Basic Life Processes, Body Fluids, and Homeostasis

Basic Life Processes in Humans

  • Distinction of Living Organisms:

    • All living organisms possess specific characteristics that distinguish them from nonliving entities.

  • Essential Human Life Processes:

    • Metabolism: The chemical processes occurring within a living cell or organism that are necessary for the maintenance of life.

    • Responsiveness: The ability of the body to detect and respond to changes in its internal or external environment.

    • Movement: Motion of the whole body, individual organs, single cells, or structures inside cells.

    • Growth: An increase in body size that results from an increase in the size of existing cells, an increase in the number of cells, or both.

    • Differentiation: The process by which unspecialized cells become specialized in structure and function.

    • Reproduction: The formation of new cells for tissue growth, repair, or replacement, or the production of a new individual.

Body Fluids and the Internal Environment

  • Extracellular Fluid (ECF):

    • The survival of body cells is dependent on the precise regulation of the chemical composition of the fluid surrounding them.

    • The fluid located outside of cells that bathes and surrounds them is known as extracellular fluid (ECF).

  • Anatomical Systems and Associated Structures:


    Anatomical structures of the Integumentary and Skeletal systems

    • Integumentary System:

      • Hair

      • Skin and associated glands

      • Fingernails

      • Toenails

    • Skeletal System:

      • Bone

      • Cartilage

      • Joint

Homeostasis and Regulatory Mechanisms

  • Definition of Homeostasis:

    • Homeostasis is a condition of equilibrium, or balance, within the body's internal environment.

    • It requires continuous monitoring and regulation of many internal factors.

    • Maintained continuously through the body's complex regulatory processes.

  • Systemic Control Systems:

    • Communication and regulation required for homeostasis are accomplished primarily by the nervous system and the endocrine system.

    • Nervous System:

      • Communicates via nervous impulses.

      • Fast-acting response mechanism.

      • Produces effects that are often short-lived.

    • Endocrine System:

      • Communicates via hormones.

      • Slow-acting response mechanism.

      • Produces effects that are often longer-lived.

Homeostatic Imbalances and Factors Affecting Health

  • Causes of Disruptions:

    • Homeostatic imbalances occur due to disruptions arising from either external environments or internal environments.

  • Consequences of Homeostatic Disruption:

    • When homeostatic control mechanisms are disrupted, it may result in:

      • Disease

      • Disorder

      • Death

  • Factors Influencing Health:

    • Genetic Make-Up: Individual hereditary factors impacting physiological resilience.

    • Air Quality: The surrounding air breathed into the lungs.

    • Dietary Intake: The food consumed providing nutrients or potential stressors.

  • Negative Feedback Control:

    • Body systems utilize regulation mechanisms such as negative feedback control for temperature regulation to counter external and internal disruptions and restore internal balance.