"Otic vesicle Otic vesicle, or auditory vesicle, consists of either of the two sac-like invaginations formed and subsequently closed off during embryonic development. It is part of the neural ectoderm, which will develop into the membranous labyrinth of the inner ear. This labyrinth is a continuous epithelium, giving rise to the vestibular system and auditory components of the inner ear. During the earlier stages of embryogenesis, the otic placode invaginates to produce the otic cup. Thereafter, the otic cup closes off, creating the otic vesicle. Once formed, the otic vesicle will reside next to the neural tube medially, and on"
"a rostral-caudal axis. E.g. HSCC: looking side to side; SSCC: head to shoulder; PSCC: nodding. SCC sends adaptive signals, unlike the otolith organs whose signals does not adapt over time. A shift in the otolithic membrane that stimulates the cilia is considered the state of the body until the cilia are once again stimulated. E.g. lying down stimulates cilia and standing up stimulates cilia, however, for the time spent lying the signal that you are lying remains active, even though the membrane resets. Otolithic organs have a thick, heavy gelatin membrane that, due to inertia (like endolymph), lags behind and"
"Otolithic membrane The otolithic membrane is a fibrous structure located in the vestibular system of the inner ear. It plays a critical role in the brain's interpretation of equilibrium. The membrane serves to determine if the body or the head is tilted, in addition to the linear acceleration of the body. The linear acceleration could be in the horizontal direction as in a moving car or vertical acceleration such as that felt when an elevator moves up or down. The otolithic membrane is part of the otolith organs in the vestibular system. The otolith organs include the utricle and the"
"Aortic arch The aortic arch, arch of the aorta, or transverse aortic arch () is the part of the aorta between the ascending and descending aorta. The arch travels backward, so that it ultimately runs to the left of the trachea. At the cellular level, the aorta and the aortic arch are composed of three layers: The tunica intima, which surrounds the lumen and is composed of simple squamal epithelial cells; the tunica media, composed of smooth cell muscles and elastic fibers; and, the tunica adventitia, composed of loose collagen fibers. Innervated by barometric nerve terminals, the aortic arch is"
"Orbit (anatomy) In anatomy, the orbit is the cavity or socket of the skull in which the eye and its appendages are situated. “Orbit” can refer to the bony socket, or it can also be used to imply the contents. In the adult human, the volume of the orbit is , of which the eye occupies . The orbital contents comprise the eye, the orbital and retrobulbar fascia, extraocular muscles, cranial nerves II, III, IV, V, and VI, blood vessels, fat, the lacrimal gland with its sac and nasolacrimal duct, the eyelids, medial and lateral palpebral ligaments, check ligaments, the"
"greater sac, and a space posterior to the stomach called the lesser sac. After this rotation the dorsal mesentery thins and forms the greater omentum, which is attached to the greater curvature of the stomach. The ventral mesentery forms the lesser omentum, and is attached to the developing liver. In the adult, these connective structures of omentum and mesentery form the peritoneum, and act as an insulating and protective layer while also supplying organs with blood and lymph vessels as well as nerves. Arterial supply to all these structures is from the celiac trunk, and venous drainage is by the"
"Neck The neck is the part of the body, on many vertebrates, that separates the head from the torso. It contains blood vessels and nerves that supply structures in the head to the body. These in humans include part of the esophagus, the larynx, trachea, and thyroid gland, major blood vessels including the carotid arteries and jugular veins, and the top part of the spinal cord. In anatomy, the neck is also called by its Latin names, cervix or collum, although when used alone, in context, the word ""cervix"" more often refers to the uterine cervix, the neck of the"
"own body. The superior colliculus (SC) or optic tectum (OT) is part of the tectum, located in the midbrain, superior to the brainstem and inferior to the thalamus. It contains seven layers of alternating white and grey matter, of which the superficial contain topographic maps of the visual field; and deeper layers contain overlapping spatial maps of the visual, auditory and somatosensory modalities. The structure receives afferents directly from the retina, as well as from various regions of the cortex (primarily the occipital lobe), the spinal cord and the inferior colliculus. It sends efferents to the spinal cord, cerebellum, thalamus"
