Mechanism of protein salting in and salting out by divalent cation salts: Balance between hydration and salt binding virus 1999 order 300 mg tinidazole amex. Mechanism of protein stabilization by glycerol: Preferred hydration in glycerol-water mixtures bacteria 80s buy generic tinidazole 300 mg on-line. Novel excipients prevent aggregation in manufacturing and formulation of protein and peptide therapeutics antibiotic resistance pbs quality 300 mg tinidazole. Overlooking subvisible particles in therapeutic protein products: Gaps that may compromise product quality antibiotics for acne in south africa generic tinidazole 300mg visa. IgG particle formation during filling pump operation: A case study of heterogeneous nucleation on stainless steel nanoparticles. The development of stable protein formulations: A close look at protein aggregation, deamination and oxidation. Polysorbates 20 and 80 used in the formulation of protein biotherapeutics: Structure and degradation pathways. Effect of surfactants on the physical stability of recombinant human growth hormone. Kinetics of temperature-induced irreversible aggregation/precipitation of bovine somatropin as studied by initial rate methods. Acute and long-term stability studies of deoxy hemoglobin and characterization of ascorbate-induced modifications. The effect of cyclodextrins on the stability of peptides in nasal enzymatic systems. Use of 2-hydroxypropyl- -cyclodextrin as a solubilizing and stabilizing excipient for protein drugs. Steric exclusion is the principle source of the preferential hydration of proteins in the presence of polyethylene glycols. Mechanism of polyethylene glycol interaction with the molten globule folding intermediate of bovine carbonic anhydrase B. Aggregation pathway of recombinant human keratinocyte growth factor and its stabilization. Assembly and dissociation of human insulin and Lys Pro- insulin hexamers: A comparison study. Benzyl alcohol-induced destabilization of interferon-gamma: A study by hydrogen-deuterium isotope exchange. Broadly, dispersed systems include suspensions (coarse or colloidal), emulsions, liposomes, and micro- or nanoparticulate systems. Dispersed systems also can be aqueous, nonaqueous, polymeric, or insoluble salt forms/complexes. Dispersed systems compose a relatively small segment of the injectable drug product market compared with solutions and freezedried products. However, the most widely used insulin dosage forms (Table 9-2) and several other therapeutic proteins (Table 9-3) are formulated as injectable suspensions. Several important small molecule products and most vaccine products are formulated as dispersed systems (Table 9-4). There is significant growth in the commercialization of dispersed systems used as depot sustained-release injectables (Tables 9-5 and 3-2). The route of administration of injectable dispersed systems depends on the particle size range of the drug particles. If the drug can be crystallized, then a crystalline suspension can be prepared that offers several advantages over an amorphous suspension. A main advantage of preparing crystals for pharmaceutical suspensions is the fact that a suspension composed of these crystals in the size range of about 1 to 40 m will likely have desirable pharmaceutical properties such as resuspendability, syringeability, and injectability. Successful, reproducible drug crystallization is significantly dependent on drug substance purity since impurities will likely influence the crystallization outcome. Two practical methods for preparing crystals can be described using the classic insulin suspensions as the models-neutral protamine Hagedorn (2) and Ultralente (3). The Ultralente insulin method involves preparing a concentrated crystal suspension that is then diluted with a suitable, aqueous suspension vehicle to produce the final formulation. One solution contains insulin and protamine dissolved in water at acidic pH and the other contains dibasic sodium phosphate adjusted to slightly basic conditions. Both solutions also contain the additional ingredients necessary to complete the crystallization and this chapter updated by Dr. Precipitation is initiated by combination of the solutions in a 1:1 ratio causing a rapid change to neutral pH conditions. Amorphous material forms immediately which then transforms over time (approximately 24 hours) to form rod-shaped crystals about 3 to 6 m long and 1 to 1. Precipitation is initiated by adjusting conditions to the isoelectric point of insulin in the presence of zinc ions, sodium chloride, and sodium acetate accomplished by mixing an acidic solution of insulin with buffer such that the appropriate pH is achieved. Most of the ingredients required for the final preparation are present during crystallization except for preservative. Concentrations for insulin and other ingredients are 10-fold higher during crystal growth and a diluent containing preservative is used to dilute the concentrated suspension to produce the final preparation. Because a monodisperse particle size distribution is desired for the final preparation, predetermined