Prometrium

By Y. Abbas. West Chester University of Pennsylvania. 2017.

Late stages of uncal hernia- The medial longitudinal fasciculus does not contain sensory fibers 200 mg prometrium mastercard. Answer C: The posterior inferior cerebellar artery (commonly called PICA by clinicians) serves the posterolateral portion of the 52. Answer D: Uncal herniation compresses the lateral portion of medulla, which encompasses the anterolateral system, spinal trigem- the brainstem, eventually resulting in compression of the corti- inal tract, and nucleus ambiguus. The anterior and medial areas of the cospinal fibers in the crus cerebri. Weakness on the patient’s left medulla (containing the pyramid, medial lemniscus, and hypoglossal side indicates damage to corticospinal fibers in the right crus. In sit- nucleus/nerve) are served by the anterior spinal artery and the an- uations of significant shift of the midbrain due to the herniation, the terolateral area of the medulla (the region of the olivary nuclei) is contralateral crus may also be damaged resulting in bilateral weak- served by penetrating branches of the vertebral artery. While all other choices contain corticospinal fibers, none of spinal artery serves the posterior column nuclei in the medulla and these areas are directly involved in uncal herniation. Answer C: The root of the oculomotor nerve conveys GSE fibers to four of the six major extraocular muscles and GVE 47. Answer D: The restiform body is a large fiber bundle located in parasympathetic preganglionic fibers to the ciliary ganglion from the posterolateral area of the medulla in the region served by pos- which postganglionic fibers travel to the sphincter muscle of the terior inferior cerebellar artery (PICA). Pressure on the oculomotor root, as in uncal herniation, will variety of cerebellar afferent fibers including those of the posterior usually compress the smaller diameter, and more superficially lo- spinocerebellar tract. Optic nerve damage results in blindness in in a tendency to fall to the ipsilateral side but will also produce that eye, injury to sympathetic fibers to the eye results in con- diplopia (double vision) and nausea; symptoms not experienced striction of the pupil, and an abducens root injury results in an in- by this patient. The anterolateral system is sensory, the nucleus ability to abduct that eye.

It has very little capacity for anaerobic muscle is inversely related to the force being exerted buy prometrium 200mg fast delivery, as metabolism. The tissue is striated in appearance, as in skeletal muscle, and the structural characteristics of the sarco- The heart is composed of several varieties of cardiac mus- meres and myofilaments are much like those of skeletal cle tissue. The regulation of contraction, involving calcium ocardium, so named for their location, are similar struc- control of an actin-linked troponin-tropomyosin com- turally, although the electrical properties of these two areas plex, is also quite like that of skeletal muscle. The mechanical properties of car- of action potentials, and their contractile ability is greatly diac muscle relate more closely to those of skeletal mus- reduced. Finally, there are the highly specialized tissues of cle, although the mechanical performance is considerably the sinoatrial and atrioventricular nodes, muscle tissue more complex and subtle. This arrangement aids in the that follow refer primarily to the ventricular myocardium, spread of electrical activity. Cardiac myocytes have a sin- the tissue that makes up the greatest bulk of the muscle of gle, centrally located nucleus, although many cells may the heart. The cell membrane and associated fine connective tissue structures form the sarcolemma, as in skeletal muscle. The sarcolemma of cardiac muscle sup- Cardiac Muscle Cells Are Structurally ports the resting and action potentials and is the location of ion pumps and ion exchange mechanisms vital to cell func- Distinct From Skeletal Muscle Cells tion. Just inside the sarcolemma are components of the SR The small size of cardiac muscle cells is one of the critical where significant amounts of calcium ions may be bound aspects in determining the function of heart muscle. This bound cells are approximately 10 to 15 m in diameter and about calcium can exchange rapidly with the extracellular space 50 m long. Cardiac muscle tissue is a branching network and can be rapidly freed from its binding sites by the pas- of cells, also called cardiac myocytes, joined together at in- sage of an action potential. Capillaries Nuclei Mitochondria Intercalated disks Branched muscle cell Connective tissue FIGURE 10. Left: striated structure of the contractile filaments, the many mitochon- A small tissue sample in longitudinal and cross dria, and the three-dimensional structure of the intercalated disks. Note the branching nature of the cells and the large (Adapted from Krstic RV.