The human cranial nerves are the twelve pair of nerves that are part of the peripheral nervous system. Although most of them exit the skull, extending throughout the upper part of the body, they arise from grey nuclei in the brainstem, especially in the pons and medulla, branching off through special opening in the skull. The cranial nerves innervate the organs and tissues of the head and neck, with the exception of the vagus nerve, which descends into the thoracic and abdominal cavities. The cranial nerves, unlike the spinal nerves, are not segmented and are highly specialized to innervate different muscles and organs.
The twelve pairs of cranial nerves
The first and second pairs of the cranial nerves are the olfactory (CN I) and optic nerve (CN II), which, unlike the other cranial nerves, originate in the brain and serve as conducting pathways for the olfactory and visual analyzers. The third, fourth, and sixth pairs are the oculomotor (CN III), trochlear (CN IV), and abducent nerve (CN VI); they innervate the muscles of the eyeball. The fifth pair, the trigeminal nerve (CN V), is associated with the region of the mandibular arch; this pair of nerves are the chief sensory nerves of the face and serve as the motor nerves of the muscles of mastication. The seventh pair, the facial nerve (CN VII), innervates the facial muscles in humans and simians. The facial nerves also contain secretory fibers to the lacrimal and salivary glands and sensory fibers to the mucous membrane of the tongue.
The eighth pair, the vestibulocochlear nerve (CN VIII), evolved from the facial nerves. These nerves are purely sensory: They are responsible for linking the organs of hearing and equilibrium with the brain. The related ninth, tenth, and eleventh pairs (the glossopharyngeal (CN IX), vagus (CN X), and accessory nerve CN XI) are unequal in fiber composition and extent of spread. Therefore, the glossopharyngeal and vagus nerve have motor, sensory, and autonomic components. Branches of the vagus nerve also form the cardiac plexus, together with sympathetic trunk nerve fibers. In mammals, the accessory nerve arises from the vagus nerve. The accessory nerve is a motor nerve (efferent) that innervates the sternocleidomastoideus and trapezius muscles. The twelfth pair, the hypoglossal nerve (CN XII) is also motor and supply the muscles of the tongue.
The cranial nerves, from CN III to CN XII, as the come of the anterior side of brainstrem. Only the first two pairs are missing: the olfactory and the optic nerve, because they arise from center in the cerebrum (brain).
There are many things people have not realized about viruses and vaccines. They are so contradictory and paradoxical that they make you doubt the official narrative and doctrine of the virus cult. For example, Edward Jenner developed and obtained the first effective vaccine against smallpox, which was an infectious disease, whose etiology (cause) he did not know was a ''virus''. Thus, in the second half of the 18th century, he did not know the concept of such invisible hyper-micro-entity, and he had never heard of it.
It was the French biochemist Louis Pasteur who coined the word ''virus'' for the first time the following century when he developed the vaccine against rabies. Both Jenner and Pasteur created vaccines for two infectious diseases without having heard the word virus. They had already seen microorganisms under an optic microscope, such as protozoan, bacteria, and multicellular parasites, but they had never seen a virus and, I think, nobody will actually see one.
Louis Pasteur took blood serum and saliva samples from a patient suffering from rabies and put it under an optic microscope. However, he did not find anything new that could have led him to point at the exact cause of the disease, that is to say a new toxin-secreting microorganism. Therefore, he theorized that the culprit might be a much smaller entity, which was invisible to an optic microscope. This new form of microorganism, a thousand times smaller than a bacterium, was the etiology (cause) of the much dreaded disease, and he called this unseen cause ''virus''. Although he did not see anything, he was able to develop an effective vaccine against the disease. Amazing, isn't it? One wonders how did the English physician and Louis Pasteur develop a vaccine to prevent getting sick from a disease without having seen the virus? They did it through acute observation of the patients symptoms, their clinical picture and their labor/social environment, much like a clinician has been doing for centuries.
What did Edward Jenner observe? He observed, what John Fewster had already observed and ascertained, that the people who worked on a dairy farm, milking cows, and got the cowpox, they never got smallpox. Cowpox was a mild form of the dreaded disease; no one died from it. Thus, Edward Jenner came to the conclusion that cowpox gave them immunity against smallpox, making their immune system stronger and conferring it with immunological memory. Then he proceeded to inoculate James Phipps with pus from the blisters on the hand of a milkmaid! And that was it. And what about the virus? Its existence would be hypothesized by Louis Pasteur a century later. When you say that something exists without nobody having ever seen it, then it is a hypothesis; in other words, the virus was a figment of Louis Pasteur's imagination.