amounts of seed crystals are added during the crystallization phase. Commercial Ultralente preparations contain rhombohedral crystals in the approximate size range of 20 to 30 m. Crystalline suspensions have been put forth as potential approaches for overcoming certain challenges associated with delivery of relatively large amounts of monoclonal antibodies (4). Solubility constraints may necessitate administering higher volumes of the preparation that can only be delivered by intravenous infusion. Forming crystals of these antibodies Protein Solution Insulin Protamine Sulfate Zinc M-Cresol Phenol pH 3. The procedure involves cocrystallizing insulin with the basic peptide protamine in the presence of all necessary excipients used in the final suspension preparation. The procedure involves preparing a concentrated suspension of insulin crystals that is then diluted with vehicle containing additional excipients. Semilente insulin is an example of a suspension composed of flocculated amorphous particles. The suspension is prepared by performing the Ultralente crystallization under less than optimum pH conditions. Physical stability has been correlated to the degree of flocculation (5) suggesting that optimization of a final preparation will be necessary even if amorphous precipitation is easily accomplished. While it is difficult to predict if amorphous suspensions of a given peptide or protein will have the desired pharmacological properties and necessary stability, Semilente insulin preparations highlight the fact that development of a completely crystalline suspension may not be an absolute requirement. Particles were formed by precipitating the protein in the presence of zinc chloride at neural pH. This preparation was claimed to have improved stability at higher concentrations and physiological pH compared with a solution of the protein. The Lente insulin preparation is an example of a suspension containing a mixture of particles having different morphology derived by combination of Ultralente and Semilente to produce a 3:7 mixture of amorphous to crystalline material. This insulin preparation was specifically designed to produce a midrange insulin release profile to minimize the number of injections. Many other techniques are available to produce drug particles, but these are the main ones for producing sterile suspension particles. Spray drying involves the active ingredient dissolved in solvent and sprayed into a drying chamber. Rapid solvent evaporation is accomplished using a hot stream of sterile gas resulting in the formation of uniform spherical particles. Super critical fluid particle formation requires a supercritical gas-like carbon dioxide that is used as either solvent or antisolvent to achieve supersaturation and subsequent generation of particles. Crystallization and lyophilization are more generally applicable because of less stressful conditions and greater ability to maintain the sterility of the dried material. However, the technique may be appropriate for small peptides that lack higher order structure or selected proteins. Increasing attention is focusing on the potential of supercritical fluid for pharmaceutical processing in particular for its suitability to peptide and protein particle formation. Regardless of the method employed to produce particles, some additional characterization studies should be performed to confirm that particle processing procedures do not adversely affect the properties of the molecule. Particle-producing procedures and particle size reduction procedures can impact other properties of the active ingredient, especially if the active ingredient is a biomolecule.
Presentation: Most local anaesthetics are poorly water-soluble weak bases that are usually presented as aqueous solutions of the hydrochloride salts of the tertiary amine 999 bacteria order 300 mg tinidazole with amex. They are therefore prepared as the water-soluble salt of an acid virus in us purchase 1000mg tinidazole with mastercard, usually the hydrochloride antibiotic names medicine discount tinidazole 1000 mg with visa, which is stable in solution infection from root canal discount 300 mg tinidazole with mastercard. Alkalisation: the addition of bicarbonate will raise the pH of the weakly acidic solution nearer the pKa. This means that more drug will exist in the non-ionised form so penetration will be more rapid. Carbonation: this is a variation on alkalisation, and is based on a similar principle but with a different site of action. Most local anaesthetics are marketed as hydrochloride salts; it is, however, possible to combine the base form with carbonic acid to form the carbonate salt rather than the hydrochloric acid. Clinical uses: Alkalisation is particularly useful in decreasing the onset time of a block when speed may be of the essence. The commonest example is when an epidural block that has been used for labour analgesia needs to be extended for surgical delivery. Further aspects of local anaesthesia about which you may be asked include: Inflammatory modulation: the inflammatory response is initiated partly by