By L. Quadir. Ryokan College. 2019.
It is directly attached to the inner surface of the bones of the cranium and to the very end of the vertebral cavity purchase 20mg accutane fast delivery acne 3 step clinique. Two infoldings go through the midline separations of the cerebrum and cerebellum order accutane canada acne under jawline; one forms a shelf-like tent between the occipital lobes of the cerebrum and the cerebellum, and the other surrounds the pituitary gland. Arachnoid Mater The middle layer of the meninges is the arachnoid, named for the spider-web–like trabeculae between it and the pia mater. The name pia mater comes from the Latin for “tender mother,” suggesting the thin membrane is a gentle covering for the brain. This procedure is called a lumbar puncture and avoids the risk of damaging the central tissue of the spinal cord. Blood vessels that are nourishing the central nervous tissue are between the pia mater and the nervous tissue. The particular pathogens are not special to meningitis; it is just an inflammation of that specific set of tissues from what might be a broader infection. Bacterial meningitis can be caused by Streptococcus, Staphylococcus, or the tuberculosis pathogen, among many others. Viral meningitis is usually the result of common enteroviruses (such as those that cause intestinal disorders), but may be the result of the herpes virus or West Nile virus. The symptoms associated with meningitis can be fever, chills, nausea, vomiting, light sensitivity, soreness of the neck, or severe headache. More important are the neurological symptoms, such as changes in mental state (confusion, memory deficits, and other dementia-type symptoms). A serious risk of meningitis can be damage to peripheral structures because of the nerves that pass through the meninges. A needle inserted into the lumbar region of the spinal column through the dura mater and arachnoid membrane into the subarachnoid space can be used to withdraw the fluid for chemical testing. Fatality occurs in 5 to 40 percent of children and 20 to 50 percent of adults with bacterial meningitis. Treatment of bacterial meningitis is through antibiotics, but viral meningitis cannot be treated with antibiotics because viruses do not respond to that type of drug. In other tissues, water and small molecules are filtered through capillaries as the major contributor to the interstitial fluid. The Ventricles There are four ventricles within the brain, all of which developed from the original hollow space within the neural tube, 574 Chapter 13 | Anatomy of the Nervous System the central canal. These ventricles are connected to the third ventricle by two openings called the interventricular foramina. The third ventricle is the space between the left and right sides of the diencephalon, which opens into the cerebral aqueduct that passes through the midbrain. The aqueduct opens into the fourth ventricle, which is the space between the cerebellum and the pons and upper medulla (Figure 13. As the telencephalon enlarges and grows into the cranial cavity, it is limited by the space within the skull. The telencephalon is the most anterior region of what was the neural tube, but cannot grow past the limit of the frontal bone of the skull. Because the cerebrum fits into this space, it takes on a C-shaped formation, through the frontal, parietal, occipital, and finally temporal regions. The two ventricles are in the left and right sides, and were at one time referred to as the first and second ventricles. The interventricular foramina connect the frontal region of the lateral ventricles with the third ventricle. The two thalami touch in the center in most brains as the massa intermedia, which is surrounded by the third ventricle. The tectum and tegmentum of the midbrain are the roof and floor of the cerebral aqueduct, respectively. The floor of the fourth ventricle is the dorsal surface of the pons and upper medulla (that gray matter making a continuation of the tegmentum of the midbrain). Cerebrospinal fluid is produced within the ventricles by a type of specialized membrane called a choroid plexus. Observed in dissection, they appear as soft, fuzzy structures that may This OpenStax book is available for free at http://cnx. By surrounding the entire system in the subarachnoid space, it provides a thin buffer around the organs within the strong, protective dura mater. From the dural sinuses, blood drains out of the head and neck through the jugular veins, along with the rest of the circulation for blood, to be reoxygenated by the lungs and wastes to be filtered out by the kidneys (Table 13. Without a steady supply of oxygen, and to a lesser extent glucose, the nervous tissue in the brain cannot keep