206 SSNS - Anatomy Flashcards
Borders of Pterygopalatine Fossa
Anterior - Posterior wall of the maxillary sinus
Posterior - Pterygoid process of the sphenoid bone
Inferior - Palatine bone and palatine canals
Superior - Inferior orbital fissure of the eye
Medial - Perpendicular plate of the palatine bone
Lateral - Pterygomaxillary fissure
Which part of the auricle is LEAST likely to be affected by an auricular hematoma?
Lobule
- The lobule is a non-cartilaginous structure, and therefore is unlikely to be affected by an auricular hematoma.
Which structure marks the end of the external auditory meatus?
Tympanic membrane
The tympanic membrane is connected to the surrounding bone by a fibrocartilaginous ring. Which bone is it connected to?
Temporal
- The tympanic membrane is connected to the surrounding temporal bone by a fibrocartilaginous ring
Which structure forms the roof of the middle ear?
Petrous part of temporal bone
- The roof is formed by a thin bone from the petrous part of the temporal bone. It separates the middle ear from the middle cranial fossa
Which nerve innervates the tensor tympani muscle?
Mandibular nerve
- The tensor tympani originates from the auditory tube and attaches to the handle of malleus, pulling it medially when contracting. It is innervated by the tensor tympani nerve, a branch of the mandibular nerve
Where are the mastoid air cells in relation to the epitympanic recess?
Posterior
In which part of the temporal bone is the inner ear located?
Petrous
- The inner ear is located within the petrous part of the temporal bone. It lies between the middle ear and the internal acoustic meatus, which lie laterally and medially respectively
What lies directly inferior to the cochlear duct?
Scala tympani
Which structure forms the lateral wall of the cochlear duct of the inner ear?
Spiral ligament
- The lateral wall is formed by thickened periosteum, known as the spiral ligament.
Which cranial nerve is most associated with the auditory pathway?
CN VIII
- CN VIII is the vestibulocochlear nerve, which carries auditory and balance information from the inner ear to the brainstem.
In the primary auditory pathway, the first order neurons receive information from which structure?
Organ of Corti
- The first order neurons receive information from hair cells in the Organ of Corti
What is the most internal layer of the scalp?
Periosteum
- The periosteum is the outer layer of the skull bones. It becomes continuous with the endosteum at the suture lines.
In a scalp laceration, the resting tone of which muscle inhibits closure of the bleeding vessel and surrounding skin?
Occipitofrontalis
Which nerve provides innervation to the area of scalp behind the pinna?
Lesser occipital
- The lesser occipital nerve is derived from the anterior rami (division) of C2 and supplies the skin behind the pinna. The auriculotemporal nerve innervates the skin anterosuperior to the pinna.
Which cranial nerve innervates the orbicularis oculi muscle?
Facial nerve
- The orbicularis oculi is a muscle of facial expression - and so it is innervated by branches of the facial nerve.
The corrugator supercilii is a muscle of facial expression. What is its main action?
Drawing the eyebrows together
- The corrugator supercilii acts to draw the eyebrows together, creating vertical wrinkles on the bridge of the nose.
Which embryological structure do the muscles of mastication develop from?
First pharyngeal arch
Which nerve provides motor innervation to the muscles of mastication?
Mandibular nerve
What is the main action of the masseter muscle?
Elevation of the mandible
- closing mouth
What is the innervation of the extraocular muscle which chiefly acts to adduct the eyeball?
Oculomotor nerve
- The main action of the medial rectus is the adduct the eyeball. It is innervated by the oculomotor nerve
Which nerve provides somatic motor innervation to the levator palpebrae superioris?
Oculomotor
Where is the lacrimal gland located within the bony orbit?
Superior and lateral
- The lacrimal gland is located anteriorly in the superolateral aspect of the orbit, within the lacrimal fossa – a depression in the orbital plate of the frontal bone.
Which nerve provides sensory innervation to the lacrimal gland?
Lacrimal nerve
- The sensory innervation to the lacrimal gland is via the lacrimal nerve. This is a branch of the ophthalmic nerve (in turn derived from the trigeminal nerve).
The tarsal plate of the eyelid lies immediately deep to which muscle?
Orbicularis oculi
Where in the eyelid do the Meibomian glands lie?
Tarsal plate
Which structure comprises the majority of the fibrous layer of the eyeball?
Sclera
Which structure forms the innermost layer of an eye?
Retina
- The inner layer of the eye consists of the retina, the light detecting part of the eye. The retina itself consists of a neural layer and pigmented layer
What is the name given to the fluid which fills the anterior and posterior chambers of the eye?
