Basic ENT Anatomy Flashcards
What structures of the neck have an endocrine function?
The thyroid and parathyroids
What are the respiratory functions of the ENT system?
Patency of airway, filters air, humidifies air, controls movement of air, warms air
What are the digestive and protective functions of the ENT system?
GI = mastication, deglutition, digestion, lubrication Protective = filters air, antimicrobial properties, reflexes, regurgitation
What are the special sensory functions of the ENT system?
Smell (nose), taste (mouth), hearing and balance (ear)
What bone is the ear associated with?
The temporal bone
What connects the middle ear to the nasopharynx?
Eustachian tube
What is the function of the external ear?
Collects soundwaves and directs them towards the middle ear
What is the function of the middle ear?
Conducts and amplifies vibrations towards the inner ear
What is the function of the inner ear?
Converts vibrations or movement of fluid into action potentials
What system does the nose belong?
Respiratory
What is the nose divided into?
Two bilateral nasal cavities
What is the nose connected to?
Paranasal sinuses, orbit and nasopharynx posteriorly
What are some functions of the throat?
Respiratory, digestive and protective
Where does the throat begin?
Starts in head and continues inferiorly within the neck towards the thorax
What are some important interconnected areas in the throat?
Pharynx and oesophagus, larynx and trachea
What are some closely related structures in the throat?
Blood vessels and nerves, palate and oral cavity, thyroid and parathyroid glands, skull base and cervical spine
How is the deep neck fascia arranged?
Ina tubular fashion
What do the compartments of the throat provide?
Route for the migration of pathologies
What vessels supply the cranial cavity?
Internal carotid artery and vertebral artery
Branches of which arteries supply the face?
Internal and external carotid arteries
What vessels supply the neck?
External carotid artery and subclavian artery branches
What is the mnemonic to remember the branches of the external carotid artery (from proximal to distal)?
Some Anatomists Like Freaking Out Poor Medical Students
What are the branches of the external carotid artery, from proximal to distal?
Superior thyroid artery, Ascending pharyngeal artery, Lingual artery, Facial artery, Occipital artery, Posterior auricular artery, Maxillary artery, Superficial temporal artery
Where do the arteries that supply the head and neck tend to form anastomoses?
Ipsilaterally and contralaterally
What courses along the peri-arterial plexus?
Post synaptic sympathetic nerve fibres
What does venous drainage tend to follow?
Mimics arterial distribution
Where do all of the veins that drain the head and neck ultimately drain into?
The internal jugular vein
What are some veins that drain the head and neck?
External jugular vein, facial vein, cavernous sinus (middle cranial fossa), pterygoid venous plexus (infratemporal fossa)
Where is the danger triangle of the face?
Between the eyebrows to either side of the mouth?
What is the concern with the danger triangle of the face?
Veins can potentially carry superficial infections to deeper areas of the head and neck
What are the cranial nerves relevant to the head and neck?
CN 1 = olfactory CN 5 = trigeminal
CN 7 = facial CN 8 = vestibulocochlear
CN 9 = glossopharyngeal CN 10 = vagus
CN 12 = hypoglossal
What are the only cranial nerves that give rise to pre-ganglionic parasympathetic axons?
CN 3 = oculomotor CN 7 = facial
CN 9 = glossopharyngeal CN 10 = vagus
What are the four bilateral parasympathetic ganglia of the head and neck?
Ciliary ganglion (from CN 3) Pterygopalatine ganglion (from CN 7) Submandibular ganglion (from CN 7) Otic ganglion (from CN 9)
What is the parasympathetic outflow?
Craniosacral
What are the parasympathetic neurons structures like?
Long preganglionic neuron, short postganglionic neuron
How are sympathetic neurons structured?
Long postganglionic neuron, short preganglionic neuron
What is the sympathetic flow in the head and neck?
Peri-arterial plexus > superior cervical ganglion > cervical sympathetic chain
What nerves provide general somatic sensory innervation to the head and neck
CN 5 (divisions 1-3), CN 9 and CN 10 = pain, touch, temperature and proprioception signals
What cranial nerves are responsible for taste and smell
Cranial nerves 1 and 2 (olfactory and optic)
What cranial nerves are responsible for taste?
Cranial nerves 7, 9 and a bit of 10
What cranial nerve is responsible for hearing and balance?
Vestibulocochlear (CN 8)
What are the sensory ganglia of the head and neck?
Trigeminal ganglion (CN 5)
Geniculate ganglion (CN 7)
Spiral and vestibular ganglion (CN 9)
Superior and inferior glossopharyngeal ganglia (CN 9)
Superior and inferior vagal ganglia (CN 10)
How many neurons are in a sensory chain?
Made up of three neurons = first, second and third order
Where do the first and second order sensory neurons synapse?
At the spinal cord or brainstem
Where do the second and third order sensory neurons synapse?
Thalamus
What does lymphatic drainage tend to follow?
Venous drainage
How is the lymphatic drainage of the head and neck divided?
Into areas that drain into the right lymphatic duct or the thoracic duct (left side) at their respective venous angles
How does the lymphatic drainage of midline structures (i.e tongue) work?
Can drain bilaterally
What does the Jugulo-digastric node drain lymphatic from?
Drains the palatine tonsil
What are some lymph node groups of the head and neck?
Parotid (pre-auricular), mastoid (post-auricular), deep cervical nodes, superficial cervical nodes
What vessel are the deep cervical nodes located along?
The internal jugular vein
What vessel are the superficial cervical nodes located along?
The external jugular vein
Where does all arterial supply to the head and neck originate from?
Either the common carotid artery or the subclavian artery
What is the definition of a ganglion?
Collection of cell bodies in the peripheral nervous system
What do ganglions contain in the motor region?
A synapse = sensory ganglia don’t have synapses
What kind of innervation do the sympathetic and parasympathetic nervous systems provide?
Motor = do not provide any sensory innervation