up its extensive electrical activity. These nutrients get into the brain through the blood, and if blood flow is interrupted, neurological function is compromised. When the blood cannot travel through the artery, the surrounding tissue that is deprived starves and dies. Sometimes, seemingly unrelated functions will be lost because they are dependent on structures in the same region. Along with the swallowing in the previous example, a stroke in that region could affect sensory functions from the face or extremities because important white matter pathways also pass through the lateral medulla. Loss of blood flow to specific regions of the cortex can lead to the loss of specific higher functions, from the ability to recognize faces to the ability to move a particular region of the body. With physical, occupational, and speech therapy, victims of strokes can recover, or more accurately relearn, functions. Ganglia can be categorized, for the most part, as either sensory This OpenStax book is available for free at http://cnx. Under microscopic inspection, it can be seen to include the cell bodies of the neurons, as well as bundles of fibers that are the posterior nerve root (Figure 13. Also, the small round nuclei of satellite cells can be seen surrounding—as if they were orbiting—the neuron cell bodies. Also, the fibrous region is composed of the axons of these neurons that are passing through the ganglion to be part of the dorsal nerve root (tissue source: canine). If you zoom in on the dorsal root ganglion, you can see smaller satellite glial cells surrounding the large cell bodies of the sensory neurons. This is analogous to the dorsal root ganglion, except that it is associated with a cranial nerve instead of a spinal nerve. For example, the trigeminal ganglion is superficial to the temporal bone whereas its associated nerve is attached to the mid-pons region of the brain stem. The other major category of ganglia are those of the autonomic nervous system, which is divided into the sympathetic and parasympathetic nervous systems. The sympathetic chain ganglia constitute a row of ganglia along the vertebral column that receive central input from the lateral horn of the thoracic and upper lumbar spinal cord. Three other autonomic ganglia that are related to the sympathetic chain are the prevertebral ganglia, which are located outside of the chain but have similar functions.
Te clinician must monitor the patient’s response in terms of clinical control and adjust the dose accordingly purchase generic accutane canada acne 6 weeks postpartum. Once control of asthma is achieved proven accutane 10mg acne 101, the dose of medication should be carefully titrated to the minimum dose required to maintain control, thus reducing the potential for adverse efects. Signs and symptoms - Fever - Retroauricular pain - Crying with ear scrubbing - Gastro intestinal signs - Otalgia - Cervical lymphadenopathy - Otorrhea (if tympanic membrane perforated) - Impaired hearing - Redness of eardrum - Sometimes bulging of the eardrum Complications - Secretory otitis media (ear glue) - Chronic otitis media with perforation - Acute mastoiditis sometimes with periosteal abscess - Intracranial (meningitis, brain abscess, subdural abscess, etc. Q every 8 hours for 7-10 days • When associated with rhinitis add Xylometazoline (Otrivine) 0. Predisposing risk factors - Inadequate management of otitis media - Frequent upper respiratory tract infections - Anatomic factor: Short Eustachian Tube - Poor living conditions, poor housing, hygiene and nutrition analphabetism - Immunosupression (e. Pharmaceutical treatment • Application of a topical antibiotics ointment to the nasal mu- cosa has been shown to be an efective treatment for recurrent epistaxis • Topical vasoconstrictor: Xylometazoline spray (otrivine) 0. It is due to intense swelling of epiglottis and surround- ing tissues with septic signs. Cardiac failure Defnition: It is the inability of the heart to deliver adequate cardiac output to meet the metabolic needs of the body. Maximum dose 8 mg/kg/day) • Supplementary Potassium if Frusemide is given for more than 5 days • Treating the underlying cause (surgical treatment): refer to a specialized centre. See section on cardiology for more details on diagnosis and treatment of cardiovascular disorders. Shock Defnition: It is an acute dramatic syndrome characterized by inadequate circulatory provision of oxygen, so that the metabolic demands of vital organs and tissues are not met. Cefotaxi- me 150-200 mg/kg/day in 3-4 divided doses per day or Cefriaxone 100 mg/kg/day given once per day) Ș If no improvement on fuid therapy ■ Give Inotropic drugs (Dopamine 5-15μg/kg/min ■ Dilution: 200 mg in 50 ml of