Human Physiology Overview Quiz

Chapter 1: The Foundation of Physiology

• Physiology is the study of body functions.
• Two processes describe body functions:
  • Teleological: Explains why a structure or function exists.
  • Mechanistic: Describes how a structure or function operates.
• Anatomy is the study of the structure of the body.
• Anatomy includes structure-function relationships.

Levels of Organization

• Levels of organization in the body include:
  • Chemical level (molecules)
  • Cellular level (cells)
  • Tissue level (layers of tissue)
  • Organ level (organs)
  • Body system level (digestive system)
  • Organism level (the whole body)

Typical Cell

• A typical cell has several structures visible under an electron microscope, such as:
  • Nucleus
  • Plasma membrane
  • Smooth endoplasmic reticulum
  • Endoplasmic reticulum
  • Peroxisome
  • Cytosol
  • Golgi complex
  • Rough endoplasmic reticulum
  • Microfilament
  • Rough endoplasmic reticulum
  • Lysosome
  • Mitochondrion-
  • Vault
  • Centriole
  • Microtubule
  • Ribosomes
  • Exocytotic vesicle
• Figure 2-1 shows a schematic three-dimensional diagram of cell structures.

Basic Cell Functions

• Cells perform several basic functions:
  • Obtain nutrients and oxygen
  • Perform chemical reactions
  • Eliminate carbon dioxide and other wastes
  • Synthesize needed cellular components
  • Control exchange of materials
  • Sensing and responding to changes in the surrounding environment
  • Reproduction

Tissues

• Tissues are groups of cells with similar structure and specialized function.
• Four primary tissue types are:
  • Muscle tissue
  • Nervous tissue
  • Epithelial tissue
  • Connective tissue

Epithelial Tissue

• Epithelial tissue is organized into two main structures:
  • Epithelial sheets
  • Secretory glands
• Figure 1-2 Details how glands are formed (exocrine and endocrine).

Connective Tissue

• Connective tissue connects, supports, and anchors various body parts.
• Examples of connective tissues include:
  • Tendons
  • Bone
  • Blood
  • Loose connective tissue

Organs

• Organs consist of two or more types of primary tissues that work together.
• Examples of organs include the stomach
• Specific examples of tissue types present in the stomach include:
  • Inside of stomach
  • Wall of stomach
  • Nervous tissue
  • Connective Tissue

Organ Systems

• Organ systems are groups of organs that perform related functions.

• The human body has 11 organ systems:

  • Circulatory
  • Digestive
  • Respiratory
  • Urinary
  • Skeletal
  • Muscular
  • Integumentary
  • Immune
  • Nervous
  • Endocrine
  • Reproductive

• Figure 1-3 Shows the components of the body systems: showing a schematic of the human body with the key systems like the digestive system, circulatory system, nervous system, skeletal system etc...

Homeostasis

• Homeostasis is the maintenance of a relatively stable internal environment.
• Homeostasis minimizes changes and responds to changes.
• Figure 1-5 Shows the interdependent relationship of cells, body systems, and homeostasis.
• Extracellular fluid (ECF) is the fluid environment surrounding cells, with two components: plasma and interstitial fluid.
• Intracellular fluid (ICF) is the fluid within cells.
• Figure 1-4 Shows the components of the extracellular fluid (internal environment).

Contributions of Body Systems to Homeostasis

• Circulatory system: Carries materials throughout the body.
• Digestive system: Breaks down food and absorbs nutrients.
• Respiratory system: Acquires oxygen and eliminates carbon dioxide.
• Urinary system: Removes wastes and excess water.
• Skeletal system: Provides support and storage.
• Muscular system: Enables movement.
• Integumentary system: Acts as a protective barrier.
• Immune system: Protects against disease.
• Nervous system: Controls and coordinates rapid responses.
• Endocrine system: Regulates activities over longer durations.
• Reproductive system: Essential for perpetuating the species, but not directly involved in homeostasis.

Homeostatic Control Systems

• Homeostatic control systems detect deviations, integrate information, and make adjustments.
•  Two types of control systems exist:
  • Intrinsic controls: inherent in an organ.
  • Extrinsic controls: initiated outside the organ (nervous or endocrine systems).
• Figure 1-4 Illustrates components of a negative feedback control system.

Homeostatic Control Mechanisms

• Feedforward: Responses in anticipation of a change.
• Feedback: Responses after a change is detected.
  • Types of feedback systems:
    • Negative feedback: Opposes initial change. (Figure 1-6 illustrates this process)
    • Positive feedback: Amplifies initial change.

Disruptions in Homeostasis

• Disruptions in homeostasis can lead to illness and death. Pathophysiology is the study of how these disruptions lead to disease.