What optical instrument do scientists use today to see a ''virus''? An electron microscope, they will tell you. When was it invented? The first electron microscope was built in 1931 by Ernst Ruska and Max Knoll, German physicist and electrical engineer, respectively. But mass media, including Wikipedia, also tells you that Karl Landsteiner and his assistant E. Popper discovered and isolated the poliovirus in 1908. Poliovirus is the ''virus'' that ''causes'' poliomyelitis. How come he was able to discover the poliovirus in 1908 when the first electron microscope was developed in 1931? Contradiction is a sign of ignorance; ignorance is the void that cannot be filled by true tangible evidence, because it is missing. What Karl Landsteiner discovered was not a virus but tissue sample of the spinal cord affected by inflammatory condition observed and described through an optical microscope. It was the pathological micro-anatomical description of sliced spinal cord of a monkey. He only showed the pathological traces of inflammation caused by poliomyelitis, but he did not see any virus.
The biggest incongruity in science that have gone awry through crooked ways.
The major incongruity and contradiction in the virus-vaccine narrative came about when scientific magazines and mass media explained the difference between Jonas Salk's and Robert Sabin's vaccine. They wrote that Jonas Salk's subcutaneous injection vaccine was prepared with a ''killed'' virus, while Robert Sabin's oral drop vaccine was made with a ''live virus''. Don't you find it odd? How can you kill something that is not a live entity but a dead particle?
Biology and medicine teach us that in order to be a live entity, it must be able to reproduce itself on its own through division of its DNA into two complete DNA strands contained in the chromosome, and that the DNA must be contained in a cytosol surrounded by a plasma membrane, consuming fuel and producing its own energy. You can kill either a prokaryotic cell (bacterium) or an Eukaryotic cell, or a protozoan, but you cannot kill something that is not alive, that is dead, that is a dud thing. Thus, as a non-living dud entity, a virus lacks the biological needs of fuel-energy consumption and replication. It does not even secret toxin to break down your cell membrane and enter into your ER to replicate. Only bacteria secret harmful toxins as byproducts from fuel/food consumption through phagocytosis.
The ''viruses'' they show you in electron microscope micrographs science magazines publish now and then are seen as blurred and vague dots, which could well be protein particles which the nucleolus in the nucleus excretes into the ER as left-over, and then it is packed up in a glycoprotein envelope and ejected out of the cell by the Golgi apparatus; in other words, non-living encapsulated protein fragments, like the trash people put in black plastic bags and set in bins outside their house for the garbageman to pick up. These fragments degrade themselves once outside the organism.
What about hepatitis, poliomyelitis, measles, flu, and many other infectious diseases? They are inflammatory conditions, with parenchyma tissue damage caused by inflammation. What triggers inflammation? Inflammatory agents, provoking an unbalanced metabolic and physiologic condition, such as acetaldehyde (produced by liver cells as ethanol metabolic byproduct), drugs, bacteria toxins, amoebas, high insulin and glucose levels, ROS (reactive oxygen species), etc. These conditions are aggravated by malnutrition. In countries, whose population is suffering from starvation, there are always infectious diseases outbreaks. These medical conditions are often called comorbidity.
Written by Carl Wayne. Carl Wayne's real name is Carlos Benito Camacho, an autodidact from Tucuman, Argentina, South America, who grew up in a shanty town. Carlos is in dire straits now, affected by Argentina's great depression created by Javier Milei's wrong and crooked economic policies. You can help Carlos to buy food, making a donation on his paypal account: carlosbenitocamacho@gmail.com - cell phone +543816264880
The pituitary gland, also called hypophysis, is the main gland of the endocrine system. It plays an important role in hormonal regulation in human beings and vertebral animals, secreting hormones that stimulate other endocrine glands. It is located at the base of the brain, below the hypothalamus, as it lies in the sella turcica of the sphenoid bone. The pituitary is bean-shaped and measures 8 mm in length and 6 mm in width, with an average weight of 550 grams in an adult individual of a human being. This gland is connected to the base of the brain by the pituitary stalk or infundibular stem, an outgrowth of the floor of the third cerebral ventricle.
