Chemistry and Physiological Reactions

Introduction to Chemistry in Anatomy & Physiology

Chemistry is fundamental to understanding all physiological processes in the human body. Every function, from movement to digestion and neural activity, relies on chemical interactions.

• Basic Chemistry: Focuses on the foundational principles of matter and energy.

• Biochemistry: Explores the chemical processes within and related to living organisms.

Basic Chemistry

Matter

Matter is anything that has mass and occupies space. It can be observed through the senses and is affected by gravity (weight = mass + gravity).

• States of Matter:

  • Solid: Definite shape and volume.

  • Liquid: Changeable shape, definite volume.

  • Gas: Changeable shape and volume.

Energy

Energy is the capacity to do work or put matter into motion. Unlike matter, energy does not have mass or occupy space.

• Kinetic Energy: Energy in action (e.g., muscle contraction).

• Potential Energy: Stored (inactive) energy (e.g., energy stored in chemical bonds).

Forms of Energy:

• Chemical Energy: Stored in bonds of chemical substances.

• Electrical Energy: Results from movement of charged particles (e.g., nerve impulses).

• Mechanical Energy: Directly involved in moving matter (e.g., muscle movement).

• Radiant/Electromagnetic Energy: Travels in waves (e.g., light, X-rays).

Energy Conversion: Energy can be converted from one form to another, but some energy is always lost as heat (inefficient conversion).

Atoms and Elements

Elements

Elements are pure substances that cannot be broken down into simpler substances by ordinary chemical means. The human body is primarily composed of four elements:

• Carbon (C)

• Oxygen (O)

• Hydrogen (H)

• Nitrogen (N)

The periodic table lists all known elements, each with unique properties.

Atoms

Atoms are the smallest units of an element that retain the properties of that element. They are the building blocks of matter.

• Each element is made up of atoms with a unique number of protons, neutrons, and electrons.

• Atoms give each element its specific physical and chemical properties.

Chemical Symbols

• Each element is represented by a one- or two-letter symbol (e.g., O for oxygen, C for carbon).

• Some symbols are derived from Latin names (e.g., Na for sodium from 'natrium', K for potassium from 'kalium').

Example Table: Major Elements in the Human Body

Additional info: This foundational chemistry knowledge is essential for understanding the molecular basis of physiological processes in anatomy and physiology.