Physiology 1 - Disease and Symptoms (Woolard)

Question 1

What are the characteristics of cancer?

Answer 1

A group of diseases with different etiology (and underlying cause)
Characterised by abnormal cell growth through which cells may acquire the potential to metastasise from the site of origin to a secondary tumour site.

Question 2

What is tumour growth dependent on?

Answer 2

The development of a system capable of delivering nutrients and oxygen via increased vascular supply (angiogenesis).

Question 3

What are the characteristics of benign tumours?

Answer 3

Encapsulated and aren’t dispersing beyond their margins. The tumour cells are well-differentiated, grow slowly and generally don’t acquire the potential to metastasise.

Question 4

What are the characteristics of a malignant tumour?

Answer 4

Cells are poorly differentiated, the process of cell division can be observed and is frequent and rapid. They gain the ability of intravasation; can break through the capsule, push away cells in the extracellular matrix and then arrest at distant sites and metastasise into a secondary tumour. Breach their “border” and can disseminate.

Question 5

What is carcinoma?

Answer 5

Most common form of cancer, originates from embyronic endoderm or ectoderm e.g. breast, lung, colon

Question 6

What is sarcoma?

Answer 6

Also reasonably prevalent; arising in cells of embryonic mesoderm, the supporting tissues of the body i.e. cartilage, fat, connective tissue and muscle

Question 7

What is lymphoma?

Answer 7

Occurs within circulatory system, arising from the lymph nodes and tissues of the body’s immune system.

Question 8

What is leukaemia?

Answer 8

Occurs within circulatory system, arising from the immature WBCs that grow in bone marrow and accumulate in large numbers in bloodstream.

Question 9

What are some of the causes of cancer?

Answer 9

Genetic factors
Tobacco
Body weight
Physical exercise
Diet
Hormones (reproduction factors, 1st pregnancy at a late age)
Sunlight (UV)
Occupational carcinogens (benzene, pesticides, asbestos)
Infection causes (virus, cervical, bacteria, H. pylori)
Medical Tx such as chemo or radio
Pollution (diesel exhausts)

Question 10

What are some symptoms of lung cancer?

Answer 10

Coughing up blood, chest pain, breathlessness, tiredness

Question 11

What are some symptoms of pancreatic cancer?

Answer 11

Jaundice, development of diabetes, weight loss, stomach or back pain

Question 12

What are some symptoms of breast cancer?

Answer 12

Lump or thickening, change in breast size, discharge, bleeding, weight loss

Question 13

What can make a cell metastatic?

Answer 13

Mutagenic initiation via chemical, radiation, virus etc
Point mutations: missense, nonsense, silent
Chromosomal alterations: deletion, insertions, extra numbers of chromosomes, translocation
Epigenetic alterations: acetylation or methylation
Changes to DNA positioning, doled, positioned etc

Question 14

How do cells get into vasculature (intravasation)?

Answer 14

Local invasion into vasculature; normally endothelial cells in the vessel wall are adhesive and held together by cadherins. Loss of cadherins increases permeability of the vessel to cancer cells and they gain entrance to the vessel.

Then the cancer cells express integrins that hold them on the vessel wall and allows them to cling on.

Question 15

How do cancer cells survive in the vasculature?

Answer 15

Expression of selectins that encourages platelets to stick to the metastatic cells and provide protection from blood flow turbulence or NK killer cells.

The cells then arrest at a different site, when flow reduces in the micro-vasculature of organ tissue. Then extravasation into the extracellular environment and set up a secondary tumour site.

Question 16

What are the steps to a metastatic cascade?

Answer 16

1. Primary tumour function
2. Localised vasculaturisation
3. Intravasation
4. Transport through circulation
5. Arrest in micro-vasculature of organs (lungs, brain, bone)
6. Extravasation
7. Formation of micro-metastases
8. Colonisation and angiogenesis

Question 17

What is angiogenesis?

Answer 17

Vasculogenesis is a normal process, we must focus on angiogenesis that is the main form of vascularisation of cancer cells.
Angiogenesis is the formation of new vessels from pre-exiting vasculature, enabling vascularisation of an avascular region.

Question 18

Is angiogenesis normal?

Answer 18

Yes, it is helpful in the repair or response to a disease such as ischaemia, diabetes, retinopathy etc. In cancer the system is high jacked and used to help tumour growth.

Question 19

What is the vasculature like in pathological angiogenesis?

Answer 19

Pathological is what we don’t want.
The vasculature is ugly, leaky, poorly designed.
There is little stability due to the high cell turnover, vessel morphology is also poor.
Endothelial cells are loosely connected with inadequate pericyte coverage (supporting structural cells).
The vessel lumen is a heterogenous mixture of tumour cells and endothelial.

Question 20

What are the curative goals of cancer?

Answer 20

Be clinically and pathologically free of disease with a similar life expectancy and quality of life as a healthy person of a similar age

Question 21

What are the maintenance goals of cancer?

Answer 21

To maintain the functional state of a patient and minimise the progression of the disease

Question 22

What are the goals of paliative care?

Answer 22

When a patient is unlikely to be cured and the chances of long term survival is low then the main goal is pain relief anf comfort,

Question 23

What are the characteristics of cancer cells?

Answer 23

Stop depending on external signals for growth, and also ignore signals for apoptosis.
Avoid cell suicide
Grow indefinitely
Disturb normal metabolism
Stimulate angiogenesis
Promote inflammation and activation of an immune response
Initiate process of metastases