Diabetes ketoacidosis is one of the most serious and acute complications of diabetes. At the time of presentation and during treatment of diabetic ketoacidosis (DKA), several metabolic and electrolyte derangements can ultimately result in respiratory compromise. Most commonly, hypokalaemia, hypomagnesemia and hypophosphatemia can eventually lead to respiratory muscles failure. Furthermore, tachypnoea, hyperpnea and more severely, Kussmaul breathing pattern can develop. Also, hydrostatic and non-hydrostatic pulmonary oedema can occur secondary to volume shifts into the extracellular space and secondary to increased permeability of the pulmonary capillaries. The presence of respiratory failure in patients with DKA is associated with higher morbidity and mortality. Being familiar with the causes of respiratory compromise in DKA, and how to treat them, may represent better outcomes for patients with DKA.

Precocious puberty is the development of secondary sexual characteristics before the age of 8 in females, and 9 in males. The first sign of early puberty in females is breast enlargement, followed by the appearance of pubic and axillary hair, and finally menarche, 2-3 years after the onset of thelarche. Precocious puberty is caused by the premature activation of the hypothalamic-pituitary-gonadal axis where FSH and LH levels are raised. Less common is the gonadotrophin independent form, which is due to excess sex hormones, but low FSH and LH levels.

Although initially thought to affect only boys, girls with DMD also have an estimated 10% chance of inheriting the condition. In girls, DMD may present with all or some clinical manifestations.

Lamotrigine does not significantly increase risk of birth defects during pregnancy.

This patient has pulmonary renal syndrome which is most commonly due to an ANCA positive vasculitis. The history of recurrent epistaxis makes Wegener’s granulomatosis the most probable diagnosis. Wegener’s granulomatosis, microscopic polyangiitis, and idiopathic pauci-immune necrotizing crescentic glomerulonephritis (NCGN) are strongly associated with antineutrophil cytoplasmic autoantibodies (ANCAs) directed against either proteinase 3 (anti-PR3) or myeloperoxidase (anti-MPO).

The inferior alveolar nerve supplies all the teeth of the respective hemimandible. It transverses the inferior alveolar canal and is a branch of the trigeminal nerve’s mandibular division. Therefore, in this case, the teeth of the right hemimandible will be numb.

The embryonic period comprises of the first 8 weeks of pregnancy. It is divided into a preembryonic phase (from the 1st to the 3rd week), in which the three germinal layers arise, and into the embryonic phase proper (from the 4th to 8th week), in which the embryonic organ anlagen arise.

Lead Poisoning Symptoms: Abdominal pain, bluish line on the gums (Burton line), wrist/foot drop, anaemia, nephropathy, encephalopathy, cognitive impairmentDiagnosis: Detectable in bloodBasophilic stippling of erythrocytes (disorder of heme synthesis) on smearTreatment: Succimer, Dimercaprol, EDTA

The umbilical cord that connects the fetus to the placenta is about 50cm long. This tissue consists of the body stalk and vitelline duct. The former containing the allantoic diverticulum and the umbilical vessels. The latter contains the connection linking the digestive tube and the yolk sac. This cord is wrapped by stratum of ectoderm and gelatinous tissue or jelly of Wharton. The right umbilical vein plus the vitelline vessels and ducts disappear and this at birth the cord has three vessels which are the umbilical vein and two umbilical arteries.

This clinical picture is typical of chickenpox, which is treated with antihistamines and calamine lotion. In the case of fever, acetaminophen can be used. Generally treatment is purely for symptomatic relief.

Not being able to form a sentence at the age of 18 months is quite normal. A combination of two words to form a sentence can be done by 2 years of age.

In the case of anterior nasal bleeds, when the bleeding point is clearly visualised the best management step is cautery, either electrical or chemical.