G-coupled-receptor proteins. Local anaesthetics have recently been shown to interact with some of these proteins to modify the physiological response. Newer preparations: the duration of action may be prolonged by the use of lipid emulsions (which increase the non-ionised proportion and release active drug more slowly), suspensions, liposomes (which are amphipathic lipid molecules encapsulating local anaesthetic) and polymer microspheres. Adjuncts to local anaesthetics: You may be asked what adjuvant drugs may be added to local anaesthetics in order to enhance their action. It is much easier to compare only two agents, which in turn is more interesting than concentrating on only one. You might conceivably be asked to talk solely about either bupivacaine or ropivacaine, but it is almost certain that some comparative information will still be required. Make sure that your knowledge of bupivacaine is thorough, because this is a drug that you will have used frequently. Both possess the same three essential functional units, namely a hydrophilic chain joined by an amide linkage to a lipophilic aromatic moiety. Structures: the parent compound of bupivacaine is mepivacaine, which has a single methyl group attached to the tertiary amine. The structure of ropivacaine (which is effectively a derivative of bupivacaine, and which is prepared as the pure S-enantiomer of propivacaine) differs only in that there is a shorter propyl (C3H7) substituent on the piperidine nitrogen atom. The affinity of local anaesthetics for the sodium channel is related to the length of the aliphatic chains. Affinity determines duration of action: hence ropivacaine, with its shorter propyl chain has a duration of action of 150 min as compared with 175 min for bupivacaine. Lipid solubility: Longer side chains also increase influence lipid solubility, which is a determinant of potency. Highly lipid-soluble agents such as bupivacaine are highly concentrated in local tissue and dislodge slowly. As measured by partition coefficients bupivacaine is twice as soluble as ropivacaine, and is more potent. The S-enantiomer has less affinity for, and dissociates faster, from myocardial sodium channels. Vasoactivity: All local anaesthetics apart from the potent vasoconstrictor cocaine show biphasic activity, being vasodilators at high concentrations and vasoconstrictors at low. The vasoconstriction at low concentrations appears to be associated particularly with the S-enantiomers. Ropivacaine probably exerts greater vasoconstrictor activity than bupivacaine, thereby reducing its potential toxicity and increasing the duration of action. As already discussed, however, it is no less toxic and has a shorter duration of action, so this vasoconstrictor activity probably confers little benefit over laevobupivacaine. It is of particular advantage when the drugs are used in continuous epidurals for labour and for surgical analgesia. Selective block is a genuine phenomenon: etidocaine, for example, demonstrates more potent motor than sensory block. Etidocaine is highly lipid soluble and penetrates better than bupivacaine into the large myelinated A- -motor fibres. This claim has been based largely on studies that have used doses that are supramaximal for sensory block, at which the greater motor-blocking effect of bupivacaine is obvious. If the doses are reduced, then little motor block will be evident with either drug, but the differences in sensory block will be revealed. It is well known that this group of local anaesthetics demonstrates preferential sensory block: the purported superiority of ropivacaine is in fact illusory, and is based on the fact that it is simply a less potent drug. Drug entry into the sodium channels occurs when the channel is open during the period of membrane depolarisation. Nerves conduct at different frequencies: pain and sensory fibres conduct at high frequency whereas motor impulses are at a lower frequency. Lignocaine, bupivacaine and ropivacaine produce a more rapid and denser block in these sensory nerves of higher frequency. This is not true of drugs such as etidocaine, which is associated with a much more profound motor block. You should be aware of the applied pharmacology, of the indications for the technique and of its potential complications. The viva You will be asked about the intravenous drugs that can be used to induce hypotension. You can, for example, talk either about their physiological sites of action or organise your answer according to the groups of drugs that are available. This is almost, but not quite the same thing: labetalol, for instance, is a hypotensive drug with more than one site of action. The drug causes venous vasodilatation more than arteriolar, and hence it decreases venous return and preload. Myocardial oxygen demand is reduced because of the decrease in ventricular wall tension. Tachyphylaxis may be seen in some patients, the mechanism underlying which is uncertain. Reflex tachycardia is common, and this may present a problem during surgery which mandates a quiet circulation. Direct vasodilators Hydralazine: this produces hypotension