Head and Neck Flashcards
What are the borders of the anterior triangle of the neck?
Invisible midline (medial) Superior border of sternocleidomastoid (lateral) Inferior border of the mandible (superior)
What are the contents of the anterior triangle?
Trachea
Oesophagus
Thyroid
Carotid sheath
What are the borders of the posterior triangle of the neck?
Inferior border of sternocleidomastoid (medial)
Middle third of the clavicle (inferior)
Medial border of trapezius (lateral)
What are the contents of the posterior triangle?
External jugular vein
Lymph
Brachial plexus
Lung apex
What are the contents of the carotid sheath?
Common carotid artery
Internal jugular vein
Vagus nerve
Deep cervical lymph nodes
What muscle is invested in the superficial fascia?
Platysma
What muscles are invested in the deep fascia of the neck?
Sternocleidomastoid
Trapezius
What are the contents of the pretracheal fascia?
Trachea
Oesophagus
Thyroid
What is the clinical significance of the retropharyngeal space?
The space communicates with the diaphragm and therefore infection or pus build up in this space and lead to mediastinitus.
What are the four suprahyoid muscles?
Diagastric
Mylohyoid
Stylohyoid
Geniohyoid
What are the four infrahyoid muscles?
Thyrohyoid
Sternohyoid
Sternothyroid
Omohyoid
What are the actions of the hyoid muscles?
Suprahyoid muscles elevate the hyoid bone and larynx during swallowing.
Infrahyoid muscles depress the hyoid and larynx during swallowing and speech.
What are the branches of the ECA?
Superior thyroid Lingual Facial Occipital Maxillary Superficial temporal Ascending pharyngeal Posterior auricular
What are the muscles of facial expression?
Occipitofrontalis
Orbicularis occuli
Zygomasticus
Orbicularis oris
What is the innervation to the muscles of facial expression?
Sensory is CN V
Motor is CN VII
What are the muscles of mastication?
Temporalis
Masseter
Buccinator
Pterygoids
What is the innervation of the muscles of mastication?
Sensory and motor innervation is CN V
What are the branches of the Facial Nerve?
Temporal Zygomatic Buccal Mandibular Cervical
What is a pharyngeal arch?
Complex tissue arches involving the brain, CVS and special sensory organs; system of mesenchymal proliferations in the neck region.
What are the three vesicle stages of the brain?
Prosencephalon (forebrain)
Mesencephalon (midbrain)
Rhombencephalon (hindbrain)
What structures are formed from Meckel’s cartilage?
Malleus
Incus
Template for the mandible
What structures are formed from Reichert’s cartilage?
Stapes
Styloid processes
Lesser and upper body of hyoid bone
What nerve is associated with pharyngeal arch 1?
CN V
What nerve is associated with pharyngeal arch 2?
CN VII
What nerve and artery are associated with pharyngeal arch 3?
ICA
CN IX
What nerve and arteries are associated with pharyngeal arch 4?
Arch of the aorta (L) and brachiocephalic (R)
CN X
What nerve and blood vessel is associated with pharyngeal arch 6?
Pulmonary arch
CN X
What structure is associated with the second pharyngeal pouch?
Palatine tonsils formed by epithelial proliferation and colonization with lymphoid precursors
What structures are associated with the third and fourth pharyngeal pouches?
Dorsally the parathyroid glands and ventrally the thymus glands.
What structures are associated with the first pharyngeal pouch?
Tympanic cavity and auditory tube
What are the branches of the brachiocephalic trunk?
Common carotid artery Vertebral artery Internal thoracic artery Thyrocervical trunk Subclavian artery
What is the carotid sinus?
Swelling in the region of bifurcation where baroreceptors are located in the walls of the artery.
What is the carotid body?
Peripheral chemoreceptors that detect arterial pO2 in the region of the carotid sinus.
What factors contribute to excessive bleeding from the scalp?
Artery walls are closely associated with connective tissue limiting vasoconstriction
Opposing pulls of the occipitofrontalis
There are numerous anastomoses
What are the layers of the scalp?
Skin Connective tissue (dense) Aponeurosis Loose connective tissue Periosteum
Explain the blood supply to the scalp and skull:
The skull is supplied by the middle meningeal artery so loss of supply to the scalp does not lead to bone necrosis as the scalp is supplied separately by the superficial temporal artery.
What are dural venous sinuses?
Endothelium-lined spaces between periosteal and meningeal layers of the dura that receive blood from large veins draining the brain.
What structures pass through the cavernous sinus?
Internal carotid artery CN III CN IV CN V1 and V2 CN VI
List the superficial arteries of the face:
Maxillary Middle meningeal Facial Superior and inferior labial Lateral nasal Angular Supratrochlear Supraorbital
What is meant by the lymphatic system?
System of drainage vessels and lymphatic vessels/tissues that returns lymph to the blood circulation.
How is one-directional flow created in the lymphatic system?
Valves
Passive constriction e.g. arterial pulsing
Intrinsic constriction of SMCs when stretched
What are lymph nodes?
Connective tissue structures with a fibrous outer capsule and reticular tissue inside, containing a large number of lymphocytes and macrophages.
What is Waldeyer’s Ring?
Anular collections of nodules surrounding superior pharynx including adenoids, palatine and lingual tonsils.
Name the bones of the skull:
Parietal Occipital Temporal Zygomatic Sphenoid Frontal Maxilla Mandible Ethmoid Lacrimal
Which four bones contribute to the pteryion?
Sphenoid
Parietal
Frontal
Temporal
What is the purpose of skull foramina?
Allow passage of anatomical structures between intracranial and extracranial components.
How is the neonatal skull different to the adult skull?
Adjacent cranial bones are held together by a thick connective tissue matrix.
Fontanelles- wide membranous tissue islands in the vicinity of the bregma and lambda.
Cranial sutures allow for interlocking of bones during the birthing process.
What drives the development of the face?
The expansion of the cranial nerve tube, pharyngeal arches and the sense of organs and palate.
What are neural crest cells?
Specialized population of cells that originates within the neuroectoderm.
What contributes to the embryological development of the nose?
Nasal placodes (thickenings of ectoderm) appear on the FNP and sink to become nasal pits; medial and lateral nasal prominences form on either side of the pits. Maxillary prominences then push the nasal prominences together to fuse in the midline.
Outline the embryological development of the palate:
Intermaxillary segment is composed of the primary palate, philtrum and four incisors.
Secondary palate is derived from the palatine shelves of maxillary prominences that grow downwards into the oral cavity.
Mandible grows large enough to allow for the tongue to drop.
Palatine shelves grow towards each other and fuse in the midline.
Nasal septum develops as a midline downgrowth and ultimately fuses with palatine shelves.
Outline the embryological development of the eyes:
Outpocketings of the forebrain (optic vesicle) form the retina and optic placodes form the lens.
Optic vesicle makes contract with lens placode which then invaginates and pinches off.
Eye primordia are on the side of the head and move to the front of the face as facial prominences grow.
Outline the embryological development of the external ear:
External auditory meatus develops from the first pharyngeal cleft and the auricles and pinna develop from proliferation within the first and second pharyngeal arches.
Outline the development of the internal ear:
Otic placodes invaginate forming auditory vesicles.
What is the role of CN I?
Olfactory- sensory receptor neurones ascend through cribriform plate of the ethmoid bone and form the olfactory bulb for the special sense of smell.
What is the role of CN II?
Optic- sensory, forming the optic nerve that supplies the eye and allows for special sense of sight.