By B. Merdarion. Knox Theological Seminary.
Area 4 is the primary somatomotor cortex generic 100mcg entocort overnight delivery, externum anchors the dural sac caudally to the inner aspect of the area 17 the primary visual cortex discount entocort 100 mcg without a prescription, and area 22 the primary audi- coccyx discount 100mcg entocort otc. Area 40 is in the supramarginal gyrus, a large part of which is called the Wernicke area. Answer B: The primary somatomotor cortex consists of the precentral gyrus and the anterior paracentral gyrus; area 4 is found 17. Answer D: The body is represented in the somatomotor cortex in these structures. Areas 3, 1, and 2 are the primary somatosen- (precentral gyrus, anterior paracentral gyrus) in the following pat- sory cortex; areas 5 and 7 make up the superior parietal lobule and tern: the face in about the lateral one-third of the precentral gyrus the precuneus; and area 6 is located rostral to area 4. Portions of above the lateral sulcus; the hand and upper extremity in about its area 6 in the caudal region of the middle frontal gyrus are the middle third; and the trunk and hip in about its medial third. Answer A: In this patient, the meningioma is located in the falx cation of the frontal eye ﬁeld. Answer C: The L4-L5 interspace is commonly used for a lum- in the anterior paracentral gyrus (somatomotor) and in the poste- bar puncture. Because the caudal end of the spinal cord (the tains the motor representation for the face (lateral part) and the conus medullaris) may be as low as L2 in some individuals, levels trunk and hip (medial part). The postcentral gyrus is part of the T12-L1 to L2-L3 are not used, as this would most likely result in somatosensory cortex. The S1-S2 vertebrae are fused so there is no intervertebral space through which a needle can pass. Answer D: The M4 segments of the middle cerebral artery serve thermore, the dural sac ends at about S2. Answer B: The oculomotor nerve (III) exits from the medial as- sels that serve the pre- and postcentral gyri (hemorrhage into ap- pect of the midbrain into the interpeduncular fossa/cistern. It tra- proximately the lower two-thirds of these gyri explain the motor verses this space, courses through the lateral wall of the cavernous and sensory deﬁcits) are the precentral branches (prerolandic), sinus to eventually enter (along with the trochlear [IV] and ab- central branches (Rolandic branches), and anterior parietal ducens [VI] nerves) the superior orbital ﬁssure. The M2 segment serves the insular cortex, and the M3 VI, and V (the ophthalmic portion of the trigeminal nerve), along segment serves the inner surface of the frontal, parietal, and tem- 1 poral opercula. The A1 segment serves hypothalamic structures, with III, pass through the cavernous sinus. Answer D: A lesion in area 44 (the pars opercularis) that spreads will affect the lower portions of the precentral gyrus in which the 26. Answer E: The uncus is a small elevation at the rostral and me- face is represented. This will result in weakness of facial muscles, dial aspect of the parahippocampal gyrus adjacent to the crus cere- accompanied by other cranial nerve deﬁcits. In addition to the catastrophic effect of de- hearing and vision are far separated from area 44. Also, a lesion in cerebration, herniation of the uncus may also affect corticospinal the primary auditory cortex will not result in a hearing loss in one and corticonuclear (corticobulbar) ﬁbers in the crus cerebri and ear.
The protein thrombin purchase entocort 100mcg with mastercard, injury order 100mcg entocort amex, or by products released from the interior of dam- which is generated by the plasma coagulation cascade entocort 100mcg for sale, is a aged cells. Hemostasis can be viewed as four separate but potent activator of platelet adherence and secretion. Rup- interrelated events: tured cells at the site of tissue injury release adenosine • Compression and vasoconstriction, which act immedi- diphosphate (ADP), which causes platelets to aggregate at ately to stop the flow of blood the damaged site. These aggregates effectively stop the • Formation of a platelet plug flow of blood from the ruptured vessels. The fibrin network traps red cells, leuko- exerted by the tissue around the injured area, and vasocon- cytes, platelets, and serum at sites of vascular damage, striction. The degree of compression varies in different tis- thereby forming a blood clot. The stable, fibrin-based sues; for example, bleeding below the eye is not readily de- blood clot eventually replaces the unstable platelet ag- terred because the skin in this area is easily distensible. Fibrin is Back-pressure increases as blood which leaks out of the dis- an insoluble polymer of proteolytic products of the rupted capillaries accumulates. Fibrin molecules are cleaved uterus after childbirth, contraction of underlying muscles from fibrinogen by thrombin, which is generated in compresses blood vessels supplying the tissue and mini- plasma during clotting. Damaged cells at the site of tissue injury mation, thrombin cleaves four small peptides (fib- release potent substances that directly cause blood vessels rinopeptides) from each molecule of fibrinogen. The fib- to constrict, including serotonin, thromboxane A2, epi- rinogen molecule devoid of these fibrinopeptides is nephrine, and fibrinopeptide B. The fibrin monomers sponta- neously assemble into ordered fibrous arrays of fibrin, resulting in an insoluble matrix of fibrous strands. At this Platelets Form a Hemostatic Plug stage, the clot is held together by noncovalent forces. First, they form plasma enzyme, fibrin stabilizing factor (Factor XIII), multicellular aggregates linked by protein strands at sites of catalyzes the formation of covalent bonds between CHAPTER 11 Blood Components, Immunity, and Hemostasis 207 strands of polymerized fibrin, stabilizing and tightening the blood clot. Blood clotting is mediated by the sequential activation of a series of coagulation factors, proteins synthesized in the liver that circulate in the plasma in an inactive state. They are referred to by number (designated by a Roman numeral) in a sequence based on the order of the discovery of each factor. The plasma coagulation factors and their common names are listed in Table 11. The sequential activation of a series of inactive mole- cules resulting in a biological response is called a metabolic cascade. The sequential activation of coagulation factors resulting in the conversion of fibrinogen to fibrin (and, hence, clotting) is called the coagulation cascade. The de- ficiency or deletion of any one factor of the cascade has se- vere consequences.