by direct vasodilatation together with a weak -antagonist action. It is less easy to titrate the dose against effect and the drug finds its main use in the control of hypertension in pregnancy. Unopposed 1-vasoconstriction may compromise the peripheral circulation without causing hypertension. It is given more commonly as a bolus (over 20 min) of 150 g kg 1 for cardiac dysrhythmias than to induce hypotension. It is a popular drug in anaesthetic, obstetric anaesthetic and intensive therapy use. Its hypotensive effects are mediated via a reduction in central sympathetic outflow and by stimulation of presynaptic 2-receptors which inhibit noradrenaline release into the synaptic cleft. There was a time when surgeons largely were oblivious to that injunction, and induced hypotension had many indications, particularly for neurosurgical and procedures in the head and neck. The indications have now shrunk to the point at which the technique is confined to a very few, very specialised surgical procedures, one example of which is the removal of choroidal tumours of the eye.
Tinidazole 1000 mg mastercard. World Health Summit 2015: Antimicrobial Resistance.
This component is carried to the muscles derived from the pharyngeal arches and is transmitted by the nerves of those arches: the trigeminal antibiotics for uti not sulfa discount tinidazole 500mg overnight delivery, facial virus 34 compression buy tinidazole 300 mg cheap, glossopharyngeal bacteria klebsiella infections 1000 mg tinidazole fast delivery, accessory (contributions to the pharyngeal plexus) antibiotic how long to work cheap 1000 mg tinidazole with mastercard, and vagus nerves. As with the typical spinal nerve, cell bodies of afferent nerve fibers of cranial nerves are located in sensory ganglia outside the central nervous system, that is, outside the brain. Central processes of these 280 Chapter 18 Cranial Nerves fibers pass via the cranial nerves into the brain to terminate on neurons that relay impulses for processing, sorting out, and coordinating the information before initiation of a motor response that may or may not be at a conscious level. All of the interconnections and workings of the brain are extremely complicated and beyond the scope of this text. Readers who want more informa- tion about this subject are referred to standard textbooks of neuroanatomy. Each of the 12 cranial nerves is described in the following sections, including information on the location of the cell bodies, the components carried, connections with other nerves, and finally the distribution and function. Cell bodies of the olfactory nerve, the nerve of smell, are found in the olfactory mucosa situated over the superior nasal concha. Axons of the olfactory nerve pass through the cribriform plate of the ethmoid bone to terminate in the olfactory bulb, which is connected to the brain by the olfactory tract, technically a part of the brain. Cell bodies of the optic nerve, the nerve of sight, are located in the ganglionic layer of cells composing the retina. Axons of these cells are gathered into bundles that leave the bulb of the eye as the optic nerve, passing posteriorly through the orbit to exit through the optic foramen. Here the axons join the optic nerve of the opposite side, forming the optic chiasma. Optic tracts continue from the chiasma to enter the base of 282 Chapter 18 Cranial Nerves Clinical Considerations Anosmia Anosmia results following a unilateral lesion either within the olfactory epithelium or within the olfactory nerve, causing the patient to experience complete loss of the sense of smell on the side of the lesion. The oculomotor nerve serves all of the extrinsic muscles of the eye, excluding the superior oblique and the lateral rectus muscles, with general somatic efferent innervation. These are preganglionic parasympathetic neurons whose fibers are destined for the ciliary ganglion within the orbit. Postganglionic fibers from the ciliary ganglion pass to the orb via short ciliary nerves and on to the ciliary body and sphincter pupillae muscles of the eye (see Table 18-2). The oculomotor nerve exits the brain near the medial side of the cerebral peduncle, passes through the free and attached borders of the tentorium cerebelli, and then passes through the lateral wall of the cavernous sinus to enter the superior orbital fissure for distribution. While in the cavernous sinus, contributions from the carotid plexus are communicated to the oculomotor nerve. These communications are the postganglionic sympathetic fibers from the superior cervical ganglion destined for the dilatator pupillae muscle of the eye. Once in the orbit, the oculomotor nerve divides into superior and inferior divisions, facilitating innervation of the extraocular muscles. Clinical Considerations Myopia and Hyperopia Changes in the longitudinal dimension of the optical axis will cause images to be focused either anterior (myopia) or posterior (hyperopia) to the retina. This is usually the result of changes in the refractive elements of the eye, notably the cornea, which experiences a slight change in shape. These