Power calculations are a important step in study design and preparation, but do not directly help with the interpretation of the results. They are used to determine how many subjects are needed in order to avoid errors in accepting or rejecting the null hypothesis. These calculations are not usually complex and for the best results, the power of the test should be set to above 80%.

Based on the clinical scenario, the most probable diagnosis for this patient is pancreatitis.Although rare in childhood, the presence of abdominal pain radiating to the back with shock and tachycardia, and a raised amylase, should raise a suspicion of pancreatitis. Possible causes include trauma, drugs, viral illness, mumps, hyperparathyroidism, hyperlipidaemia and cystic fibrosis. Other options:- Normal LFTs in this patient make hepatitis unlikely. – Gastroenteritis with severe diarrhoea and vomiting may account for the shock and tachycardia, but guarding on abdominal examination and the raised amylase would not be explained by gastroenteritis. – Pregnancy is an important diagnosis to consider in an adolescent with abdominal pain, but the raised amylase and other features point to a diagnosis of pancreatitis.

The glossopharyngeal nerve is the primary sensory nerve for the tonsillar fossa. The lesser palatine nerve makes a smaller contribution. Because of this, otalgia may occur following tonsillectomy.Anatomical Rationale:Each palatine tonsil has two surfaces, a medial surface which projects into the pharynx and a lateral surface that is embedded in the wall of the pharynx.The primary arterial supply is from the tonsillar artery, a branch of the facial artery. Its veins pierce the constrictor muscle to join the external palatine or facial veins. The external palatine vein is immediately lateral to the tonsil, which may result in bleeding during a tonsillectomy.Lymphatic drainage is the jugulodigastric node and the deep cervical nodes.TonsillitisThe inflammation of tonsils is usually due to bacterial aetiology (50%) – group A Streptococcus, the remainder of the causes are viral.May be complicated by the development of an abscess (quinsy), which may distort the uvula.Indications for tonsillectomy include recurrent acute tonsillitis, and enlargement causing sleep apnoea.Dissection tonsillectomy is the preferred technique with haemorrhage being the most frequent complication. Delayed otalgia may occur owing to irritation of the glossopharyngeal nerve.

The property described in the question is heterogeneity.Heterogeneity is when a single phenotype or genetic disorder can be caused by multiple numbers of genetic mutations.Other options:- Pleiotropy occurs when a single gene influences multiple phenotypic traits. The underlying mechanism is that the gene codes for a product that is used by various cells. A classic example of pleiotropy is the human disease PKU (phenylketonuria).- The penetrance of a disease-causing mutation is the proportion of individuals with the mutation who exhibit clinical symptoms. For example, the gene responsible for a particular autosomal dominant disorder has 70% penetrance, then 70% of those with the mutation will develop the disease, while 30% will not.

Retinopathy screening need not be done on an annual basis for a 9-year-old child. Screening for diabetic retinopathy should begin at the age of 12.Diabetes mellitus is an increasing problem in both developing and developed countries alike. Some of the risk factors include:ObesityFamily historyFemale sex Asian and African racesPresence of acanthosis nigricans is seen with type 2 but not type 1 diabetesThe diagnosis is mostly incidental or subacute.The treatment aims are good blood sugar control, maintenance of normal BMI, and reduction of complications. The treatment modality also includes lifestyle modifications and cessation of smoking. Even after all this, diabetic ketoacidosis can still occur.Management of diabetes mellitus – NICE guidelines (Updated, 2015): – Standard release metformin should be offered from the moment of diagnosis.- HBA1c should be measured every three months. The target HBA1c level of 48 mmol/mol (6.5%) or lower is ideal for minimising the risk of long term complications.- Children should undergo an eye examination by an optician every two years.- Annual immunisation against influenza and pneumococcal infections are essential.- There is an increased risk of psychological and psychosocial difficulties if the child with type 1 diabetes is on insulin or oral hypoglycaemic medications. These include anxiety disorder, depression, behavioural and conduct disorders and family conflict.- Annual monitoring to be done for:Hypertension starting at diagnosis.Dyslipidaemia starting at diagnosis.Screening for microalbuminuria starting at diagnosis.Diabetic retinopathy from 12 years of age.

