Organisation In The Body Learning Objective: How are cells organized into tissues, organs, organ systems?

But how do we organise it? The body is wonderful thing… But how do we organise it?

Because we are multicellular organisms it’s very complex.

What is the body fundamentally made of?

Cells

We can study the body at the cellular level We can study the body at the cellular level. Cells is the first level of organisation.

Cells carry out their own “tasks” to ensure that the body as a whole continues to function

In multicellular organisms, cells rarely work alone.

Cells that are similar in structure and function are usually joined together to form tissues. Tissues is the second level of organisation.

Tissues There are four basic/major types of tissues in the human body: Epithelial tissue Muscle tissue Connective tissue Nerve tissue

Epithelial Tissue Covers and lines body surfaces, cavities and ducts. Cells look regular, geometric shaped with obvious nuclei.

Muscle Tissue Tightens and loosens itself to move other body parts

Connective Tissue Connects and supports other parts of the body. Blood, bone, fat and cartilage are all examples of connective tissue.

Nerve Tissue Carries messages -between the brain and the body

When a group of different types of tissues work together, they form and organ. Organs is the third level of organisation.

What organs do you already know? Here, several different types of tissues have separate jobs, but they all form one larger structure – an organ. Students draw around a student on the floor with whiteboard pens and try and label the different organs they know Can use different coloured pens to show which organs they think work together What organs do you already know?

Organs Let’s look at the human torso!

Just as cells act together in tissues, and tissues act together in organs, organs act together in organ systems. Organ systems is the fourth level of organisation.

Organ Systems Organ system is a group of organs that work together to perform a major function.

Organ Systems

Organ Systems D= Endocrine system E= Circulatory system A and B= Muscular and Skeletal systems D= Endocrine system E= Circulatory system C= Nervous system

Organ Systems I= Digestive system G= Lymph system F= Skin and hair H= Respiratory system I= Digestive system G= Lymph system

Organ Systems Excretory system Reproductive system

All of the organ systems come together to form an organism All of the organ systems come together to form an organism. Organism is the fifth level of organisation.

Let’s review: 1st Level: Cells working together form 2nd Level: Tissues, which can form 3rd Level: Organs, which work together to form 4th Level: Organ Systems, which work together to form 5th Level: Organisms!

There’s also one more level: Scientists are learning about how cells work by studying the chemical reactions that go on inside cells. This is the job of biochemists. They study the body at the biochemical level.