conditions can be diagnosed and treated with prescription-ground glasses that can optically correct for the alteration in the longitudinal dimension of the optical axis. Sudden jolts absorbed in the orbit may detach the retina, causing a medical emergency. The detached retina is sightless but sight can usually be restored by surgical reattachment of the retina. Cataract Cataract is an age-related condition where the lens loses its transparency and becomes clouded, causing blurred vision. Modern techniques now permit surgical placement of plastic lenses, resulting in restored vision. This is because the myelin surrounding the optic nerves is produced by glial cells rather than by Schwann cells, as in other cranial nerves. It results from the inability of the eye to focus on close objects (accommodation), which is related to the lens becoming less elastic, thus light cannot be focused properly on the retina. Additional communications to the ganglion are from the nasociliary nerve, a branch of the ophthalmic division of the trigeminal nerve. These communications are purely sensory, passing through the ganglion without synapsing there. Thus, these somatic sensory nerves reach their destination in the orb by way of the short ciliary nerves. Postganglionic sympathetic fibers may also communicate with the ganglion in a fashion similar to that of the nasociliary nerve; however, these sympathetic fibers are destined for the dilatator pupillae muscle. Proprioceptive fibers of the extraocular muscles are carried in the oculomotor nerve, then transmitted to the ophthalmic division of the trigeminal nerve to join it in the orbit, or via communications while it passes through the walls of the cavernous sinus. Terminations of these fibers are described in the section on the trigeminal nerve. Clinical Considerations Oculomotor Nerve Injury Injury to the oculomotor nerve will result in palsy on the ipsilateral side with dilated pupil and ptosis. Additionally, the bulb of the eye will turn down and out with a concomitant inability to move the eye either up or down; moreover, the pupillary reflex will be lost. Note the ciliary ganglion and the distribution of the postganglionic parasympathetic fibers from it. This is the only cranial nerve originating on the dorsal surface of the brainstem. From there, it passes around the midbrain to pierce the tentorial dura, thus entering the cavernous sinus. While coursing through the wall of the cavernous sinus, the trochlear nerve communicates with the carotid plexus and the ophthalmic division of the trigeminal nerve. Proprioceptive fibers from the superior oblique muscle are thought to communicate with the ophthalmic nerve at that point. The largest of the cranial nerves, the trigeminal nerve serves much of the face, the teeth and supporting structures, most of the anterior portion of the oral cavity, and the mucous membranes of the head with cutaneous sensation. Also, it provides motor innerva- Clinical Considerations Trochlear Nerve Injury the trochlear nerve provides motor innervation only to the superior oblique muscle. When this cranial nerve is injured, the superior oblique muscle on the ipsilateral side will be paralyzed, causing the eyeball to rotate outward, resulting in double vision. The larger, sensory root, which lies lateral to the motor root, contains the central processes of the neurons whose cell bodies are found in the trigeminal (semilunar) ganglion, the sensory ganglion of the trigeminal nerve. This ganglion is located under the cover of the dura in a pocket (the Meckel cave) on the trigeminal impression located near the apex of the petrous portion of the temporal bone. Peripheral processes of the sensory neurons located in the flat, semilunar-shaped ganglion are gathered in three separate bundles. These bundles leave the ganglion as the ophthalmic, maxillary, and mandibular divisions of the trigeminal nerve. The motor root courses beneath the trigeminal ganglion, proceeds medial to the sensory root, and the two leave the skull via the foramen ovale and then join each other to form the mandibular division of the trigeminal nerve. The ophthalmic and maxillary divisions are purely sensory, and they leave the cranial vault via the superior orbital fissure and foramen rotundum, respectively. The four parasympathetic ganglia of the head are in close association with the trigeminal nerve, although, functionally, these ganglia are not part of the trigeminal nerve. Postganglionic parasympathetic fibers arising in these ganglia are transmitted to the structures they serve by joining branches of the trigeminal nerve for distribution. The parasympathetic ganglia, the preganglionic motor root, and the associated divisions of the trigeminal nerve are listed in Table 18-2. The ophthalmic nerve supplies the bulb and conjunctiva of the eye, the lacrimal gland, the skin of the forehead and nose, and the mucous membranes of the paranasal sinuses with sensory innervation. The ophthalmic nerve leaves the superior aspect of the trigeminal ganglion, then lies in the lateral wall of the cavernous sinus as it courses to the orbit. In its course, the ophthalmic nerve communicates with the carotid plexus in the cavernous sinus and with other cranial nerves represented in the orbit. Lacrimal Nerve the lacrimal nerve, the smallest branch of the ophthalmic division, runs along the lateral rectus muscle distributing to the lacrimal gland and adjacent conjunctiva.