Types of DNA mutations and their impactpoint mutation:Substitution: One base is incorrectly added during replication and replaces the pair in the corresponding position on the complementary strand as in Sickle cell anaemiaInsertion: One or more extra nucleotides are inserted into replicating DNA, often resulting in a frameshift as in one form of beta-thalassemiaDeletion: One or more nucleotides is skipped during replication or otherwise excised, often resulting in a frameshift as in Cystic fibrosis.Chromosomal mutation:Inversion: One region of a chromosome is flipped and reinserted as in Opitz-Kaveggia syndromeDeletion: A region of a chromosome is lost, resulting in the absence of all the genes in that area as in Cri du chat syndromeDuplication: A region of a chromosome is repeated, resulting in an increase in dosage from the genes in that region as in some cancers and Charcot-Marie toothTranslocation: A region from one chromosome is aberrantly attached to another chromosome as in One form of leukaemiaCopy number variation:Gene amplification: The number of tandem copies of a locus is increased as in Some breast cancersExpanding trinucleotide repeat: The normal number of repeated trinucleotide sequences is expanded as in Fragile X syndrome, Huntington’s disease

Codman’s triangle is the triangular area of new subperiosteal bone that is created when a lesion, often a tumour, raises the periosteum away from the bone. The main causes for this sign are osteosarcoma, Ewing’s sarcoma, eumycetoma, and a subperiosteal abscess.

Marfan syndrome is a disorder that affects the connective tissue found throughout the body, Marfan syndrome can affect many systems, often causing abnormalities in the heart, blood vessels, eyes, bones, and joints. The two primary features of Marfan syndrome are vision problems caused by a dislocated lens (ectopia lentis) in one or both eyes and aortic root disease, leading to aneurysmal dilatation, aortic regurgitation and dissection is the main cause of morbidity and mortality in Marfan syndrome.

Bilious (green) gastric aspirate or emesis indicates that the intestines are obstructed below the ampulla of Vater.Gastrointestinal (GI) endoscopy is actually considered an essential diagnostic and therapeutic technique. Upper GI endoscopy in neonatal age allows for exploration of the oesophagus, stomach and duodenum| instead lower GI endoscopy easily reaches the sigmoid-colon junction.

The most probable diagnosis for this patient would be congenital hypertrophic pyloric stenosis.Congenital Hypertrophic Pyloric Stenosis (CHPS):Pyloric stenosis should be ruled out in any baby who presents with a long-term history of vomiting and failure to thrive. Infants typically present with projectile, non-bilious vomiting and are said to be hungry and wanting to feed despite poor weight gain. A blood gas would be helpful in this instance, although the diagnosis can be made more accurately by observing the stenosis during ultrasound. Many infants have symptoms of gastroesophageal reflux disease, although only a small minority are unable to gain weight adequately. A UTI in infants can present with non-specific symptoms, but they might have a fever and can show poor feeding. Malrotation will present with bilious vomiting.The definitive surgical management is the Ramsteadt’s pyloromyotomy.

This is the clinical picture of dermatitis herpetiformis associated with gluten-sensitive enteropathy. To establish the diagnosis, you should measure the coeliac antibodies. Darrier’s sign (where the skin urticates when it is stroked) is positive in urticaria pigmentosa.

Teenagers may have poor eating habits and neglect to take their vitamin supplements. They are less likely than older women to be of adequate pre-pregnancy weight or to gain an adequate amount of weight during pregnancy. Low weight gain increases the risk of having a low birthweight baby. Weight gain is maximal during the 2nd trimester.aPTT and gallbladder emptying is decreased during pregnancy whereas d-dimers is increased.

