Introduction to Anatomy and Physiology

Definition and Scope

Anatomy is the study of the structure of body parts and their relation to one another. Physiology is the study of the function of body parts. Both disciplines are foundational to understanding the human body.

• Cytology: Study of cells

• Histology: Study of tissues

Major Themes in Anatomy and Physiology

• Systemic anatomy: Study of individual organ systems

• Regional anatomy: Study of body areas divided into regions

• Surface anatomy: Study of surface markings of the body

• Gross anatomy: Study of structures visible to the naked eye

• Microscopic anatomy: Study of structures requiring a microscope

Homeostasis and Feedback Loops

Definition and Importance

Homeostasis is the ability of the body to maintain a relatively stable internal environment. It is essential for survival and proper function.

• Negative Feedback Loop: Returns variables to within normal range of values; most common for maintaining homeostasis. Example: Regulation of body temperature.

• Positive Feedback Loop: Increases/reinforces initial stimulus on regulated variable. Example: Blood clotting, childbirth.

Characteristics of Life

Seven Key Characteristics

• Homeostasis: Maintain the internal environment

• Organization: Every organism is made up of at least one cell

• Metabolism: Anabolism (building up) + Catabolism (breaking down)

• Growth and Development: Increase in size, cells divide and differentiate

• Reproduction: Sexual and asexual

• Universal Genetic Code: Living things are based on DNA

Levels of Structural Organization

Hierarchy from Chemical to Organism

• Chemical Level: Atoms and molecules essential for life

• Cellular Level: Cells, the basic units of life

• Tissue Level: Groups of similar cells performing a common function

• Organ Level: Two or more tissue types working together to perform specific functions

• Organ System Level: Groups of organs that work together to accomplish a common purpose

• Organism Level: The complete living being

Major Organ Systems and Their Functions

Overview of the 11 Organ Systems

• Integumentary System: Skin, hair, nails protect underlying tissue; regulates body temperature

• Muscular System: Skeletal muscles move bones; generates heat

• Skeletal System: Bones provide a frame to support and protect the body

• Cardiovascular System: Heart pumps blood through all blood vessels

• Respiratory System: Lungs absorb oxygen and release carbon dioxide

• Urinary System: Removes waste from the blood and regulates the body's fluid

• Reproductive System: Produces and delivers sperm/eggs; nourishes and shelters unborn baby

• Nervous System: Sends electrical messages throughout the body

• Lymphatic System: Returns leaked fluids to blood vessels; gets rid of harmful germs

• Digestive System: Breaks down food into nutrients that can be absorbed into the body

• Endocrine System: Glands regulate body functions by sending out chemical messengers (hormones)

Major Tissue Types

Four Major Types

1. Muscle Tissue: Movement

2. Nervous Tissue: Signal transmission

3. Connective Tissue: Support

4. Epithelial Tissue: Covering and protection

Structure and Function Relationship

Form Follows Function

• Structures are shaped to perform specific functions

• Example: Enzymes have specific shapes for catalyzing reactions

Gradients in the Body

Types and Importance

• Gradient: More of one thing on one side than the other

• Temperature Gradient: Heat leaves from its source

• Concentration Gradient: Substances diffuse to lower concentration

• Pressure Gradient: Gas and liquid molecules diffuse to lower concentration

Cell Communication

Mechanisms

• Communication is vital to coordinate body functions

• Uses chemical and electrical signals

• Chemical Signals:

  • Endocrine signaling: Release of hormones into the bloodstream

  • Paracrine signaling: Cell signaling where a cell produces a signal to create change in nearby cells

  • Autocrine signaling: Self-signaling, common in the immune response

  • Juxtacrine signaling: Contact of surface molecules in adjacent cells

• Example: A nerve cell stimulates a muscle cell

Atoms, Elements, and Chemical Bonds

Atomic Structure

• Atom: Smallest unit of matter; consists of protons, neutrons, and electrons

• Proton: Positive charge; found in the center of atom; weight 1 AMU

• Neutron: No charge; found in the center of atom; weight 1 AMU

• Electron: Negative charge; found in electron shells around atom

• Atomic mass:

Chemical Bonds

• Ionic Bonds: Involving transfer of electrons

• Covalent Bonds: Involving sharing of electrons

• Metallic Bonds: Involving a "sea" of electrons

• Hydrogen Bonds: Responsible for unique properties of water

Major Elements in Living Things

• Oxygen

• Carbon

• Hydrogen

• Nitrogen

These four elements make up about 96% of the human body's mass.

Isotopes and Radioisotopes

Definitions and Applications

• Isotope: Atoms of the same element with different numbers of neutrons

• Radioisotope: Emits radiation; used in medicine for imaging and treatment (e.g., iodine-131 for thyroid disorders)

Octet and Duet Rules

• Atoms are most stable when their outermost shell contains 8 electrons (octet rule)

• Very small atoms are most stable with 2 electrons (duet rule)

Electrolytes

• Substances that ionize in water (can conduct electricity)

• Essential for nerve impulse transmission, muscle contraction, and maintaining fluid balance

Types of Energy and Chemical Reactions

Types of Energy

• Chemical Energy: Potential energy stored in chemical bonds

• Electrical Energy: Flow of ions

• Mechanical Energy: Energy directly transferred from one object to another

Endergonic vs. Exergonic Reactions

• Endergonic: Products have higher energy than reactants; requires energy input Example: Photosynthesis

• Exergonic: Reactants have higher energy than products; releases energy Example: Cellular respiration

Organic vs. Inorganic Chemistry

• Organic Chemistry: Compounds contain carbon bonded to hydrogen (e.g., proteins)

• Inorganic Chemistry: Compounds do not generally contain carbon bonded to hydrogen (e.g., water, acids, bases, salts)

Enzymes and Reaction Rates

Enzyme Properties

• Enzymes are biological catalysts, highly specific, and reusable

• Factors affecting enzyme activity: temperature, concentration of substrate and products, pH

Water and pH

Properties of Water

• Water is polar and can dissolve many ionic and polar substances

• Acts as a lubricant between adjacent surfaces

• Hydrophilic vs. hydrophobic properties

pH and Buffers

• pH: Measures the concentration of H+ ions in a solution

• High pH is basic; low pH is acidic

• Buffer: Molecules that prevent rapid shifts in pH by releasing or binding H+ ions as needed

Macromolecules

Four Major Types and Their Monomers

• Carbohydrates: Monomer: monosaccharides (e.g., glucose); bond: glycosidic bond

• Proteins: Monomer: amino acids; bond: peptide bond

• Nucleic Acids: Monomer: nucleotides; bond: phosphodiester bond

• Lipids: Monomer: fatty acids and glycerol; bond: ester bond

HTML Table: 11 Major Organ Systems and Their Functions

Additional info:

• Some content was expanded for clarity and completeness, such as definitions and examples of feedback loops, gradients, and chemical bonds.

• Equations and formulas were formatted in LaTeX as required.