Biological Science

October 20, 2011

Circulatory System

• The circulatory system is responsible for– The distribution of oxygen throughout the body– Carrying nutrients– Transporting hormones throughout the body

Heart Animation

http://www.fed.cuhk.edu.hk/~biology/teaching/transport/animations/HyperHeart.swf

What makes up our blood?

• RED BLOOD CELLS (Erythrocytes) – The most abundant cells in our blood; they are produced in the bone marrow and contain a protein called hemoglobin that carries oxygen to our cells.

• WHITE BLOOD CELLS (Leukocytes) – They are part of the immune system and destroy infectious agents called pathogens.

• PLASMA – This is the yellowish liquid portion of blood that contains electrolytes, nutrients and vitamins, hormones, clotting factors, and proteins such as antibodies to fight infection.

• PLATELETS (Thrombocytes) – The blood clotting factors that are carried in the plasma; they clot together in a process called coagulation to seal a wound and prevent a loss of blood.

Red blood Cells

• Carbon dioxide is transported:– Via plasma– Combine with hemoglobin– As bicarbonate ions

• Live for about one year

White Blood Cells (WBC)

• WBC cells function to defend the body against bacterial infection and invasion by other foreign substances

Plasma

• Excess fluids and proteins in the body are returned to the bloodstream by the lymphatic system

Red Blood Cells (RBC)

• Mature red blood cells do not have a nucleus• Hemoglobin is the iron containing molecule in the RBC• RBC transport respiratory gases

Red blood Vessels

• Capillaries are red blood vessels that are one cell thick• Many veins have valves to limit the downhill flow of blood• Arteries usually carry oxygen-rich blood, Away from heart• Smallest most abundant are the capillaries• Pulmonary circulation flows to and from the lungs

Heart• The amount of blood pumped each minute depends on the

heart rate.• The ventricles are the chambers of the heart that pump blood

to the lungs and the rest of the body• Blood entering the right atrium is deoxygenated• Oxygenated blood from the lungs is received by the left atrium• The only artery that carries deoxygenated blood is the

pulmonary artery• The pacemaker responsible for starting the heartbeat is a small

bundle of cells at the entrance to the artrium

The sinoatrial node is the heart's pacemaker. Normally, the heartbeat begins in the right atrium when the sinoatrial (SA) node, a special group of cells, transmits an electrical signal across the heart. This signal spreads throughout the atria and to the atrioventricular (AV) node. The AV node connects to a group of fibers in ventricles that conducts the electrical signal and sends the impulse to all parts of the ventricles. This exact route must be followed to ensure that the heart pumps properly. www.youtube.com/watch?v=SMXBR_YFocs

Macrophages

• These blood cells scavenge worn-out or dead cells in the body.

Arteries Away!

• Some arteries carry oxygenated blood and other arteries carry deoxygenated blood

• An artery is a blood vessel that carries blood away from the heart.

• The arteries that carry blood from the heart to the lungs (Pulmonary Artery) carry deoxygenated blood that has returned to the heart from the body.

• The arteries that carry blood from the heart to the rest of the body carry oxygenated blood that has returned to the heart from the lungs.

What makes up your Blood?

Oxygen Absorption and Transport

• Red blood cells are filled with hemoglobin, which is an iron-containing protein that gives blood its red color.

• Oxygen binds easily to the hemoglobin iron, making red blood cells efficient oxygen carriers that circulate throughout the body as they flow with the plasma.

• http://www.dnatube.com/video/274/Hemoglobin--Cooperative-Oxygen-Binding

Blood Facts

The average adult has about FIVE liters of blood inside of their body, which makes up 7-8% of their body weight.

Blood is living tissue that carries oxygen and nutrients to all parts of the body, and carries carbon dioxide and other waste products back to the lungs, kidneys and liver for disposal. It also fights against infection and helps heal wounds, so we can stay healthy.

There are about one billion red blood cells in two to three drops of blood. For every 600 red blood cells, there are about 40 platelets and one white cell.

Genetics of Blood Types

• Your blood type is established before you are BORN, by specific GENES inherited from your parents.

• These two genes - one gene from your MOTHER and one from your FATHER -determine your blood type by causing proteins called AGGLUTINOGENS to exist on the surface of all of your red blood cells.

What are blood types?

http://learn.genetics.utah.edu/units/basics/blood/types.cfm

There are 3 alleles or genes for blood type: A, B, & O. Since we have 2 genes, there are 6 possible combinations.

Blood Types

AA or AO = Type ABB or BO = Type B

OO = Type OAB = Type AB

How common is your blood type?

Rh Factors• While studying Rhesus monkeys, a

certain blood protein was discovered. This protein is also present in the blood of some people. Other people, however, do not have the protein.

• The presence of the protein, or lack of it, is referred to as the Rh (for Rhesus) factor.

• If your blood does contain the protein, your blood is said to be Rh positive (Rh+). If your blood does not contain the protein, your blood is said to be Rh negative (Rh-).

A+ A-B+ B-

AB+ AB-O+ O-

Blood TransfusionsA blood transfusion is a procedure in which blood is given to a patient through an intravenous (IV) line in one of the blood vessels. Blood transfusions are done to replace blood lost during surgery or a serious injury. A transfusion also may be done if a person’s body can't make blood properly because of an illness.

Who can give you blood?

People with TYPE O blood are called Universal Donors, because they can give blood to any blood type.

People with TYPE AB blood are called Universal Recipients, because they can receive any blood type.

Rh + Can receive + or - Rh - Can only receive -

Universal Donor

Universal Recipient

Respiration

• Air moves into and out of the lungs in stages.• When the diaphragm and rib muscles contract, the diaphragm

moves downward and the rib cage moves up and outward.• This expands the chest cavity, lowering the air pressure in the

lungs and causing air to flow in.• When the diaphragm and rib muscles relax, the diaphragm

moves upward and the rib cage moves down and inward.• This reduces the size of the chest cavity, raising the pressure of

the air in the lungs and causing air to flow out.• http://www.youtube.com/watch?v=pc2MmhkUW_E&feature=related