Tuberous sclerosis, an autosomal dominant disorder, may present with a variety of symptoms, including seizures, developmental delay, behavioural problems, skin abnormalities, and lung and kidney disease. Hamartomas are often associated.

Meconium aspiration syndrome (MAS) refers to breathing problems that a new-born baby may have when: – There are no other causes, and- The baby has passed meconium (stool) into the amniotic fluid during labour or deliveryThe most recent guidelines are as follows:- If the baby is vigorous (defined as having a normal respiratory effort and normal muscle tone), the baby may stay with the mother to receive the initial steps of new-born care. A bulb syringe can be used to gently clear secretions from the nose and mouth.- If the baby is not vigorous (defined as having a depressed respiratory effort or poor muscle tone), place the baby on a radiant warmer, clear the secretions with a bulb syringe, and proceed with the normal steps of new-born resuscitation (i.e., warming, repositioning the head, drying, and stimulating). If, after these initial steps are taken, the baby is still not breathing or the heart rate is below 100 beats per minute (bpm), administer positive pressure ventilation.Resuscitation should follow the same principles for infants with meconium-stained fluid as for those with clear fluidContinued care in the neonatal intensive care unit (NICU):Maintain an optimal thermal environment to minimize oxygen consumption.Minimal handling is essential because these infants are easily agitated. Agitation can increase pulmonary hypertension and right-to-left shunting, leading to additional hypoxia and acidosis. Sedation may be necessary to reduce agitation.An umbilical artery catheter should be inserted to monitor blood pH and blood gases without agitating the infant.Continue respiratory care includes oxygen therapy via hood or positive pressure, and it is crucial in maintaining adequate arterial oxygenation. Mechanical ventilation is required by approximately 30% of infants with MAS. Make concerted efforts to minimize the mean airway pressure and to use as short an inspiratory time as possible. Oxygen saturations should be maintained at 90-95%.Surfactant therapy is commonly used to replace displaced or inactivated surfactant and as a detergent to remove meconium. Although surfactant use does not appear to affect mortality rates, it may reduce the severity of disease, progression to extracorporeal membrane oxygenation (ECMO) utilization, and decrease the length of hospital stay.

This girl most probably has Turner’s syndrome, which is caused by the absence of one set of genes from the short arm of one X chromosome.Turner syndrome is a lifelong condition and needs lifelong oestrogen replacement therapy. Oestrogen is usually started at age 12-15 years. Treatment can be started with continuous low-dose oestrogens. These can be cycled in a 3-weeks on, 1-week off regimen after 6-18 months| progestin can be added later.In childhood, growth hormone therapy is standard to prevent short stature as an adult.Fetal ovarian development seems to be normal in Turner syndrome, with degeneration occurring in most cases around the time of birth so pulsatile GnRH and luteinising hormone would be of no use.

Homonymous hemianopia (HH) is a visual field defect involving either two right or the two left halves of the visual field of both eye. It results from the damage of the visual pathway in its suprachiasmatic part. The causes of HH include stroke, brain tumours, head injuries, neurosurgical procedures, multiple sclerosis and miscellaneous conditions. HH result in a severe visual impairment and affect a variety of cognitive visual functions. Patients with HH frequently have difficulties with reading and scanning scenes in sufficiently rapid fashion to make sense of things as a whole. They stumble, fall or knock objects in their surroundings, since they cannot see them and they are frequent surprised that somebody or something suddenly appeared in their visual field. The prognosis of visual field deficit recovery is highly variable and depends on the cause and severity of brain nd optic pathway injury.

Kawasaki disease is an acute febrile illness of early childhood characterized by vasculitis of the medium-sized arteries. Diagnostic criteria include fever of at least 5 days duration along with 4 or 5 of the principal clinical features – extremity changes, polymorphous rash, oropharyngeal changes, conjunctival injection and unilateral nonpurulent cervical lymphadenopathy.

