HEENT Anatomy PDF

Bones of the Skull (cranium) ↙ ↘ Neurocranum (8) Viscerocranium (14) ↓ ↓ Frontal Nasal (2) Parietal (2) Lacrimal (2) Temporal (2) Palatine Bone Occipital Inferior Nasal (concha) (2) Sphenoid Maxilla (2) Ethmoid Zygomatic (2) Vomer Mandible 5 special senses: 1. Smell (olfaction) →...

Bones of the Skull (cranium) ↙ ↘ Neurocranum (8) Viscerocranium (14) ↓ ↓ Frontal Nasal (2) Parietal (2) Lacrimal (2) Temporal (2) Palatine Bone Occipital Inferior Nasal (concha) (2) Sphenoid Maxilla (2) Ethmoid Zygomatic (2) Vomer Mandible 5 special senses: 1. Smell (olfaction) → olfactory receptors 2. Taste (gustation) → gustatory receptors 3. Vision → photoreceptors 4. Hearing → hair cells of the cochlea 5. Equilibrium → hair cells of the ampulla & macuale Bones of neurocranum 1. Frontal Bone 3. Temporal Bone 4. Occipital Bone 2. Parietal Bone 2 IMPORTANT OPENINGS OF THE SPHENOID 5. Sphenoid Bone → bat shaped a. Optic foramen: i. CNII (vision) → orbit into the carnival cavity b. Superior orbital fissure: i. Long slit between greater & lesser wings ii. CN III, IV, VI pass-through c. Foramen rontundum: i. lateral to sella turcica & CNV passes through d. Foramen ovale: i. Posterior to sella turcica& CNV passes through e. i. Foramen Spinosum Middle meningeal artery MAJOR PARTS OF THE ETHMOID BONE 6. Ethmoid Bone → between nasal & orbital cavity a. Cribriform plates i. Houses roof of nasal cavities; olfactory foramina (transmits fibers of CNI) b. Ethmoidal labyrinth i. Interconnected network of ethmoidal air cells ii. Mostly superior & middle nasal conchae c. Perpendicular plate i. Forms superior part of nasal septum ii. Lots of sinuses Viscerocranium (Facial bones) 1. Nasal Bone (2) 5. Inferior Nasal (concha) Bone 2. Lacrimal (2) 6. Mandible 3. Vomer Bone (1) 7. Zygomatic Bone 4. Palatine Bone AREAS OF THE MAXILLA BONES 8. Maxilla Bone (2) a. Palatine processes i. Form the anterior part of hard palate b. Frontal processes i. Lateral aspect of bridge of nose connects with the frontal & nasal bones c. Zygomatic processes i. Connects w/ the zygomatic bones d. Inferior orbital Fissure i. Opening w/in each orbit, formed by the maxillae & sphenoid e. Infrorbital foramen i. Opening under each; allows for passage of the infraorbital nerves & vessels f. Alveolar margin i. Oral margin of the maxillae that contains the upper teeth THE NOSE 1. Lies superior to hard palate 2. Includes external nose & nasal cavity 3. Functions of the nose: a. Smell b. Respiration c. Filtration d. Humidification e. Reception & elimination of secretions from the paranasal sinuses & nasolacrimal ducts EXTERNAL NOSE: 1. Inferiorly → cartilage & skin 2. Superiorly = Dorsum a. nasal bones b. frontal process of the maxillae c. Nasal part of the frontal bone d. Nasal spine 3. Nerve supply from CNV1 (Trigeminal Nerve, Ophthalmic Branch) 4. Opening of nasal cavity → “Nares” Nasal Cavities 1. Right & Left a. Own Nares (nostrils) → divided by nasal septum 2. Communicates posteriolry w/ nasopharynx 3. Entire cavity lines w/ mucous membrane 4. Roof of cavity → openings in cirbriform plate of ethmoid bone a. Olfactory nerves communicate w/ olfiactory bulb (CN-1) Nasal Septum 1. Divides nasal chamber → 2 nasal cavities 2. Bony and cartilaginous parts 3. Main parts: a. Perpendicular plate of the ethmoid bone b. Vomer bone c. Septal cartilage Nasal Cavities 1. Lateral wall has 3 projecting conchae (turbinates) a. ↑ SA for cleansing, humidification & temperature control of inspired air 2. Vascular supply from branches of the facial, ophthalmic, & maxillary arteries a. Anterior inferior nasal septum to form the Kiesselbach pleux (triangle) Paranasal Sinuses 1. 4 paid air-filled extensions of the respiratory part of the nasal cavity a. Ethmoid - can only see on CT scan b. Frontal c. Maxillary d. Sphenoid - can only see on CT scan 2. Lighten the weight of the skull 3. Frontal & maxillary sinuses → palpable during the physical exam Olfaction (smell): 1. Olfactory Epithelium - mucous membrane on roof of nasal cavity 2. Olfactory Nerve(s) → CNI a. Exit through the cribriform plate of the ethmoid bone b. Pick up molecules of smell then go to bulbs 3. Olfactory bulbs 4. Olfactory tract - the final portion of sense of smell then goes to cerebrum for processing THE EAR 1. Hearing & equilibrium/balance system 2. 