Top Banner
One more type of tissue to discuss •A type of tissue that none of us want in our body
60

One more type of tissue to discuss

Feb 24, 2016

Download

Documents

donagh

One more type of tissue to discuss. A type of tissue that none of us want in our body. Cancer. Cancer. Cancer accounts for nearly one-quarter of deaths in the United States, exceeded only by heart diseases. In 2003, there were 556,902 cancer deaths in the US. % of all Deaths. Cause of Death. - PowerPoint PPT Presentation
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Page 1: One more type of tissue to discuss

One more type of tissue to discuss

• A type of tissue that none of us want in our body

Page 2: One more type of tissue to discuss

Cancer

Page 3: One more type of tissue to discuss

Cancer

• Cancer accounts for nearly one-quarter of deaths in the United States, exceeded only by heart diseases. In 2003, there were 556,902 cancer deaths in the US.

Page 4: One more type of tissue to discuss

• Heart diseases• Cancer• Cerebrovascular• Chronic Respiratory• Accidents• Diabetes• Flu and pneunomia

• 28%• 22%• 6.4%• 5.2%• 4.5%• 3.0%• 2.7%

Cause of Death

% of all Deaths

Page 5: One more type of tissue to discuss

Cancer• 1 in 4 deaths are due to cancer• 1 in 17 deaths are due to lung

cancer• Lung cancer is the most common

cancer in men• Breast cancer is the most

common cancer in women

Page 6: One more type of tissue to discuss

• There are over 100 different forms of cancer

Cancer

Page 7: One more type of tissue to discuss

Lung cancer cells

Page 8: One more type of tissue to discuss

Breast cancer cells

Page 9: One more type of tissue to discuss

Brain Cancer Cell 

Page 11: One more type of tissue to discuss

Colon Cancer cells

Page 12: One more type of tissue to discuss

Cancer cell under attack by the immune system

Page 13: One more type of tissue to discuss
Page 14: One more type of tissue to discuss
Page 15: One more type of tissue to discuss
Page 17: One more type of tissue to discuss
Page 18: One more type of tissue to discuss
Page 19: One more type of tissue to discuss
Page 20: One more type of tissue to discuss
Page 21: One more type of tissue to discuss
Page 22: One more type of tissue to discuss
Page 23: One more type of tissue to discuss
Page 24: One more type of tissue to discuss
Page 25: One more type of tissue to discuss
Page 26: One more type of tissue to discuss
Page 27: One more type of tissue to discuss
Page 28: One more type of tissue to discuss
Page 29: One more type of tissue to discuss
Page 30: One more type of tissue to discuss
Page 31: One more type of tissue to discuss
Page 32: One more type of tissue to discuss
Page 33: One more type of tissue to discuss
Page 34: One more type of tissue to discuss
Page 35: One more type of tissue to discuss
Page 36: One more type of tissue to discuss
Page 37: One more type of tissue to discuss
Page 38: One more type of tissue to discuss
Page 39: One more type of tissue to discuss
Page 40: One more type of tissue to discuss

• The division of normal cells is precisely controlled. New cells are only formed for growth or to replace dead ones.

• Cancerous cells divide repeatedly out of control even though they are not needed, they crowd out other normal cells and function abnormally. They can also destroy the correct functioning of major organs.

Page 41: One more type of tissue to discuss

Ancient Awareness• 80 Million years ago – Dinosaur

bones show evidence of cancer• 3000 BC - Egyptian mummies –

bone cancer• 1600 BC – Egypt – 8 cases of

breast tumors (or ulcers)Treated by cauterization – with the “fire drill”

Page 42: One more type of tissue to discuss

Ancient Awareness• 300 BC – Hippocrates named

tumors as carcinos or carcinoma – tumors spread out like legs of a crab

• 1500 – autopsy start to provide a greater understanding of cancer

• 1650 – more knowledge with advance in medical science tools like the microscope

Page 43: One more type of tissue to discuss

• Cancer is the uncontrolled multiplication of cells.• Benign – cancerous cells are

contained in one place• Malignant – cancerous have

spread to other areas

What is Cancer?

