Study unit 1.2.2 Homeostasis_All

Homeostasis

  • Definition: Homeostasis refers to the process by which organisms maintain a stable internal environment despite changes in external conditions.

Types of Homeostasis

  • Physiological Homeostasis: Pertains to the physical and chemical processes that maintain the body's internal environment, such as temperature and pH levels.

  • Psychological Homeostasis: Involves mental and emotional balance, influencing physiological processes through stress management and emotional regulation.

Mechanisms for Maintaining Physiological Homeostasis

  • Temperature Regulation:

    • Regulation of Body Temperature: Maintained typically between 36.0°C and 37.5°C.

    • Factors Affecting Body Temperature:

      • Age (newborns and elderly individuals have different temperature regulation)

      • Exercise (increases body heat production)

      • Hormonal variations (e.g., during ovulation)

      • Stress (increases metabolism and heat production)

      • Environmental conditions.

    • Clinical Considerations:

      • Hyperthermia: Elevated body temperature; signs include sweating, confusion, and dizziness.

      • Hypothermia: Low body temperature; likely to see shivering, slurred speech, and confusion.

      • Nursing Interventions: Monitor vital signs, adjust environmental conditions, and maintain adequate hydration and nutrition.

Pulse

  • Definition: Pulse is the wave of blood created by contractions of the heart's left ventricle.

  • Key Concepts:

    • Differentiates between pulse rate and cardiac output.

    • Factors Influencing Pulse:

      • Age (pulse rate decreases with age)

      • Sex (males generally have a lower pulse rate post-puberty)

      • Medications (can raise or lower pulse rate)

      • Physical activity, fever, and stress can influence pulse.

    • Assessment: Evaluating rate, rhythm, and volume of the pulse is essential.

Respiration

  • Terminology:

    • Inhalation (Inspiration): Air intake into the lungs.

    • Exhalation (Expiration): Air expulsion from the lungs.

    • Ventilation: The overall process of air moving in and out of the lungs.

  • Breathing Mechanisms:

    • Costal (Thoracic) Breathing: Involves intercostal muscles.

    • Diaphragmatic (Abdominal) Breathing: Engages the diaphragm for deeper breaths.

  • Control of Respiration: Managed by respiratory centers responding to oxygen and carbon dioxide levels.

Blood Pressure

  • Definition: The pressure of blood against arterial walls, measured as systolic (contraction of ventricles) and diastolic (ventricles at rest).

  • Determinants of Blood Pressure:

    • Heart's pumping action (stronger contractions increase pressure).

    • Peripheral Vascular Resistance (narrower vessels increase pressure).

    • Blood Volume (lower volume decreases pressure; higher volume increases pressure).

    • Blood Viscosity (higher viscosity leads to higher pressures).

  • Factors Influencing Blood Pressure:

    • Age, exercise, stress, medication, and hormonal influences can all affect blood pressure.

    • Blood Pressure Classifications:

      • Normal: Systolic < 120 mmHg, Diastolic < 80 mmHg

      • Prehypertension: Systolic 120-139 mmHg, Diastolic 80-89 mmHg

      • Hypertension Stage 1: Systolic 140-159 mmHg, Diastolic 90-99 mmHg

      • Hypertension Stage 2: Systolic > 160 mmHg, Diastolic > 100 mmHg.