Blood

 A 70kg adult has about 5.5L of blood consisting of: - Plasma (fluid) 55% total volume - Blood cells – 45% total volume

Blood  A 70kg adult has about 5.5L of blood consisting of: - Plasma (fluid) 55% total volume - Blood cells – 45% total volume  The most common type of blood cells are red blood cells (5 million per mL)

Blood  A 70kg adult has about 5.5L of blood consisting of: - Plasma (fluid) 55% total volume - Blood cells – 45% total volume  The most common type of blood cells are red blood cells (5 million per mL)  White blood cells (7500 per mL)

Blood  A 70kg adult has about 5.5L of blood consisting of: - Plasma (fluid) 55% total volume - Blood cells – 45% total volume  The most common type of blood cells are red blood cells (5 million per mL)  White blood cells (7500 per mL)  Platelets (7000 per mL)

Red Blood cells  Are biconcave discs – this shape increases surface area: volume ratio = rapid uptake and release of oxygen.

Red Blood cells  Are biconcave discs – this shape increases surface area: volume ratio = rapid uptake and release of oxygen.  Capillaries have similar diameter to that of a RBC and the shape of a RBC can alter as it squeezes along it = further reducing the diffusion distance  further increasing rate of oxygen movement into cells.

Red Blood cells  Are biconcave discs – this shape increases surface area: volume ratio = rapid uptake and release of oxygen.  Capillaries have similar diameter to that of a RBC and the shape of a RBC can alter as it squeezes along it = further reducing the diffusion distance  further increasing rate of oxygen movement into cells.  Contain haemoglobin – a large molecule that binds oxygen and transport it through the blood.

Red Blood Cells  Have no nucleus so they can’t replicate or repair themselves.

Red Blood Cells  Have no nucleus so they can’t replicate or repair themselves.  Have an average survival of about 120 days.

Red Blood Cells  Have no nucleus so they can’t replicate or repair themselves.  Have an average survival of about 120 days.  Constantly broken down in the spleen and liver, and constantly made in the bone marrow.

Red Blood Cells  Have no nucleus so they can’t replicate or repair themselves.  Have an average survival of about 120 days.  Constantly broken down in the spleen and liver, and constantly made in the bone marrow.  People with insufficient numbers of RBC lack energy, look pale, and are said to be anaemic.

White blood cells (leucocytes)  Made in the bone marrow.

White blood cells (leucocytes)  Made in the bone marrow.  Contain a nucleus and protect the body against disease.

White blood cells (leucocytes)  Made in the bone marrow.  Contain a nucleus and protect the body against disease.  Lymphocytes are white blood cells that produce antibodies.

White blood cells (leucocytes)  Made in the bone marrow.  Contain a nucleus and protect the body against disease.  Lymphocytes are white blood cells that produce antibodies.  Antibodies are proteins that ‘tag’ foreign objects, and when these are tagged they can be recognised and destroyed by other WBC’s called phagocytes.

White blood cells (leucocytes)  Made in the bone marrow.  Contain a nucleus and protect the body against disease.  Lymphocytes are white blood cells that produce antibodies.  Antibodies are proteins that ‘tag’ foreign objects, and when these are tagged they can be recognised and destroyed by other WBC’s called phagocytes.  Phagocytes can alter their shape and move to sites of infection where they engulf pathogens.

White Blood cells (leucocytes)  The specific region on a foreign object that the antibody recognises is called an antigen – these are usually proteins.

White Blood cells (leucocytes)  The specific region on a foreign object that the antibody recognises is called an antigen – these are usually proteins.  Each different antigen stimulates the production of a specific antibody that will only recognise that particular antigen.

White Blood cells (leucocytes)  The specific region on a foreign object that the antibody recognises is called an antigen – these are usually proteins.  Each different antigen stimulates the production of a specific antibody that will only recognise that particular antigen.  WBC’s are not confined to blood vessels – they can leave and travel through the lymph and tissue fluid around cells, seeking out pathogens.

White Blood cells (leucocytes)  The specific region on a foreign object that the antibody recognises is called an antigen – these are usually proteins.  Each different antigen stimulates the production of a specific antibody that will only recognise that particular antigen.  WBC’s are not confined to blood vessels – they can leave and travel through the lymph and tissue fluid around cells, seeking out pathogens.  When leucocytes fail to mature properly, a person suffers from leukaemia.

Platelets (thrombocytes)  Involved in blood clotting.

Platelets (thrombocytes)  Involved in blood clotting.  Release a chemical at the injury site that converts soluble blood protein fibrinogen into insoluble fibrin.

Platelets (thrombocytes)  Involved in blood clotting.  Release a chemical at the injury site that converts soluble blood protein fibrinogen into insoluble fibrin.  Fibrin forms a tangle of fibres at the clot, trapping further blood cells to form a permanent clot.

Transport of blood gases  As blood passes through the lungs, oxygen from the lungs binds to haemoglobin (Hb) in RBC’s to form oxy- haemoglobin (oxy-Hb)

Transport of blood gases  As blood passes through the lungs, oxygen from the lungs binds to haemoglobin (Hb) in RBC’s to form oxy- haemoglobin (oxy-Hb)  Oxy-Hb releases oxygen in regions of the body low in oxygen.

Transport of blood gases  As blood passes through the lungs, oxygen from the lungs binds to haemoglobin (Hb) in RBC’s to form oxy- haemoglobin (oxy-Hb)  Oxy-Hb releases oxygen in regions of the body low in oxygen.  Hb is a large, complex protein containing a few Fe (iron) atoms.

Transport of blood gases  As blood passes through the lungs, oxygen from the lungs binds to haemoglobin (Hb) in RBC’s to form oxy-haemoglobin (oxy-Hb)  Oxy-Hb releases oxygen in regions of the body low in oxygen.  Hb is a large, complex protein containing a few Fe (iron) atoms.  Carbon dioxide is transported from tissues to the lungs as bicarbonate ions (HCO 3 -) in the blood plasma.

The lymphatic system  This works like a drainage system.

The lymphatic system  This works like a drainage system.  Lymph capillaries and lymph vessels, similar to veins, drain excess tissue fluid from around the cells.

The lymphatic system  This works like a drainage system.  Lymph capillaries and lymph vessels, similar to veins, drain excess tissue fluid from around the cells.  Lymph fluid is similar to blood, except that it contains no RBC’s and little protein.

The lymphatic system  This works like a drainage system.  Lymph capillaries and lymph vessels, similar to veins, drain excess tissue fluid from around the cells.  Lymph fluid is similar to blood, except that it contains no RBC’s and little protein.  Lymph returns to the blood system via two large lymph vessels which empty into the superior vena cava – the large vein that connects to the right atrium of the heart.