normal saline Ș Abscess, if present should be drained • Cardiogenic shock Ș See section on management of cardiac diseases • Anaphylactic shock Ș General measures as above Ș Place patient in Tredelenberg position with head at 30 degree angle below the feet. Use one of the follow- ing solutions (in order of preference) and according to availability ■ Ringer’s lactate with 5% Glucose (dextrose) or ■ Half Normal saline with 5% Glucose (dextrose) or ■ Half-strength Darrow’s solution with 5% Glucose (dextrose) or if these are unavailable give Ringer’s lactate Ș Measure the pulse and breathing rate at the start and every 5–10 minutes thereafer. Recommendations - If isolated right sided heart failure: use furosemide (see dosage above) and aldactone 2mg/kg/day divided in 2 doses. Repeat the dose according to estimated fuid overload up to 8mg/kg/day • Correct arrhythmia if present with digoxin 0. Causes - Heart not removing fuid from lung circulation properly (cardio- genic pulmonary edema) - A direct injury to the lung parenchyma Signs and symptoms - Breathlessness/ Respiratory distress - Sweating - Cyanosis (decreased oxygen saturation) - Frothy blood-tinged sputum - Ronchi and crepitations/wheezes Investigations - Chest x-ray shows loss of distinct vascular margins, Kerley B lines, difuse haziness of lung felds, pleural efusion. Ofen divided into two types, non-cyanotic and cyanotic (blue discolor- ation caused by a relative lack of oxygen). Some congenital heart diseases can be treated with medication alone, while others require one or more surgeries. Cyanotic heart diseases Defnition: Cyanotic heart disease is a heart defect, present at birth (con- genital), that results in low blood oxygen levels (< 90 % even with oxygen). Acute rheumatic fever Defnition: Tis is an acute, systemic connective tissue disease in children related to an immune reaction to untreated group A Beta haemolytic strep- tococcus infection of the upper respiratory tract. Te initial attack of acute rheumatic fever occurs in most cases between the ages of 3 and 15 years. Rheumatic Heart Diseases Defnition: It is an infammatory damage of the heart valves, as a com- plication of acute rheumatic fever. Te mitral valve is the most commonly involved valve, although any valve may be afected. Types - Mitral regurgitation/stenosis - Aortic regurgitation/stenosis - Tricuspid regurgitation - Mixed regurgitation and stenosis - Multivalvular heart diseases Signs and symptoms - May be asymptomatic when minor lesions - Heart murmurs over afected valve Complications - Congestive cardiac failure with pulmonary oedema - Bacterial endocarditis. Infective endocarditis Defnition: Infection of the endothelial surface of the heart. Suspect infec- tive endocarditis in all children with persistent fever and underlying heart disease. Note: All highly suspected cases of infective endocarditis must be referred to the cardiologist where blood cultures and proper management will be done. Classifcation - Classifcation based on the predominant structural and functional abnormalities: • Dilated cardiomyopathy: primarily systolic dysfunction, • Hypertrophic cardiomyopathy: primarily diastolic dysfunc- tion, • Restrictive cardiomyopathy: primarily diastolic but ofen combined with systolic dysfunction 5. Rheumatic carditis, juvenile rheuma- toid arthritis, systemic lupus erythematosus, dermatomyositis, systemic lupus erythematosus) - Drugs toxicity (e. Restrictive cardiomyopathy Defnition: Restrictive cardiomyopathy refers to a group of disorders in which the heart chambers are unable to properly fll with blood because of stifness in the heart muscle. Pericarditis/Pericardial Efusion Defnition: Pericarditis is the infammation of the pericardium. Pericardial efusion is the abnormal build-up of excess fuid that develops between the pericardium, the lining of the heart, and the heart itself. Causes - Infection such as viral, bacterial (tuberculosis) - Infammatory disorders, such as lupus - Cancer that has spread (metastasized) to the pericardium - Kidney failure with excessive blood levels of nitrogen - Heart surgery (postpericardectomy syndrome) Signs and symptoms - Pericardial tamponade - Chest pressure or pain and signs of congestive heart failure with shock in some cases Note: Many patients with pericardial efusion have no symptoms. Te condition is ofen discovered on a chest x-ray or echocardio- gram that was performed for another reason. A sustained Blood Pressure of > 115/80 is abnormal in children between 6 weeks and 6 years of age. Convulsions Defnition: Convulsions or seizure are disturbance of neurological function caused by an abnormal or excessive neuronal discharge. Causes Causes Clinical signs/symptoms Meningitis - Very