Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
NasoOroLaryngopharynx Oral cavity and what’s important Dentition – 2 – 1 – 2 – 3 , dentition pattern, neuroectoderm Palate – hard – 3 bones make it up, intermaxillary process (from two medial nasal processes fuse together) and the palatine shelves. What covers the bones? Mucosa, it secretes, oral cavity has to stay wet at all times to work. What innervates the inferior surface of the palate? Greater palatine n. (terminal branch of V2, which is purely sensory (GSA), but parasympathetics from CN VII (postparasymp) and postsymp from carotid plexus) Blood supply? Greater palatine a. is a terminal branch of the maxillary a. No mm involved w/ hard palate except using it as an attachment point. Soft – covered w/ mucosa (needs parasympathetic innervation, from the lesser palatine n., brach of V2 w/ same fibers that the greater palatine carried). No true skeletal element, but the tensor aponeurosis is the tendon that attaches two mm bellies (9 – mm attach to soft palate, 4 paired mm and one unpaired: tensor veli palatini (2, innervated by CN V3, tenses the soft palate by wrapping around the hook of the hamulus of the medial pterygoid plate), levator veli palatini (X, lifts the palate), palatopharyngeus (X, longitudinal mm of the pharynx, elev and pos pharynx for deglutition and phonation), palatoglossus (X, final mm we use when we swallow, lifts the posterior portion of the tongue up pushing bolus), musculis uvuli (X, lifts and retracts the uvula so we don’t gag, IX supplies sensory to the uvula for the gag reflex). You can take the tensor veli palatini off the hook of the hamulus and you turn it into a levator. Tongue – 5 CNs assoc w. the tongue, 2 have motor influence (palatoglossus by X, the rest of the mm are innervated by XII), 8 pairs of mm here, 4 extrinsic pairs and 4 intrinsic pairs. Intrinsic pairs are innervated by CN XII for motor and they change the shape of the tongue. He doesn’t care about the intrinsic mm. 4 pairs of extrinsic mm, these mm move the tongue, major positional changes. Genioglossus (CN XII, if XII is damaged, the tongue deviates towards the lesioned side) is one of the first one used by kids to protrude, and the biggest; a unique mm, only anchored at one end, only has a proximal attachment, the genial tubercles of the mandible. Geniohyoid attaches there too. Hyoglossus (CN XII) – attaches to hyoid bone and the lateral surface of the posterior of the tongue, retracts the entire tongue and depresses the posterior of the tongue. Styloglossus (CN XII) – attaches to styloid process and inserts on lateral surface of the hyoglossus mm and the posterior portion of the tongue. Action is to retract and elev the posterolateral portion of the tongue. W/ hyoglossus they retract the tongue. Palatoglossus (CN X) – attaches to lateral surface of soft palate and tensor aponeurosis of soft palate. Inserts on posterolateral surface of the tongue, retracts the tongue some, but elevates the tongue to help swallow mainly. Innervation of the tongue – drew a tongue, ID median sulcus, terminal sulcus, and foramen coecum, these lines give us borders of innervation changes. Anterior to terminal sulcus (anterior 2/3 of tongue) is innervated V3 (lingual nerve, sensory), VII (chorda tympani, special sensory). Then drew valleculae epiglottica, b/t that and the anterior 2/3 of tongue, general sensory is IX, taste is IX. Very back of tongue, just after valleculae epiglottica is innervated by: GSA – X and taste X. Deficit in any of these mm, know the actions so you can answer these questions. Styloglossus, stylohyoid and stylopharyngeus attach to styloid process (all innervated differently). Floor – Principle mm of the floor of the mouth is the mylohyoid. Attachment points for mylohyoid are the hyoid and the mylohyoid line on the body of the mandible, innervated by nn to mylohyoid, branch of inferior alveolar, branch of V3, principally a sensory nn, except for mm derived from 1st pharyngeal arch which receive innervation from V3. Myloyhyoid elevates the floor of the mouth, closing it off for swallowing Geniohyoid found here too – innervated by C1, which also innervates the thyrohyoid. The branch that goes to thyrohyoid continues as the ansa cervicalis. Geniohyoid doesn’t do much. If you lose V3, can we still swallow? Yes Blood supply – Drew the aorta w/ brachiocephalic trunk (RCC and RSC aa.) and LCC and LSC aa. Common carotids split into the internal and external carotid aa. External carotid aa has the branches we are concerned with. 1st branch is superior thyroid aa., the 2nd branch is the lingual aa, 3rd branch is the facial aa. Blood supply to tongue comes off the lingual aa., passes medial to the hyoglossus, where it branches to the dorsal lingual aa (posterior 1/3 of the tongue and the root), also a branch that goes to anterior portion of the tongue, the deep lingual aa., and the last branch the sublingual aa. Goes to floor of the mouth. Venous drainage parallels this, venous commitantes. Pharynx – made up of three parts, depending on where they are located, naso, oro, and laryngo. Drew out the borders and the pharynx. Mainly made up of mm. Five components to the pharynx: mucosa, submucosa, pharyngobasilar