Human Human Circulatory Circulatory

SystemSystemChapter 24.2Chapter 24.2

Circulatory SystemCirculatory System Circulatory system is Circulatory system is

responsible for moving responsible for moving nutrients, gases like nutrients, gases like oxygen and carbon oxygen and carbon dioxide, hormones dioxide, hormones (signal molecules) and (signal molecules) and fluids like water fluids like water throughout the body throughout the body of a multicellular of a multicellular organism.organism.

Circulatory SystemCirculatory System

OverviewOverview Circulatory systems Circulatory systems

includes:includes: Heart – a muscular Heart – a muscular

pumppump Blood vessels – tubes Blood vessels – tubes

that transport the that transport the bloodblood

Blood – fluid that Blood – fluid that transports substances transports substances around the bodyaround the body

Also called the Also called the cardiovascular cardiovascular system.system.

Circulatory SystemCirculatory System

Closed system – meaning that blood is Closed system – meaning that blood is always confined to vesselsalways confined to vessels Some simpler animals have open circulation Some simpler animals have open circulation

– blood surrounds the organs and tissues, – blood surrounds the organs and tissues, oozing around open cavities inside the oozing around open cavities inside the organism. This is less efficient.organism. This is less efficient.

Blood VesselsBlood Vessels Blood vessels – tubes that transport bloodBlood vessels – tubes that transport blood

60,000 miles of blood vessels in human body!!!60,000 miles of blood vessels in human body!!! 3 types – What are they? What does each do?3 types – What are they? What does each do?

Arteries – carry blood away from the heartArteries – carry blood away from the heart Capillaries – where material exchange occursCapillaries – where material exchange occurs Veins – carry blood to the heartVeins – carry blood to the heart

arteries arteries capillaries capillaries veinsveins

ArteriesArteries Carry blood away from Carry blood away from

the heartthe heart Have relatively thick, Have relatively thick,

muscular walls muscular walls because blood in because blood in arteries is under arteries is under pressurepressure

Elastic - expand as Elastic - expand as blood is pumped into blood is pumped into them, return to normal them, return to normal as pressure decreases. as pressure decreases.

If arteries become If arteries become hardened because of hardened because of cholesterol deposits cholesterol deposits or old age, blood or old age, blood pressure increases, pressure increases, which increases work which increases work load of the heart.load of the heart.

Major artery is the aortaMajor artery is the aorta

Blood VesselsBlood Vessels Capillaries Capillaries

Site of materials exchange between blood and cellsSite of materials exchange between blood and cells Tiny – only one cell thickTiny – only one cell thick

Thin barrier maximizes exchange of gases, nutrients Thin barrier maximizes exchange of gases, nutrients and wastesand wastes

Blood flow slows down to allow time for movement of Blood flow slows down to allow time for movement of oxygen, carbon dioxide, water, glucose and other oxygen, carbon dioxide, water, glucose and other materials into and out of the blood.materials into and out of the blood.

Blood VesselsBlood Vessels Red blood cells must go through single fileRed blood cells must go through single file So numerous that So numerous that everyevery cell in the body is cell in the body is

near a capillary!near a capillary! So delicate that it will rupture under a So delicate that it will rupture under a

tension 1/3,000 that required to tear toilet tension 1/3,000 that required to tear toilet tissue!tissue!

Veins Veins Carry blood toward the heartCarry blood toward the heart Have thinner, less muscular Have thinner, less muscular

walls because blood in veins walls because blood in veins is under much lower is under much lower pressurepressure

Have valves that prevent Have valves that prevent blood from flowing backwardblood from flowing backward

Movement of body helps Movement of body helps push blood through veinspush blood through veins

Sometimes sitting or Sometimes sitting or standing still for long standing still for long periods can cause blood periods can cause blood to pool in leg veins, so to pool in leg veins, so not enough blood not enough blood available to brain, and available to brain, and the person faints.the person faints.

Major veins are the Major veins are the vena cava (upper vena cava (upper and lower)and lower)

Blood VesselsBlood Vessels

Remember:Remember: Arteries carry blood away from the heartArteries carry blood away from the heart Veins take it toward the heartVeins take it toward the heart It has It has nothingnothing to do with whether the blood to do with whether the blood

is oxygenated or not!is oxygenated or not!

