The Cardiovascular System

Q - How many liters of blood does the adult human body contain?

A.5 litersB.10 litersC.15 liters

A – A. 5 liters5.3 quarts7-8% of a person’s body

weight

Q - How long does a red blood cell survive in the bloodstream?

A. 120 daysB. 1 yearC. Forever

A – A. 120 daysAs red blood cells age, they

are removed by microphages in the liver and spleen

Q – What is hemoglobin?A. A chemical that stimulates the

production of blood cellsB. A molecule specially designed to hold

waste products and remove them from the body

C. A molecule specially designed to hold oxygen and carry it to cells that need it

A – C. A molecule specially designed to hold oxygen and carry it to cells that need itHemoglobin is a protein that carries the

oxygen throughout the body

Q – What is a hematocrit?A. The measure of red blood cells in

the blood.B. A hormone that stimulates

production of blood cells.C. The nucleus of a red blood cell.

A – A. The measure of red blood cells in the blood. The ratio of cells in normal blood is

600 red blood cells for each white blood cell and 40 platelets.

Q – How does blood get its red color?A. From proteins located in the bone

marrow. B. From the waste products in the blood.C. From the iron in hemoglobin.

A – C. From the iron in hemoglobin.Each molecule of hemoglobin contains

four iron atoms, and each iron atom can bind with one molecule of oxygen.

Q – What is the function of white blood cells?A. To carry oxygen from the lungs.B. To fight infection.C. To create clots.

A – B. To fight infectionWhite blood cells help fight infection

in the body.

Q – What does it mean when there’s an increase of white blood cells in the body?A. There’s an infection somewhere in the

body.B. Your body just finished fighting an

infection.C. There’s no oxygen in the blood.

A – A. There’s an infection somewhere in the body.A normal adult body has 4,000 to

10,000 white blood cells per microliter of blood

Q – What substance makes up the majority of plasma?A. ProteinsB. WaterC. Electrolytes

A – B. WaterPlasma is 90% waterThe other 10% dissolved into plasma are

materials such as proteins, electrolytes, carbohydrates, cholesterol, hormones, and vitamins.

Q - If you are a universal donor, what blood type do you have?

A. Type AB. Type ABC. Type O

A – C. Type OPeople with Type O blood are universal donors,

because anyone can get a type O blood transfusionSomeone with Type AB blood is a universal

recipient because this blood has no antibodies that could react with donated blood

More than a third of the US population has Type O+

Q – How does blood enter the heart?A. Pulmonary arteryB. Superior vena cava & inferior vena

cavaC. Mitral valve

A – B. Superior vena cava and inferior vena cavaNo blood gets into the heart

without passing through the superior vena cava and the inferior vena cava first.

Q – How many gallons of blood does the heart pump in a day?

A. 20 gallonsB. 200 gallonsC. 2,000 gallons

A – C. 2,000 gallons2,000 gallons = 7,571 liters

Q – How many times does your heart beat each day?

A. 1,000 timesB. 10,000 timesC. 100,000 times

A – C. 100,000 timesThe heart beats 100,000 times daily

to supply every cell in the body with freshly oxygenated blood

The Cardiovascular SystemThe Cardiovascular SystemMajor functions of this system:

delivers oxygen

removes carbon dioxide & other waste products

Simply the job of the cardiovascular system is transportation.

Roughly the size of a clenched fist.

Hollow and cone–shaped

Weighs less then one pound

Beats about 100,000 times in ONE day and about 35 million times in a year.

Heart Anatomy

Heart Anatomy

Where is the heart located?

•Superior surface of diaphragm

•Enclosed within the mediastinum

•Flanked on either side by the lungs

•Anterior to the vertebral column, posterior to the sternum

Orientation of the Heart

Apex – Bottom pointed part of heart. Points toward the left hip and rests on the diaphragm. Around the 5th intercostal space

*Maximal impulse, where heart sounds are loudest

Base – Posterosuperior aspect of the heart. Points toward the right shoulder and lies beneath the second rib.

Heart wall

The heart walls are composed of three layers:

1.Epicardium – Covers the outer surface of the heart (squamous epithelial cells)

2. Myocardium – Forms most of the heart wall, this is the layer that contracts

3. Endocardium – Heart’s inner layer; bundles of smooth muscle

Chambers of the heart- The heart has four hollow chambers.

- Two atria (singular: atrium); pump blood into the ventricles

-Two ventricles ; serve as the pumping chambers of the heart

Heart valvesThe heart is equipped with four valves. The valves allow forward

flow of blood through the heart and prevent backward flow

from the atria through the ventricles out the great arteries leaving the heart.

Aortic Valve

Tricuspid Valve

Bicuspid (mitral) Valve

Pulmonary Valve

Bicuspid and Tricuspid Valves (AV valves)Bicuspid or Mitral valve (left AV valve)

- Consists of two flaps

Tricuspid Valve

-Is the right AV valve

-Has three flaps

Semilunar valvesBetween the ventricle & an artery

1. Pulmonic2. Aortic

http://video.about.com/heartdisease/How-the-Valves-Work.htm

Each set of valves operates at a different time.

1. The AV valves are open during heart relaxation and closed when the ventricles are contracting.

2. The semilunar valves are closed during heart relaxation and are forced open when the ventricles contract.

Posterior View

Heart Valves and Heart Sounds

• Placement of a stethoscope varies depending on which heart sounds and valves are of interest.

• Closure of the AV valves create the 1st heart sound (‘lub’).

• Closure of the semilunar valves create the 2nd heart sound (‘dub’).

Blood Vessels (Tubes)

The three major types of vessels are arteries,capillaries, and veins:

1. Arteries carry blood away from the heart 2. Veins carry blood toward the heart

**longest veins in the body are the great saphenous veins (leg and thigh)

3. Capillaries are the smallest blood vessels. They carry blood to and from all the small places in the body.

** Arterioles and venules are also vessels

http://www.mayoclinic.com/health/circulatory-system/MM00636

Circulatory System Blood flows through a network of blood vessels that extend

between the heart and peripheral tissues The vascular system has 2 distinct circulations:1. Pulmonary circulation – short loop that runs from the heart

to the lungs and back to the heart.2. Systemic circulation – routes blood through a long loop to

all parts of the body and returns to the heart. Each circuit begins and ends at the heart, and blood travels

through these circuits in sequence Blood returning to the heart from the systemic circuit must

complete the pulmonary circuit before reentering the systemic circuit

Pulmonary circuit - from heart

to lungs

back to heart

Systemic circuit- from heart

to body

back to heart

Systemic and Pulmonary Circulations

http://www.mayoclinic.com/health/circulatory-system/MM00636

Circulation – Roles of atria and ventriclesThe right atrium receives blood from the systemic circuit

and passes it to the right ventricle.The right ventricle then pumps blood into the pulmonary

circuit.The left atrium collects blood from the pulmonary circuit

and empties it into the left ventricle.The left ventricle then pumps blood into the systemic circuit.When the heart beats, first the atria contract, and then the

ventricles contract.The two ventricles contract at the same time and eject equal

volumes of blood into the pulmonary and systemic circuits.

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101-5 Pulmonary Circuit

6-10 Systemic Circuit

Circulation CycleVena cavaRight atriumRight ventriclePulmonary arteriesLungsPulmonary veinsLeft atriumLeft ventricleAortaBody