Anatomy and Physiology Overview

Anatomy and Physiology

• Anatomy is the study of the body's structure, its parts, and their relationships.
• Physiology is the study of the body's functions, how systems work together.
• Anatomy and physiology are intrinsically linked. Structure dictates function.

Structural Hierarchy of the Body

• Chemical level: Atoms, molecules
• Cellular level: Cells (basic units of life)
• Tissue level: Groups of similar cells performing a common function
• Organ level: Different tissues working together to perform a specific task
• Organ system level: A group of organs working together to perform a specific function
• Organismal level: Complete living being, all organ systems functioning together

Four Tissue Types

• Epithelial: Covers body surfaces, lines cavities, forms glands (protection, secretion, absorption)
• Connective: Supports, connects, and separates other tissues (binding, support, protection)
• Muscle: Moves the body (movement)
• Nervous: Controls and coordinates body activities (communication)

Four Macromolecules

• Carbohydrates: Provide energy (sugars and starches)
• Lipids: Store energy, structural components (fats, oils, steroids)
• Proteins: Diverse functions (structural support, enzymes, transport)
• Nucleic acids: Store and transmit genetic information (DNA, RNA)

Smallest Unit of Life

• Cell

Eleven Systems of the Human Body

• Integumentary: Protection, temperature regulation
• Skeletal: Support, protection, movement
• Muscular: Movement, posture, heat production
• Nervous: Control, communication
• Endocrine: Hormone production, regulation
• Cardiovascular: Blood circulation, transport
• Lymphatic: Immunity, fluid balance
• Respiratory: Gas exchange
• Digestive: Nutrient absorption
• Urinary: Waste removal, fluid balance
• Reproductive: Produce offspring

Autocrine vs. Paracrine

• Autocrine: A cell releasing a signal that affects itself.
• Paracrine: A cell releasing a signal that affects nearby cells.

Homeostasis

• Homeostasis: Maintaining a stable internal environment.
• Importance: Allows for optimal function of all body processes

Sign vs. Symptom

• Sign: Objective, measurable observation (e.g., fever, rash)
• Symptom: Subjective experience (e.g., pain, dizziness)

Feedback Loops: Five Steps

• Stimulus: Change in the environment
• Receptor: Detects the change
• Control center: Processes info, sends commands
• Effector: Carries out the change
• Response: Counteracts the original stimulus

Positive and Negative Feedback

• Negative feedback: Maintains stability, returns system to normal (e.g., blood glucose regulation, body temperature)
• Positive feedback: Amplifies the stimulus, causes a larger response (e.g., childbirth, blood clotting)

Directional Terms, Regions, Chambers, and Quadrants

• Precise anatomical language to describe locations and positions

Plasma Membrane Structure and Function

• Structure: Phospholipid bilayer with embedded proteins and carbohydrates.
• Function: Separates intracellular from extracellular environments, regulates passage of materials.
• Lipids: Phospholipids, Cholesterol
• Proteins: Integral (transmembrane), peripheral, and receptor proteins
• Carbohydrates: Glycoproteins, glycolipids (cell recognition)

Membrane Proteins

• 5 types: Channel proteins, carrier proteins, receptor proteins, enzymes, and junction proteins.

Changing Protein Shape

• Environmental changes (pH, temperature, presence of molecules)

Selectively Permeable Membrane

• The membrane allows some substances to pass through while restricting others.

Microvilli and Cilia

• Microvilli: Increase surface area for absorption.
• Cilia: Move fluid or substances across cell surfaces.

Cell Structures and Organelles

• Nucleus: Contains DNA
• Cytoplasm
• Ribosomes: Protein synthesis
• Endoplasmic Reticulum (smooth and rough): Synthesis, folding, and transport
• Golgi apparatus: Processing and packaging
• Mitochondria: Energy production
• Lysosomes: Cellular waste breakdown

Mechanisms of Transport Through Plasma Membranes

• Passive Transport: Requires no energy (diffusion, osmosis, facilitated diffusion)
• Active Transport: Requires energy (primary and secondary active transport, endocytosis, and exocytosis)

Endocytosis

• Phagocytosis: Engulfing large particles
• Pinocytosis: Engulfing fluids and small particles
• Receptor-mediated endocytosis: Specific uptake of molecules

Exocytosis

• Release of materials from the cell

Examples of Transport Mechanisms

• Diffusion: Oxygen, carbon dioxide
• Osmosis: Water
• Facilitated diffusion: Glucose, amino acids
• Primary active transport: Sodium-potassium pump
• Secondary active transport: Glucose transport coupled with sodium transport
• Endocytosis: Large molecules
• Exocytosis: Hormones, neurotransmitters

Osmolarity and Tonicity

• Osmolarity: Concentration of solutes in a solution.
• Tonicity: The ability of a solution to cause a cell to gain or lose water.

Effects of Solutions on Cells

• Isotonic: No net water movement
• Hypotonic: Cell gains water (lysis)
• Hypertonic: Cell loses water (crenation)

Primary Active Transport

• Directly uses ATP to move molecules against a concentration gradient.

Secondary Active Transport

• Uses energy from an ion gradient created by primary active transport to move another molecule against its gradient.