Introduction to Anatomy & Physiology

Characteristics of Life

What is Anatomy and Physiology?

Anatomy•The study of the structure of the body and the relationship of various parts to one another.

Physiology•The study of the functions of those parts.

Biology•The study of life

What is life?• Life is Cells

• All living things are composed of one or more cells.

• Every living organism and every individual cell within an organism have everything they need to be self sufficient.

• In multi-cellular organisms , like us, specialisation increases until some cells only carry out certain activities.

• Every cell uses the same operating system.

• These are called the 7 characteristics of life.

The 7 Characteristics of life

• Organisation - different types of cells have different tasks within a living being. This process continues until differentiation occurs – this is where the cells group together to make a different form, composed of particular types of cells (specific) . For example, the blood, the heart, the nerves etc.

The 7 Characteristics of life cont.

• Metabolism - chemical activities of cells - these involve use of energy and other substances obtained from food we eat and air we breathe to perform vital functions (growth, repair, movement). Metabolic rate is usually referred to as the speed at which we use energy from food we eat (calories) to carry out these functions. Energy Use – Respiration, Ingestion, digestion, excretion of waste .

The 7 Characteristics of life cont.

• Homeostasis - maintaining a balanced internal environment - i.e. temperature, water and chemical content of the body or cell. For example, humans sweat in order to cool us down when we get too hot.

The 7 Characteristics of life cont.…

• Sensitivity and responsiveness - living organisms have the ability to sense changes in the external or internal environment and make adjustments that help maintain life, e.g. moving away from danger or towards food.

Adaption - These are changes to an organism so that it is best suited to its own environment (evolution) . All living things are able to compete with each other for food and space to survive.

The 7 Characteristics of life cont.…

• Growth and Development - All life grows and changes. Life /cells continue in a cycle of growth, repair, degeneration and dying.

• Reproduction - All living things have a way to reproduce for continuation of that species. Heredity - All living things receive some hereditary traits from their parent organisms.

The 7 Characteristics of life

LEVELS OF STRUCTURAL ORGANISATION

• CHEMICAL LEVEL

• CELLULAR LEVEL - basic functioning unit • TISSUE LEVEL - cells with similar tissue

• ORGAN LEVEL - performs a function, have a recognisable shape

• SYSTEM LEVEL - tissues with a common function

• BODY AS A WHOLE

Systems of the body

The Cell

CELL STRUCTURE AND FUNCTION

All living things are composed of one or more cells – some are a single cell (bacteria) and others (e.g. humans), have many cells. Human cells only function as part of a larger organism – the body

There is considerable variation in the size, shape and make up of different types of cells in the body according to their function, although, there are common characteristics:

The Cell

NucleolusCellMembrane

Cytoplasm

Cell Reproduction

HISTOLOGY

This is microscopic anatomy.

It is the branch of biology, which deals with the minute structure of tissues, which are the basis of cell life. It is the study of tissues.

TISSUES

Tissue: A group of closely associated cells that work together to perform a specific function or a group of functions.

TISSUESThere are 4 main types of Tissue

1. Nervous = Transmits signals

2. Muscular = Skeletal, Cardiac and Smooth

3. Connective = Areolar, Adipose, Lymphoid, bone, blood, cartilage

4. Epithelium = Simple and compound

Epithelium

Squamous Provides thin smooth inactive lining. (Heart, lungs, blood vessels). Substances pass through them easily as they are very flat.

Cuboidal Forms tubules of kidneys and is found in some glands. Secrete and absorb.

Columnar Line organs of the alimentary canal, gall bladder, and bile duct. Some cells absorb products of digestion; others secrete (mucous from goblet cells).

Ciliated Cilia sweep or propel things on (food in intestine, also bronchi, trachea, larynx, nose, uterine tubes).

Stratified Non keratinized stratified epithelium. Found on wet surfaces (mouth lining, conjunctiva, oesophagus) Keratinized stratified epithelium found on dry surfaces. (Skin, hair, nails). Surface layers are dead and protect and prevent drying out of deeper cells.

Transitional Several layers of pear shaped cells lining the uterus and bladder.

Simple

Compound

Lets Recap the main points

• What is Anatomy and Physiology• 7 Characteristics of Life• Organisational levels• Body Systems• The Cell• Types of Cells• Cell reproduction• Tissues