Aqueous humor
- the anterior and posterior chambers are filled with aqueous humor; a clear plasma-like fluid that nourishes and protects the eye.
What are the 4 functions of nose?
- Warms and humidifies the inspired air.
- Removes and traps pathogens and particulate matter from the inspired air.
- Responsible for sense of smell.
- Drains and clears the paranasal sinuses and lacrimal ducts.
What are the 3 divisions of nasal cavity?
- Vestibule
- Respiratory region
- Olfactory region
What are the 3 conchae & 4 meatuses?
Conchae: inferior, middle, superior
Meatuses
- Inferior meatus – between the inferior concha and floor of the nasal cavity.
- Middle meatus – between the inferior and middle concha.
- Superior meatus – between the middle and superior concha.
- Spheno-ethmoidal recess – superiorly and posteriorly to the superior concha.
Whats the function of conchae?
↑ S.A. of nasal cavity - ↑ amount of inspired air that come into contact with cavity walls
Disrupt fast, laminar flow of air, making it slow & turbulent → air spends longer time and can be humidified
What passes through cribriform plate?
Olfactory nerve
What passes through incisive canal?
Nasopalatine nerve & greater palatine artery
What are the internal & external carotid branches that supply the nose?
Internal carotid branches:
- Anterior ethmoidal artery
- Posterior ethmoidal artery
External carotid branches:
- Sphenopalatine artery
- Greater palatine artery
- Superior labial artery
- Lateral nasal arteries
What’s the Little’s area?
Found on the anterior nasal septum
Anastomoses of 5 arteries: anterior ethmoidal artery posterior ethmoidal artery sphenopalatine artery greater palatine artery septal branch of the superior labial artery
Which nerve innervates (special) the nose?
Olfactory
Which nerve innervates (general) septum & lateral walls of nose?
Nasopalatine nerve (branch of maxillary nerve) & Nasociliary nerve (branch of ophthalmic nerve)
Which nerve innervates (general) external skin of nose?
Trigeminal nerve
What is the epithelial lining of the respiratory region of the nasal cavity?
Pseudostratified
- The respiratory region is lined by a ciliated pseudostratified epithelium, interspersed with mucus-secreting goblet cells.
Which structure marks the opening of the frontal, maxillary and anterior ethmoidal sinuses in the nasal cavity?
Semilunar hiatus
- The semilunar hiatus is a crescent-shaped groove on the lateral wall of the middle meatus.
The cribriform plate forms the roof of the nasal cavity. Which cranial bone does it belong to?
Ethmoid
What are the 3 major functions of the oral cavity?
- Digestion
- Communication
- Breathing
Where does oral cavity span between?
Oral fissure & oropharyngeal isthmus
What divides the oral cavity in 2 parts? What are the 2 parts?
Upper & lower dental arches divides the oral cavity into the vestibule & mouth cavity proper
What forms the roof, cheeks, & floor of mouth proper?
Roof - hard & soft palates
Cheeks - buccinator
Floor - Muscular diaphragm, geniohyoid muscles, tongue, salivary glands & ducts
A biopsy is taken from the mucosa covering the inferior surface of the hard palate. Assuming the biopsy is normal, what will it show?
Stratified squamous
- The hard palate is covered superiorly by respiratory mucosa (ciliated pseudostratified columnar epithelium) and inferiorly by oral mucosa (stratified squamous epithelium).
Which nerve innervates the buccinator muscle?
Buccal branches of facial nerve
- The buccinator is a muscle of facial expression and therefore is innervated by the facial nerve. The muscles of mastication are innervated by the mandibular nerve.
Which muscle largely controls the diameter of oral fissure?
Orbicularis oris
The ‘pit’ in the posterior midline of the tongue is known as the foramen __________.
Cecum
- The foramen cecum is a blind-ended pit located in the midline of the tongue at the junction of the anterior 2/3 and posterior 1/3.
What attaches the inferior aspect of the tongue to the oral mucosa?
Frenulum
Which nerve is responsible for the majority of taste sensation?
Facial nerve
- The chorda tympani branch of the facial nerve supplies taste sensation to the anterior 2/3 of the tongue.
Borders of the parotid gland
Superiorly – Zygomatic arch
Inferiorly – Inferior border of the mandible
Anteriorly – Masseter muscle
Posteriorly – External ear & sternocleidomastoid
Which structures can be found immediately superior to the parotid gland?
Zygomatic arch
Which nerve branches within the parotid gland?
Facial nerve
Which vein is responsible for venous drainage of the parotid gland?
Retromandibular vein
Which passageway in the hard palate transmits the nasopalatine nerve?
