By X. Falk. American Global University.
Excessive traction tears the If MR images demonstrate sprain of the tibial collat- capsule or meniscus order 10mg lotrisone visa. Conversely buy cheap lotrisone 10mg on line, the posterior oblique eral ligament, a knee-jerk reflex (pun intended) should ligament or medial meniscus may tear before the anteri- next occur: focus attention on the meniscocapsular junc- or cruciate ligament. First on coronal images, follow the peripheral bor- ternal rotation or valgus force or both, the anterior cruci- der of meniscus posteriorly from the level of tibial col- ate ligament becomes the last remaining check against lateral ligament to the posteromedial corner, searching anterior tibial translocation, markedly increasing its risk for contour abnormalities and soft-tissue edema or hem- for rupture. Then, on sagittal images, fol- Rupture of the anterior cruciate ligament is often ob- low the medial meniscus and meniscocapsular junction vious or strongly suspected based on history and physical medially from the posterior thirds to the posteromedial examination. Depending on the knee position during imaging, ligamentous rupture, but rather to identify other intraar- either the coronal or sagittal images may better demon- ticular lesions that might further destabilize the knee. The strate peripheral meniscal tear or avulsion at the postero- absence or presence of such a lesion may determine medial corner. For example, if MR images show Anterior Cruciate Ligament and Medial a destabilizing meniscocapsular injury at the posterome- Meniscus dial corner, primary repair might be performed (rather than subtotal meniscectomy) in conjunction with anterior The anterior cruciate ligament is made up of two bundles. The anterolateral bundle is tighter in knee flexion and the High-grade tears of the anterior cruciate ligament are posterolateral bundle is tighter in extension. In the acute set- cruciate ligament is the primary restraint to anterior tib- ting, mass-like hematoma occupies the expected location ial displacement, providing 75-85% of resistance de- of the ligament, which may be completely invisible. Tension is least at several days or weeks, the torn ligamentous margins be- 40-50° of flexion, and greatest at either 30° or 90° of come organized and better defined as thickened stumps flexion [92,93]. Quadriceps contraction pulls the tibia separated from each other by a variable distance. Axial forward and creates greatest stress on the anterior cruci- images are superb for confirming a normal ligament that ate ligament at 30° of knee flexion. Because of this is indistinct in the sagittal plane due to volume averaging. Partial tear is unusual, but may major secondary restraint to anterior tibial translocation.
The hydrogen bonds between these bases are rela- tively weak and can be easily split during cellular division (fig 10 mg lotrisone with amex. During division cheap 10 mg lotrisone, the sequence of bases along the sides Structure of RNA and RNA Synthesis of the DNA molecule serves as a template that determines the sequence along each new strand. In the process of protein synthesis, DNA produces a messenger molecule of RNA of complementary structure to transport the James Watson and Francis Crick, who devised the double- helix model, first described their vision of DNA in 1953, in the genetic information. The closing sentence of their brief arti- nucleotides joined together by sugar-phosphate bonds. Cytology © The McGraw−Hill Anatomy, Sixth Edition of the Body Companies, 2001 Chapter 3 Cytology 67 T A G C RNA C G G T DNA C C G C G C G G G G G C A G C A T U A C T G C G G A G U G T C C C G C G G C G FIGURE 3. Four types of RNA are produced within the nucleus, each with a FIGURE 3. Notice that different composition and function: only one of the two DNA strands is used to form a single-stranded 1. Messenger RNA (mRNA), which contains the code for rectly through its regulation of RNA and protein synthesis. Transfer RNA (tRNA), which transfers amino acids and strand of DNA that is several thousand nucleotide pairs long. In which is needed for decoding the genetic message con- order for the genetic code to be translated for the synthesis of tained in mRNA; and specific proteins, the DNA code must first be transcribed into an 4. During RNA synthesis, the enzyme RNA polymerase breaks The DNA that codes for rRNA synthesis is located in the nucle- the weak hydrogen bonds between