"cases the sclerites are fused to various degrees. Thorax The thorax or chest (from the Greek θώραξ ""thorax"" ""breastplate, cuirass, corslet"" via ) is a part of the anatomy of humans and various other animals located between the neck and the abdomen. The thorax includes the thoracic cavity and the thoracic wall. It contains organs including the heart, lungs, and thymus gland, as well as muscles and various other internal structures. Many diseases may affect the chest, and one of the most common symptoms is chest pain. In humans and other hominids, the thorax is the chest region of the"
"Orbitofrontal cortex The orbitofrontal cortex (OFC) is a prefrontal cortex region in the frontal lobes of the brain which is involved in the cognitive process of decision-making. In non-human primates it consists of the association cortex areas Brodmann area 11, 12 and 13; in humans it consists of Brodmann area 10, 11 and 47. The OFC is considered anatomically synonymous with the ventromedial prefrontal cortex. Therefore, the region is distinguished due to the distinct neural connections and the distinct functions it performs. It is defined as the part of the prefrontal cortex that receives projections from the medial dorsal nucleus"
"opisthosoma or abdomen. Segmentation has almost entirely been lost and the prosoma and opisthosoma are fused, only the positioning of the limbs indicating the location of the segments. At the front of the body is the gnathosoma or capitulum. This is not a head and does not contain the eyes or the brain, but is a retractable feeding apparatus consisting of the chelicerae, the pedipalps and the oral cavity. It is covered above by an extension of the body carapace and is connected to the body by a flexible section of cuticle. The mouthparts differ between taxa depending on diet;"
"Thorax The thorax or chest (from the Greek θώραξ ""thorax"" ""breastplate, cuirass, corslet"" via ) is a part of the anatomy of humans and various other animals located between the neck and the abdomen. The thorax includes the thoracic cavity and the thoracic wall. It contains organs including the heart, lungs, and thymus gland, as well as muscles and various other internal structures. Many diseases may affect the chest, and one of the most common symptoms is chest pain. In humans and other hominids, the thorax is the chest region of the body between the neck and the abdomen, along"
"the utricle, the other called the saccule. The utricle contains a patch of hair cells and supporting cells called a macula. Similarly, the saccule contains a patch of hair cells and a macula. Each hair cell of a macula has 40-70 stereocilia and one true cilium called a kinocilium. The tips of these cilia are embedded in an otolithic membrane. This membrane is weighted down with protein-calcium carbonate granules called otoliths. These otoliths add to the weight and inertia of the membrane and enhance the sense of gravity and motion. With the head erect, the otolithic membrane bears directly down"
"Cortex (anatomy) In anatomy and zoology, the cortex (Latin for bark, rind, shell or husk) is the outermost (or superficial) layer of an organ. Organs with well-defined cortical layers include kidneys, adrenal glands, ovaries, the thymus, and portions of the brain, including the cerebral cortex, the best-known of all cortices. The cerebral cortex is typically described as comprising three parts: the sensory, motor, and association areas. These sensory areas receive and process information from the senses. The senses of vision, audition, and touch are served by the primary visual cortex, primary auditory cortex and primary somatosensory cortex. The cerebellar cortex"
"that it provides information about identity."" In mice, individual body odors are represented at the major histocompatibility complex (MHC). In a study performed with rats, the orbitofrontal cortex (OF) was found to play an important role in odor recognition. The OF is reciprocally connected with the perirhinal and entorhinal areas of the medial temporal lobe, which have also been implicated in recognition memory. Gustatory recognition memory, or the recognition of taste, is correlated with activity in the anterior temporal lobe (ATL). In addition to brain imaging techniques, the role of the ATL in gustatory recognition is evidenced by the fact"
"Otolith An otolith (, ' ear + , ', a stone), also called statoconium or otoconium or statolith, is a calcium carbonate structure in the saccule or utricle of the inner ear, specifically in the vestibular system of vertebrates. The saccule and utricle, in turn, together make the ""otolith organs"". These organs are what allows an organism, including humans, to perceive linear acceleration, both horizontally and vertically (gravity). They have been identified in both extinct and extant vertebrates. Counting the annual growth rings on the otoliths is a common technique in estimating the age of fish. Endolymphatic infillings such as"
"Ornithine transcarbamylase Ornithine transcarbamylase (OTC) (also called ornithine carbamoyltransferase) is an enzyme () that catalyzes the reaction between carbamoyl phosphate (CP) and ornithine (Orn) to form citrulline (Cit) and phosphate (P). In plants and microbes, OTC is involved in arginine (Arg) biosynthesis, whereas in mammals it is located in the mitochondria and is part of the urea cycle. OTC is a trimer. The monomer unit has a CP-binding domain and an amino acid-binding domain. Each of the two discrete substrate-binding domains (SBDs) have an α/β topology with a central β-pleated sheet embedded in flanking α-helices. The active sites are located"