Incisive canal
- The incisive canal is located in the anterior midline of the hard palate, and transmits the nasopalatine nerve.
What is the Waldeyer’s ring?
Ring of lymphoid tissue in the naso- and oropharynx formed by the paired palatine tonsils, the adenoid tonsils and lingual tonsil.
What’s the pharyngeal plexus formed by?
Pharyngeal branches from the glossopharyngeal nerve (CN IX).
Pharyngeal branch of the vagus nerve (CN X).
Branches from the external laryngeal nerve.
Sympathetic fibres from the superior cervical ganglion.
Which vertebral level marks the inferior end of the pharynx?
C6
- The pharynx begins at the base of the skull and ends at the inferior border of the cricoid cartilage - this is approximately C6.
Which muscle of the pharynx is innervated by the glossopharyngeal nerve?
Stylopharyngeus
- The stylopharyngeus is innervated by the glossopharyngeal nerve (CN IX). The remaining muscles of the pharynx are innervated by the vagus nerve.
Which anatomical landmark marks the boundary between the oropharynx and laryngopharynx?
Epiglottis
- The superior border of the epiglottis marks the end of the oropharynx and beginning of the laryngopharynx
What type of epithelium can be predominantly found in the larynx?
Ciliated pseudostratified columnar
- The interior surface of the larynx is lined by pseudostratified ciliated columnar epithelium. An important exception to this is the true vocal cords, which are lined by a stratified squamous epithelium.
Which vertebral levels does the larynx span?
C3 - C6
The arytenoid cartilage is a paired cartilage found in the larynx. Which structure articulates with the base of each arytenoid cartilage?
Cricoid cartilage
- The arytenoid cartilages sit on the cricoid cartilage - the base of the arytenoid articulates with the superior border of the cricoid cartilage
Name the 3 unpaired & 6 paired laryngeal cartilages.
Unpaired: thyroid cartilage, cricoid cartilage, epiglottis
Paired: Arytenoid cartilages, corniculate cartilages, cuneiform cartilages
The vocal ligament is formed the by the upper edge of which ligament?
Cricothyroid ligament
- The cricothyroid ligament originates from the cricoid cartilage and extends superiorly, where it terminates with an free (unattached) upper margin – which forms the vocal ligament.
The space between the vocal folds is known as the:
Rima glottidis
What are the extrinsic ligaments in the larynx?
Thyrohyoid membrane
Hyo-epiglottic ligament
Cricotracheal ligament
Median cricothyroid ligament
What are the intrinsic ligaments in the larynx?
Cricothyroid ligament
Quadrangular membrane
What are the borders of infratemporal fossa?
Lateral – condylar process Medial – lateral pterygoid plate Anterior – posterior border of the maxillary sinus Posterior – carotid sheath Roof – greater wing of the sphenoid bone Floor – medial pterygoid muscle
Which cranial foramina transmits the mandibular nerve from the cranial cavity to the infratemporal fossa?
Foramen ovale
- The mandibular nerve passes through the foramen ovale to enter the infratemporal fossa
The lateral boundary of the infratemporal fossa is formed by?
Ramus of the mandible
- The lateral border of the infratemporal fossa is formed by the condylar process and ramus of the mandible bone.
Which vessel arises from the maxillary artery in the infratemporal fossa?
Middle meningeal
- The middle meningeal artery arises from the maxillary artery, and exits the infratemporal fossa via the foramen spinosum
What muscles are associated with infratemporal fossa?
Muscles of mastication
Medial & lateral pterygoids located within; masseter & temporalis insert and originate into borders
What nerves pass through the infratemporal fossa?
Mandibular nerve
Auriculotemporal, buccal, lingual and inferior alveolar nerves
Chorda tympani
Otic ganglion
What vascular structures does the infratemporal fossa contain?
Maxillary artery
Pterygoid venous plexus
Maxillary vein
Middle meningeal vein
4 layers of deep cervical fascia (superficial to deep)
Investing layer
Petracheal layer
Prevertebral layer
Carotid sheath
What is enclosed by the pretracheal fascia?
Trachea, esophagus, thyroid gland - muscular part
Infrahyoid muscles - vascular part
Which muscles are surrounded by the investing layer of cervical fascia?
Sternocleidomastoid
Trapezius
- The investing layer of deep cervical fascia completely encloses the trapezius and sternocleidomastoid muscles.
Which potential space in the neck could allow for the tracking of pus into the posterior mediastinum?
Retropharyngeal
- The retropharyngeal space extends from the base of the skull to the posterior mediastinum
The prevertebral fascia forms the floor of which anatomical space?