Anatomical Description and Origin
The hypophysis is connected to the hypothalamus through the pituitary stalk. The gland is composed of three lobes: anterior (glandular), intermediate, and posterior (neural). The anterior and intermediate lobes originate in the embryo as an evagination of the epithelium of the roof of the primitive oral cavity. The posterior lobe, on the other hand, is formed from the floor of the infundibulum of the diencephalon. The embryonic rudiment of the anterior and intermediate lobes subsequently separates from the epithelium of the primitive oral cavity, grows toward the brain, and unites with the rudiment of the posterior lobe.
The posterior lobe of the pituitary gland is innervated by a large number of nerve fibers that enter it from the hypothalamus through the stalk and along the walls of the hypophyseal arteries that arise from the internal carotid. These nerve fibers are arranged in two tracts or bundles; one arising and descending from the paraventricular nucleus and the other from the supraoptic nucleus of hypothalamus. Once they make their way into the stalk, they get together to form the supraoptico-hypophysial tract. The anterior lobe, on the other hand, receives nerve fibers from the tuberal nuclei through the tuberoinfundibular tract.
Function
The anterior lobe of the pituitary gland plays a glandular-secretory role. Growth, reproduction, and basal, fat, protein, carbohydrate and mineral metabolism depend upon its normal functioning. Thus, the anterior lobe secretes seven hormones: growth hormone (somatotropin), thyrotropic hormone, follicle-stimulating hormone, luteinizing hormone (lutropin), luteotropic hormone, lactogenic hormone (prolactin), and adrenocorticotropic hormone (ACTH). All these hormones are protein in nature and can be obtained in pure form. Thyrotropic and gonadotropic hormones are produced by the basophilic cells, which are divided accordingly into thyrotrophs and gonadotrophs. The oxyphilic cells manufacture growth hormone and prolactin. The cells that produce ACTH have not been determined, although it is probable that the basophilic cells are involved.
The posterior lobe of the pituitary gland takes part in the regulation of blood pressure and urine output, through the hormone vasopressin. It also takes part in the activity of the uterine muscles, through the hormone oxytocin. Vasopressin and oxytocin are formed in the paraventricular and supraoptic nuclei of the hypothalamus, from which they enter the posterior lobe of the pituitary. Both hormones have been synthesized. Meanwhile, the intermediate lobe of the pituitary manufactures the hormone intermedin, or melanin-stimulating hormone, which influences skin color in fish and amphibians. The physiological role of this hormone in birds and mammals is still unclear.
Blood Supply
The pituitary gland is supplied with oxygenated blood by the superior and inferior hypophysial artery, which arise from the internal carotid. These two arteries enter the median emminence of hypothalamus, forming the superficial external plexus, which in turn gives rise to a network of capillaries. Meanwhile, the gland is drained by the hypophysial portal system of capillaries and venules, which empty deoxygenated blood into the cavernous sinus.
Above, schematic picture showing the pituitary gland with its arterial blood supply and the hypophysial portal system that end up in the veins to the dural cavernous sinuses. The nerve tracts from hypothalamic nuclei can also be seen.
The hypophysis gross anatomy, showing the three lobes and the pituitary stalk.
The muscles of abdomen are flat, broad, and strong, holding up the internal viscera in place. They can be distinguished and separated according to their topographical location. Thus, they can be grouped into the anterior, lateral, and posterior abdominal wall muscles. Action: when they contract, they move the trunk in different directions in relation to the pelvis: forwards, sideways, and backwards. Exercising them help reduce the unhealthy white fat located around the waist.
The muscles of the anterior abdominal wall are: 1) the rectus abdominis muscle, which is the most conspicuous and the longest of them all, popularly known as the washboard when a person has an athletic figure; 2) the pyramidalis muscle, which is small and triangular, lying at the base of the rectus abdominis.
The muscles of the lateral abdominal wall are: 1) the external oblique muscle, which stretches obliquely from the ribs all the way down to the anterior half of iliac crest (of pelvis); 2) the internal oblique muscle, which lies under the external oblique, arising from iliac crest and inguinal ligament to be inserted into tenth to twelfth ribs; 3) transversus abdominis muscle, which is flat and broad, occupying the deepest layer of the anterolateral aspect of the abdominal wall.
