Anatomy & Physiology: Foundations and Biomolecules (Chapters 1-3 Study Guide)

Chapter 1: Introduction to Anatomy & Physiology

Definition and Scope of Physiology

Physiology is the scientific study of the functions and mechanisms occurring in living organisms. It explains how anatomical structures work individually and together to sustain life.

• Definition: Physiology is the study of how the body and its parts function.

• Levels of Organization: The body is organized from the simplest to the most complex levels as follows:

  1. Atoms

  2. Molecules

  3. Organelles

  4. Cells

  5. Tissues

  6. Organs

  7. Organ Systems

  8. Organism (the whole body)

  9. Biosphere (all living things on Earth)

Mechanistic vs. Teleological Explanations

• Mechanistic Explanation: Describes how a process occurs (the steps or mechanisms involved).

• Teleological Explanation: Describes why a process occurs (the purpose or function).

• Example: The heart pumps blood (mechanistic: by muscle contraction; teleological: to deliver oxygen to tissues).

Major Organ Systems of the Body

The human body contains ten major physiological organ systems, each with specific functions:

• Integumentary (skin, hair, nails): protection, temperature regulation

• Muscular: movement, posture, heat production

• Skeletal: support, protection, blood cell production

• Nervous: control, communication, response to stimuli

• Endocrine: hormone production, regulation of metabolism

• Cardiovascular: transport of nutrients, gases, wastes

• Lymphatic/Immune: defense against pathogens, fluid balance

• Respiratory: gas exchange (O2 and CO2)

• Digestive: breakdown and absorption of nutrients

• Urinary: waste elimination, water and electrolyte balance

• Reproductive: production of offspring

Homeostasis

• Definition: The maintenance of a stable internal environment despite external changes.

• What Happens When Homeostasis Fails? Disease or dysfunction may occur if homeostasis is not maintained.

• Example: Blood glucose regulation by insulin and glucagon.

Water Compartments in the Body

• Major Compartments: Intracellular fluid (ICF) and extracellular fluid (ECF).

• Importance: Water balance is crucial for cell function and overall health.

Control Systems and Feedback

• Components of a Control System: Receptor (sensor), control center (integrator), effector.

• Types of Feedback:

  • Negative Feedback: Reduces the effect of the stimulus (e.g., body temperature regulation).

  • Positive Feedback: Enhances the effect of the stimulus (e.g., blood clotting).

  • Feedforward Control: Anticipates change and initiates response (e.g., salivation before eating).

• Example: Regulation of blood pressure by baroreceptors (negative feedback).

Placebo and Nocebo Effects

• Placebo Effect: Positive health outcome from an inactive treatment due to patient expectations.

• Nocebo Effect: Negative health outcome from an inactive treatment due to negative expectations.

• Influence on Experimental Studies: Both effects can bias results; double-blind studies help control for these effects.

Chapter 2: Biomolecules and Chemical Bonds

Major Groups of Biomolecules

Biomolecules are organic molecules essential for life, classified into four major groups:

• Carbohydrates: Energy source and structural components

• Lipids: Energy storage, membrane structure, signaling

• Proteins: Enzymes, structural support, transport, signaling

• Nucleic Acids: Storage and transmission of genetic information

Biological Roles of Electrons

• Electrons determine the chemical reactivity and bonding of atoms.

• Electron transfer is essential in cellular respiration and photosynthesis.

Covalent and Noncovalent Bonds

• Covalent Bonds: Atoms share electron pairs; strong and stable (e.g., H2O, CO2).

• Noncovalent Bonds: Include ionic bonds, hydrogen bonds, van der Waals forces; weaker but important for molecular interactions.

• Structure and Solubility: Polar molecules dissolve in water; nonpolar molecules do not.

Interactions and Molecular Shape

• Noncovalent interactions (hydrogen bonds, ionic bonds, hydrophobic interactions) determine the three-dimensional shape of molecules.

• Molecular shape is critical for function (e.g., enzyme-substrate specificity).

Acids, Bases, and Buffers

• Acid: Substance that donates H+ ions.

• Base: Substance that accepts H+ ions.

• pH: Mathematical expression of hydrogen ion concentration: $pH = -\log_{10}[H^+]$

• Buffers: Substances that minimize changes in pH.

• Example: Bicarbonate buffer system in blood.

Soluble Proteins in the Body

• Include enzymes, antibodies, transport proteins, and hormones.

• Essential for metabolism, defense, and regulation.

Chapter 3: Cell Structure and Function

Cellular Compartments and Organelles

• Major Compartments: Nucleus, cytoplasm, organelles (mitochondria, endoplasmic reticulum, Golgi apparatus, lysosomes, peroxisomes).

• Function: Each compartment has specialized roles (e.g., mitochondria for ATP production).

Animal Cell Organelles and Functions

• Cilia: Move fluid across cell surfaces.

• Flagella: Propel cells (e.g., sperm cells).

• Comparison: Cilia are shorter and more numerous; flagella are longer and usually singular.

Cell Junctions

• Types: Tight junctions, desmosomes, gap junctions.

• Functions: Cell adhesion, communication, barrier formation.

Five Functional Categories of Epithelia

• Exchange

• Transporting

• Ciliated

• Protective

• Secretory

Connective Tissue

• Seven Main Categories: Loose connective, dense connective, adipose, blood, cartilage, bone, lymph.

• Functions: Support, protection, transport, energy storage.

Tissue Types in Organ Systems

• Each organ system is composed of one or more of the four basic tissue types: epithelial, connective, muscle, and nervous tissue.

• Example: The stomach contains all four tissue types: epithelial (lining), connective (support), muscle (movement), and nervous (control).