cranial system

Cranial nerves and cranial nerves are twelve pairs of nerves that start from the base of the brain or brain stem level and emerge through the holes in the skull base, distributed by the head, neck, chest and abdomen. The International Anatomical Nomenclature includes the terminal nerve as cranial nerve, despite being atrophic in humans and closely related to the olfactory nerve.

The cranial nerves are apparent origin that is where it leaves or enters the brain. The real origin is different according to the function they perform. The fibers of the cranial nerves with motor function (efferent) originate from cell clusters that are deep in the brain stem (motor nuclei) and are homologous to the anterior horn cells of the spinal cord. The fibers of the cranial sensory function or sensory (afferent) have their cells of origin (first order nuclei) outside the brain stem, usually in glands that are homologs of the dorsal root of spinal nerves. The second-order sensitive cores are in the brainstem.

The nuclei of cranial nerves where they leave are located in a region widely known as the tegmentum that runs through the brain stem.

At the level of the midbrain, the upper structure of the brain stem, split the pair III

and IV

At the level of the pons, the average structure of the brain stem, split pairs V, VI, VII and VIII

At the level of the medulla oblongata, the lower structure of the brain stem, split cranial nerves IX, X, XI and XII

functional classification

According to its functional aspect, they are grouped as follows:

The pairs I, II and VIII are devoted to special sensory input.

The couple III, IV and VI control eye movements, reflexes fotomotores and accommodation.

The couple XI and XII are pure motor nerves (XI for the sternocleidomastoid and trapezius muscles and XII for the tongue).

The pair V, VII, IX and X are mixed.

The couple III, VII, IX and X are parasympathetic fibers

Disorders

The causes of alteration of the morphology of the skull are called craniosynostosis primarily, caused by premature closure of one or multiple sutures, preventing normal growth of the skull and

craneosinostósicas cranial deformities that are not positional cranial remodeling produced in the intrauterine or more commonly postnatal

The craniosynostosis can be simple, when you commit a single suture and multiple, the first may be classified as:

a) Scaphocephaly: caused by closure of the sagittal suture, is the most common form corresponding to 60% of the synostosis.

b) Plagiocephaly anterior / posterior: generated by unilateral closure of the coronal suture (anterior, or frontal parietal bregmatic) or lambdoid suture (posterior parietal or occipital).

c) trigonocephaly: commitment caused by suture

metopic (between the two frontal bones). The craniosynostosis are classified as:

a) Brachycephaly: originated by bilateral locking of the coronal suture. The subsequent mild braquicefalias may be positional, but if

are severe are due to a true synostosis.

b) Oxicefalia: commitment generated by coronal and sagittal sutures simultaneously

Skull

The skull (from the Greek and Latin κρανίον kranion cranium) is a bony case that protects and contains the brain primarily. The human skull consists of 8 huesos1 joint, forming an open cavity of variable thickness and ovoid, with an approximate capacity of 1,450 ml (adults).

The skeleton of the head, or solid neo-facial skeleton is the set of skull bones (ossa cranii PNA) and facial bones (ossa faciei PNA), known colloquially as skull, but anatomically is the head bone, the skull being a part of the head. It is common to the whole skull designates the bone head, which is improper in the anatomy study. However, in other areas (embryology, biology, etc..) Is considered synonymous with the skull of the head skeleton.

The distinction between skull and face is very clear: the skull houses the brain essentially-the-neurocranium, while the face provides attachment for the muscles of facial expression and mastication and houses some of the sense organs. The skull plays an important role as it is concerned to contain the entire central nervous system, except for the core.

bones of the skull

The bones of the skull are eight, four are odd and half situation, and the other four are two pairs and symmetrical lateral position.

Front (1)

Parietal (2)

Temporary (2)

Occipital (1)

Sphenoid (1)

Ethmoid (1)

sutural bones

The skull, as a cavity, can be seen from inside the cavity as endocranium, or from the outside as exocráneo. In turn, overall, can be divided by a horizontal section passing through the middle frontal eminence and the external occipital protuberance, in two parts:

a top, the cranial vault or skull (calvaria PNA);

a bottom, the base of the skull (basis cranii PNA).

This division is not arbitrary. Part of different embryological origin of the bony structures: endochondral ossification for the bones of the skull base, and intramembranous ossification for the bones of the skull.

The vault is formed by the parental (vertical part), the parietal, temporal scales of the occiput (top). It is covered by the scalp, bones are joined by a few joints called sutures: coronal suture or frontoparietal, between the frontal and parietal, interparietal or sagittal suture between the two parietal or parietooccipital and lambdoid suture between the occipital and parietal.

joints

The joints of the skull bones are sinartrosis, immobile joints that hold the bone pieces together by cartilage (synchondrosis) or fibrous connective tissue (sinfibrosis).

