General Physiology — the first-year Physiology chapter on how a cell lives

Anatomy asks where a part is. Physiology asks what it does. General Physiology is where that second question begins, and it begins small, with a single cell.

The NCH syllabus gives “General Physiology” chapter one of Physiology and Biochemistry (HomUG-PB). The sheet lists five topics. It is a short list, but each topic is a big idea that the rest of the subject keeps using. This piece explains what each one asks, in plain words.

Topic one: cellular physiology

The sheet says “Introduction to cellular physiology”.

Cellular physiology is the study of how a cell works. How it takes in what it needs. How it gets rid of waste. How it makes energy. How it talks to other cells. This topic is an introduction, so expect the big picture here and the details in later chapters.

If you have already met the cell in Anatomy, you know its parts. Here, the question changes from “what is it made of?” to “what does it do?”.

Topic two: cell junctions

Cells in a tissue do not float about freely. Many are joined to their neighbours. A cell junction is the point where two cells are joined or connected.

Different junctions do different jobs. Some hold cells tightly together. Some let small things pass from one cell to the next. Your textbook will name the types. For each, learn two things: what it looks like, and what it is for.

Topic three: transport and the resting membrane potential

This line on the sheet is a long one: “Transport through cell membrane and resting membrane potential”. It holds two ideas.

Transport through the cell membrane. The membrane is the thin outer boundary of a cell. Things must cross it to get in and out. Some cross without the cell spending energy. Others need the cell to spend energy to push them across. Your textbook will name each method.

Resting membrane potential. A small electrical difference exists across the membrane of a cell at rest. That difference is the resting membrane potential. It matters most for nerve and muscle cells, which use changes in it to send signals. First-year Physiology returns to this in its Nerve Muscle Physiology chapter.

A tip: make a two-column table for transport. One column for methods that need no energy, one for methods that do. It keeps a long topic tidy.

Topic four: body fluid compartments

The water in your body is not all in one place. It is held in compartments. Some is inside cells. Some is outside cells, including in the blood.

This topic asks you to know the compartments and how fluid is shared between them. Your textbook will give the figures to learn. Chapter four of the same subject, “Body Fluid and Immune Mechanism”, builds on this with blood, lymph and tissue fluid.

Topic five: homeostasis

Homeostasis means keeping the inside of the body steady while the outside keeps changing. Temperature, water, salts and many other things are held within a safe range.

This idea will follow you through the whole subject. Much of physiology is about how the body keeps something steady, and what it does when that thing drifts. Learn the general idea well here. You will meet examples of it in almost every chapter, including body temperature in the Skin chapter.

A thought for a homoeopathy student. The Organon has its own language for health and for the living whole. Your Organon teachers will explain it. It can be useful to notice where physiology and the Organon talk about the same body in different words. Keep the two vocabularies labelled and apart in your answers.

How the chapter sits in the year

General Physiology is the first chapter of the subject. It sets up ideas the later chapters depend on. Bio-Physical Sciences comes next, with the physical processes behind them, such as osmosis and diffusion. Then come skin, blood, nerve and muscle, and the organ systems one by one.

What to take from it

1. Know what cellular physiology studies, in one line.
2. Name the kinds of cell junction and what each is for.
3. Build the two-column table for membrane transport.
4. Explain the resting membrane potential in plain words.
5. Know the body fluid compartments and the meaning of homeostasis.

The sheet is thin. It gives five names and nothing more. It does not give figures, types or methods. Those come from your textbook and your teachers.

Where to go next on the platform

This piece is in the first-year Physiology and Biochemistry room. “Bio-Physical Sciences — the first-year Physiology chapter on the physics inside the body” is the chapter that follows. “General Anatomy — the first-year Anatomy chapter that teaches the language of the body” covers the cell from the Anatomy side.