Pre-Diploma Biology Year 10 BLOOD WHAT IS IT? WHERE DOES IT COME FROM?

PLASMA CARRYING BLOOD CELLS Blood consists of: PLASMA and BLOOD CELLS Plasma is the liquid part of the blood and forms about 40% of blood. It is straw coloured. The blood cells (corpuscles) form the other 60% of blood, and include red cells, white cells and platelets.

A SLIDE SMEAR OF HUMAN BLOOD This is what human blood might look like through the HP (x 400) lens of a microscope. Notice how few white cells there are. Can you see the platelets? When might there be more white cells in the blood?

BLOOD PLASMA Blood plasma carries chemicals in suspension or solution These molecules include fats, glucose, amino acids, blood proteins, hormones, and vitamins Synthetic blood plasma is often used in hospitals

AN ELECTRON MICROGRAPH OF HUMAN BLOOD (X 1500)

NAMING THE BLOOD CELLS These are the different cells found in human blood. You would be very unlikely to see all these white cells at the same time. (No-one expects you to identify and learn the name of all the different types of WBC’s!)

RED BLOOD CELLS Red blood cells are more properly called ERYTHROCYTES Their function is to carry oxygen, attached to the protein haemoglobin

WHITE BLOOD CELLS White blood cells are more properly called LEUCOCYTES Their function is to help the body in disease defence and immunity. There are several different leucocytes, with different functions.

SO, WHEN MIGHT YOU HAVE A HIGH WHITE CELL COUNT?

PLATELETS Platelets are more properly called THROMBOCYTES Their principle function is to assist in clotting the blood at wounds

MAKING NEW BLOOD CELLS Blood is made in bone marrow, from stem cells.

HOW BLOOD DIFFERENTIATES Not a good slide! Sorry! But you get the idea. Undifferentiated ‘raw’ cells, called stem cells, are programmed to become different sorts of blood cell.

MORE ABOUT DIFFERENTIATION

MORE ABOUT STEM CELLS – WHAT HUGE POTENTIAL FOR HUMAN MEDICINE! 1. Get the stem cells from marrow or an early embryo 2. Cultivate the stem cells 3. Enable the stem cells to specialise into the tissue (or organs?) you want

WHAT COULD BE DONE WITH STEM CELLS?

CAN STEM CELL ‘REPAIR’ OR REPLACEMENT BE SUCCESSFUL? A Swedish hospital reports its doctors implanted a synthetic windpipe into a 36-year-old man who had tracheal cancer, in what its officials call the first successful procedure of its kind. The medical team first built a scaffold and a bioreactor - a device specially designed to simulate natural tissue growth. New cells to line and cover the windpipe were then grown on the scaffold for two days prior to the transplant. The plastic compound used to make the artificial windpipe has a spongy surface that speeds cell growth.