fascia, muscular layer, and buccopharyngeal fascia (danger space immediately behind that, goes from base of skull to aorta) 2 groups of mm that make up the pharynx: longitudinal (aka vertical) and constrictors (aka circular). Longitudinal mm vertically position the pharynx, they all attach to the thyroid cartilage at the bottom (posterior lamina to be specific). These lift and tilt the thyroid cartilage slightly forward. Longitudinal mm are innervated by IX and X, 3 longitudinal mm: stylopharyngeus – originates at styloid process, innervated by IX (sens/motor), derived from 3rd pharyngeal arch. Palatopharyngeus – innervated by IX (sensory) and X (motor) Salpingopharyngeus – innervated by IX (sensory) and X (motor) Cosntrictor mm – superior, middle and inferior, motor innervation to all is by X, sensory comes from IX. Pharyngeal plexus made up by IX and X. Constrictors squeeze peristaltically from top to bottom overlapping, bottom overlaps the top. Anterior attachment for superior constrictors is the pterygomandibular raphe of the buccinators, posterior attachment is the pharyngeal raphe and the pharyngeal tubercle. Anterior attachment of middle constr mm is the cornua of the hyoid, posteriorly it attaches to pharyngeal raphe. Anterior attachment of inferior constrictor is thyroid and cricoid cartilage, posterior attachment is pharyngeal raphe. Larynx – thyroid cricoid arytenoid cartilages are the important ones. Epiglottic might come into play. CN X is the only nerve we are worried about, sensory and motor innervation, two branches: superior laryngeal nerve (goes to larynx, 2 branches: external (motor innervation to cricothyroid mm, only mm not innervated by recurrent laryngeal n, and internal (sensory)) and recurrent laryngeal n. (sensory below the vocal fold and motor to all mm except cricothyroid m.); these two are divided by the vocal fold. 4 joints here, 2 cricothyroid (tilts cricoid cart on thyroid cart, stretches/loosens vocal fold for pitch and 2 cricoarytenoid joints ( 3 important parts to larynx: Vocal ligament – know what it is Vocalis mm Thyroid cartilage Cricoid cartilage Arytenoid cartilage 4 things that make up the vocal fold? Mucosa, vocal Lost it at this point, no more notes from this guy, this is recorded. Embryology Covering face and neck (pharyngeal arches and prominences) and some respiratory embryo Face 5 swellings lead to the formation of the face, 4 of these swelling come from the first pharyngeal arch. Mandibular swellings meet in the middle and fuse make the mandible. Just superior to the mandibular swellings are the maxillary swellings. Maxillary swellings never meet. Maxillary swelling make the maxilla and cheeks. The fifth swelling is the frontonasal prominence. The single most important to develop an appropriate face? All of them, failure in any of them lead to problems. Treacher Collins – first arch syn, deaf and underdeveloped mandible. Drew picture of swellings. Point of fusion b/t mandibular swellings is the mandibular raphe. Maxillary swelling grow, but don’t meet. Frontonasal prominence develop thickening of tissue on the lateral portion (nasal placode, thickening of tissue) which envaginates, then it is the nasal pit. Once the pit is developed we get a furrow in the midline which divides this into the lateral and medial nasal processes. Medial nasal processes form the bridge of the nose and most of the ala of the nose. Lat processes form the rest of the ala of the nose and the cheek. Looking laterally at the nasal pits (one on each side), once the buccopharyngeal membrane breaks down and on the anterior end is the oral canal and the other end is the foramen of Paulman. As the pits envaginate medially and posteriorly they end up fusing together. Now there are two holes leading to common open cavity. At the posterior of the cavity apoptosis occurs, leading downward until fusion w/ the posterior cavity of the oral cavity is made, this opening is the primitive choana. The tissue that was isolated during this process breaks down until only a wedge is left, the intermaxillary process. As the maxillary folds grow medially they meet the intermaxillary process and they fuse together. Now we have two lines of fusion on the upper lip, the philtrum (ectocerm overlying the maxillary swellings and intermaxillary process). The primary palate is made when the maxillary folds fuse with the intermaxillary process. We do not have a divided nasal cavity nor a complete palate yet, have to continue. Need to grow and modify some structures. Looking from front, we see our primary palate, oral cavity and nasal cavity posterior and superior. How do we make two halves of a nasal cavity? Grow septal downward (cartilage and mucosa), cartilage will mostly ossify. On the lateral sides we develop extensions of the palatine bone, the palatine shelves. Do the palatine shelves grow directly to the midline? No, grow downward at 40 dg angle, aiming at root of tongue, when they aare 2/3 of full size, the proliferate on the bottom side and apoptose on the top side and they hinge up to a level position, the shelves grow into and fuse w/ the primary palate on the sides of the primary palate and the two shelves fuse together posterior