What Am I?

• I stretch over 96, 000 km and I serve over 100 trillion customers

• My power source is no larger than a fist and weighs only 300g

• I pump enough liquid over a lifetime to fill two ocean tankers

• I am one of the many organ systems that allows animals to live……

• The body contains 4 to 5L of my blood

Circulatory System

NOT THIS

But This…

..

…And This

What Does blood do?

1. Carries Nutrients to cells

2. Carries Waste Away from the Cell

WASTE

3. Carries Oxygen to cells

4. Helps protect against invaders- white blood cells are part of the immune system that keeps us healthy!

5. Distributes hormones from the endocrine system and heat

What makes this possible?1. Diffusion membrane: In order for there to be

an efficient exchange of oxygen, waste and nutrients there must be an high S.A between the blood and the cells and the diffusion membrane must be thin ( 1 cell thick)

Surface Area

Cells must be less than 2 cells away from a blood vessel

1…2

2. A fluid that transports (circulates) materials through the body

3. A network of tubes in which fluid circulates

Simple diffusion cannot reach

every cell. I would take to long to support life.

We need blood

vessels

4. A pump that pushes the fluid through the tubes

Circulatory systems can be……

Or

Examples of Closed Systems-humans-squids-worms

Examples of Open Systems-Snails-Insects (grashoppers)-Crustaceans (crayfish, lobster)

Open = blood+ interstitial

Open = blood+ interstitial• The circulating fluid is called hemolymph

which is a mixture of blood and interstitial fluid

• Blood is forced out of the circulatory tubes called blood vessels, and through the body cavities /sinus(es) by one or more hearts

• When the heart(s) relax fluid is returned back to the heart through pores called ostia

• BATHE CELLS DIRECTLY

Open• Inefficient• Insects can get by with this type system

because they have numerous openings in their bodies (spiracles) that allow the "blood" to come into contact with air

Sinus/cavity surrounding

organsheart

Closed= vessels

blood and

interstitial

separate

Closed Circulatory System

• All vertebrates and some invertebrates like earthworms, squids and octopus have closed circulatory systems

• Contained in a network of tubes (blood vessels)• Interstitial fluid is found outside these vessels

and surrounds tissues thus facilitating diffusion

Main categories

Continuous loop : fish

3 chamber: amphibian

4 chamber: Humans

4 chamber partial septum: lizard

Simple Closed

• Continuous loop or circuit: The circuit carries blood to the gills, where it takes up oxygen and releases carbon dioxide and from the gills it circulates to the rest of the body releasing oxygen and removing carbon dioxide

3-chambered heart• Amphibians• Two atria and a single ventricle• Left atrium receives oxygenated blood from skin and

lungs• Right atrium receive deoxygenated blood from the

body• Single ventricle pumps the blood to both to the

lungs and to the bodyL

R

Gills

Systemic

4 chambered heart: partial septum

• Reptiles, snakes, lizard, the ventricle is partially separated by a septum

• A septum is a wall of tissue that divides a body cavity into smaller parts (i.e.. A septum divides the ventricles in a mammalian heart)

• Some mixing of oxygenated and deoxygenated blood as they enter the ventricle

4 chamber: Two circuit Circulatory

• Mammals, crocodilians, and birds have a 4 chamber heart with 2 atria and 2 ventricles and a complete septum

• This creates 2 separate circuits– Pulmonary Circuit : to and from the lungs to get

oxygenated– Systemic Circuit: To and from the body to deliver

oxygen and comes back to the heart deoxygenated

Circuits: Pulmonary and Systemic

Components of Blood 1. Plasma (50-55%) 2. Erythrocytes

3. Leukocytes 4. Platelets

8% of the human body is blood

45-50% of blood is comprised of

cells

Plasma

• A protein-rich liquid in which blood cells and platelets are suspended (90% water)

• Oxygen, proteins, nutrients, minerals, dissolved ions and vitamins are dissolved in it

• Proteins include albumins, globulin and fibrinogen– Albumin : determines water content– Globulin: transport lipids, cholesterol and fat soluble

vitamins– Fibrinogen: for clotting

Erythrocytes- RED BLOOD CELLS carry oxygen and carry CO2 back- Formed in bone marrow (spine, ribs, skull, legs and arms)- Contain hemoglobin that increases how much oxygen can

be carried- Biconcave to increase S.A. for exchange - approx 7 (μm ) in size (135 RBC would measure ~ 1mm)- Live only 120 days- 2 – 3 million produced per second- If oxygen levels drop then the brain signals EPO hormone production. Increasing RBCells

Anemia

• The reduction in blood oxygen due to low levels of hemoglobin (which contains iron)

• or poor red blood cell production where these blood cells carry less hemoglobin and get stuck in blood vessels easily ( sickle cell anemia).

White Blood Cells: Leukocytes• Formed in bone marrow as well• Bodies defense against harmful bacteria, viruses

and other organisms (fungi, parasites)• Located in the spleen and the liver• Monitor and regulate the number and age of red

blood cells• Remove debris (dead blood cells) and hemoglobin

is released• All types have a nucleus• Outnumbered by RBC 700 to 1

• Many different types– Granular lymphocyte (cytoplasmic granules)• Contain various chemicals to digest materials that are

brought into the cell – Agranular lymphocyte (no cytoplasmic granules)• Engulf bacteria or microorganisms and produce

antibodies to attack foreign material

• Engulphing (phagocytosis)• Antibody (used by the immune system to identify and

neutralize foreign objects)

• Remnant leukocytes (pus)

Platelets

• Small cell fragments with No nucleus, and are produced in bone marrow

• Are pieces of cytoplasm broken of from a large cell in bone marrow

• Pass through blood vessels and rupture if they hit a rough edge, like where there

is a cut. They help clot blood (coagulation)

Blood Clotting

• When a blood vessel is broken, platelets stick to the collagen fibers of the tissue.

• More and more stick until a big enough clot is created to seal the hole

• After the clot, fibrinogen in plasma is converted to long strands of Fibrin

forming a mesh that traps more blood and white blood cells

Clotting Disorders

• Strokes: clotting that dislodges from one area and then moves to stop the flow of blood in the brain

• Hemophilia: A disorder that results in poor clotting or slow clotting. Lack specific clotting factors.

Counting Blood

• A complete blood count tells us the number of erythrocytes, leukocytes and platelets in our blood– Low erythrocyte=anemia– High leukocyte = fighting infection or sign of

leukemia a type of cancer– Low platelet count= issues clotting blood

Blood Types

Can accept from

A or O B or O A, B, AB or O O

42% 10% 3% 45%

Transfusions

• Individuals may require a blood transfusion to treat a medical problem (trauma, hemophilia)

• However not all blood types are compatible• When individuals receive blood containing

antigens that are different from their own, the immune system recognizes it as a foreign invader and attacks by producing antibodies

• Causes agglutination: blood cells clump together blocking circulation and oxygen supply

Transfusions• Take a minute to figure out the following

– Who can donate to all blood types?– Who can receive blood from all types?– Who can a B blood type receive from?– Who can an A blood type receive from?

• O can donate to all since they lack protein markers “Universal donor”

• AB can receive from all “universal acceptor”• A can receive from O and A, and B can receive from B and O• O can only accept from other O donors

Rhesus Factor

• An individual either has or lacks the Rhesus factor antigen on their RBC

• Rh+ :has the antigen• Rh- : does not have• Blood donation:– Rh – to anyone– Rh + only to Rh+

Thank you