Exam 1 Learning Objectives: Human Body Orientation, Chemistry, Cells, and Tissues

Chapter 1: The Human Body – An Orientation

Definitions and Subdivisions

• Anatomy: The study of the structure of body parts and their relationships to one another. Subdivisions include gross anatomy, microscopic anatomy, and developmental anatomy.

• Physiology: The study of the function of body parts and how they work together. Subdivisions include cellular, systemic, and pathological physiology.

Levels of Structural Organization

• Chemical Level: Atoms and molecules.

• Cellular Level: Cells and their organelles.

• Tissue Level: Groups of similar cells.

• Organ Level: Contains two or more types of tissues.

• Organ System Level: Organs that work closely together.

• Organismal Level: All organ systems combined to make the whole organism.

Organ Systems of the Body

• Integumentary System: Skin, hair, nails; protects body.

• Skeletal System: Bones, joints; supports and protects.

• Muscular System: Muscles; movement.

• Nervous System: Brain, spinal cord, nerves; control and communication.

• Endocrine System: Glands; hormone production.

• Cardiovascular System: Heart, blood vessels; transport of blood.

• Lymphatic System: Lymph nodes, vessels; immunity.

• Respiratory System: Lungs, airways; gas exchange.

• Digestive System: Stomach, intestines; breakdown and absorption of food.

• Urinary System: Kidneys, bladder; waste removal.

• Reproductive System: Ovaries, testes; reproduction.

Functional Characteristics Necessary for Life

• Maintaining boundaries

• Movement

• Responsiveness

• Digestion

• Metabolism

• Excretion

• Reproduction

• Growth

Homeostasis

• Definition: The maintenance of a stable internal environment.

• Significance: Essential for survival; prevents disease.

• Feedback Mechanisms: Negative feedback (reduces change), positive feedback (enhances change).

Anatomical Position and Terms

• Anatomical Position: Standing upright, facing forward, arms at sides, palms forward.

• Directional Terms: Superior, inferior, anterior, posterior, medial, lateral, proximal, distal.

• Body Landmarks: Regions such as abdominal, thoracic, pelvic, etc.

Body Quadrants and Regions

• Four Quadrants: Right Upper, Left Upper, Right Lower, Left Lower; used to locate organs.

• Nine Regions: More precise divisions (e.g., epigastric, umbilical, hypogastric).

Chapter 2: Chemistry Comes Alive

Chemical Elements and Atoms

• Chemical Elements: Substances that cannot be broken down; four major elements in the body are carbon, hydrogen, oxygen, and nitrogen.

• Atom: Smallest unit of an element; consists of protons, neutrons, and electrons.

• Atomic Number: Number of protons.

• Atomic Mass: Sum of protons and neutrons.

• Isotopes: Atoms with same number of protons but different neutrons.

Molecules and Mixtures

• Molecule: Two or more atoms bonded together.

• Mixtures: Physical combinations of substances; types include solutions, colloids, and suspensions.

• Solutions: Homogeneous mixtures; solute particles are very small.

• Colloids: Heterogeneous mixtures; solute particles are larger but do not settle.

• Suspensions: Heterogeneous mixtures; solute particles settle out.

Chemical Bonds

• Ionic Bonds: Transfer of electrons.

• Covalent Bonds: Sharing of electrons.

• Hydrogen Bonds: Weak attractions between molecules.

Role of Electrons and Chemical Reactions

• Electrons determine chemical reactivity.

• Factors affecting reactions: temperature, concentration, particle size, catalysts.

Water and pH

• Importance of Water: Solvent, temperature regulation, chemical reactions.

• pH Scale: Measures acidity/alkalinity; ranges from 0 (acidic) to 14 (basic).

• Formula: $\text{pH} = -\log_{10}[\text{H}^+]$

Enzymes

• Definition: Biological catalysts that speed up reactions.

• Role: Lower activation energy.

Chapter 3: Cells – The Living Units

Membrane Transport

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

• Facilitated Diffusion: Movement via carrier proteins.

• Osmosis: Diffusion of water across a membrane.

• Endocytosis: Cell takes in substances.

• Exocytosis: Cell expels substances.

• Pinocytosis: Cell drinking; intake of fluid.

• Phagocytosis: Cell eating; intake of large particles.

• Receptor-mediated Endocytosis: Specific intake via receptors.

Membrane Potential

• Definition: Voltage across the cell membrane.

• Resting Membrane Potential: Established by ion gradients, mainly sodium and potassium.

Cell Organelles

• Mitochondria: Powerhouse; ATP production.

• Ribosomes: Protein synthesis.

• Endoplasmic Reticulum: Synthesis and transport of proteins/lipids.

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

• Lysosomes: Digestive enzymes; breakdown of waste.

• Peroxisomes: Detoxification.

Cytoskeleton and Cellular Extensions

• Cytoskeleton: Structural support; includes microtubules, microfilaments, intermediate filaments.

• Cilia: Move substances across cell surface.

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

Nucleus and Genetic Material

• Nuclear Envelope: Surrounds nucleus.

• Nucleolus: Ribosome production.

• Chromatin: DNA and protein complex.

Cell Cycle and DNA Replication

• Phases: Interphase (G1, S, G2), Mitotic phase (mitosis and cytokinesis).

• DNA Replication: Semiconservative process; each new DNA has one old and one new strand.

Protein Synthesis

• Gene: Segment of DNA coding for a protein.

• Genetic Code: Sequence of nucleotides.

• Phases: Transcription (mRNA synthesis), Translation (protein synthesis).

• mRNA: Messenger RNA; carries code.

• tRNA: Transfer RNA; brings amino acids.

• rRNA: Ribosomal RNA; forms ribosomes.

• Triplets: DNA base groups.

• Codons: mRNA base groups.

• Anticodons: tRNA base groups.

Apoptosis

• Definition: Programmed cell death; essential for development and health.

Chapter 4: Tissue – The Living Fabric

Structural and Functional Characteristics of Tissues

• Tissue: Group of cells with similar structure and function.

• Four basic types: epithelial, connective, muscle, nervous.

Epithelial Tissue

• Classification: By cell shape (squamous, cuboidal, columnar) and layers (simple, stratified).

• Functions: Protection, absorption, filtration, secretion.

• Locations: Skin, lining of organs.

Glands

• Exocrine Glands: Secrete products into ducts (e.g., sweat, salivary glands).

• Endocrine Glands: Secrete hormones into blood.

• Unicellular Glands: Single-celled (e.g., goblet cells).

• Multicellular Glands: Many cells; classified as merocrine (secrete by exocytosis), apocrine (secrete by losing part of cell).

Connective Tissue

• Common Characteristics: Extracellular matrix, varying vascularity.

• Structural Elements: Cells, fibers (collagen, elastic, reticular), ground substance.

• Types: Loose, dense, cartilage, bone, blood.

• Functions: Support, protection, transport.

Muscle Tissue

• Types: Skeletal (voluntary), cardiac (involuntary, heart), smooth (involuntary, organs).

• Functions: Movement, posture, heat production.

Nervous Tissue

• Function: Communication via electrical impulses.

• Components: Neurons and supporting cells.