HeartHeart

The heartThe heart VersesVerses Can you believe…?Can you believe…?

Heart beats an average of 70 times per Heart beats an average of 70 times per minute, 100,000 times per day, or 2.5 billion minute, 100,000 times per day, or 2.5 billion times in an average lifespantimes in an average lifespan

Heart pumps 2,000 gallons of blood per day Heart pumps 2,000 gallons of blood per day or 60 million gallons in an average lifespanor 60 million gallons in an average lifespan

HeartHeart Heart is a 4-Heart is a 4-

chambered muscular chambered muscular pump that provides pump that provides energy to move blood energy to move blood throughout the body.throughout the body.

Designed to prevent Designed to prevent mixing of oxygenated mixing of oxygenated and deoxygenated and deoxygenated bloodblood

Right side handles Right side handles deoxygenated blooddeoxygenated blood

Left side pumps Left side pumps oxygenated bloodoxygenated blood

Designed to ensure Designed to ensure one-way flow of bloodone-way flow of blood

HeartHeart AnatomyAnatomy

4 chambers4 chambers 2 2 atriaatria –thin walled –thin walled

chambers that collect chambers that collect blood from veins and blood from veins and empty it into the empty it into the ventriclesventricles

2 2 ventricles ventricles – larger, – larger, thick-walled chambers thick-walled chambers that contract, pumping that contract, pumping blood out into arteriesblood out into arteries

Left ventricle is the Left ventricle is the largest because it is largest because it is working under working under highest pressurehighest pressure

HeartHeart 4 valves – prevent blood from flowing 4 valves – prevent blood from flowing

backward in the heartbackward in the heart AV (atrioventricular) valves between atria and AV (atrioventricular) valves between atria and

ventriclesventricles Semilunar valves between ventricles and arteriesSemilunar valves between ventricles and arteries

HeartHeart

Blood vesselsBlood vessels VeinsVeins

Vena cava collect blood Vena cava collect blood from the bodyfrom the body

Pulmonary vein brings Pulmonary vein brings blood from the lungs to blood from the lungs to the heart (note this vein the heart (note this vein carries oxygenated carries oxygenated blood)blood)

ArteriesArteries Pulmonary takes blood Pulmonary takes blood

from heart to lungsfrom heart to lungs Aorta takes blood from Aorta takes blood from

left ventricle to the bodyleft ventricle to the body

HeartHeart

HeartHeart

Cardiac cycleCardiac cycle Blood enters right atriumBlood enters right atrium from vena cava from vena cava As atrium fillsAs atrium fills, AV valve opens and , AV valve opens and right right

ventricle begins to fillventricle begins to fill Atrium contracts, filling the ventricleAtrium contracts, filling the ventricle Ventricle contractsVentricle contracts, AV valve closes, , AV valve closes,

semilunar valve opens, semilunar valve opens, blood moves into blood moves into pulmonary arterypulmonary artery, then to the lungs, then to the lungs

HeartHeart Blood enters capillaries in lungsBlood enters capillaries in lungs, where it , where it

picks up oxygen, releases carbon dioxidepicks up oxygen, releases carbon dioxide Oxygenated blood flows into pulmonary Oxygenated blood flows into pulmonary

vein, then enters left atriumvein, then enters left atrium AV valve opens and AV valve opens and left ventricle begins to left ventricle begins to

fillfill Atrium contracts, filling the ventricleAtrium contracts, filling the ventricle Ventricle contractsVentricle contracts, AV valve closes, , AV valve closes,

semilunar valve opens, semilunar valve opens, blood moves into blood moves into aortaaorta and is distributed to the body. and is distributed to the body.

Cardiac CycleCardiac Cycle

Heart muscle itself gets its blood supply Heart muscle itself gets its blood supply from the coronary arteries (which from the coronary arteries (which branch off the aorta), not the blood branch off the aorta), not the blood flowing through it.flowing through it.