Sensory nerve endings located going off antibiotics for acne discount tinidazole 1000 mg line, for example antibiotic resistance understanding and responding to an emerging crisis cheap tinidazole 300 mg with amex, in the patellar ligament of the knee do not have their Figure 3-11 antibiotic 7 day purchase tinidazole 500mg online. Rapid opening of the mouth as a result of painful stimuli from biting down on a piece of bone while chewing is an example of a reflex arc in the fifth cranial nerve antibiotic resistance jobs discount tinidazole 500mg amex. The central nervous system is represented by the brain, which is housed with the skull, and the spinal cord, which is housed within the vertebral canal surrounded by the divisions of the vertebrae. The brain and spinal cord are responsible for analysis, integration, and response for the body via sensory input and motor output. The autonomic system is subdivided into the enteric, sympathetic, and parasympathetic systems. The enteric nervous system is located in the wall of the digestive system and functions in the autonomic control of the digestive system. The enteric nervous system is not associated with the head and neck and, therefore, will not be discussed in this textbook. The sympathetic nervous system is that system which puts the body ready for action ("fight or flight"). Each is delicately covered by several layers of meninges and is protected by bone- either the skull around the brain or the bony vertebral column that surrounds the spinal cord. Three separate layers make up the meninges: a tough outer layer, the dura mater; an inner delicate layer closely applied to the brain and the spinal cord and their vessels, the pia mater; and an intermediate layer, the arachnoid, which is closely applied to the dura. Only a potential space exists between the dura and arachnoid, known as the subdural space. The sympathetic system generally prepares the body for action-as in the "fight or flight" response- by increasing heart rate, respiration, blood pressure, and blood flow to the skeletal muscles; dilating the pupils; and generally "shutting down" visceral activity. Thus, they are often referred to as the thoracolumbar outflow of visceral efferent fibers. The parasympathetic nervous system serves to "calm" the body, returning it to a homeostatic state. Parasympathetic innervation, conversely, functions to calm the body by decreasing heart rate, respiration, and blood pressure; constricting the pupils; and increasing visceral activity. Both systems innervate many organs of the body where their antagonistic actions serve to balance functioning to maintain homeostasis. Neurons of the parasympathetic system originate either in the brain in certain nuclei of cranial Autonomic System Summary Bite. The autonomic nervous system, by definition, is a motor system controlling the viscera, cardiac and smooth muscle, and glands. The autonomic (involuntary, visceral) nervous system exerts control over the viscera of the body, serving Chapter 3 Body Systems 27 Figure 3-12. The axon of this neuron will synapse on the cell body of the second neuron in the chain, located in one of the autonomic ganglia; thus, this axon is preganglionic. The axon of the second neuron is postganglionic and extends to the effector organ. The sympathetic system is served by the autonomic ganglia located along most of the spinal segments. These ganglia are known as the sympathetic chain ganglia (paravertebral ganglia) and are connected to each other by the sympathetic trunk and the several collateral ganglia (preaortic ganglia) along the major abdominal blood vessels. Ganglia of the parasympathetic system are located close to the structures innervated and are called terminal ganglia, four of which are in the head, whereas others, the enteric ganglia, are located within the wall of the alimentary canal. Preganglionic sympathetic fibers reach the chain ganglia via the white rami communicantes, a connection between the spinal nerve and the ganglion transmitting the myelinated fibers. The postganglionic fiber may enter the spinal nerve via the gray rami communicantes directly or after ascending or descending in the sympathetic trunk. Preganglionic fibers synapse only one time; therefore, those destined to synapse in the collateral ganglia do not synapse in the chain ganglia. Acetylcholine is the neurotransmitter of both preganglionic sympathetic and parasympathetic neurons and postganglionic parasympathetic neurons. However, noradrenaline is the primary neurotransmitter of postganglionic sympathetic neurons 28 Chapter 3 Body Systems Parietal distribution Visceral distribution Blood vessels of visceral structures, blood vessels, sweat glands, and arrector muscles of hairs Eye (iris) C1 C2 C3 C4 