to the primary palate. Failure of the intermaxillary process to fuse to the maxillary swellings is how we get cleft lip (unilateral or bilateral). If the lines of fusion b/t the primary palate and the shelves fail, we have cleft palate (uni or bilateral). Failure of line of fusion b/t palatine shelves is the worst of all (still a cleft palate), wide open choana, cannot swallow, food goes into your nasal cavity. Dermal bone makes the rest of the face and the eyes and ears. Pharyngeal arches – remnants of the gills; 1/2/3/4/6, 5th pharyngeal arch structures don’t exist in humans; each arch contains an artery, nerve, and muscles, and cartilage. What do we know about the arteries here? Don’t care. If arteries fail to develop, we die. 1 – CN V, mm of mastication,, incus, malleus 2 – CN VII, mm of facial expression, stapes, styloid process, lesser cornua of the hyoid bone and upper rim of hyoid 3 – CN IX, stylopharyngeus m. , lower rim of hyoid bone and greater cornua 4 – CN X (superior laryngeal), pharyngeal constrictors, cricothyroid m., laryngeal cartilage 6 – CN X (recurrent laryngeal), intrinsic mm of the larynx, laryngeal cartilages Reviewed the arteries with these, but said we didn’t have to worry about them for the test. Be able to tell him if we have a failure of neural crest migration into arch one, they can’t hear. The cartilages are primarily derived from neural crest cells, saw them during 4th week of development. Be able to say what arch deficits came from and what fiber type of motor innervation is involved. SVE is the type of fibers that we see here. GSA w/ CN V for sensory info for the face. Clefts Only important one is the first cleft. First cleft, without first pharyngeal cleft we can’t stick our keys in our ears, becomes the external auditory meatus. What happens to the other clefts? They get overgrown by a proliferation of the 2nd arch, if they don’t fill in we get a lateral cervical sinus, which can turn into a lateral cervical cyst fluid filled, cut it out. The cervical cyst can have an internal or external fistula. If you have both the baby leaks. What does the region b/t the first and 2nd arch become? Tympanic membrane. Pouches How many pouches important? All of them 1st pouch – tympanic cavity and the auditory tube 2nd pouch – palatine tonsils, envagination of tissue which fills in with lymphoid tissue, almost a complete ring around, Waldeyer’s tonsilar ring 3rd pouch – inferior parathyroids and the thymus 4th pouch – superior parathyroids 5th pouch – Calcitonin producing C cells Gotta make the tongue – arises from the floor of the arches, four of the arches contribute. 1st portion of the tongue comes from the floor of the first arch, a distal tongue bud. From floor of 2nd arch, we form the copula. From the floor of 3rd and 4th arches we form the hypopharyngeal eminence. CNs V, VII, IX, and X are here. CNXII comes later when mm come in. Distal tongue bud develops into two lateral lingual swellings which overgrow the distal tongue bud. They hypopharyngeal eminence overgrows the copula. Most of the cells from the copula undergo apoptosis, leaving innervation from CN VII (chorda tympani). The line of fusion b/t hypopharyngeal eminence and lateral lingual swellings is the … and the line of fusion b/t the lateral swellings is the… About the time the lateral lingual swellings and hypopharyngeal eminence fuse, we see the thyroid gland come in. Thyroid tissue, placode of endothermal tissue, migrates down the neck, can have ectopic thyroid tissue. While the thyroid is migrating downward, the sup and inf parathyroid glands have to cross along the way to find their final position. Lungs Buccopharyngeal membrane and an anal membrane when we develop w/ the gut tube connecting them. We develop resp sys off the gut tube. In the anterior portion of the gut tube, we develop a diverticulum which elongates and develops two swellings at the end, called bronchial buds turning into left and right lungs. As it grows it splits and closes off and makes a connection to the pharynx (laryngeal atticus), now that we have split we split again, we will split the right side into three and the left one into two. Three lobes on right lung, two lobes on the left lung. Primary bronchus, then secondary bronchi, then split to tertiary bronchi. 10 tertiary bronchopulmonary segments on the right and 8 on the left. These continue to divide. Before we have a major split, just an outpouching, but doesn’t look like resp tissue, we are in the pseudoglandular. As we branch, we are now in canalicular phase. When we start seeing pseudoalveoi and terminal sacs, we are in the terminal sac or saccular phase. Towards end of saccular phase we can gas exchange, surfactant is produced now, but squamous epithelium is too thick across the resp membrane so not good exchange yet. When the epithelial of the resp membrane starts to thin, we are in alveolar stage (32 wks). Born at 26 wks, 10-15% chance of survival. Once in alveolar stage, only have half the alveolar functioning needed, so we go in an incubator and get surfactant. Surfactant produced in an embryonic lung, once it reaches a certain level, the baby spits some out, and Mom starts to contract, baby ready to breath.