The muscles of the posterior abdominal wall are: 1) the quadratus lumborum muscle, which is the only one on this side of abdomen. It is a paired flat muscle, which fills the space between the twelfth rib and the posterior portion of iliac crest of pelvis, being separated from the deep muscles of back by the deep layer of the lumbar fascia. It is innervated by intercostal and lumbar nerves (from T12 to L3).
Muscles of abdomen; anterior and lateral aspect. The external oblique muscle is cut away as it covers the internal oblique.
The external oblique muscle is a flat and broad muscle that lies on the anterolateral surface of the abdominal wall. It arises from the lateral surface of the lower eight ribs by eight slips. Then it extends down vertically, covering the internal oblique, to be inserted into the anterior half of the outer lip of iliac crest through its aponeurosis.
Although the external oblique muscle, as a whole, stretches vertically downwards, its fibers run obliquely down and forwards, towards the middle line of abdomen, ending up in the aponeurosis (a sheet of fibrous tissue). The upper part of this aponeurosis extends to the midline, contributing to the formation of the anterior wall of the rectus abdominis muscle sheath of connective tissue.
There is an oval opening in the lower portion of the aponeurosis of the external oblique, near the inguinal ligament. It lets the spermatic cord (in males) and the round ligament of the uterus (in females) run through and out.
Action/function
Along with the rectus abdominis, the external oblique muscle contributes to pull the trunk downwards (from a standing position), and upwards (from a supine position). It also rotates the trunk to the opposite side.
Blood Supply
It receives oxygenated blood from the intercostal, lateral thoracic, and the superficial circumflex iliac artery.
Innervation
The external oblique muscle is supplied by the intercostal nerves (5th to 12th) and the lumbar nerve (T5 to T12 and L1)
Above, a schematic picture of the abdominal muscles, showing the external oblique (cut away) and the internal oblique muscle.
The transversus abdominis is a flat and broad muscle which is situated in the anterolateral aspect of the abdominal wall, occupying the deepest position. It is composed of transverse fibers which run horizontally across the anterolateral part of the abdomen, beneath the abdominal internal oblique muscle, whose fibers travels down obliquely.
The transversus abdominis muscle originates from the inner surfaces of the lower six costal cartilages, lumbar fascia, inner lip of iliac crest, and the lateral two third of the inguinal ligament. With its fibers traveling horizontally forwards, it ends in aponeurosis, which extends behind the rectus abdominis muscle. This aponeurosis contributes to the formation of the linea alba on the midline.
A few fibers run out of the lower parts of the transversus abdominis to meet similar fibers of the abdominal internal oblique to give shape to the cremaster muscle. A laterally convex line is formed at the junction of the muscular fibers with the aponeurosis; it is called the linea semilunaris.
Action/function
It flattens the abdominal wall, compressing abdominal contents.
Blood Supply
The transversus abdominis muscle is supplied by the inferior and superior epigastric as well as by musculophrenic artery.
Nerve Supply
It is innervated by the intercostal, iliohypogastric, and the ilioinguinal nerves.
The anterior abdominal wall muscles are broad and long muscles which lie on the anterior aspect of the abdomen. They are two in number: the rectus abdominis and the pyramidalis muscle. These paired muscles are situated on both sides of the linea alba, which is a fibrous median band extending vertically the entire length of the abdominal wall midline.
Action
The anterior abdominal wall muscles flex the trunk forwards as when we sit up and rise from a supine position or when we do sit-ups while working out. They are also part of the prelum abdominale. They maintain the intra-abdominal pressure at a certain level by their muscular tone, which is important for holding the abdominal organs in a definite position.
When the tonus of the anterior abdominal wall muscles reduces (atony), intra-abdominal pressure drops, as a result of which the organs are displaced downwards. On the other hand, contraction of these muscles reduces the capacity of the abdominal cavity and the organs are compressed backwards and upwards; this action helps in their evacuation (defecation, urination, and childbirth). As a result, they are called prelum abdominale.
Innervation
The anterior abdominal wall muscles are innervated by the intercostal and lumbar nerves ( T5 to T12 and L1).
Blood Supply
These muscles receives oxygenated blood from the superior and inferior epigastric artery, with the former originating from the internal thoracic and the latter from the external iliac artery.
Above, muscles of the anterior and lateral abdominal wall. The rectus abdominis muscle and the pyramidalis are located on the anterior abdominal wall.