C5 C6 C7 C8 T1 White ramus communicans T2 T3 T4 T5 T6 T7 Gray rami to anterior primary rami of all spinal nerves for distribution to body walls and limbs (vasomotion, sudomotion, and pilomotion) T8 T9 T10 T11 T12 L1 L2 L3 L4 L5 S1 S2 S3 S4 S5 Inferior mesenteric ganglion Superior mesenteric ganglion Large intestine Small intestine Kidney Suprarenal (adrenal) gland Rectum Internal anal sphincter Bladder Penis (or clitoris) Gonad 4 Aorticorenal ganglion 1 2 3 Stomach Pancreas Spleen Celiac ganglion Abdominopelvic splanchnic nerves Cephalic arterial ramus Carotid periarterial plexus Cardiopulmonary splanchnic nerves Heart Larynx Trachea Bronchi Lungs Liver Diaphragm Gallbladder Sympathetic fibers Presynaptic Postsynaptic A nervous system. It receives preganglionic sympathetic fibers which synapse on chromaffin cells of the medulla, stimulating them to produce catecholamines, which give rise to epinephrine and norepinephrine, which are released into the bloodstream. The epinephrine produced here prepares the body for "fight or flight" during stress or fear. The Oral Cavity, Palate, and Pharynx 4 Chapter Outline Teeth Odontogenesis Pharynx Clinical Considerations Lips Clinical Considerations Vestibule Clinical Considerations Oral Cavity Proper Tongue Clinical Considerations Palate Clinical Considerations Key Terms Lips are the highly vascular fleshy structures that guard the entrance to the oral cavity. Oral Cavity Proper is that part of the oral cavity lying within the space created by the dental arches and their surrounding gingiva of each jaw. Palate forms the roof of the oral cavity proper and consists of an anteriorplaced bony palate and the posterior soft palate. Pharynx is a mucous-lined tube attached to the base of the cranium coursing inferiorly to become continuous with the esophagus. It serves as an airway to the larynx and as a passageway for food and drink to the esophagus. Teeth are arranged on both the maxillary and mandibular arches and articulate with the teeth on the opposing arch during occlusion. While they are in occlusion the oral cavity proper and the vestibule are separated. The deciduous dentition possesses 20 teeth, which is later replaced by the permanent dentition possessing a complement of 32 teeth. Tongue forms the floor of the oral cavity proper and consists of the body, the freely moving portion, and the base which is attached to the hyoid bone. Vestibule is that portion inside the oral cavity lying between the dental arches and the cheeks laterally and the lips anteriorly. Chapter 12 31 32 Chapter 4 the Oral Cavity, Palate, and Pharynx 5 6 1 2 his chapter provides an overview of the anatomy of the oral cavity as it would be observed in an oral examination. In addition, some pertinent clinical aspects of the variations in normal anatomy of the oral cavity are addressed where appropriate. Subsequent chapters detail regional dissections pertinent to a thorough understanding of the anatomic structures of the head and neck. It is bounded anteriorly by the lips and posteriorly by the oropharyngeal isthmus (isthmus faucium), a more or less circular aperture that guards the entrance to the pharynx. The oral cavity is lined with mucous membrane composed of stratified squamous epithelium and an underlying dense, irregular, collagenous connective tissue that houses minor salivary glands. For purposes of description, the oral cavity is subdivided into two major regions: the outer vestibule and the inner oral cavity proper. They are covered externally with skin that overlies muscle, glands, and connective tissue. The red portion of the lips, whose coloration is caused by a rich vascular bed visible through the thin epithelium, is termed the vermilion zone. Because it is not a wet membrane, it must be kept moistened with the tongue to prevent drying. The superior lip is bounded laterally by the nasolabial groove extending from the ala (wing) of the nose to a short distance lateral to the corner of the mouth. The two lips are connected laterally by the labial commissures, which are thin folds of tissue that are easily viewed when the mouth is slightly opened. Occasionally a slight depression is noted in the center of the labial commissure, known as the commissural lip pit. The oral fissure (rima of the mouth) is the zone between the superior and inferior lips, which may be opened or, when the two lips are in contact with each other, closed. The lips develop from several sources, including the median nasal (intermaxillary segment), maxillary, and mandibular processes. Many of the structures just described are fusion remnants of these embryologic origins and often become more pronounced with advancing age. A more detailed description of the development and congenital deformities of the lips is presented in Chapter 5. The vestibule is the space between the lips and the cheeks external to the teeth in occlusion. The vestibule is the cleft or space between the lips and cheeks externally and the teeth and gingiva of the dental arches internally when the teeth are in occlusion.
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