BIOC21H3 Lecture Notes - Lecture 8: Endothelium, Blood Vessel, White Blood Cell

50 views2 pages

ceriseporpoise507

16 Sep 2012

School

Department

Course

Professor

For unlimited access to Class Notes, a Class+ subscription is required.

Document Summary

Reaction of the microcirculation (venules, capillaries, arterioles react to damage or pathogen) characterized by movement of fluid and leukocytes from blood into extravascular tissues. Protective response to cell injury, intended to remove the cause of injury along with any necrotic cells and tissues. Lasts from a few minutes to a few days. Dealing with the presence of dead neutrophils. Use neutrophils because they are easier and cheaper (energetically) to produce. Main focus is rapid delivery of leukocytes to affected tissues. Slows down laminar (blood) flow leukocytes marginate, make contact. Influx of blood calor and rubor with endothelium: cell surface molecules produced by endothelial cells will give signal to leukocytes for where site of infection is and where inflammation should occur, vascular permeability. Endothelial cell contraction pull away from each other to expose junctional complexes. Reorganization of junctional complexes allows blood to flow through easily. Increased transcytosis transport across the endothelium into the underlying tissues: leukocyte extravasation.

Related Questions

1. Briefly describe three outcomes of the complement activation?

2. What are opsonins? List 6 examples of opsonins.

3. In the case of inflammation, _______ refers to the movement of leukocytes out of the blood vessel into the infected tissue through the more permeable blood membrane.

1. Inflammation is generally a protective response, which would normally be beneficial. Is it an exclusively beneficial response? Explain 2 pts

2. You are a physician and your patient has had a heart attack resulting in decreased blood flow to the heart tissue. Once blood flow is reestablished, what might be a major concern? 2pts

3. One of the first steps in inflammation is the development of increased adhesiveness of neutrophils to the endothelium cells of venules. How does this occur? Give details 3 pts

4. What approach might stop the P- and E-selectin-mediated step in inflammation, thus blocking the process? 2pts

5. What sequence of events is triggered by the initial adhesion of neutrophils? 2pts

6. For no known reason, a person is found to make autoimmune antibodies against the ?2 subunit of leukocyte integrins. What symptoms, if any, is s/he likely to exhibit? (2pts each)

How might leukocyte adhesion deficiency be treated?

How might antibodies against the ?2 subunit of integrins prove useful medically?

7. Cancer cells from a person suffering from malignant melanoma are analyzed and found to have an elevated ability to bind to laminin; they also secrete much higher than normal levels of a certain proteolytic enzyme activity. How would these differences from normal, control cells promote metastasis of these cancer cells? Explain 4 pts

8. Why would cells that express less E-cadherin be more likely to become malignant and give rise to epithelial cell tumors? Explain 3 pts

9. What would happen if you were able to inject the gene for ?5?1 integrin (a fibronectin receptor) into some tumor cells in such a way that it was expressed extremely efficiently? Explain 3pts