irritable - Stiff neck or bulging fontanelles - Petechial rash (meningococcal meningitis only) - Fever Cerebral malaria (only - Blood smear positive for malaria in children exposed to P. Child having 3rd convulsion Lasting < 5mins in < 2 hours* Convulsion stops by 10 minutes? Coma Defnition: It is a state of extreme unresponsiveness, in which an individual exhibits no voluntary movements or behaviour and cannot be aroused to consciousness. Causes Causes Clinical signs/Symptoms Meningitis - Very irritable - Stiff neck or bulging fontanelles - Petechial rash (meningococcal meningitis only) - Fever Cerebral malaria - Blood smear positive for malaria parasites (only in children - Jaundice exposed to P. When seizures are recurrent, persistent or associated with a syndrome, then the child may be diagnosed with epilepsy. Combination therapy should be initiated by or in close consultation with a pediatric specialist or neurologist. Phenytoin and Phenobarbital may be used together but vital signs must be monitored closely and patient should be referred as soon as possible. Tis medication should be prescribed by or in close consultation with a neurologist. May increase dose weekly to maximum to 40 mg/kg/day in 2 divided doses with a maximum dose of 1. It is given as add-on therapy for many seizure types drug-resistant pediatric epileptic syndromes, such as Lennox-Gastaut Syndrome - Levetiracetam: Dosing not established for children <4 years. It is not recommended as mainte- nance therapy for children older than 2 years due to side efects such as sedation, behavioral disturbances, hyperkinesia and dependence, except in situations where there is poor adherence to other drugs. Children ages 2-4 years may metabolize the medication more quickly, as such for children <20 kg, consider initial dose of 16-20 mg/kg/day divided in 2 doses. If >8 years: initial dose is 125-250 mg/kg day at bedtime and may be increased weekly by 125-250mg/day to the usual dose of 750-1500 mg/day in 3-4 divided doses.
Calcium 20mg accutane with amex acne conglobata, Phosphorus best accutane 5mg acne 10, Alkaline phosphatase, Bone marrow examination (sternal puncture), serum protein electrophoresis 123 c) Treatment: Chemotherapy and cortisones 16) Name of condition: Malignant bone tumour – Metastatic Bone Tumours I. It is important to note that symptoms due to the primary disease are often lacking and only the secondary deposits cause symptoms. After suspecting a metastatic deposit, after x-ray examination patient has to be referred to a metro level hospital. For a pathological fracture (or an impending fracture), curettage of the lesion, filling with bone cement and internal fixation preferably with an intramedullary nail is palliative and gives comfort for the rest of the life. The common question that needs to be answered by the primary clinician is whether the foot is normal at birth – when dorsiflexed the dorsum of the neonatal foot touches the shin of tibia. Differential Diagnosis: Other conditions which produce the talipes equino varus deformity should be thought of – meningomyelocele (or spina bifida occulta in adolescents as revealed by external tell tale scars like fobrofatty nodule in the lumbar 124 spine, tuft of hair or pigmented skin patch), Cerebral palsy of lower limbs, Arthrogryposis congenita, nerve injuries to lateral popliteal nerve, anterior poliomyelitis. Prevention: Avoiding consanguineous marriages might prevent, at least partly, the incidence of congenital anomalies V. Clinician has to examine to find out a cause for the deformity as explained in differential diagnosis. Depending on how much deformity is passively correctible, it can be classified as mild, moderate and severe. The chil must be examined for the presence of other congenital anomalies – orthopedic and non-orthopedic b) Investigations: x-ray in an older child. If the improvement is not satisfactory by 8 months of age surgery in the form of posteromedial release is suggested followed by serial plaster casts. Once correction is achieved and the child is not yet walking a Denis-Browne splint is prescribed. If the heel varus is persisting even at 6 yrs age, Dwyer’s calcaneal osteoteotomy is advised. For persisting round contour of the lateral border of the foot one of the lateral column shortening operations is performed. A supramalleolar osteotomy of tibia is indicated for persisting excessive tibial torsion. Incidence: The exact incidence in India is not worked out though the condition is not very rare. Dislocated hip has a short limb, increased creases on the inner aspect of thighs, femoral head present anteriorly , abduction of hip is restricted and telescopy positive. If the acetabular coverage is not