3 general parts: a. External ear b. Middle ear c. Inner ear EXTERNAL EAR 1. Auricle (pinna) 2. External Auditory Meatus (auditory canal) 3. Tympanic membrane (externally) AURICLES 1. Helix 2. Tragus 3. Lobule EXTERNAL ACOUSTIC MEATUS (AUDITORY CANAL) 1. ~2.5 -4 cm long from auricle to tympanic membrane (TM) 2. External ⅓ formed by cartilage; inner ⅔ by bone (temporal bone) 3. Cartilage part wider than bony part & has sebaceous & ceruminous glands 4. Direct sound waves to the TM MIDDLE EAR 1. Amplifies sound a. Tympanic Membrane (internally) b. Auditory Ossicles - vibrate sound and get it to our brain i. Malleus ii. Incus iii. Stapes - smallest & most medial - attach to oval window c. Pharyngotypanic (Eustachian) tube - connection of our ear to throat TYMPANIC MEMBRANE (TM) 1. Composed of thin skin external surface, fibrous middle layer, & mucous membrane internal surface (middle ear) 2. Pars Flaccida - small triangular portion of TM; lacks fibrous layer 3. Pars Tensa - remainder of TM 4. “Cone of Light” - triangular reflection of light on the anterior inferior portion of the TM 5. Ubmo - most depressed center part of the TM ; end of Malleus MIDDLE EAR 1. Maleous & incus → visible on PE INNER EAR 1. Bony Labyrinth a. Cochlea & semicircular canals 2. Membranous labyrinth a. Cochlear duct & 3 semicircular canals b. Semicircular canals connected by saccule & utricle 3. 2 functions → acoustic apparatus & vestibular apparatus EQUILIBRIUM 1. Vestibule → detects the movement of the body relative to the forces of gravity (static equilibrium) → bases on forces of gravity a. Saccule b. Utricle 2. Semicircular canals → detect the angular movements of the body (dynamic equilibrium) → movement of the head a. Semicircular ducts b. Ampullae NERVE SUPPLY TO THE EAR 1. Auricle & external auditory meatus a. Mostly CNV b. Minor CN VII & X 2. TM a. External i. CNV & small ear CN X b. Internal i. CNIX 3. Middle Ear a. Mix of CNV3 & VII 4. Internal Ear a. CNVIII → sense of hearing & balance ( vestibular nerve & acoustic nerve) LIPS & MOUTH 1. Open to oral cavity 2. Controlled by series of muscles 3. Edge of lips (colored part) is called vermillion border Oral Cavity - starts by definition behind your teeth 1. Lined w/ mucous membrane 2. Normal oral bacterial flora → bacterial & fungal pathogens 3. Openings for salivary gland ducts a. Partoid → buccal surface of upper cheek opposite the 2nd maxillary molar i. Stensen’s Duct Orifice b. Submandibular → each side of the lingual frenulum @ the base of the tongue i. Wharton’s Duct Orifice c. Sublingual → numerous openings in the floor of the mouth along the sublingual folds 4. Teeth a. Children → deciduous → 20 b. Adults → permanent → 32 c. Upper teeth → maxillar d. Lower teeth → mandible e. Innervated → Trigeminal nerve (CN V) 5. Maxillary Gingiva → mucous membrane & fibrous tissue hold maxillary (upper) teeth a. Outer (buccal) surface → cheek side of gingiva b. Inner (lingual) surface → tongue side of gingiva 6. Mandibular Gingiva → mucous membrane & fibrous tissue hold mandibular (lower) teeth 7. Bones of oral cavity a. Mandible → lower jaw; hinge joint at TMJ b. Maxilla (palatine process) → anterior ⅔ of hard palate c. Palatine (Horizontal plate) → posterior ⅓ of hard palate TONGUE → a muscle 1. Functions a. Forms words during speaking b. Swallowing c. Taste d. Oral cleansing 2. 4 intrinsic muscles → confined w/in tongue, not attached to bone a. Geniglossus → bilateral depresses tongue b. Hypoglossus → depresses tongue c. Styloglossus → retrudes tongue & curls tongue d. palatoglossus → depress the soft palate 3. 