The diversity of cellular life

Colonies of primitive unicellular organisms don’t show emergent

properties Prokaryotic organisms or

primitive eukaryotic organisms (algae, protistae) exist in colonies of identical cells

While the cells co-operate, they do not fuse to form a single mass and so don’t form a single organism

Each cell has identical structure and function

Multicellular organisms have differentiated cells

Cells are specialised: Blood cells Muscle cells Retinal cells Glandular cells Epithelial cells

Each cell type has a special task and structureEach cell has the same DNA, but only a section of it is expressed

Levels of ‘organisation’ in a multicellular organism

1.CELL2.TISSUE

3.ORGANS4.ORGAN SYSTEMS

Cardiac myocytes

Heart

Cardiovascular system

4 key animal tissue types1.Epithelial

2.Connective3.Muscle4.Nervous

Human Anatomy, Larry M. Frolich, Ph.D.

Human Anatomy, Larry M. Frolich, Ph.D.

Simple: just one layer or cell shape

Stratified: multiple layers and cell shapes

Classes of Epithelia

“ciliated” literally = eyelashes(see next page)

Stratified: regenerate from below

CONNECTIVE TISSUES“Areolar tissue” as modelUniversal in bodyUnderlies epithelium, supports capillaries,

small nerves

Cells of Connective TissuesFibroblasts make fibres – cartilage, ligaments,

blood, boneImmune cells in areolar tissue

Human Anatomy, Larry M. Frolich, Ph.D.

Different types of Connective tissues

DenseLigamentsCartilageBone

LooseFatAreolar

Tissue types3. Muscle tissueSkeletalCardiacSmooth

Tissue types3. Nervous tissueSkeletalCardiacSmooth

Neuroglia

Cell Differentiation Harvard Animation

What are stem cells?Cells that are able to generate more specialised

types of cell types through the process of cell differentiation

Cells that can divide to make identical copies of themselves, through self-renewal

You can learn all about stem cells by watching the beautiful animation from Utah Genetics here:

Stem Cells

Different types of stem cells

1. Embryonic Stem Cells Here, you can learn how

embryonic stem cells are made:

Quck guide to Embryonic stem cells

Here is the BBC video on how embryonic stem cells are made:

How to make stem cells

Different types of stem cells

2. Somatic Stem Cells (also called adult stem

cells) Exist naturally in the

body Used for bone marrow

transplants Can only differentiate

into dedicated cell types

Adult Stem Cells are committed to become one

type of cell

Stem cells in the adult brain:Are they still working for us now?

Embryonic Stem cells are pluripotent

Different types of stem cells

3. Induced pluripotential Stem Cells Created artificially in the

lab by ‘reprogramming’ a patients own cells

Made from patient’s own cells – fat, skin, fibroblasts

Can become any cell in the body (even a whole mouse!)

Induced pluripotential Stem Cells – The future!

Learn the story of iPS stem cells from Utah Genetics…

IPS stem cells

Stem Cells used in medicine: Treatment of leukaemia

Stem cell transplants have been successfully used since 1968 to treat patients with leukaemia

Patients with leukaemia first have their own abnormal blood cells destroyed by radiotherapy

Then the patients own bone marrow stem cells are replaced with a transplant (into the bloodstream) from a healthy patient’s bone marrow

If the transplant is successful, then the stem cells will migrate into the bone marrow and begin to produce new, healthy leucocytes

You can learn all about leukaemia treatment by linking here onto Utah Inc:

Utah Genetics

What can we use Stem Cells for?

To provide lab-grown human or animal tissue for identifying new treatments for disease (rather than using animals in research)

TO produce new human tissue and organs to replace damaged ones

To repair tissue by stimulating stem cells already in the body To use stem cells from patients with inherited genetic

diseases (e.g. cystic fibrosis, some forms of Parkinson’s disease) to study the disease

To better understand diseases like cancer To investigate human development

Stem Cell Research is a fast-moving subject

Stem cell grandparentsBrand new spermFirst trial of human embryonic stem cellsTracheal transplantStem cell nobel prize

The Stem Cell Ethical Debate

Links on ethics related to Stem Cell research

Stem Cell Ethics FactsheetEthics and Embryos FactsheetAre embryos human? – a conversation…