enough, Salter’s innominate osteotomy is indicated. In a slightly older child, in addition femoral shortening derotational osteotomy may be beneficial. Introduction: Gout characterized by recurrent attacks of acute inflammatory arthritis— a red, tender, hot, swollen joint. The metatarsal-phalangeal joint at the base of the big toe is the most commonly affected (approximately 50% of cases). It is caused by elevated levels of uric acid in the blood which crystallize and are deposited in joints, tendons, and surrounding tissues. It very rarely affects pre- menopausal women & such a patient should be viewed with suspicion if a diagnosis of gout is made. Gout can present in a number of ways, although the most usual is a recurrent attack of acute inflammatory arthritis. The metatarsal- phalangeal joint at the base of the big toe is affected most often, accounting for half of cases. Other symptoms that may occur along with the joint pain include fatigue and a high fever. Long-standing elevated uric acid levels (hyperuricemia) may result in other symptomatology, including hard, painless deposits of uric acid crystals known as tophi. Elevated levels of uric acid may also lead to crystals precipitating in the kidneys, resulting in stone formation and subsequent urate nephropathy. A number of factors have been found to influence rates of gout, including age, race, and the season 127 of the year. Clinical diagnosis: Usual presentation is acute inflammatory arthritis—a red, tender, hot, swollen joint. The metatarsal-phalangeal joint at the base of the big toe is the most commonly affected (approximately 50% of cases). It is caused by elevated levels of uric acid in the blood which crystallize and are deposited in joints, tendons, and surrounding tissues. Referral criteria: For further evaluation and management of cases not responding to conventional therapy. A variety of causes—hereditary, developmental, metabolic, and mechanical—may initiate processes leading to loss of cartilage, When bone surfaces become less well protected by cartilage, bone may be exposed and damaged. As a result of decreased movement secondary to pain, regional muscles may atrophy, and ligaments may become more lax. Case Definition: Osteoarthritis can be classified into either primary or secondary depending on whether or not there is an identifiable underlying cause. A number of studies have shown that there is a greater prevalence of the disease among siblings and especially identical twins, indicating a hereditary basis. Clinical diagnosis: The main symptom is pain, causing loss of ability and often stiffness. It commonly affects the hands, feet, spine, and the large weight bearing joints, such as the hips and knees, although in theory, any joint in the body can be affected. X Ray - Particularly standing xrays for knees in which eccentric joint space reduction is the diagnostic crieterion as compared to inflammatory where there is concentric space reduction. Referral criteria: For further evaluation and management of cases not responding to conventional therapy. Physical therapy is effective for patients with osteoarthritis of the knee: a randomized controlled clinical trial. Wandel - Effects of glucosamine, chondroitin, or placebo in patients with osteoarthritis of hip or knee: network meta-analysis -- Wandel et al. Introduction: Osteomalacia is a generalized bone condition in which there is inadequate mineralization of the bone. Many of the effects of the disease overlap with the more common osteoporosis, but the two diseases are significantly different. There are two main causes of osteomalacia: (1) insufficient calcium absorption from the intestine because of lack of dietary calcium or a deficiency of or resistance to the action of vitamin D; and (2) Phosphate deficiency caused by increased renal losses b. Case Definition: Osteomalacia is the softening of the bones due to defective bone mineralization secondary to inadequate amounts of available phosphorus and calcium. It may show signs as diffuse body pains, muscle weakness, and fragility of the bones. In the Middle East, a high prevalence of rickets and osteomalacia has been described in Muslim women and their infants, perhaps due to increased clothing coverage of the skin. Clinical diagnosis: Osteomalacia in adults starts insidiously as aches and pains in the lumbar (lower back) region and thighs, spreading later to the arms and ribs.