4 extrinsic muscles → outside the tongue & attach to it a. Superior longitudinal → curls tongue; elevating apex b. Inferior longitudinal → curls tongue; depressing apex c. Transverse → narrow & elongate tongue d. vertical → flattens & broadens tongue 4. Taste buds a. Groups of taste cells 5. Lingual Papillae 4 types a. Vallate b. Foliate c. Fungiform d. Filliform 6. Muscles of movement a. All are innervated → CN XII b. EXCEPT palatoglossus muscle → CNX 7. Attached to the floor of the oral cavity → frenulum a. Short @ birth → tongue-tied 8. Anterior ⅔ tongue sensory innervation a. CNV → touch & pain b. CNVII → taste 9. Posterior ⅓ sensory a. CNIX & small area for CN X LINGUAL PAPILLAE 1. Vallate papillae → bitter taste a. Largest of the papillae b. ~12 found @ the back of the tongue in inverted V-shaped 2. Foliate papillae → sense of bitter, sour, and salty taste a. Found on the lateral surfaces 3. Fungiform papillae → sweet taste a. Found on the anterior part of the dorsal surface of the tongue 4. Filiform → no taste bunds but responsible for pain a. Found over most of the presulcal, dorsal area of the tongue TONSILS 1. Lymphoid tissue a. Trap bacteria & viruses entering the throat b. Produces antibodies to help protect from infections 2. Palatine → “tonsils” a. Lie in tonsillar fossa bilaterally posterior oral cavity between the palatoglossal & palatopharyngeal folds 3. Innervated → branches of CN V & IX 4. Lingual → located on the posterior oral surface of the tongue 5. Adenoid → are found @ the posterior of the nasal cavity PHARYNX “THE THROAT” 1. Connects the nasal cavity & mouth → larynx & esophagus a. Passageway for both air & food 2. Extends past the larynx 3. Separated into 3 sections a. Nasopharynx b. Oropharynx - protects the laryngopharynx c. Laryngopharynx EPIGLOTTIS 1. Part of the larynx 2. Elastic cartilage 3. Function: a. Protect larynx from food b. Allows food to go down esophagus HYOID BONE 1. @ level of the 3rd cervical vertebrae between mandible & thyroid cartilage of the larynx 2. Only bone to NOT articulate w/ another bone in the body 3. Provides support for the larynx & airway 4. Muscles of deglutition (swallowing) attach to it for swallowing LARYNX 1. Found in the anterior neck @ level of C3-C6 2. Composed of 9 cartilages connected by membranes & ligaments 3. Contains the vocal cords 4. Connects oropharynx w/ trachea 5. Function → guard air passages, especially during swallowing 6. Soft spot anteriorly (palpable) between the thyroid & cricoid cartilages → cricothyroid membrane (ligament) LARYNX STRUCTURE 1. Thyroid → less prominent in females than males (adamapples) 2. Cricoid → below thyroid → need a trachea → goes through cricoid 3. Epiglottic 4. Arytenoid x2 5. Corniculate x2 6. Cuneiform x2 SWALLOWING (DEGLUTITION) 1. Process by which food → oral cavity → esophagus → stomach 2. Involves the teeth, tongue, larynx/pharynx & esophagus 3. 3 phages - oral, pharyngeal, esophageal a. Oral: contraction of tongue to push food bolus up against soft palate & then posteriorly into the oropharynx b. Pharyngeal phase: elevation of larynx causes epiglottis to block the trachea & allow bolus to pass to the esophagus c. Esophageal: food bolus moves through esophagus to stomach via peristalsis Temporomandibular Joint 1. Most active join in the human body 2. Formed → fossa & articular tubercle of the temporal bone & condyle of the mandible 3. Head of mandibular condyle AND mandibular fossa of temporal bone a. Articular fibrocartilage → can get arthritis MUSCLE OF MASTICATION 1. Masseter, temporalis, medial pterygoid a. Responsible for elevating the mandible & closing the mouth 2. Lateral pterygoid a. Responsible for depressing the mandible to open the mouth 3. All are innervated by CNV MUSCLE OF THE NECK 1. Necessary for neck movement, chewing, swallowing, & facial expression 2. Flexion muscles: a. Sternocleidomastoid → divides neck into anterior & lateral cervical regions ( anterior & posterior triangles) b. scalene, & longissimus capitis 3. Extension muscles: splenius capitis & cervicis PLATYSMA → more superficial than sternocleidomastoid 1. Broad thin sheet of muscle in the subcutaneous tissue of the neck 2. Innervvated → CNVIII 3. Deep to the platysma is the external jugular vein 4. Functions → tense the skin of the neck 5. Muscle of facial expression → platysma serves to convey tension or stress LYMPH NODES 1. Filters of lymphatic fluid that is from the IF (extracellular) compartments 2. Small masses of lymphatic tissue found along the course of lymphatic vessels all over the body eventually draining → venous systems 3. Contains lymphocytes → help fight infection HEAD & NECK LYMPH NODE DRAINAGE 1. Posterior half of auricle drains → Postauricular nodes 2. Anterior half of auricle drains → Preuaricular nodes 3. Lobe of ear drains → Superficial Cervical nodes 4. Anterior chin & central part of lower lip → Submental nodes 5. Upper lip, lateral jaw & lower teeth → submandibular nodes 6. Lymph from deep parotid nodes → deep cervical lymph nodes 7. Lymph lateral part of the face & scalp, including eyelids → superficial parotid lymph nodes 8. Posterior scalp → occipital nodes 9. Oropharynx → superficial & posterior cervical nodes 10. Neck → supraclavicular nodes 11. Supraclavicular nodes → left into thoracic duct & right into venous angle @ junction of internal jugular & subclavian veins DEEP CERVICAL FASCIA: white shiny tissue that covers muscle & connects to hypodermis 1. Investing fascia a. Surrounds the entire neck deep into the skin & subcutaneous tissue b. Holds muscles of the neck in their respective compartments 2. pretracheal fascia a. Anterior neck encasing muscle of swallowing & structures involved 3. Prevertebral fascia a. Surrounds cervical vertebrae b. NAVLs of carotid sheath c. Posterolateral neck muscles 4. Alar fascia a. Separates retropharyngeal space from the “danger space” i. Connecting & stabilizing carotid sheaths CERVICAL FASCIAL SPACES 1. Pretracheal a. Space between the investing fascia & pretracheal fascia b. Continues from hyoid bone superiorly to superior anterior mediastinum in chest 2. Prevertebral a. Space between cervical & upper thoracic vertebrae & the prevertebral fascia 3. Retropharyngeal space a. Space between the prevertebral fascia anteriorly & the carotid sheath & alar fascia THE EYE COMPONENTS 1. Orbit 2. Globe 3. Extra ocular muscles (EOM) 4. Tear gland & duct 5. Eyelids THE ORBIT 1. Boney socket for the globe 2. Protects the eyeball (globe) from injury 3. Composed of 7 bones a. Frontal b. Zygomatic c. Maxilla d. Nasal e. Sphenoid f. Ethmoid g. Lacrimal 4. Provides openings for nerves & blood vessels to the globe, orbit, & eyelids THE GLOBE 1. Composed of 3 layers (tunics) w/ fluid & gel-like substances a. Outer layer (fibrous) - clear & cornea b. Middle layer (vascular) - choroid c. Inner layer (neural) retina 2. 3 chambers a. Anterior b. Posterior c. Vitreous OUTER LAYERS (FIBROUS) 1. Sclera: white of the eye 2. Cornea: transparent convex covering the anterior part of the eye 3. Conjunctiva: not actually part of the eyeball, but covers the clear & lines the lids MIDDLE LAYER (VASCULAR) 1. Choroid: layer that contains a rich network of blood & lymphatic vessels a. Red-flex to eye → helps absorb light 2. Ciliary body (muscle & connective tissue): anterior thickening portion of the choroid composed of smooth muscle a. Sits behind the iris b. Supports the lens & iris c. Ciliary body & lens divide the anterior cavity into anterior & posterior chambers 3. Iris: pigmented part of glob a. 2 distinct muscle layers that control constriction & dilation of pupil THE IRIS & THE PUPIL 1. Pupil: black area in the middle of the iris that allows for light transmission into the eye 2. Iris: contains 2 involuntary muscles that control the size of the pupil a. Sphincter pupillae (constricts the pupil/ makes it smaller) b. Dilator pupillae (dilates the pupil/makes it bigger) INNER LAYER (NEURAL) 1. Retina: a. Photoreceptors b. Associated w/ neurons & fibers c. Fundus: area of light focus on retina i. Rods & cones for vision sense 1. Rods = B&W vision 2. Cones = color vision d. Macula Lutea = yellow spot i. Area of retina that provides clearest vision ii. contains only photoreceptors 1. Fovea centralis = vision is most accurate e. Optic disk f. i. Entry point for sensory