Those bones which form part of the skull base, developed by endochondral ossification are joined together through synchondrosis. And the bones from the cranial vault (and also facial bones), developed from sketches of connective tissue, are joined together by sutures sinfibrosis or (suturae PNA).

Depending on the configuration of the articular surfaces involved in bone union, there are four types of sutures (sinfibrosis) in the skull:

serrated sutures arising from the union "for gear" of the articular surfaces. It is the joint that connects the frontal, occipital, parietal, sphenoid and ethmoid (fronto-parietal joints; parieto-parietal, parieto-occipital, fronto-ethmoidal, fronto-sphenoidal) and joints with craniofacial (fronto-malar; fronto-nasal, etc.)..

the sutures arising from the union of rough surfaces and "bevel cut". Temporomandibular joint is parietal.

the joint is esquindilesis vomer (face) with the sphenoid (skull) formed by the union of a ridge-shaped surface (lower sphenoidal crest) which meshes with a complementary shaped surface groove (between the wings of vomer)

acrania

Acrania is a cephalic disorder of a human fetus characterised by a partial or complete absence of the cranium. The condition is frequently, though not always, associated with anencephaly. The anomaly Acrania is a partial or complete absence of the calvarium with abnormal brain tissue development. This anomaly is lethal in all cases and has important implications for obstetrical management and counseling. Acrania can be diagnosed early in pregnancy through an ultrasound. The fetus is said to suffer from acrania if it meets the following criteria: the fetus should have a perfectly normal facial bone, a normal cervical column but without the fetal skull and a volume of brain tissue equivalent to at least one third of the normal brain size. When no brain or little traces of it are detected, the anomaly is referred to as Anencephaly

Diagnosis

Ultrasound can be Involved in diagnosis.This anomaly Appears During The Beginning or end of the fourth week of the fetus' development, when to the previous neuropore closes. The desmocranium Normally Becomes the epidermis of the scalp, But Remains in acrania desmocranium to the membranous coverage. THEREFORE, the migration of tissue under the calvarium mesenchmal ectoderm does not happen, leading to an Absence of the calvarial bones of the skull dermal, related musculature, and dura mater. The brain may still Develop Normally, But without the walls of the cranium shaping it, it will not differentiate Between the two Hemispheres and will morph into a single mass That will not be Able to sustain life. In all cases Acrania is lethal, no human being can live without the skull and there is

Craniosynostosis

It is a congenital (present at birth) that causes abnormal premature closure of one or more sutures on a baby's head. Sutures are connections that separate each individual skull bones. The early closing of a suture leads to an abnormally shaped head.

Causes, incidence, and risk factors

The cause of craniosynostosis. The abnormal head shape is determined depending on the sutures involved.

Your genes may play a role in craniosynostosis. The hereditary form often occurs with other defects that can cause seizures, diminished intellectual capacity and blindness. Genetic disorders commonly associated with craniosynostosis include Crouzon, Apert, Carpenter, Chotzen, and Pfeiffer.

However, most cases of craniosynostosis occur in a family with no history of illness and children with the disease, except for this, are healthy and have normal intelligence.

There are different types of craniosynostosis sagittal synostosis (scaphocephaly) is the most common type that affects the main (sagittal) either at the top of the head. The early closing forces the head to grow long and narrow, instead of growing in width. Babies with this type of craniosynostosis tend to have a broad forehead and a condition is more common in boys than in girls.

Frontal plagiocephaly is the next most common is the closure of one side of the suture that runs from ear to ear at the top of the head, and is more common in girls.

Metopic synostosis is a rare form of craniosynostosis that affects the suture close to the front. The shape of the child's head can be described as trigonocephaly, and the deformity may range from mild to severe.

symptoms

Absence of the normal feeling of a "soft spot" (fontanelle) on the baby's skull

Disappearance of the fontanelle early

Raised hard ridge along the affected sutures

Irregular head shape

Little or no increase in head size over time as the baby grows

Signs and tests

The doctor will feel the baby's head and perform a physical exam. A neurological exam would also help diagnose the condition. You can perform the following tests:

A measurement of the circumference of the baby's head

Radiographs of the skull

Head CT

treatment

The main treatment for craniosynostosis is surgery that is performed while the child is still a baby, and whose objectives are:

Relieve any pressure on the brain

Ensure there is enough space in the skull to allow for proper brain growth

Improve the appearance of the child's head

spina bifida

Spina bifida is a congenital neural tube, which is characterized by one or more vertebral arches have not fused properly later in pregnancy and spinal cord is no bone protection.