The related structures of upper lip and palate significantly contribute to the majority of face abnormalities accutane 40mg with amex acne hat. The head and neck structures are more than just the face cheap 30 mg accutane free shipping skin care victoria bc, and are derived from pharyngeal arches 1 - 6 with the face forming from arch 1 and 2 and the frontonasal prominence. Each arch contains similar Arch components derived from endoderm, mesoderm, neural crest and ectoderm. Because the head contains many different structures also review notes on Special Senses (eye, ear, nose (http://embryology. The thyroid gland being one of the first endocrine organs to be formed has an important role in embryonic development. Early Face and Pharynx Pharynx - begins at the buccopharyngeal membrane (oral membrane), apposition of ectoderm with endoderm (no mesoderm between) Pharyngeal Arch Development branchial arch (Gk. During week 4 a series of thickened surface ectodermal patches form in pairs rostro-caudally in the head region. Recent research suggests that all sensory placodes may arise from common panplacodal primordium origin around the neural plate, and then differentiate to eventually have different developmental fates. These sensory placodes will later contribute key components of each of our special senses (vision, hearing and smell). Other species have a number of additional placodes which form other sensory structures (fish, lateral line receptor). Note that their initial postion on the developing head is significantly different to their final position in the future sensory system Otic placode in the stage 13/14 embryo (shown below) the otic placode has sunk from the surface ectoderm to form a hollow epithelial ball, the otocyst, which now lies beneath the surface surrounded by mesenchyme (mesoderm). The epithelia of this ball varies in thickness and has begun to distort, it will eventually form the inner ear membranous labyrinth. Lens placode lies on the surface, adjacent to the outpocketing of the nervous system (which will for the retina) and will form the lens. Head Growth continues postnatally - fontanelle allow head distortion on birth and early growth bone plates remain unfused to allow growth, puberty growth of face Skull Overview Chondrocranium - formed from paraxial mesoderm cranial end of vertebral column modified vertebral elements occipital and cervical sclerotome bone preformed in cartilage (endochondrial ossification) Cranial Vault and Facial Skeleton - formed from neural crest muscle is paraxial mesoderm somitomeres and occipital somites Calveria - bone has no cartilage (direct ossification of mesenchyme) bones do not fuse, fibrous sutures 1. Embryonic Primary palate, fusion in the human embryo between stage 17 and 18, from an epithelial seam to the mesenchymal bridge. This requires the early palatal shelves growth, elevation and fusion during the early embryonic period. As the tongue develops "inside" the floor of the oral cavity, it is not readily visible in the external views of the embryonic (Carnegie) stages of development. Contributions from all arches, which changes with time begins as swelling rostral to foramen cecum, median tongue bud Arch 1 - oral part of tongue (ant 3/2) Arch 2 - initial contribution to surface is lost Arch 3 - pharyngeal part of tongue (post 1/3) Arch 4 - epiglottis and adjacent regions tongue development animation | Development of the Tongue (http://embryology. Salivary Glands epithelial buds in oral cavity (wk 6-7) extend into mesenchyme parotid, submandibular, sublingual tongue muscle Abnormalities Cleft Lip and Palate 300+ different abnormalities, different cleft forms and extent, upper lip and ant. First Arch Syndrome There are 2 major types of associated first arch syndromes, Treacher Collins (Mandibulofacial dysostosis) and Pierre Robin (Pierre Robin complex or sequence), both result in extensive facial abnormalites. Treacher Collins Syndrome Pierre Robin Syndrome Hypoplasia of the mandible, cleft palate, eye and ear defects. Initial defect is small mandible (micrognathia) resulting in posterior displacement of tongue and a bilateral cleft palate. DiGeorge Syndrome absence of thymus and parathyroid glands, 3rd and 4th pouch do not form disturbance of cervical neural crest migration Cysts Many different types Facial Clefts extremely rare Holoprosencephaly shh abnormality Maternal Effects Retinoic Acid - present in skin ointments 1988 associated with facial developmental abnormalities Fetal Alcohol Syndrome Due to alcohol in early development (week 3+) leading to both facial and neurological abnormalities lowered ears, small face, mild+ retardation Microcephaly - leads to small head circumference Short Palpebral fissure - opening of eye Epicanthal folds - fold of skin at inside of corner of eye Flat midface Low nasal bridge Indistinct Philtrum - vertical grooves between nose and mouth Thin upper lip Micrognathia - small jaw Exposure of embryos in vitro to ethanol simulates premature differentiation of prechondrogenic mesenchyme