SCIWLM CHAPTER 7

Introduction

  • Breathing difficulty is termed Dyspnea.

  • Immediate artificial respiration is critical following stoppage of breathing, as survival without oxygen lasts only 3-5 minutes.

  • Seek medical attention urgently for severe breathing issues.

Cellular Respiration

  • Cellular respiration involves breaking down glucose with oxygen to produce ATP (adenosine triphosphate).

  • Roles of ATP include fueling cell functions such as growth and repair.

  • Glucose is sourced from photosynthesis in plants or ingestion in animals; oxygen can be absorbed or inhaled.

  • Necessary stages of cellular respiration:

    • Glycolysis

    • Transition stage

    • Citric Acid Cycle

    • Electron Transport Chain

Breathing Types

  • Key definitions to know:

    • Dyspnea: Difficulty in breathing.

    • Apnea: Temporary cessation of breathing.

    • Hyperpnea: Increased depth and rate of breathing.

Methods to Detect Stoppage of Respiration

  • Absence of chest/abdomen movement.

  • No air movement detected by stethoscope.

  • Mirror test: condensation indicates breath.

  • Cotton fiber movement test at nostrils.

  • Winslow's Test: lack of movement in a glass of water over the chest.

Heart Action and Circulation

  • No heart action for 5-10 minutes indicates certain death.

  • Heart may continue beating for up to an hour after certain types of fatal trauma or conditions.

  • Methods to assess heart action:

    • Palpation and auscultation

    • Electrocardiogram (ECG)

    • Magnus Test (ligature test)

    • Icard's Test (dye injection)

    • Diaphanous Test (light test on hand)

Algor Mortis (Loss of Body Heat)

  • Body temperature drops after death, typically matching surrounding temperatures.

  • Temperature decrease is rapid within the first 4 hours; a significant drop indicates possible death.

  • Cooling follows Newton's Law of Cooling, proportional to the temperature difference with the environment.

Eye Changes at Death

  • Eyeballs soften due to loss of intraocular tension.

  • Corneal light reflex disappears, leading to hazy cornea.

  • Pupils dilate and fix; presence of Tache’ noir (triangular brown spot) noted in sclera.