The main cause of spina bifida is the deficiency of folic acid in the mother during the months prior to pregnancy and three months, although a 5% of cases of unknown cause. Already today it has been found that spina bifida is not a hereditary component, which would inherit the mother's difficulty to process folic acid, which occurs very rarely. It was also found that a person with spina bifida children will not necessarily with the same disability. There are basically two types of spina bifida, spina bifida occulta and open spina bifida or cystic.

Spina bifida occulta

Displayed a small defect or gap in one or more vertebrae. Some have a lipoma, dimple, hairy, dark spot or bump on the affected area. The spinal cord and nerves are not altered.

Many people with spina bifida occulta not know they have it, or your symptoms do not appear until later. These symptoms can be of three types:

Neurological: Weakness in the lower extremities, atrophy of the leg or foot, low sensitivity or impaired reflexes.

Genito-Urinary incontinence of urine or feces or urine retention.

Orthopedic foot deformity or differences in size.

Open spina bifida or cystic

This is the most serious, the injury is clearly seen as a lump as a cyst in the back area affected. Are several types:

Meningocele and lipomeningocele

Forms are less frequent. One or more vertebrae present a looming opening a cyst filled with cerebrospinal fluid that contains part of the meninges but not the spinal nerves. Its consequences are less severe, both locomotives and urinary functions. The most effective treatment for any type of spina bifida is the movement.

myelomeningocele

Is the more severe and more frequent. The cyst contains both membranes and nerve roots of the spinal cord and often the cord itself. Occasionally the spinal cord and nerves are exposed. It is necessary to surgically close the opening once the baby is born to avoid infection.

Causes and risk factors

Spina bifida usually comes from the union of a genetic predisposition and environmental factors. Among the environmental causes we can say:

98% of cases are caused by a deficiency of folate in the mother in the moments before or immediately after pregnancy occur.

Maternal treatment with drugs: valproic acid (anticonvulsant), etetrinato (treatment for psoriasis and acne), carbamazepine (psychiatric treatment) and hormonal medications.

Other risk factors:

Maternal age: teenage mothers, or more than 35 years

foot deformity

The deformity has always anatomic integrity (present all the bones, muscles and the different structures of the deformed body). The failure occurred during the fetal period and affects the evolution and growth of structures already formed and complete

equinus

Foot deformity characterized in that the entire it is held in position with plantar flexion

relation to the leg. Contracture of the triceps muscle (Achilles shortened) causes the foot

adopt this position. The individual will perform up with support from the forefoot (up on tiptoe) .

There is often an isolated disease entity. usually

be associated with other deformities of the foot:

- Pie equinovarus (clubfoot).

- Tip foot valgus (posterior tibial muscle paralysis).

- Pie equine neuromuscular disorders. Especially cerebral palsy (ICP). is the

most common deformity in these patients.

His assessment and treatment should be performed in pediatric orthopedic service.

valgus

This type of deformation is defined as the foot whose heel is everted and the distal part is in eversion and abduction. The arc of dorsiflexion and ankle plantar flexion is normal.

There is one way in which the foot is in complete eversion (valgus) with maximum dorsiflexion, which constitutes the talipes valgus. The soft tissues of dorsal and lateral foot contraction show (peroneal muscle contracture) and limits the plantar flexion and inversion. Radiographically, they are feet normal bone structure. No dislocation or subluxation of the tarsal bones.

foot varus

It is the foot deformity in which the heel (rearfoot) is reversed and the distal part of the foot is adducted and investment, with the limits of normal dorsiflexion. The isolated varus deformity of the hindfoot does not exist. Usually accompanies or associates of the forefoot adduction deformity with cavus, or horses, constituting cavo-varus foot or equine-varus (clubfoot), which are often associated with neuromuscular processes of the type of myelomeningocele, Charcot-Marie-Tooth or spastic paralysis. Must be treated by specialists in pediatric orthopedics, requiring in most cases surgical treatment

cavus foot

Is the foot that has an abnormal increase in the height of the arch in the midfoot flexion accentuated the metatarsals. It is a complex entity given the etiological diversity, their different developments and

its many forms of treatment. The age of onset is between 8 12 years, although sometimes present at birth with the first finger claw 9

.

Rarely idiopathic, most of the time (80%) associated with a neurological cause (especially, look for a lesion of the conus medullaris that is accompanied sometimes a nocturnal enuresis, or a birthmark in the lumbar region) ; to illness heredodegenerative type Charcot-Marie-Tooth, or lumbosacral malformation (spina bifida occulta, spondylolisthesis).

Behaves classically arched feet:

- An increase in the convexity of the arch of the foot back to the age progresses slowly from 5 to 11 years.

- A calcaneal varus (valgus rarely).

- Claw fingers flattening of the talus.

Heels

The heel or heel is the back foot at the bottom of the leg below the calf.The heel most famous in literature is that of Achilles, for whom it was his only weakness, dying to be hurt in that place by an arrow shot by Paris.