of the facial primordia (1999) Fetal Alcohol Syndrome (http://embryology. Structures derived from Membranes At the bottom of each groove lies the membrane which is formed from the contact region of ectodermal groove and endodermal pouch. The function of the pathway will be to alter the cell directly or 2009 Lecture 12 From Embryology Contents Neural Crest Development Introduction The neural crest are bilaterally paired strips of cells arising in the ectoderm at the margins of the neural tube. These cells migrate to many different locations and differentiate into many cell types within the embryo. This means that many different systems (neural, skin, teeth, head, face, heart, endocrine, gastrointestinal tract) will also have a contribution fron the neural crest cells. In the body region, neural crest cells also contribute the peripheral nervous system (both neurons and glia) consisting of sensory ganglia (dorsal root ganglia), sympathetic and parasympathetic ganglia and neural plexuses within specific tissues/organs. In the head region, neural crest cells migrate into the pharyngeal arches (as shown in movie below) forming ectomesenchyme contributing tissues which in the body region are typically derived from mesoderm (cartilage, bone, and connective tissue). Lectopia Audio Lecture Date: 01-09-2009 Lecture Time: 12:00 Venue: BioMed E Speaker: Mark Hill Neural Crest (http://lectopia. Understand how neural crest cells contribute to the pharyngeal arches and the head structures they form. Francis-West - Chapter 4 p74-82 - Chapter 5, experimental methods; Chapter 12 Development of the Head, the Neck, the Eyes, and the Ears pp349 - 418 Early Development and Neural Derivatives bilaminar embryo- hyoblast trilaminar embryo - ectoderm layer neural plate - neural groove - neural tube and neural crest cranial expansion of neural tube - central nervous system caudal remainder of neural tube - spinal cord Neural Crest dorsal root ganglia parasympathetic / sympathetic ganglia. Interactions between the neural plate and epidermis can generate neural crest cells, since juxtaposition of these tissues at early stages results in the formation of neural crest cells at the interface. At cranial levels, neuroepithelial cells can regulate to generate neural crest cells when the endogenous neural folds are removed, probably via interaction of the remaining neural tube with the epidermis. Progenitor cells in the neural folds are multipotent, having the ability to form multiple ectodermal derivatives, including epidermal, neural crest, and neural tube cells the neural crest is an induced population that arises by interactions between the neural plate and the epidermis. The competence of the neural plate to respond to inductive interactions changes as a function of embryonic age. Diagram of an E10 embryo showing the origins of neural crest cells that colonize the developing gastrointestinal tract (http://www. Thus transplanation and subsequent histological processing allowed identification of the migration path and final destination of transplanted neural crest cells. Similar later experiments have now been carried out using the neural crest cells molecularly tagged with (LacZ). Neuroblastoma Velo-cardio-facial syndrome, Hypoplasia of thymus and parathyroids, third and fourth pharyngeal pouch syndrome. Abnormalities: cardiovascular, thymic and parathyroid, craniofacial anomalies, renal anomalies, hypocalcemia and immunodeficiency. Clinically this is detected by one or more tests (barium enema and x ray, manometry or biopsy) and can currently only be treated by surgery. A temoporary ostomy (Colostomy or Ileostomy) with a stoma is carried out prior to a more permanent pull-through surgery. Melanoma In Australia each year 8,800 people are diagnosed with melanoma, and almost 1000 people die (Data, Cancer Council Australia). Two different findings on the reprogramming of melanoma cells, which have a neural crest origin, when transplanted between species into embryos. Multiple café-au-lait spots (flat skin patches darker than the surrounding area) appear in early childhood which increase in both size and number with age. In the iris of the eye, Lisch nodules (benign growths) also appear (French, café-au-lait = coffee with milk) Atlas of Genetics and Cytogenetics in Oncology- Neurofibroma (http://atlasgeneticsoncology. Segmental restriction of neural crest cells and motor neurons by the ephrin proteins of the sclerotome (http://www. Diagram of an E10 embryo showing the origins of neural crest cells that colonize the developing gastrointestinal tract (http://www. In the body, this is mainly about mesoderm differentiation beginning with an embryonic connective tissue structure, the mesenchyme.