A 10 year old child, with a history of URTI and haematuria, presents a picture consistent with a diagnosis of IgA nephropathy. This condition can present with proteinuria and generalized swelling. However, an important differentiating point from rapidly progressive GN is the duration. IgA nephropathy is usually <10 days (commonly 4-5 day history of infection).

The first sign of pubarche in females is breast-bud development (thelarche).This begins between the ages of 9 and 12 years and continues to 12–18 years. Pubic hair growth occurs next (said to occur in stage 3), at ages 9–14 years, and is complete at 12–16 years. Menarche occurs relatively late in stage 4 (age 11–15 years) and is associated with a deceleration in growth. The peak height velocity is reached earlier (10–13 years) and growth is completed much earlier than in boys.

Upper respiratory tract infection when not treated accordingly can lead to otitis media and the patient presents with severe earache and fever.

The clinical presentation and leucocytes on the urine dipstick is suggestive of a urinary tract infection. To confirm the diagnosis, urine should be sent for culture and sensitivity.

Mittelschmerz is midcycle abdominal pain due to leakage of prostaglandin-containing follicular fluid at the time of ovulation. It is self-limited, and a theoretical concern is treatment of pain with prostaglandin synthetase inhibitors, which could prevent ovulation. The pain of mittelschmerz usually occurs in the lower abdomen and pelvis, either in the middle or to one side. The pain can range from a mild twinge to severe discomfort and usually lasts from minutes to hours. In some cases, a small amount of vaginal bleeding or discharge might occur. Some women have nausea, especially if the pain is very strong.Diagnosis of pelvic pain in women can be challenging because many symptoms and signs are insensitive and nonspecific. As the first priority, urgent life-threatening conditions (e.g., ectopic pregnancy, appendicitis, ruptured ovarian cyst) and fertility-threatening conditions (e.g., pelvic inflammatory disease, ovarian torsion) must be considered. Many women never have pain at ovulation. Some women, however, have mid-cycle pain every month, and can tell by the pain that they are ovulating.As an egg develops in the ovary, it is surrounded by follicular fluid. During ovulation, the egg and the fluid, as well as some blood, are released from the ovary. While the exact cause of mittelschmerz is not known, it is believed to be caused by the normal enlargement of the egg in the ovary just before ovulation. Also, the pain could be caused by the normal bleeding that comes with ovulation.Pelvic inflammatory disease can be ruled out if the patient is not sexually active.

Congenital hypothyroidism is associated with failure to thrive, macroglossia, prolonged jaundice of a new-born and constipation.

When a child with joint problems presents with red-eye, the likelihood of anterior uveitis must be excluded by involving an ophthalmologist in the assessment. This is because uveitis is the most common extra-articular manifestation of juvenile idiopathic arthritis.Other options:- Cataract: It does not give rise to a red-eye, but leukocoria. Often this would have been picked up at an earlier age. – A patient with a corneal foreign body almost would almost invariably give a suspicious history (onset while playing outdoors etc.), as well as have marked symptoms of ocular discomfort (red, watery and painful eyes). – A child with periorbital cellulitis often presents acutely unwell and distressed. – A child with an uncorrected refractive error often complains of being unable to see in class and does not normally present with ocular redness.

Achondroplasia is one of the commonest forms of skeletal dysplasias that lead to dwarfism. Multiple skeletal deformities are associated with it but the common cranial abnormalities are macrocephaly, frontal bossing, depressed nasal bridge, narrowed foramen magnum, and the presence of communicating hydrocephalus. A prominent maxilla is not associated with achondroplasia.

The patient has bloody diarrhoea that sounds like a food poisoning in the clinical scenario. Campylobacter is the most common cause of this in the United Kingdom. This is then followed by Salmonella and Shigella. The symptoms are usually self limiting. This is more likely to be bacterial from the food than a viral gastroenteritis.

