Anatomy & Physiology: Foundational Concepts and Learning Objectives

Introduction to the Human Body

Overview of Anatomy and Physiology

Anatomy and physiology are closely related disciplines that study the structure and function of the human body. Understanding their relationship is essential for comprehending how the body operates as an integrated system.

• Anatomy: The study of body structure, including gross anatomy (visible to the naked eye) and microscopic anatomy (cells and tissues).

• Physiology: The study of body function, focusing on how anatomical structures work together to sustain life.

• Major Subdisciplines: Includes circulatory, nervous, endocrine, reproductive, integumentary, skeletal, respiratory, muscular, urinary, and immune systems.

• Anatomical Position: Standard reference posture for describing locations and directions on the body.

• Directional Terms: Terms such as superior, inferior, anterior, posterior, medial, and lateral are used to describe locations.

• Body Cavities: Major cavities include cranial, thoracic, abdominal, and pelvic, each housing specific organs.

• Abdominopelvic Regions and Quadrants: Used to locate organs and describe pain or injury.

Example: The heart is located in the thoracic cavity, medial to the lungs.

Chemistry of Life

Basic Chemistry Concepts

Chemistry underpins all biological processes. Understanding atomic structure, chemical bonds, and the properties of water is fundamental to physiology.

• Atoms: Consist of protons, neutrons, and electrons.

• Periodic Table: Organizes elements by atomic number and properties.

• Atomic Number and Mass Number: Atomic number is the number of protons; mass number is protons plus neutrons.

• Isotopes: Atoms of the same element with different numbers of neutrons.

• Ions: Atoms that have gained or lost electrons, acquiring a charge.

• Molecules and Compounds: Molecules are two or more atoms bonded together; compounds are molecules of different elements.

• Chemical Bonds: Includes ionic, covalent, and hydrogen bonds.

• Polar and Nonpolar Bonds: Polar bonds have unequal sharing of electrons; nonpolar bonds share electrons equally.

• Properties of Water: Water is polar, an excellent solvent, and participates in hydrogen bonding.

• Chemical Reactions: Involve breaking and forming bonds; enzymes catalyze reactions.

• Enzymes: Biological catalysts that speed up reactions; affected by temperature, pH, and substrate concentration.

Equation:

$\text{H}_2\text{O} + \text{CO}_2 \rightarrow \text{H}_2\text{CO}_3$ (Formation of carbonic acid)

Example: Sodium chloride (NaCl) forms from the ionic bond between sodium and chloride ions.

Biomolecules

Biomolecules are essential for structure and function in living organisms. They include carbohydrates, lipids, proteins, and nucleic acids.

• Carbohydrates: Include monosaccharides (glucose), disaccharides (sucrose), and polysaccharides (starch, glycogen).

• Lipids: Include triglycerides, phospholipids, and steroids; important for energy storage and membrane structure.

• Proteins: Made of amino acids; function as enzymes, structural components, and signaling molecules.

• Nucleic Acids: DNA and RNA store and transmit genetic information.

Equation:

$\text{Enzyme} + \text{Substrate} \rightarrow \text{Enzyme-Substrate Complex} \rightarrow \text{Product} + \text{Enzyme}$

Example: Lactase is an enzyme that breaks down lactose into glucose and galactose.

Cell Structure & Permeability

Cellular Components and Functions

Cells are the basic units of life, containing specialized structures (organelles) that perform distinct functions.

• Organelles: Includes ribosomes (protein synthesis), nucleus (genetic material), mitochondria (energy production), and others.

• DNA and RNA: DNA stores genetic information; RNA is involved in protein synthesis.

• Protein Synthesis: Involves transcription (DNA to RNA) and translation (RNA to protein).

• Cell Membrane: Regulates entry and exit of substances; composed of phospholipid bilayer.

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

• Osmosis: Diffusion of water across a semipermeable membrane.

• Tonicity: Refers to the effect of solutions on cell volume (isotonic, hypertonic, hypotonic).

Equation:

$\text{C}_6\text{H}_{12}\text{O}_6 + 6\text{O}_2 \rightarrow 6\text{CO}_2 + 6\text{H}_2\text{O} + \text{Energy}$ (Cellular respiration)

Example: Red blood cells placed in a hypertonic solution will shrink due to water loss.

Tissues

Classification and Functions of Tissues

Tissues are groups of similar cells that perform specific functions. The human body has four major tissue types.

• Epithelial Tissue: Covers body surfaces and lines cavities; functions in protection, absorption, and secretion.

• Connective Tissue: Supports, binds, and protects organs; includes bone, cartilage, adipose, and blood.

• Muscle Tissue: Responsible for movement; includes skeletal, cardiac, and smooth muscle.

• Nervous Tissue: Transmits electrical impulses; consists of neurons and supporting cells.

Table: Major Tissue Types and Functions

Tissue Type	Main Function	Examples
Epithelial	Protection, absorption, secretion	Skin, lining of GI tract
Connective	Support, binding, protection	Bone, cartilage, adipose, blood
Muscle	Movement	Skeletal muscle, heart (cardiac), smooth muscle
Nervous	Communication, control	Brain, spinal cord, nerves

Example: Adipose tissue stores energy in the form of fat.

Additional info: Nervous tissue is unique in that it is the only tissue type specialized for rapid communication via electrical impulses.