Secretion canals

Khera, 1975) for any species studied. There is one report that very large amounts of vitamin B5 inhibit prolactin secretion (Canales et al, 1976) and, subsequently, could be detrimental to the lactating women. Pyridoxine at high doses does cause convulsive disorders, especially the pyridoxal hydrozones (Dubnick et al, 1960 Dipalama and Ritchie, 1977). 

Ancillary treatments such as humidifiers, vaporizers, and saline nasal sprays or drops are used to moisturize the nasal canal and impair crusting of secretions along with promoting ciliary function. Although many patients report benefit from such therapies, there are no controlled studies that support their use.32,34,36... 

The CSF flows through the ventricles, downward through the central canal of the spinal cord, and then upward toward the brain through the subarachnoid space that completely surrounds the brain and spinal cord. As the CSF flows over the superior surface of the brain, it leaves the subarachnoid space and is absorbed into the venous system. Although CSF is actively secreted at a rate of 500 ml/day, the volume of this fluid in the system is approximately 140 ml. Therefore, the entire volume of CSF is turned over three to four times per day. 

Alimentary canal sympathetic dilates, parasympathetic constricts, especially the rectum (see effect of D.F.P. in treatment of post-operative paralytic ileus, p. 196). Furthermore, parasympathetic stimulates glandular secretion. 

Interpretation (1953-1955) of the ultrastructures which, after cell disruption and differential centrifugation, gave rise to microsomes, proved quite difficult. Porter described a vacuolar system with canal-iculi and cistemae which was particularly evident in protein-secreting cells such as the acinar cells of the pancreas. The appearance was... 

Eccrine glands can be found on the entire body surface of humans, except for the lips, external ear canal, clitoris, and labia minora. These glands play an important role in thermoregulation, which is necessary for fluid and electrolyte homeostasis. They secrete a milky or oily odorless liquid which produces the characteristic body smell after metabolism through surface bacteria of the skin. 

The principal determinants of lOP are the rate of aqueous fluid production by the ciliary epithelium and the rate of fluid drainage (outflow) in the canal of Schlemm. Aqueous fluid production involves passive, near-isosmolar fluid secretion driven by active salt transport across the ciliary epithelium. Ion and solute transporters have been identified on pigmented and non-pigmented layers of the ciliary epithelium that probably facilitate active solute secretion. Aqueous fluid drainage is believed to involve pressure-driven bulk fluid flow in the canal of Schlemm, as well as fluid movement through the sclera by seepage across the ciliary muscle and supraciliary space. 

Structures of the anterior chamber of the eye. Tissues with significant autonomic functions and the associated ANS receptors are shown in this schematic diagram. Aqueous humor is secreted by the epithelium of the ciliary body, flows into the space in front of the iris, flows through the trabecular meshwork, and exits via the canal of Schlemm arrow). Blockade of the 13 adrenoceptors associated with the ciliary epithelium causes decreased secretion of aqueous. Blood vessels (not shown) in the sclera are also under autonomic control and influence aqueous drainage. 

The ciliary body, situated posterior to the iris, performs several functions. It connects the anterior part of the choroid to the circumference of the iris, and contains the ciliary muscles necessary for accommodation. The ciliary body secretes aqueous humor into the posterior together with nutrients to nourish the lens. In the ciliary body, melanin is located only in the outer pigmented epithelium [24]. Aqueous humor is actively secreted and passively filtered by the ciliary body. Although the rate of secretion is about 2 pL/min the same volume is drawn-off via Schlemm s canal from where it is conducted into veins [25]. 

---