RED ALERT!The Circulatory System and the

Blood

Blood• Blood is a heterogeneous

mixture. It is a COLLOID, and has four main components

1. Red corpuscles (red

blood cells)

1. White corpuscles (white blood cells)

2. Plasma (fluid)

3. Platelets

Red Blood Cells

• Carry Oxygen and Carbon Dioxide with the help of Hemoglobin

• They are produced in the bone marrow

• They live only 3-4 months and have no nucleus

Blood Types• Red blood cells will have proteins which stick

out. They are called Antigens• The opposite of antigens are Antibodies• If an antigen meets it’s antibody, they clump

and form clots, which are BAD!!

ABO Blood Types Blood TypeBlood Type Antigen on red Antigen on red

blood cellblood cellAntibody in Antibody in

PlasmaPlasma

AA AA Anti-BAnti-B

BB BB Anti-AAnti-A

ABAB A & BA & B NoneNone

OO NoneNone Anti-A & Anti-BAnti-A & Anti-B

Rh antigen: Rhesus System

• Blood, of all types, can also have an Rh antigen on them and there is an antibody for it.

• If a person has this antigen, they will have a + next to their blood type (ex: A+ means they have the A and Rh antigen)

• If a person does not have this antigen, they will have a – next to their blood type (ex: A- means they only have the A antigen)

Donors & Recipients• When you are looking at donors and

recipients, you must make sure the antibodies of the recipient do not attack the antigens of the donor

• ONLY LOOK AT ANTIBODIES OF RECIPIENT AND ANTIGENS OF DONOR!!!

• The antibodies of the donor are not recognized by the recipients body and are destroyed

• O- is the universal donor and AB+ is the universal recipient for blood transfusions.

Rh- Rh+

Plasma

• It carries Nutrients and Hormones (chemical messages) to the cells

• It carries Urea and Carbon dioxide away from the cells.

• Plasma suspends red and white blood cells so they can flow through the body. It also has:

- clotting factor - antibodies and - carries off solid waste.

Platelets• Smaller than red blood cells

• Responsible for clotting

• Link together to form scabs when in contact with air.

White blood cells• They are the main defense

against disease.

• No hemoglobin

• Can pass through capillary walls.

White blood cells• White blood cells kill bacteria and viruses

through:

1) Phagocytosis – eating them with help from antibodies

2) Antibodies – Latch onto bacteria/viruses

Pathogens • Pathogens are viruses and bacteria.

VirusVirus BacteriaBacteria

Smallest pathogenSmallest pathogen

Invade cellsInvade cells

Few drugs to fight Few drugs to fight themthem

To kill the virus, you To kill the virus, you must kill the cellmust kill the cell

Single cell organismsSingle cell organisms

Reproduce quicklyReproduce quickly

Produce toxins which Produce toxins which destroy cellsdestroy cells

Can be killed with Can be killed with antibioticsantibiotics

The Circulatory System• The Circulatory System is the major

transportation system in the body.

Pulmonary circulation carries blood that contains carbon dioxide TO THE LUNGS, where it gets rid of the waste and is resupplied with oxygen

Systemic circulation carries the oxygenated blood to cells in the body and supplies them with nutrients as well.

Purpose

• It serves to: • 1)transport food and

oxygen to the body, • 2) Pick up waste

produced for removal from the body,

• 3) Help regulate body temperature.

The Heart

• This is the motor (pump) that makes the system work.

Inside the Heart

• The Heart is made up of muscle tissue and has four main chambers

1. The right atrium

2. The right ventricle

3. The left atrium

4. And the left ventricle

The heart also has valves to prevent backflow of blood

The Human Highways• The “highways” and “roads” of the body are collectively, they are called

blood vessels. They are:

1)Arteries

2)Veins

3) Capillaries.

Arteries• Arteries take blood away from the heart.• Arterioles are smaller arteries.• They have thick walls and contain a layer of

muscle.• Blood pumped from the heart is under high

pressure, so it produces small bulges along the artery.

Veins• They carry blood to the heart.• Venules are smaller veins• They have a thinner muscular layer with lower

blood pressure.• Surrounding muscles help blood to flow though

veins• They also contain backflow valves.

Capillaries

• Link Arterioles to Venules

• Have thin walls so gas exchange can happen.

Blood Circulation• Right Atrium Right Ventricle

Pulmonary Artery Arterioles Pulmonary capillaries blood gets oxygenated Venules Pulmonary Veins Left Atrium Left Ventricle

• Left ventricle Aorta Arterioles BODY’s capillaries Venules/Veins Vena Cavae (superior or inferior) Right atrium

The walls of the left ventricle are thicker (more muscular) than those of the right ventricle because the left ventricle has to push blood into the entire body, whereas the right ventricle only has to push blood as far as the lungs.

BLOOD ALWAYS LEAVES THE VENTRICLES, GOES THROUGH THE BODY, AND COMES BACK INTO THE ATRIUMS!!

Blood Pressure• Blood Pressure has two types, Systolic and Diastolic. • Systolic pressure is measured when pressure

exerted by blood on artery walls is at its maximum (when the ventricles in the heart contact)

• Diastolic pressure is measured when pressure exerted by blood on artery walls is at its minimum (when ventricles are not contracting)

• Blood pressure = systolic pressure (bigger #) diastolic pressure (smaller #)

REVIEW: Pressure• Mathematically, Pressure (symbol: ‘p')

is the force per unit area applied on a surface.

p = F A

F= ForceA= AreaThe units are N/m2 or Pa or mm of Hg

REVIEW: What is pressure?• Pressure is the result of molecules or

atoms bouncing off each other and the surfaces that hold the fluid in.

• So what happens to pressure if we increase temperature?

• Hint: IT INCREASES!!

So…..• What happens to pressure if:

– You have a lot of force acting on a small area?

• High Pressure

– Same force but over a larger area?

• Lower Pressure

– Lower force acting on a huge area?

• Very Low Pressure

Area FormulaWhat general shape do you think our blood vessels are?

They are Cylinders!

Arteries have a bigger surface area so that they can withstand high force of heart on blood and pressure will be lower

Compressible/Non-compressible Fluids

• In general fluids (gases and liquids) fit into two categories.

• Compressible: With increased pressure, the volume and temperature will change (decrease).

• Non-compressible: With increased pressure the volume and temperature will NOT change (decrease).

• Blood is a non-compressible fluid

• Fluids move from high pressure to low pressure area.

• What if the fluid can not pass?

• The blood vessel will burst!

Heart Health

• If blood pressure is to high, you have Hypertension, to low, Hypotension.

• Hypertension is usually cause by a narrowing of blood vessels due to cholesterol build up.