Lecture Notes on Inflammation and Systemic Response

Chemicals and Inflammation

Stages of inflamation

1. Dolor (pain)

2. Calor (heat)

3. Rubor (redness)

4. Tumor (swelling)

5. Fonctio Laesa (loss of function)

• Histamine's Role: Initiates inflammation, which is a localized response to injury or infection.

• Inflammation Process:

  • Leads to increased blood flow to the site of the cut or injury.

  • Margination: Monocytes adhere to the walls of capillaries.

  • Diapedesis: White blood cells (WBCs) squeeze through the pores of the capillary walls to reach the site of infection or injury.

  • Phagocytosis: WBCs engulf and kill pathogens.

• Purpose of Inflammation: Contains pathogens, preventing their spread and facilitating tissue repair.

Systemic Response

• Definition: A response that involves the entire body, not just the local site of infection or injury.

• Example: Fever

  • Characterized by an elevated body temperature affecting the whole body.

• Body Thermal Regulation Feedback Loop:

  1. Sensor:

     • Senses the current body temperature.

     • Usually involves neurons that are sensitive to temperature changes.

     • Macrophages play a crucial role; they not only perform phagocytosis but also secrete pyrogens.

     • Pyrogens lead to an increase in body temperature.

     • Examples of pyrogens: interleukin-1 (IL-1) and tumor necrosis factor-alpha (TNF-$( \alpha )$$).

  2. Comparator:

     • The hypothalamus acts as the control center for body temperature regulation.

     • The hypothalamus receives signals from macrophages and then signals the effector.

  3. Effector:

     • Causes a change in body temperature.

     • Muscles receive signals and begin to shiver to generate heat, thus increasing body temperature.