Page 44: One more type of tissue to discuss

What causes cancer?

• Cancer arises from the mutation of a normal gene.• Mutated genes that cause cancer

are called oncogenes.• It is thought that several mutations

need to occur to give rise to cancer

Page 45: One more type of tissue to discuss

What causes cancer?

• Cells that are old or not functioning properly normally self destruct and are replaced by new cells.• However, cancerous cells do not

self destruct and continue to divide rapidly producing millions of new cancerous cells.

Page 46: One more type of tissue to discuss

• A factor which brings about a mutation is called a mutagen.

• A mutagen is mutagenic.• Any agent that causes cancer is

called a carcinogen and is described as carcinogenic.

• So some mutagens are carcinogenic.

Page 47: One more type of tissue to discuss

• Ionising radiation – X Rays, UV light

• Chemicals – tar from cigarettes• Virus infection – papilloma virus

can be responsible for cervical cancer.

Page 48: One more type of tissue to discuss

• Hereditary predisposition – Some families are more susceptible to getting certain cancers. Remember you can’t inherit cancer its just that you maybe more susceptible to getting it.

Page 49: One more type of tissue to discuss

Benign or malignant?• Benign tumors do not spread from

their site of origin, but can crowd out (squash) surrounding cells eg brain tumor, warts.

• Malignant tumors can spread from the original site and cause secondary tumors. This is called metastasis. They interfere with neighbouring cells and can block blood vessels, the gut, glands, lungs etc.

Page 50: One more type of tissue to discuss

Genetically altered cell

The DNA of the cell highlighted above has a mutation that causes the cell to replicate even though this tissue doesn't need replacement cells at this time or at this place.

Page 51: One more type of tissue to discuss

Spread and second mutation

• The genetically altered cells have, over time, reproduced unchecked, crowding out the surrounding normal cells. The growth may contain one million cells and be the size of a pinhead. At this point the cells continue to look the same as the surrounding healthy cells. After about a million divisions, there's a good chance that one of the new cells will have mutated further. This cell, now carrying two mutant genes, could have an altered appearance and be even more prone to reproduce unchecked.

Page 52: One more type of tissue to discuss

Spread and second mutation

• After about a million divisions, there's a good chance that one of the new cells will have mutated further. This cell, now carrying two mutant genes, could have an altered appearance and be even more prone to reproduce unchecked.

Page 53: One more type of tissue to discuss

Third mutation

• Over time and after many cell divisions, a third mutation may arise. If the mutation gives the cell some further advantage, that cell will grow more vigorously than its predecessors and thus speed up the growth of the tumour.

Page 54: One more type of tissue to discuss

Fourth mutation

• The new type of cells grow rapidly, allowing for more opportunities for mutations. The next mutation paves the way for the development of an even more aggressive cancer.

Page 55: One more type of tissue to discuss

Breaking through the membrane

• The newer, wilder cells created by another mutation are able to push their way through the epithelial tissue's basement membrane. At this point the cancer is still too small to be detected.

Page 56: One more type of tissue to discuss

Angiogenesis

• Angiogenesis is the recruitment of blood vessels from the network of neighbouring vessels.

• Now the size of a small grape, is large enough to be detected as a lump

Page 57: One more type of tissue to discuss

Invasion and dispersal

• Individual cells from the tumor enter into the network of newly formed blood vessels, using these vessels as highways by which they can move to other parts of the body.

Page 58: One more type of tissue to discuss

Invasion and dispersal

• A tumor as small as a gram can send out a million tumor cells into blood vessels a day.

Page 59: One more type of tissue to discuss

Tumor cells travel -

metastasis• What makes

most tumors so lethal is their ability to metastasize -- that is, establish new tumor sites at other locations throughout the body.

Page 60: One more type of tissue to discuss

QuizNext time!