BIO 163 Unit 1 Study Guide: Human Body Orientation, Chemistry, Cells, and Tissues

Chapter 1: The Human Body – An Orientation

Body Orientation and Directional Terms

Understanding anatomical terminology is essential for accurately describing locations and directions on the human body.

• Anatomical Position: The body is standing upright, facing forward, arms at the sides with palms facing forward.

• Directional Terms:

  • Superior (Cranial): Toward the head or upper part of a structure.

  • Inferior (Caudal): Away from the head or toward the lower part of a structure.

  • Anterior (Ventral): Toward the front of the body.

  • Posterior (Dorsal): Toward the back of the body.

  • Medial: Toward the midline of the body.

  • Lateral: Away from the midline of the body.

  • Proximal: Closer to the origin of a body part or point of attachment.

  • Distal: Farther from the origin of a body part or point of attachment.

  • Superficial: Toward or at the body surface.

  • Deep: Away from the body surface; more internal.

• Regional Terms: Specific areas of the body (e.g., brachial = arm, femoral = thigh).

Example: The knee is distal to the thigh but proximal to the ankle.

Body Planes

• Frontal (Coronal) Plane: Divides the body into anterior and posterior parts.

• Sagittal Plane: Divides the body into right and left parts (midsagittal = equal halves).

• Transverse (Horizontal) Plane: Divides the body into superior and inferior parts.

Body Systems and Their Functions

• Integumentary: Protection, temperature regulation (skin, hair, nails).

• Skeletal: Support, movement, blood cell production (bones, cartilage).

• Muscular: Movement, heat production (skeletal muscles).

• Nervous: Control, communication (brain, spinal cord, nerves).

• Endocrine: Hormone production, regulation (glands such as thyroid, pancreas).

• Cardiovascular: Transport of nutrients and wastes (heart, blood vessels).

• Lymphatic: Immunity, fluid balance (lymph nodes, spleen).

• Respiratory: Gas exchange (lungs, trachea).

• Digestive: Breakdown and absorption of food (stomach, intestines).

• Urinary: Waste elimination, water balance (kidneys, bladder).

• Reproductive: Production of offspring (ovaries, testes).

Body Cavities

• Dorsal Cavity: Contains cranial and vertebral cavities (brain and spinal cord).

• Ventral Cavity: Contains thoracic and abdominopelvic cavities (heart, lungs, digestive organs).

Functional Characteristics of Life

• Maintaining boundaries

• Movement

• Responsiveness

• Digestion

• Metabolism

• Excretion

• Reproduction

• Growth

Structural Organization of the Body

• Atom → Molecule → Organelle → Cell → Tissue → Organ → Organ System → Organism

Homeostasis

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

• Mechanisms: Involves receptors, control center, and effectors.

Feedback Loops

• 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, labor contractions).

Chapter 2: Basic Chemistry

Molecules and Compounds

• Molecule: Two or more atoms bonded together (e.g., O2).

• Compound: Two or more different atoms bonded together (e.g., H2O).

Types of Chemical Reactions

• Synthesis (Combination): $A + B \rightarrow AB$

• Decomposition: $AB \rightarrow A + B$

• Exchange (Displacement): $AB + C \rightarrow AC + B$

Structure of Phospholipids

• Composed of a glycerol backbone, two fatty acid tails (hydrophobic), and a phosphate group (hydrophilic).

• Major component of cell membranes.

Structure of ATP (Adenosine Triphosphate)

• Consists of adenine, ribose (a sugar), and three phosphate groups.

• Primary energy carrier in cells.

Solutions: Solute, Solvent, and Solution

• Solute: Substance dissolved in a solution (e.g., salt).

• Solvent: Substance that dissolves the solute (e.g., water).

• Solution: Homogeneous mixture of solute and solvent.

Biomolecules: Monomers and Polymers

• Carbohydrates:

  • Monomer: Monosaccharide (e.g., glucose)

  • Polymer: Polysaccharide (e.g., starch, glycogen)

• Proteins:

  • Monomer: Amino acid

  • Polymer: Polypeptide/protein

• Lipids:

  • Monomer: Fatty acids and glycerol

  • Polymer: Triglycerides, phospholipids

Chapter 3: Cells and Tissues

Cell Structure and Function

• Plasma Membrane: Phospholipid bilayer with embedded proteins; described by the fluid mosaic model.

• Membrane Proteins: Include channels, carriers, receptors, enzymes, and structural proteins.

• Selective Permeability: The membrane allows some substances to pass while restricting others.

• Major Organelles:

  • Nucleus: Contains genetic material (DNA).

  • Mitochondria: Site of ATP production.

  • Ribosomes: Protein synthesis.

  • Endoplasmic Reticulum (ER): Synthesis and transport of proteins (rough ER) and lipids (smooth ER).

  • Golgi Apparatus: Modifies, sorts, and packages proteins and lipids.

  • Lysosomes: Digestion of cellular waste.

  • Cytoskeleton: Provides structure and facilitates movement (microtubules, microfilaments).

Transport Across the Plasma Membrane

• Passive Transport: Does not require energy.

  • Simple Diffusion: Movement of molecules from high to low concentration.

  • Facilitated Diffusion: Movement via membrane proteins.

  • Osmosis: Diffusion of water across a selectively permeable membrane.

  • Filtration: Movement due to pressure differences.

• Active Transport: Requires energy (ATP).

  • Solute Pumps: Move substances against their concentration gradient.

  • Vesicular Transport: Includes endocytosis (phagocytosis, pinocytosis) and exocytosis.

Osmotic Solutions and Cellular Effects

Solution Type	Definition	Effect on Cell
Isotonic	Same solute concentration as cell	No net water movement; cell remains the same
Hypertonic	Higher solute concentration than cell	Water leaves cell; cell shrinks (crenation)
Hypotonic	Lower solute concentration than cell	Water enters cell; cell swells or bursts (lysis)

Genetic Code and Protein Synthesis

• Codon: Sequence of three mRNA nucleotides coding for an amino acid.

• Anticodon: Sequence of three tRNA nucleotides complementary to the codon.

• Ribosomes: Site of protein synthesis.

• mRNA: Carries genetic code from DNA to ribosome.

• tRNA: Brings amino acids to ribosome during translation.

Chromosomal Structures

• Chromatid: One of two identical halves of a duplicated chromosome.

• Centromere: Region where sister chromatids are joined.

• Chromosome: Structure containing DNA and proteins; visible during cell division.

Cell Division

• Interphase: Cell grows and DNA replicates.

• M Phase (Mitosis): Division of nucleus and cytoplasm.

  • Prophase

  • Metaphase

  • Anaphase

  • Telophase

  • Cytokinesis

Tissues of the Human Body

Tissues are groups of similar cells performing a common function. There are four main types:

• Epithelial Tissue:

  • Layers: Simple (one layer), Stratified (multiple layers)

  • Cell Shapes: Squamous (flat), Cuboidal (cube-shaped), Columnar (tall)

  • Examples: Simple squamous epithelium (lung alveoli), stratified squamous (skin)

• Connective Tissue:

  • Supports, protects, binds other tissues

  • Examples: Bone, cartilage, adipose (fat), blood

• Muscle Tissue:

  • Responsible for movement

  • Types: Skeletal (voluntary), cardiac (heart), smooth (walls of organs)

• Nervous Tissue:

  • Conducts electrical impulses

  • Examples: Brain, spinal cord, nerves

Additional info: For each tissue type, structure relates to function. For example, simple squamous epithelium allows for rapid diffusion, while stratified squamous provides protection.