"nasus (nose), oris (mouth), and mentum (chin). The neck area is called the cervix or cervical region. Examples of structures named according to this include the frontalis muscle, submental lymph nodes, buccal membrane and orbicularis oculi muscle. Sometimes, unique terminology is used to reduce confusion in different parts of the body. For example, different terms are used when it comes to the skull in compliance with its embryonic origin and its tilted position compared to in other animals. Here, ""Rostral"" refers to proximity to the front of the nose, and is particularly used when describing the skull. Similarly, different terminology"
"Sciatic nerve The sciatic nerve (also called ""ischiadic nerve"", ""ischiatic nerve"") is a large nerve in humans and other animals. It begins in the lower back and runs through the buttock and down the lower limb. It is the longest and widest single nerve in the human body, going from the top of the leg to the foot on the posterior aspect. The sciatic nerve provides the connection to the nervous system for nearly the whole of the skin of the leg, the muscles of the back of the thigh, and those of the leg and foot. It is derived"
"the horizontal contents from medial to lateral) The optic nerve lies just above and outside the cavernous sinus, superior and lateral to the pituitary gland on each side, and enters the orbital apex via the optic canal. It receives tributaries from: The veins of exit are to the superior and inferior petrosal sinuses as well as via the emissary veins through the foramina of the skull (mostly through foramen ovale). There are also connections with the pterygoid plexus of veins via inferior ophthalmic vein, deep facial vein and emissary veins. It is the only anatomic location in the body in"
"Head and neck anatomy This article describes the anatomy of the head and neck of the human body, including the brain, bones, muscles, blood vessels, nerves, glands, nose, mouth, teeth, tongue, and throat. The head rests on the top part of the vertebral column, with the skull joining at C1 (the first cervical vertebra known as the atlas). The skeletal section of the head and neck forms the top part of the axial skeleton and is made up of the skull, hyoid bone, auditory ossicles, and cervical spine. The skull can be further subdivided into: The occipital bone joins with"
"Aorta The aorta ( ) is the main artery in the human body, originating from the left ventricle of the heart and extending down to the abdomen, where it splits into two smaller arteries (the common iliac arteries). The aorta distributes oxygenated blood to all parts of the body through the systemic circulation. In anatomical sources, the aorta is usually divided into sections. One way of classifying a part of the aorta is by anatomical compartment, where the thoracic aorta (or thoracic portion of the aorta) runs from the heart to the diaphragm. The aorta then continues downward as the"
"the dens, used in the diagnosis of dissociation injuries. Genetic disorders can cause a prominent occiput as found in Edwards syndrome, and Beckwith–Wiedemann syndrome. The identification of the location of the fetal occiput is important in delivery. Occipital : from Latin occiput ""back of the skull,"" from ob ""against, behind"" + caput ""head"" . distinguished from sinciput (anterior part of the skull). In many animals these parts stay separate throughout life; for example, in the dog as four parts: squamous part (supraoccipita); lateral parts–left and right parts (exoccipital); basilar part (basioccipital). The occipital bone is part of the endocranium, the"
"Body-stalk The body-stalk, also known as the allantoic stalk, is a band of mesoderm that connects the caudal end of the embryo to the chorion in development. With the formation of the caudal fold, the body-stalk assumes a ventral position; a diverticulum of the yolk-sac extends into the tail fold and is termed the hindgut. With continued development, the body-stalk is later replaced by the umbilical cord. Body stalk anomalies occur in approximately 1 in 15,000 births. They are due to defects in the formation of cephalic, caudal, and lateral embryonic body folds, that result in a reduced or absent"
"uterus. Thus the adjective ""cervical"" may refer either to the neck (as in ""cervical vertebrae"" or ""cervical lymph nodes"") or to the uterine cervix (as in ""cervical cap"" or ""cervical cancer""). The neck contains vessels that link structures in the head to the body. In humans these structures include part of the esophagus, larynx, trachea, thyroid and parathyroid glands, lymph nodes, and the first part of the spinal cord. Major blood vessels present include the carotid arteries and the jugular veins. Cervical lymph nodes surround the blood vessels. The thyroid gland and parathyroid gland are endocrine glands involved in the"