The study described in the question is a ‘cohort’ study.Other options:A prospective observational study – When groups are classified according to one or more factors at a given time and followed forward to determine outcomes (usually some health status)- Although there is in one sense a control group (those who do not develop the health problem), this is not generally called a ‘controlled’ trial. – An ecological study would look at outcomes in different groups (countries or regions usually) who follow different practices.

Infections of the superficial skin around the eyes are called periorbital, or preseptal, cellulitis. It is predominantly a paediatric disease. Erysipelas is a bacterial skin infection involving the upper dermis which extends into the superficial cutaneous lymphatics. Sinusitis is in sinuses. Orbital infections and conjunctivitis are within the eye.

The patient’s symptoms are most likely due to phenytoin intake.Note:Hypertrichosis occurs in 5–12% of patients on phenytoin and is most prominent on the extremities. Other options:- Hypertrichosis is the excess hair growth, whereas hirsutism is the development of male-pattern-dependent hair growth, as seen in polycystic ovarian syndrome. – A Becker’s naevus is associated with localised hypertrichosis in the naevus. – Cyclosporine intake can typically lead to diffuse hair growth that begins within 2–4 weeks of starting the drug. – Hereditary gingival fibromatosis is associated with variable hypertrichosis occurring on the eyebrows, face, limbs and mid-back.

Also known as the hyoid arch, it forms the side and front of the neck. From its cartilage develops the styloid process, stylohyoid ligament and lesser cornu of the hyoid bone. The muscular derivatives include the muscles of facial expression, stapedius, stylohyoid and the posterior belly of the digastric. All these are innervated by cranial nerve VII but migrate into the area of the mandibular arch.

Coarctation of the aorta may be defined as a constricted aortic segment that comprises localized medial thickening, with some infolding of the medial and superimposed neointimal tissue.The presence of associated defects and aortic arch anomalies, the extent of patency of the ductus arteriosus, the rapidity of the process of closure of the ductus arteriosus, and the level of pulmonary vascular resistance determine the timing of clinical presentation and the severity of symptoms. Young patients may present in the first few weeks of life with poor feeding, tachypnoea, and lethargy and progress to overt CHF and shock. These patients may have appeared well before hospital discharge, and deterioration coincides with closure of the patent ductus arteriosus. Presentation may be abrupt and acute with ductal closure.Neonates may be found to have tachypnoea, tachycardia, and increased work of breathing and may even be moribund with shock. Keys to the diagnosis include blood pressure (BP) discrepancies between the upper and lower extremities and reduced or absent lower extremity pulses to palpation. However, when the infant is in severe heart failure, all pulses are diminished.The murmur associated with coarctation of the aorta may be nonspecific yet is usually a systolic murmur in the left infraclavicular area and under the left scapula.

Umbilical vein catheterization utilizes the exposed umbilical stump in a neonate as a site for emergency central venous access up to 14 days old. Umbilical vein catheterization can provide a safe and effective route for intravenous delivery of medications and fluids during resuscitation.The indication for umbilical vein catheterization is when there is a need for IV access in a neonate for resuscitation, transfusions, or short-term venous access when otherwise unobtainable.

The most probable diagnosis for this patient’s symptoms is psoriasis. Psoriasis:Chronic plaque psoriasis is characterised by pinkish-red hyperkeratotic plaques, which occur mainly on extensor surfaces such as knees and elbows. The lower back, ears and scalp can also be involved. Koebner phenomenon: Psoriasis typically exhibits this phenomenon where new plaques of psoriasis occur particularly at sites of skin trauma. Diagnosis:Skin biopsy of psoriatic plaques reveals acanthosis and parakeratosis, reflecting increased skin turnover. Capillary dilatation within the dermis also occurs, surrounded by a mixed neutrophilic and lymphohistiocytic perivascular infiltrate.

