Chemistry Foundations for Anatomy & Physiology: Matter, Energy, and Elements

Chemistry in Anatomy & Physiology

Why Study Chemistry in A & P?

Chemistry is fundamental to understanding Anatomy & Physiology because the human body is composed of chemical substances that interact continuously. All physiological processes are driven by chemical reactions, and knowledge of chemistry is essential for understanding the effects of food, medicines, and cellular functions.

• Chemical substances interact to sustain life.

• Physiological processes are chemical in nature.

• Applications: Nutrition, pharmacology, and metabolism.

Matter

Definition and States of Matter

Matter is anything that occupies space and has mass. In scientific terms, matter consists of materials that require at least one subatomic particle, most commonly atoms. The mass of an object is the amount of matter it contains and remains constant under normal conditions.

• States of matter:

  • Solids: Example - bones

  • Liquids: Example - blood

  • Gases: Example - air

• Most matter can be seen, smelled, or felt.

Additional info: There are at least six states of matter (including plasma and Bose-Einstein condensates), but this course focuses on solids, liquids, and gases.

Energy

Definition and Forms of Energy

Energy is the capacity to do work and does not possess mass or weight. It is measured by its effects on matter, such as causing matter to move. Energy exists in various forms and can be converted from one form to another.

• Kinetic energy: Energy of action or movement.

• Potential energy: Stored energy, available for use.

• Forms of energy:

  • Chemical energy: Stored in chemical bonds (e.g., ATP in cells).

  • Electrical energy: Movement of charged particles (e.g., nerve impulses).

  • Mechanical energy: Directly moves matter (e.g., muscle contraction).

  • Radiant (electromagnetic) energy: Travels in waves (e.g., light, ultraviolet radiation).

Examples and Applications

• Chemical energy: Food energy is stored as ATP; when ATP bonds are broken, energy is released for cellular work.

• Electrical energy: Nervous system uses electrical currents for nerve impulses; heart contractions are stimulated by electrical currents.

• Mechanical energy: Muscles provide mechanical energy to move body parts.

• Radiant energy: Light is essential for vision; ultraviolet light is important for vitamin D synthesis but can cause sunburn.

Elements

Definition and Examples

All matter is composed of elements, which are substances that cannot be broken down into simpler substances by ordinary chemical means. Elements are the building blocks of all materials, including those found in the human body.

• Examples of elements:

  • Carbon (C)

  • Oxygen (O)

  • Hydrogen (H)

Additional info: The human body is primarily composed of four elements: carbon, hydrogen, oxygen, and nitrogen, which make up about 96% of body weight. Trace elements such as calcium, sodium, iron, and zinc are present in smaller amounts but are essential for metabolic reactions.