"lateral side of the tibia. The part of the ankle joint known as the talocrural joint, is a synovial hinge joint that connects the distal ends of the tibia and fibula in the lower limb with the proximal end of the talus. The articulation between the tibia and the talus bears more weight than between the smaller fibula and the talus. The tibia is ossified from three centers; a primary center for the diaphysis (shaft) and a secondary center for each epiphysis (extremity). Ossification begins in the center of the body, about the seventh week of fetal life, and gradually"
"an estimated 7% of individuals. The ""aortic knob"" is the prominent shadow of the aortic arch on a frontal chest radiograph. Aortopexy is a surgical procedure in which the aortic arch is fixed to the sternum in order to keep the trachea open. Aortic arch The aortic arch, arch of the aorta, or transverse aortic arch () is the part of the aorta between the ascending and descending aorta. The arch travels backward, so that it ultimately runs to the left of the trachea. At the cellular level, the aorta and the aortic arch are composed of three layers: The"
"of amplification through positive feedback. This positive feedback mechanism is achieved through a somatic motor and a hair bundle motor which operate independently of one another. The somatic motor is the OHC cell body and its ability to elongate or contract longitudinally due to changes in membrane potential. This function is aptly associated with the OHC structure within the Organ of Corti. As seen through scanning electron micrograph imagery, the apical side of the OHC is mechanically coupled to the reticular lamina while the basal side of the OHC is coupled to the Deiter's cell cupula. Because the cell body"
"Opisthotonus Opisthotonus or opisthotonos, from Greek roots, ὄπισθεν, ""opisthen"" meaning ""behind"" and τόνος ""tonos"" meaning ""tension"", is a state of severe hyperextension and spasticity in which an individual's head, neck and spinal column enter into a complete ""bridging"" or ""arching"" position. This extreme arched pose is an extrapyramidal effect and is caused by spasm of the axial muscles along the spinal column. It has been shown to occur naturally only in birds and placental mammals, among existing animals; it is observed in some articulated dinosaur fossils. Opisthotonus is a symptom of some cases of severe cerebral palsy and traumatic brain"
"of the thalamus, and is thought to represent emotion and reward in decision making. It gets its name from its position immediately above the orbits in which the eyes are located. Considerable individual variability has been found in the OFC of humans. A related area is found in rodents. The OFC is divided into multiple broad regions distinguished by cytoarchitecture, including brodmann area 47/12, brodmann area 11, brodmann area 14, brodmann area 13, and brodmann area 10. Four gyri are split by a complex of sulci that most frequently resembles a ""H"" or a ""K"" pattern. Extending along the rostro-caudal"
"Lesser sac The lesser sac, also known as the omental bursa, is the cavity in the abdomen that is formed by the lesser and greater omentum. Usually found in mammals, it is connected with the greater sac via the omental foramen (previously known as the ""Foramen of Winslow""). In mammals, it is not uncommon for the lesser sac to contain considerable amounts of fat. Anterior margin, named from the top-to-bottom margin: Quadrate lobe of the liver, lesser omentum, stomach, gastrocolic ligament Lateral margin, named from the most anterior to the most posterior margin: Gastrosplenic ligament, spleen, phrenicosplenic ligament Posterior margin:"
"not known, but its anatomical connections with the ventral striatum, amygdala, hypothalamus, hippocampus, and periaqueductal grey support a role in mediating reward and fear related behaviors. Meta analyses of neuroimaging studies in OCD report hyperactivity in areas generally considered to be part of the orbitofrontal segment of the cortico-basal ganglia-thalamo-cortical loop such as the caudate nucleus, thalamus and orbitofrontal cortex. OCD has been proposed to reflect a positive feedback loop due to mutual excitation of the OFC and subcortical structures. While the OFC is usually overactive during symptom provocation tasks, cognitive tasks usually elicit hypoactivity of the OFC; this may"
"to: the posterior parietal cortex, which guides voluntary movements, and; the dorsolateral prefrontal cortex, which decides which voluntary movements to make according to higher-order instructions, rules, and self-generated thoughts. Cortex (anatomy) In anatomy and zoology, the cortex (Latin for bark, rind, shell or husk) is the outermost (or superficial) layer of an organ. Organs with well-defined cortical layers include kidneys, adrenal glands, ovaries, the thymus, and portions of the brain, including the cerebral cortex, the best-known of all cortices. The cerebral cortex is typically described as comprising three parts: the sensory, motor, and association areas. These sensory areas receive and"