Posterior triangle
- The anterolateral portion of prevertebral fascia forms the floor of the posterior triangle of the neck
What structure forms the anterior border of the posterior triangle?
Posterior border of the sternocleidomastoid
Complete the sentence: Travelling within the investing layer of fascia, the _______ nerve crosses the posterior triangle of the neck in an oblique infero-posterior direction.
Accessory
- The accessory nerve lies relatively superficial in the posterior triangle, leaving it vulnerable to injury.
Which structure crosses the posterior triangle of the neck and divides it into two?
Inferior belly of omohyoid
- The inferior belly of the omohyoid crosses the posterior triangle, travelling in a supero-medial direction.
What splits the posterior triangle into 2? What are the subdivisions?
The omohyoid muscle splits the posterior triangle into the occipital triangle & subclavian triangle
What divides the anterior triangle? And the subdivisions of the anterior triangle?
Subdivided by the hyoid bone, suprahyoid and infrahyoid muscles: Carotid Triangle Submental Triangle Submandibular Triangle Muscular Triangle
Which important vascular structure bifurcates within the carotid triangle?
Common carotid artery
- The common carotid artery bifurcates into the external and internal carotid arteries
What are the 5 layers of scalp?
SCALP Skin Dense Connective tissue Epicranial Aponeurosis Loose Areolar Connective Tissue Periosteum
Borders of the orbit
Roof – frontal bone
Floor – maxilla, palatine & zygomatic bones
Medial – ethmoid, maxilla, lacrimal & sphenoid bones
Lateral – zygomatic bone
Apex – optic foramen
Base – Opens out into the face, and is bounded by the eyelids - orbital rim
3 pathways into the orbit
Optic canal
Superior orbital fissure
Inferior orbital fissure
Anatomical relations of the lacrimal gland
Superior – zygomatic process of frontal bone
Anterior – orbital septum
Posterior – orbital fat
Inferolateral – lateral rectus muscle
5 main layers of eyelids (superficial to deep)
Skin and subcutaneous tissue Orbicularis oculi Tarsal plates Levator apparatus Conjunctiva
What are the 2 parts of the external ear?
Auricle
External acoustic meatus (ends at tympanic membrane)
What are the 2 parts of the middle ear?
Tympanic cavity
Epitympanic recess
Borders of middle ear
Roof – petrous part of the temporal bone
Floor – jugular wall
Lateral – tympanic membrane
Medial – lateral wall of the internal ear
Anterior – a thin bony plate with two openings; for the auditory tube and the tensor tympani muscle
Posterior - mastoid wall
What are the 2 main functions of the inner ear?
Mechanical (from middle ear) → electrical; transfer info to auditory pathway
Maintain balance by detecting position & motion
What are the 2 openings to middle ear?
Oval window
Round window
Auditory pathway
1°
- Organ of corti → cochlear nerve → cochlear nucleus
- Crossover – primary; ipsilateral – secondary
2°
Cochlear nucleus → superior olivary complex (brainstem)
3°
- Superior olivary complex (brainstem) → lateral lemniscus (pons) → inferior colliculus (midbrain)
4°
- Inferior colliculus (midbrain) → medial geniculate nucleus (thalamus)
- Most stay ipsilateral, but some crossover
5°
- Medial geniculate nucleus (thalamus) → auditory cortex (temporal lobe)
What’s the medial geniculate body?
Part of the auditory thalamus and represents the thalamic relay between the inferior colliculus (IC) and the auditory cortex (AC).
Music goes to medial, light goes to lateral.
What’s the lateral geniculate body?
A relay center in the thalamus for the visual pathway.
Music goes to medial, light goes to lateral.
Which sympathetic cervical ganglion is associated with the cardiac plexus?
Superior cervical ganglia
Middle cervical ganglia
Inferior cervical ganglia
- The superior, middle and inferior cervical ganglia each contribute a branch to the cardiac plexus.
Which artery is most associated with the post-ganglionic fibres of the middle cervical ganglion?
Inferior thyroid
- The post-ganglionic fibres of the middle cervical ganglion hitchhike along the inferior thyroid artery.
Which cervical ganglion is associated with the innervation of the superior tarsal muscle?
Superior cervical ganglion
- The superior cervical ganglion gives rise to the internal carotid nerve, which provides innervation to the superior tarsal muscle
What are the 4 parasympathetic ganglia located within the head?
Ciliary
Otic
Pterygopalatine
Submandibular
Parasympathetic system
“rest and digest”
Sympathetic system
“fight or flight”
What are the 3 sympathetic ganglia located within the head?
Superior, middle and inferior cervical ganglia.