Cardiac CycleCardiac Cycle

Animation Animation http://www.guidant.com/condition/hehttp://www.guidant.com/condition/heart/interact_5.htmlart/interact_5.html

BloodBlood Blood is the fluid that transports Blood is the fluid that transports

substances around the body. substances around the body. Its job is to “nourish and cleanse each living Its job is to “nourish and cleanse each living

cell.” cell.” ((In His ImageIn His Image, Brand and Yancey, p.59), Brand and Yancey, p.59)

Consists of cells suspended in plasma (liquid)Consists of cells suspended in plasma (liquid)

BloodBlood CellsCells

Red blood cells Red blood cells (erythrocytes)(erythrocytes)

Round cells that carry Round cells that carry oxygen oxygen

Contain Contain hemoglobinhemoglobin, an , an iron-containing iron-containing protein that binds protein that binds oxygen very strongly oxygen very strongly in lungs, then in lungs, then releases it in oxygen-releases it in oxygen-poor environment of poor environment of the capillariesthe capillaries

BloodBlood

Don’t have a Don’t have a nucleusnucleus

Live about 120 daysLive about 120 days Made in the bone Made in the bone

marrowmarrow We make about 2 We make about 2

million new RBC per million new RBC per secondsecond

Normally have Normally have about 5 million RBC about 5 million RBC in speck of blood in speck of blood the size of a letter the size of a letter “o”“o”

BloodBlood White blood cells White blood cells

(leukocytes)(leukocytes) Several different Several different

types, all part of types, all part of immune systemimmune system

Defend the body Defend the body against disease against disease (bacteria, viruses (bacteria, viruses fungi worms), fungi worms), toxins and cancertoxins and cancer

Many act by Many act by surrounding surrounding and engulfing and engulfing invaders invaders

BloodBlood When infection present in the body, WBC count When infection present in the body, WBC count

increases to combat it. Doctors measure WBC increases to combat it. Doctors measure WBC levels to determine presence and extent of levels to determine presence and extent of infections. infections.

More Than Meets the EyeMore Than Meets the Eye

BloodBlood

Platelets – small Platelets – small fragments of WBC that fragments of WBC that help form blood clots help form blood clots when a blood vessel is when a blood vessel is damaged.damaged.

Platelets stick to Platelets stick to wound site, attract wound site, attract more plateletsmore platelets

BloodBlood Clotting proteins Clotting proteins

circulating in blood circulating in blood become activatedbecome activated

Fibrin becomes Fibrin becomes activated by clotting activated by clotting factors, forms a factors, forms a network of threads network of threads (like a spiderweb) (like a spiderweb) that traps more that traps more platelets and RBC to platelets and RBC to form a clot form a clot

BloodBlood Plasma – watery Plasma – watery

fluid containing fluid containing cells and dissolved cells and dissolved molecules like molecules like proteins, oxygen, proteins, oxygen, carbon dioxide, carbon dioxide, nutrients (glucose, nutrients (glucose, amino acids and amino acids and fats), waste fats), waste products (like urea) products (like urea) and hormonesand hormones

End of Chapter 7End of Chapter 7

Circulatory SystemCirculatory System

Introduction (slide 2 for me)Introduction (slide 2 for me) Talked about how cells move substances Talked about how cells move substances

across cell membranes across cell membranes How?How?

Respiratory system brings oxygen into Respiratory system brings oxygen into the body, gets rid of carbon dioxidethe body, gets rid of carbon dioxide

Excretory system removes wastes from Excretory system removes wastes from cellscells

Circulatory SystemCirculatory System Goals for this unit: (Slide 4 for me)Goals for this unit: (Slide 4 for me)

Know what the circulatory system is.Know what the circulatory system is. Know the components of the systemKnow the components of the system

What the circulatory system does.What the circulatory system does. How each of the components contributes to How each of the components contributes to

the overall function of the whole.the overall function of the whole. What are some of illnesses that result What are some of illnesses that result

from problems in the circulatory from problems in the circulatory system? (You will get this from the system? (You will get this from the written assignment you’re doing.)written assignment you’re doing.)