The most prudent course of action in the given clinical scenario is an ovary-sparing cystectomy. The history is 3-months and is already chronic. Furthermore, the cyst is greater than 5cm in size and at risk of torsion. This will relieve the cause of pain, reduce the risk of torsion and save ovarian function.Other options:- This is a simple cyst and not a malignancy, so imaging and referral are not indicated.- Open oophorectomy was done in the past. However, this is very aggressive, and the modern approach is ovary-sparing.- As the cyst is 7cm and at risk of torsion, conservative management is not appropriate.

Haemolytic uremic syndrome belongs to a heterogeneous group of disorders characterized by a triad of thrombocytopenia, microangiopathic haemolytic anaemia, and acute kidney injury. It is one of the most common causes of renal injury in children. The clinical findings are due to thrombotic microangiopathy, which leads to arterioles and capillary wall thickening along with endothelial swelling and detachment. The significant laboratory findings include increased white cell count, raised serum urea and creatinine, increased serum LDH, decreased platelet count, haematuria, and proteinuria.

Presentation can vary by individual. Early stages are often characterized by malaise, fatigue, and lethargy. One to 3 months of inadequate intake can lead to anaemia, myalgia, bone pain, easy bruising (Figure 3), swelling, petechiae, perifollicular haemorrhages, corkscrew hairs, gum disease, poor wound healing, mood changes, and depression. Perifollicular haemorrhages and easy bruising are often first seen in the lower extremities, as capillary fragility leads to an inability to withstand hydrostatic pressure. Late stages of scurvy are more severe and life threatening| common manifestations include generalized oedema, severe jaundice, haemolysis, acute spontaneous bleeding, neuropathy, fever, convulsions, and death.

The baby most likely has umbilical granuloma – granulation tissue may persist at the base of the umbilicus after cord separation| the tissue is composed of fibroblasts and capillaries and can grow to more than 1 cm.Medical therapy is indicated only when an infection is present.Silver nitrate application to umbilical granulomas is usually successful. One or more applications may be needed. Care must be taken to avoid contact with the skin. Silver nitrate can cause painful burns. Small umbilical granulomas with a narrow base may be safely excised in the office setting. Large granulomas and those growing in response to an umbilical fistula or sinus do not resolve with silver nitrate and must be surgically excised in the operating room setting.

The nerve supply to the tensor tympani is the mandibular nerve.The mandibular nerve is the only division of the trigeminal nerve that carries motor fibres.Tensor tympani is a muscle that lies in a bony canal just superior to the pharyngotympanic tube. It originates from the cartilaginous portion of the pharyngotympanic tube, the bony canal in which it sits, and the greater wing of the sphenoid bone. It inserts into the upper part of the handle of the malleus. When contracted, it pulls the handle of the malleus medially. This action increases the tension across the tympanic membrane, reducing the magnitude of vibrations transmitted into the middle ear. This dampens loud noises or noises produced by chewing. Tensor tympani is innervated through the nerve to tensor tympani, which arises from the mandibular nerve.Other options:- The vestibulocochlear nerve is the eighth cranial nerve. This nerve has two components, a vestibular division that carries balance information, and a cochlear division that carries hearing information.- The glossopharyngeal nerve is the ninth cranial nerve. It has a wide range of functions. It carries taste and sensation from the posterior third of the tongue, as well as sensation from the pharyngeal wall and tonsils, the middle ear, external auditory canal and auricle. It carries parasympathetic fibres that supply the parotid gland. It also supplies the baroreceptors and chemoreceptors of the carotid sinus and supplies the secretomotor fibres to the parotid gland.- The maxillary nerve carries only sensory fibres.- The facial nerve is the seventh cranial nerve. It supplies the muscles of facial expression, as well as stylohyoid, the posterior belly of digastric, and stapedius (the only other muscle associated with the middle ear). It carries taste from the anterior two-thirds of the tongue and sensation from part of the external acoustic meatus, parts of the auricle and the retro-auricular area. It provides secretomotor fibres which supply to the submandibular gland, sublingual gland (via chorda tympani nerve), nasal glands and lacrimal glands.