1.1 Cells, Tissues and Organs
There are different levels of structural organisation within the
human body. Knowledge of these will help you to understand
what the body is made up of.
Chemical level - The body is made up of chemical elements,
the main four being oxygen, carbon, hydrogen and nitrogen.
These elements are essential to maintain life and are made
up of atoms joined together in different ways to form amino
acids, proteins, enzymes and other structures.
Cellular level - The body’s many structures join to form cells,
which are the basic building blocks of the body. The body is
made up of many different types of cells, each type having a
different function within the body.
Tissue level - A tissue is a set of similar cells that work
together to carry out a particular function. For example,
some tissues work to move body parts, while others move
nutrients around the body.
Organ level - Different types of cells and tissue join together
in parts of the body to form organs. Organs usually have a
recognisable shape and perform specific functions.
Examples of organs are the heart, lungs, liver and brain.
System level - A group of organs work together and have a
common function. For example, all the organs in the
digestive system work to breakdown food for use by the
body. The body has a number of different systems and they
all have a particular function. In most cases one system
affects another system, so they are inter-related.
The body systems are:


Integumentary system 

Musculoskeletal system 

Nervous system 

Perceptual system – smell, taste, vision,
equilibrium and hearing 

Endocrine system 

Cardiovascular system 

Lymphatic system 

Respiratory system 

Digestive system 

Urinary system 

Reproductive system u:\course materials\courses\sis30313 certificate iii in fitness\sisffit305a\sisffit305a learner guide_v1_2014-09-05_63.docx
Organism level - All the different systems of the body combine
to make up one of the most complex machines ever created,
the human body.
1.2 Cells
A cell is the basic structural unit of the body, the smallest part
of the body that is able to perform life processes such as
reproduction, movement, respiration, digestion and
excretion. There are many different types of cell in the
human body but not all cells have the ability to perform all of
these life processes.
Cells are microscopic, which means that to be able to see
them they must be viewed under a microscope. Most cells
have a plasma membrane surrounding their contents and this
regulates what is allowed in and out of the cell. Inside the
cell are many different structures called organelles, which are
suspended in a fluid called cytoplasm. One of the organelles
is the nucleus. It is the control centre of the cell and it
contains the chromosomes that make up your DNA.
Extract from http://www.genetherapyreview.com/gene-therapy-education/59-humancell.html
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1.3 The Six Levels of Structural Organisation in the
Human Body
1.
Chemical level is
the chemical level which is the
simplest level of organization. 2.
Cellular level is
the smallest unit of life and
varies widely in size and shape according to
the cells’ function. 3.
Tissue level is
function. 4.
Organ level is
5.
Organ system level is
6.
Organismal level is
groups of cells having a common
made up of discrete structures
that are composed of at least two groups of
tissues that work together to perform a
specific function in the body. a group of organs that work
closely together to accomplish a specific
purpose. the total of all structures
working together to promote life.
http://classes.midlandstech.edu/carterp/Courses/bio210/chap01/chap01.html
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