paired DNA bases. Pre-mRNA and tRNA synthesis is controlled by DNA lo- not occur throughout the length of DNA, but only in the re- cated elsewhere in the nucleus. Double-stranded DNA, therefore, Genetic Transcription—RNA Synthesis separates in these regions so that the freed bases can pair with During cell division, the chromosomes are inactive packages of the complementary RNA nucleotide bases that are freely avail- DNA. The genes do not become active until the chromosomes able in the nucleus. Cytology © The McGraw−Hill Anatomy, Sixth Edition of the Body Companies, 2001 68 Unit 3 Microscopic Structure of the Body T G G A G G T T C G T C G A C T C A C G G C C A G C DNA G T double G A C C G G helix C DNA coding strand T A C C C G A G G T A G C C G C G T C G T A U G G G C U C C A U C G G C G C A G C A Messenger RNA Codon 1 Codon 2 Codon 3 Codon 4 Codon 5 Codon 6 Codon 7 Methionine Glycine Serine Isoleucine Glycine Alanine Alanine Protein FIGURE 3. The association of mRNA with ribosomes is needed for pairing: guanine bonds with cytosine (and vice versa), and ade- genetic translation—the production of specific proteins according nine bonds with uracil (because uracil in RNA is equivalent to to the code contained in the mRNA base sequences.
These cells are limited to certain types of ability of the cell membrane buy 10mg lotrisone amex. Describe the various kinds of movements across the cell (nuclear envelope) (fig discount lotrisone 10mg on-line. Describe the structure and function of the following cyto- cleolemma cisterna (sis-ter′na). Minute nuclear pores are lo- plasmic organelles: rough endoplasmic reticulum, Golgi cated along the nuclear membrane. Cytology © The McGraw−Hill Anatomy, Sixth Edition of the Body Companies, 2001 64 Unit 3 Microscopic Structure of the Body Nuclear pore Nuclear membrane Nucleolus Outer layer Nucleolemma Nucleus cisterna Inner layer (a) Chromatin (b) FIGURE 3. Cytology © The McGraw−Hill Anatomy, Sixth Edition of the Body Companies, 2001 Chapter 3 Cytology 65 CELL CYCLE A cell cycle consists of growth, synthesis, and mitosis. Synthesis is the production of DNA and RNA to regulate cellular activity. Mi- tosis is the division of the nucleus and cytoplasm of a cell that re- sults in the formation of two daughter cells. Objective 14 List the stages of mitosis and discuss the events of each stage. Through the process of cellular division called mitosis (mi-to′sis), a multicellular organism can develop and be maintained. Mitosis enables body growth and the replacement of damaged, diseased, or worn-out cells. The process ensures that each daughter cell will have the same number and kind of chromosomes as the orig- inal parent cell. In an average healthy adult, over 100 billion cells will die and be mitotically replaced during a 24-hour period.
When the Save As dialog box appears discount 10mg lotrisone with mastercard, select HTML as the file type generic lotrisone 10mg otc, and save the file. Add the file to a heading or subheading in the table of contents, at the location in the course where you want it to appear. Select the file, and WebCT will link to it as another page in the course. PowerPoint presentations As with Microsoft Word, you may not be able to count on every student having PowerPoint or the PowerPoint Viewer. If you can count on all of your students having PowerPoint or PowerPoint Viewer, then you can simply upload the PowerPoint documents through the WebCT File Manager, and add them to the Content Module as described above for PDF files. In this way, students will be able to view the presentations, but not be able to edit them. The best way to use PowerPoint presentations in a course is to save them as Web pages. This is preferable because students are not required to have either PowerPoint or the viewer installed on their computer. The download times are also much faster, since students get the presentation slide by slide, rather than all at once. In PowerPoint, go to the File Menu, and choose the option to Save as Webpage. On the Save As dialog box, you can change the page title of the presentation, using the Change Title button. The most important thing is to use the Publish button to change the browser that will be needed to view the presentation. PowerPoint will create one HTML file for the presentation, and an associated folder at the next level. For instance, if the presentation is called Procedures, the file created will be called Procedures.