O2-sensing mecha- carotid chemoreceptors (A) Would not apply to the regulation nisms in excitable cells: Role of plasma (C) Is exaggerated by hypoxia of the membrane K channels generic entocort 100mcg without a prescription. Annu Rev of PaCO2 medullary chemoreceptors (B) Anticipate future events Physiol 1997;59:23–41 discount entocort 100mcg fast delivery. Nunn’s Applied Respiratory relationship to arterial oxygen content sensitive Physiology purchase entocort 100mcg free shipping. Oxford, UK: Butterworth- (E) Is a sensitive mechanism for (D) Are ineffective if the properties of Heinemann, 2000. Potassium and breathing in range of blood gases (E) Are not necessarily stable exercise. CHAPTER 22 The Control of Ventilation 375 CASE STUDIES FOR PART V • • • antiproteases. In emphysema, excess proteolytic activity de- CASE STUDY FOR CHAPTER 19 stroys elastin and collagen, the major extracellular matrix Emphysema proteins responsible for maintaining the integrity of the A 65-year-old man went to the university hospital emer- alveolar-capillary membrane and the elasticity of the lung. He also complained of arise through an increase in protease levels, a decrease in a cough productive of green sputum. Chronic obstructive pulmonary disease: An overview smoked two packs of cigarettes a day for the past 30 years, of pathology and pathogenesis. Novartis Found Symp he had recently decreased his habit to one pack a day. Although CASE STUDY FOR CHAPTER 20 he has had dyspnea upon exertion for the last 2 years, he continues to maintain an active lifestyle. He still mows his Chest Pain lawn without much difficulty, and can walk 1 to 2 miles on A 27-year-old accountant recently drove cross-country to a flat surface at a moderate pace. He denied having had any other sig- move, she started to experience chest pains. She drove nificant past medical problems, including heart disease, to the emergency department after experiencing 24 hypertension, edema, childhood asthma, or any allergies. She denied any sputum pro- An initial exam shows that the patient is thin but has duction, hemoptysis, coughing, or wheezing. His tive and walks daily and never has experienced any blood pressure is 130/80 mm Hg; respiratory rate, 28 to swelling in her legs. She has never been treated for any 32 breaths/min; heart rate, 92/minute; and oral tempera- respiratory problems and has never undergone any sur- ture, 37.
