Anatomy and Physiology Fundamentals

Anatomy and Physiology Fundamentals

• Anatomy is the study of the body's structure, focusing on "what" the body is made of.
• Gross anatomy examines large structures visible to the naked eye.
• Physiology studies how the body works, focusing on "how" functions occur.
• Pathophysiology explores how body functions are disrupted in diseases.
• A disease is a disorder of structure or function within the human body.

Levels of Organization

• The body's organization is hierarchical, from cells to the complete organism.
• Cells are the basic structural units.
• Tissues are groups of similar cells working together.
• Organs are structures composed of multiple tissues.
• Organ systems consist of interacting organs.
• Organisms are collections of systems maintaining life.

Basic Chemistry and Cells

• Matter is anything that occupies space and has mass.
• Elements are substances made of atoms.
• Atoms have a nucleus (protons and neutrons) and orbiting electrons.
• Atomic number is the number of protons in the nucleus.
• Atomic mass is the number of protons plus neutrons.
• Isotopes are forms of the same atom with different masses.
• Chemical bonds include ionic bonds (electron transfer) and covalent bonds (electron sharing).
• Hydrogen bonds are weak bonds between polar molecules.
• Ions are charged atoms. Electrolytes are ions dissolved in water, conducting electricity.
• Molecules are two or more atoms bonded together, while compounds involve different types of atoms.
• Chemical reactions involve atoms/molecules interacting to form new combinations.
• Acids release hydrogen ions; bases combine with hydrogen ions.
• pH measures H+ concentration, with 7 neutral.
• Common pH in blood is slightly alkaline (7.35-7.45).
• Energy exists in various forms: chemical, mechanical, thermal, electrical, and radiant (i.e. light).

Skeletal System

• The skeletal system supports the body, protects organs, facilitates movement, stores minerals, and produces blood cells
• Components include bones, joints, cartilage, and ligaments.
• Common bone classification types include long, short, flat, and irregular bones.
• Bones are composed of compact and spongy bone.
• Compact bone forms the shafts of long bones, while spongy bone is often found in the ends of bones.
• Bone cells include osteocytes, osteoblasts, and osteoclasts.
• Osteogenic cells are bone stem cells; osteoblasts form new bone; osteocytes maintain bone; osteoclasts remove and reshape bone.
• Ossification is bone formation.
• Intramembranous ossification replaces connective tissue with bone and endochondral ossification replaces cartilage with bone.
• Bone growth occurs at the epiphyseal discs.
• Osteoclasts hollow the bone, while osteoblasts deposit bone on the outer surface.

Muscular System

• Muscles are skeletal, smooth, or cardiac.
• Skeletal muscle structure includes fascia layers, fascicles, tendons, and aponeurosis.
• The sarcomere is the functional unit found within the muscle fiber.
• Contraction relies on the sliding filament mechanism involving actin and myosin.
• Calcium and ATP are critical for muscle contraction; ATP powers interactions between the proteins.
• Muscle terminology includes origin, insertion, prime mover, synergist, antagonist, and other terms for muscle action.
• Muscles hypertrophy with use and atrophy with disuse.
• Muscles can respond with a single twitch or tetanus (repeated stimuli).

Cell Division and Metabolism

• Mitosis is cellular reproduction for growth and repair
• Metabolism covers cellular processing of raw materials.
• Anabolism builds larger molecules.
• Catabolism breaks down molecules to release energy.
• Carbohydrates are organic compounds used for energy; stored as glycogen or fat.
• Glycolysis is anaerobic glucose breakdown.
• Aerobic respiration breaks down glucose with oxygen to produce CO2, water, and ATP
• Lipids (fats and oils) play roles such as energy storage and membrane structure.
• Proteins are crucial for many bodily functions; essential amino acids must be consumed,
• Apoptosis is programmed cell death.
• Necrosis is cell death resulting from injury

Additional Concepts

• Homeostasis is maintaining a stable internal environment.
• Negative feedback mechanisms oppose initial changes to maintain stability
• Positive feedback mechanisms amplify initial changes
• Pathogens are disease-causing microorganisms
• Sterilization is killing all living organisms
• Types of pathogens include bacteria, viruses, fungi, protozoa, worms, arthropods.