Cardiac CycleCardiac Cycle

  

Patients requiring blood almost never receive transfusions of whole blood. Instead, a Patients requiring blood almost never receive transfusions of whole blood. Instead, a patient typically receives only the components necessary to treat their clinical patient typically receives only the components necessary to treat their clinical condition. Therefore, whole blood donations must be processed to separate out each condition. Therefore, whole blood donations must be processed to separate out each component. Each component plays a different role in the health and survival of a component. Each component plays a different role in the health and survival of a patient. patient. Red blood cells Red blood cells comprise 40-50% of blood volume. They carry oxygen to comprise 40-50% of blood volume. They carry oxygen to vital organs and are required by surgical patients who lose blood during surgery or by vital organs and are required by surgical patients who lose blood during surgery or by trauma victims who have lost blood as a result of an accident or injury. Red blood trauma victims who have lost blood as a result of an accident or injury. Red blood cells that have been donated can be stored in a refrigerator for up to 42 days. If they cells that have been donated can be stored in a refrigerator for up to 42 days. If they are not used within six weeks, they must be thrown away. They can also be stored are not used within six weeks, they must be thrown away. They can also be stored frozen for up to 10 years. Red cells are the most commonly transfused blood frozen for up to 10 years. Red cells are the most commonly transfused blood component and most whole blood collections are done with the specific intent of component and most whole blood collections are done with the specific intent of capturing the red cell component. Red Blood Cells carry oxygen to organs.     capturing the red cell component. Red Blood Cells carry oxygen to organs.       PlateletsPlatelets account for a small percentage of whole blood volume. They are used account for a small percentage of whole blood volume. They are used therapeutically to control bleeding and are often transfused in multiple doses to therapeutically to control bleeding and are often transfused in multiple doses to cancer patients undergoing chemotherapy. Platelets must be stored at room cancer patients undergoing chemotherapy. Platelets must be stored at room temperature to retain their visibility. Therefore, they have only a five day shelf life temperature to retain their visibility. Therefore, they have only a five day shelf life before they must be discarded due to possible growth of bacteria. Platelets aid in before they must be discarded due to possible growth of bacteria. Platelets aid in clotting.      clotting.      Plasma: Plasma: The remainder of blood volume is plasma, a watery substance The remainder of blood volume is plasma, a watery substance in which proteins that trigger blood clotting mechanisms are suspended. Plasma can in which proteins that trigger blood clotting mechanisms are suspended. Plasma can be transfused directly to a patient, but, more often, plasma is used as a raw material be transfused directly to a patient, but, more often, plasma is used as a raw material for pharmaceuticals. Plasma is “fractionated” into its different protein components, for pharmaceuticals. Plasma is “fractionated” into its different protein components, which are then manufactured into pharmaceuticals. Factor VIII, which is required by which are then manufactured into pharmaceuticals. Factor VIII, which is required by hemophiliacs to control bleeding, is one such plasma derived medicine. Plasma can hemophiliacs to control bleeding, is one such plasma derived medicine. Plasma can be stored frozen for up to one year. Plasma: the fluid portion of blood.be stored frozen for up to one year. Plasma: the fluid portion of blood.

BloodBlood IllnessesIllnesses

Anemia – too few RBC, can’t carry enough Anemia – too few RBC, can’t carry enough oxygen. Person gets very tired, prone to oxygen. Person gets very tired, prone to infections. Treat with iron for less severe infections. Treat with iron for less severe cases or blood transfusion for severe cases. cases or blood transfusion for severe cases. Females especially prone to this.Females especially prone to this.

Sickle cell anemiaSickle cell anemia

Hemophilia – inadequate clottingHemophilia – inadequate clotting

Mutations in clotting proteins cause profuse Mutations in clotting proteins cause profuse bleeding from even minor wounds.bleeding from even minor wounds.

Treat by giving clotting factor. Used to be Treat by giving clotting factor. Used to be obtained from blood donors, so many patients obtained from blood donors, so many patients contracted HIV and hepatitis. Now use factors contracted HIV and hepatitis. Now use factors produced by bacteria. (Insert human gene into produced by bacteria. (Insert human gene into bacteria and have them mass produce the bacteria and have them mass produce the correct protein.) correct protein.)

BloodBlood Clotting disordersClotting disorders

Clots can form in blood vessels due to internal Clots can form in blood vessels due to internal damage (fatty plaques, for example). If clot damage (fatty plaques, for example). If clot obstructs vessels to heart heart attack. obstructs vessels to heart heart attack. Obstruct vessels to brain stroke. Both are Obstruct vessels to brain stroke. Both are debilitating and can be fatal. debilitating and can be fatal.