Apparent effects of the antagonist in vivo could also depend on whether there is any tonic activation of the benzodiazepine receptor by an endogenous ligand order entocort 100 mcg with amex. Flumazenil is available in the clinic for intravenous infusion to reverse benzodiazepine-induced sedation (e buy 100 mcg entocort. However purchase 100mcg entocort with visa, because it has a half-life of only 1 h in humans, it is only of realistic benefit in reversing the actions of agonist benzodiazepines with a short half-life, such as midazolam. The potential benefits of benzodiazepine partial agonists are as non-sedative, anti- anxiety agents. Because of their low efficacy, it was predicted that a partial agonist should not induce sedation even if their receptor occupancy exceeds that normally required for an anti-anxiety effect when using a full agonist. One such compound, bretazenil, has been developed but failed to reach the clinic because it displayed some sedative activity and, more problematic, there were end-of-dose rebound effects that were undoubtedly exacerbated by its short half-life. Currently, the partial agonist, abecarnil (a b-carboline), is undergoing clinical trials. For the current status of the development of partial agonists and other promising benzodiazepine receptor ligands see Cheetham and Heal (2000). Even benzodiazepine inverse agonists might yet find some useful applications such as in the relief of cognitive deficits (which are increased by benzodiazepine full agonists) (Abe, Takeyama and Yoshimura 1998). With the rapidly expanding understanding of different combinations of subunits that comprise the GABAA receptor, it is hoped to develop compounds that target specific subunit combinations and improve cognitive function in dementia but which lack any proconvulsant or anxiogenic actions. However, three candidates have been given prominent attention, albeit for different reasons, and are worthy of mention. Although subsequently found to be an artefact of the extraction process, this compound turned out to be a ligand for the benzodiazepine receptor, nonetheless, and was the first inverse agonist to be identified. The anxiogenic effects in humans of its more stable congener, FG 7142, are described graphically in a report by Dorow et al. Both these peptides are neuroactive and ODN turns out to have inverse agonist activity at GABAA receptors both in vivo and in vitro and to have marked effects on behaviour (e. However, there is scepticism as to whether the brain can manufacture sufficient peptide to regulate the ubiquitous GABAA receptor on a moment-to-moment basis. Currently, the binding of TTN to the peripheral benzodiazepine site, and its effect on neurosteroid synthesis, is attracting greater interest (Do Rego et al. Finally, the presence in human post-mortem brain tissue of the active metabolite of diazepam, desmethyldiazepam, raised some curiosity and frank alarm (Sangameswaran et al. At the time of its discovery in the brain it was thought that there was no enzyme system capable of producing such halogenated compounds and that its presence in the brain reflected dietary intake from an environment contaminated by overuse of its parent compound. However, its discovery in stored brain tissue which had been obtained before the synthesis of the benzodiazepines allayed these fears. It is now thought possible that some benzodiazepines, including desmethyl- diazepam, occur naturally and that they are taken in as part of a normal diet (Table 19.
In the electron-microscopic image (H) buy entocort 100 mcg with mastercard, tives of the neural crest are the cells of the however entocort 100 mcg without prescription, this boundary does not exactly autonomic ganglia order entocort 100mcg with visa, the paraganglia, and the coincide with the Redlich–Obersteiner adrenal medulla. Foreachaxon,theboundaryismarked by the last node of Ranvier prior to the en- From the capsule (A3) of the spinal gan- trance into the spinal cord. Up to this point, glion,whichmergesintotheperineuriumof the peripheral myelin sheath is surrounded the spinal nerve, connective tissue extends by a basal membrane (blue in H). The next to the interior and forms a sheath around internode no longer has a basal membrane. The innermost sheath, however, also marked by the basal membrane of the is formed by ectodermal satellite cells (BE5) enveloping Schwann cell. Thus, the basal and is surrounded by a basal membrane membranes around the spinal cord form a comparable to that around the Schwann boundary that is only penetrated by the cellsoftheperipheralnerve. The remainder consists of medium-sized and small ganglion cells with poorly myeli- nated or unmyelinated nerve fibers which arethoughttoconduct pain signals and sen- sations from the intestine. During development, however, the two processes fuse to form a single trunk which then bifurcates in a T-shaped man- ner. Spinal Ganglion and Posterior Root 63 A Spinal ganglion B Detail of A 3 5 6 4 1 2 2 C Development of the spinal ganglion 5 D Development of the pseudounipolar ganglion cell 8 E Spinal ganglion cell and satellite cells 7 F Posterior root G Redlich–Obersteiner zone H Posterior root, electron-micro scopic diagram (according to Andres) Kahle, Color Atlas of Human Anatomy, Vol. The pia mater contains numerous small blood vessels that penetrate from the The spinal dura mater forms the outermost surface into the spinal cord. A connective sheath which is separated from the perios- tissue plate, the denticulate ligament (A17), teum-like lining of the vertebral canal, the extends on both sides of the spinal cord endorhachis (A4), by the epidural space (A5). Forthispurpose,withthepatientbending cushion for the dural sac, which moves to- over, a needle is deeply inserted between the gether with the vertebral column and the processes of the second to fifth lumbar vertebrae head. Bending the head pulls the dural sac until CSF begins to drop (lumbar puncture) (E). The arachnoidea borders closely onto the inner surface of the dura mater. It forms the boundary of the subarachnoidal space (AC11), which is filled with cerebrospinal fluid (CSF). Between the inner surface of the dura and the arachnoidea lies a capillary cleft, the subdural space, which widens into a real space only under pathological conditions (subdural bleeding). Dura and arachnoidea accompany the spinal roots (AC12), pass with them through the intervertebral foramina, and also envelope the spinal gan- glia (AC13). The dura then turns into the epineurium (A14), and the arachnoidea into the perineurium (A15) of the spinal nerves. The part of the root leaving the vertebral canal, the radicu- Kahle, Color Atlas of Human Anatomy, Vol.