotid artery and external carotid artery
109
Q

branches of the internal carotid artery

A
  • no branches in the neck
  • runs behind the external carotid artery to enter the skull through the carotid foramen
  • supplies the brain
110
Q

branches of the external carotid artery

A
  • 7 main branches
  • superior thyroid artery- comes off immediately to supply the thyroid and parathyroid glands
  • ascending pharyngeal artery- supplies the pharynx and soft palate
  • lingual artery- comes off at the level of the hyoid to supply the tongue
  • facial artery- curves around the lower edge of the mandible to ascend into the face
  • occipital artery- supplies the back of the head
  • posterior auricular artery- supplies the scalp behind the ear
  • maxillary artery- comes off just below the jaw joint and branches to the mandible, the flat bones of the cranium and the maxilla
  • after the maxillary artery comes off the external carotid changes its name to superficial temporal artery -> runs anterior to the ear
111
Q

branches of the subclavian artery

A
  • vertebral artery- comes off first and runs up the beck through the foramina transversarium of the cervical vertebrae -> enters skull through foramen magnum to supply brain
  • internal thoracic artery- runs into the thorax behind the ribs just lateral to the sternum
  • thyrocervical trunk- also a branch of the subclavian -> divides into 3 branches -> suprascapular artery (supplies scapular muscles), inferior thyroid artery (supplies the thyroid and parathyroid glands), the transverse cervical artery
112
Q

veins

A
  • deep and superficial
  • internal jugular vein
  • subclavian vein
  • brachiocephalic vein
  • superior thyroid vein
  • middle thyroid vein
  • inferior thyroid vein
  • common facial vein
  • retromandibular vein
  • facial vein
  • posterior auricular vein
  • occipital vein
  • external jugular vein
  • anterior communicating vein
  • anterior jugular vein
  • vertebral vein
113
Q

internal jugular vein

A
  • exits the skull via the jugular foramen
  • runs down the neck along the lateral surfaces of the internal and common carotid arteries
  • merges with subclavian veins -> forms the brachiocephalic veins
  • vein, artery, vagus nerve are surrounded by tube of fascia -> Carotid sheath for most of their conjoint length
  • receives blood from the superior thyroid vein and the middle thyroid vein (and the common facial vein from the retromandibular vein and the facial vein)
114
Q

subclavian vein

A
  • internal jugular veins drains into subclavian vein

- forms a junction with brachiocephalic vein

115
Q

brachiocephalic vein

A
  • forms function with a subclavian vein
  • brachiocephalic veins join to form the superior vena cava
  • left brachiocephalic vein crosses the midline behind the manubrium receiving the inferior thyroid vein -> joins the right brachiocephalic -> forms superior vena cava
116
Q

inferior thyroid vein

A

-drains into the left brachiocephalic vein

117
Q

retromandibular vein

A
  • bifurcates
  • one branch -> drains into the common facial vein
  • the other is joined by the posterior auricular and occipital vein -> forms the external jugular vein
  • retromandibular and facial veins join to make the -> anterior communicating vein
118
Q

external jugular

A
  • branch of the retromandibular is joined by the posterior auricular and occipital vein -> forms the external jugular vein
  • drains into the subclavian vein
119
Q

anterior communicating vein

A
  • drains into the anterior jugular vein

- retromandibular and facial veins join to make the -> anterior communicating vein

120
Q

anterior jugular vein

A

-drain into the external jugular vein

121
Q

vertebral vein

A
  • exits the skull through the foramen magnum and runs through the foramina transversarium of the cervical vertebrae
  • drains into the junction of the external jugular vein and subclavian vein
122
Q

aortic arch

A

-gives of brachiocephalic trunk -> left common carotid -> left subclavian artery

123
Q

brachiocephalic trunk

A

-divides into right common carotid artery and right subclavian artery behind the sternoclavicular joint

124
Q

thoracic duct

A
  • largest of the lymphatic channels
  • enters the neck from the thorax on the left side of the esophagus
  • ascends to the level of the thyroid gland
  • turns inferolaterally to drain into the subclavian vein at its junction with the internal jugular vein
  • right lymphatic duct -> drains into the right subclavian vein at its junction with the internal jugular vein
125
Q

pleural dome

A
  • space bounded anteriorly by the carotid and subclavian arteries, medially by the trachea and esophagus, and posterolaterally by the 1st ribs is occupied by the apex of the pleural dome
  • lungs protrude into the pleural dome during deep inspiration
126
Q

exocrine gland

A
  • secretes its product into a duct

- transports it to outer surface of the body or onto the lumen of an organ

127
Q

endocrine gland

A
  • secretes its products (hormone) into the space around the secretory cell
  • hormone diffuses into capillaries and is transported by the circulatory system throughout the body
128
Q

thyroid gland

A
  • lies at the junction of the larynx and trachea
  • H-shaped
  • 2 lateral lobes connected by horizontal isthmus
  • lobes cover the lower sides of the thyroid cartilage, the cricoid cartilage, and the upper 6 tracheal rings
  • isthmus lies in front of the 2nd to 4th tracheal rings
  • about 50% of people have a fingerlike pyramidal lobe that projects upward onto the larynx from the middle of the isthmus
  • 4 lentil sized parathyroid glands are embedded on the back of the thyroid gland
  • gland in the superior pair lie at the level of the lower margin of the pharynx -> the position of the glands in the inferior pair is more variable
129
Q

blood supply of the glands-

A
  • thyroid and parathyroid are highly vascular (bc they are endocrine glands)
  • they derive their blood supply from superior and inferior thyroid arteries
  • superior thyroid artery- branch of the external carotid artery; runs down across the thyroid cartilage to the gland
  • inferior thyroid artery- a branch of the thyrocervical trunk; emerges from the subclavian artery
  • blood from the glands is drained by the superior thyroid vein and the middle thyroid vein -> drain into internal jugular vein (also drained by inferior thyroid veins which unite to drain into the left brachiocephalic bein behind the manubrium)