nerves & blood vessels ii. Blind spont of the inner eye Optic nerve (CN II) i. Passes from the back of the glov via the optic canal in the sphenoid bone 3 CHAMBERS OF THE EYE 1. Anterior chamber: a. Cornea & the iris 2. Posterior chamber: a. Iris & the lens 3. Vitreous chamber: a. Lens & the retina ANTERIOR, POSTERIOR CHAMBER& AQUEOUS HUMOR 1. Ciliary processes of the ciliary body a. Aqueous humor = nourishes the iris, lens, & cornea 2. Circulates from the posterior chamber of the pupil & into the anterior chamber 3. Trabecular meshwork (canal of schlemm) = angle @ the edge of the cornea & iris a. Drains aqueous humor into scleral venous sinus 4. Aqueous production = drainage a. Intraocular pressure (IOP) = stable VITEROUS CHAMBER & VITREOUS HUMOR 1. Vitreous humor a. Vitreous body b. Between the retina & the lens 2. Jelly like 3. Transmits light 4. Holds retina in place 5. Supports the lens 6. Helps maintain eye shape EYE MOVEMENT 1. Movement of the glove occurs from the contraction of one or more extraocular muscles depending on the direction of gaze 2. 6 EOMs are a. Superior rectus b. Inferior rectus c. Medial d. Lateral e. Superior oblique f. Inferior oblique EYE MOVEMENT INNERVATION 1. CNVI (abducens): lateral rectus 2. CNIV (trochlear): superior oblique 3. CNIII (oculomotor): all other muscle a. LR6SO4AO3 b. Important for testing EOM functions for intact movement NERVE OF THE EYE 1. Ophthalmic (branch of CN-V) a. Branches supply: i. lacrimal gland ii. Forehead iii. Frontal sinus iv. Eyelid v. Sensory of cornea (corneal reflex) 2. Optic - CN II - sense of vision; joins contralateral optic nerve @ optic chiasm then on the brain (occipital lobe) via optic tract 3. CNs III (oculomotor, IV (trochlear), & VI (abducens) - supply EOMs for motion of globe BLOOD VESSELS OF THE EYE 1. Ophthalmic artery a. Branch of internal carotid artery b. Enters orbit thru the optic canal inferior to optic nerve c. 11 branches that supply contents of: i. Orbit ii. Ethmoid sinuses iii. Forehead & scalp iv. Most important of these 11 is the Central retinal artery wich supplies the retina d. End artery → does NOT anastomose w/ other arteries & only supplies the internal aspect of retina i. Occlusion results in blindness VEINS OF THE EYE 1. Drainage occurs → superior & inferior ophthalmic veins 2. Scleral venous sinus → vascular structure encircling anterior chamber of eye LACRIMAL APPARATUS 1. Lacrimal gland a. Located in the upper lateral orbit on the lateral rectus & levator palpebrae superioris muscles 2. Lacrimal Canaliculi a. 2 curved canals that begin as openings (punctum or pore) i. Medial margin of the eyelids & open into the lacrimal sac to drain fluid ( tears) 3. Lacrimal Sac a. Upper dilated end of the nasolacrimal duct 4. Nasolacrimal duct a. Opens into the inferior nasal meatus of the nasal cavity 5. Tear movement a. Lacrimal gland → gravity/ blinking → lacrimal duct → lacrimal sac → nasolacrimal duct EYELIDS 1. Covers eyeball anteriorly & protects it from injury & excessive light 2. Keep cornea moist by spreading lacrimal fluid when blinking 3. Exterior = skin 4. Interior = palpebral conjuctiva 5. Upper & lower lids → dense band of CT (tarsi) → provide support of the tissue (like a skeleton) 6. Tarsal glands: a. Embedded in tarsi b. Produce lipid secretion to keep eyelids from sticking together 7. Eyelashes a. Feelers sensing approaching dangers (bugs, fingers, etc) b. Lubricated by ciliary glands (large sebaceous glands) 8. Orbicularis Oculi a. Closes eyelids & wrinkles forehead b. Palpebral part “gently” closes lids c. Orbital part “tightly” closes lids 9. Levator Palpebrae superiors a. Elevates upper eyelid (innervated by CN III) VISION 1. Refraction of light & accommodation a. Bending of light rays & ability to alter the eye to focus on different objects via changing shape & length of lens 2. Close-up vision a. Lens becomes more convex (short & thick) 3. Distant a. Lens becomes less convex (long & thin) 4. Convergence a. Ability to maintain binocular vision & track a common object moving towards the eyes