Ch 13 The Circulatory System

The main function of the circulatory system

Transports oxygen and nutrients to cells; removes carbon dioxide and waste products from cells.

The four main parts of the circulatory system

The heart, blood vessels, the blood, and the lymphatic system.

Pericardium

The fluid-filled membrane or sac that surrounds and protects the heart.

Systole

The contraction phase of the heart cycle.

Diastole

The relaxation phase of the heart cycle.

Coronary arteries and veins

Surface vessels responsible for supplying blood directly to and from the heart muscle.

The four internal chambers of the heart

Right atrium, left atrium, right ventricle, and left ventricle.

Atrioventricular (AV) valves

The bicuspid (mitral) and tricuspid valves, located between the atria and the ventricles.

Semilunar valves

The pulmonic and aortic valves, located between the ventricles and the major exiting blood vessels.

"Lub-dub" heart sounds

Sounds caused by the sequential closing of the heart valves.

• Lub = closing of the bicuspid and tricuspid valves

• Dub = closing of the semilunar valves

Pulmonary circulation pathway

Right atrium -> Tricuspid valve -> Right ventricle -> Pulmonic valve -> Pulmonary artery -> Lungs -> Pulmonary vein -> Left atrium.

Systemic circulation pathway

Left atrium -> Mitral/Bicuspid valve -> Left ventricle -> Aortic valve -> Aorta -> Body tissues.

Oxygen status of the pulmonary artery

Carries deoxygenated blood from the right ventricle to the lungs.

Oxygen status of the pulmonary vein

Carries oxygenated blood from the lungs back to the left atrium.

Portal circulation

A specialized circulatory pathway that serves only the internal organs, carrying substances on which those organs react.

Microcirculation flow pattern

Arteries -> Arterioles -> Capillaries -> Venules -> Veins.

Sinoatrial (SA) node

The natural pacemaker of the heart, located in the right atrium, which initiates the electrical impulse.

Atrioventricular (AV) node

The node that receives the electrical impulse from the SA node and transmits it to cause ventricular contraction.

Cardiac rhythm disorders

Conditions involving an interruption in the electrical impulse or a deviation in the regularity of the heartbeat.

Artificial pacemaker

A device used to cause the heart to contract effectively when drug therapy fails to correct rhythm disorders.

Vagus and accelerator nerves

The two primary nerves responsible for controlling the rate of the heart.

Three types of blood vessels

Arteries, veins, and capillaries.

Main systemic arteries

Aorta, gastric, splenic, renal, carotid, pulmonary, brachial, radial, ulnar, femoral, tibial, and dorsalis pedis.

Main systemic veins

Tibial, saphenous, femoral, common iliac, inferior and superior vena cava, jugular, brachial, cephalic, and pulmonary.

Superior vena cava

The major vein returning deoxygenated blood to the heart from the head and upper extremities.

Inferior vena cava

The major vein returning deoxygenated blood to the heart from the lower extremities and abdomen.

Components of blood

Plasma, red blood cells (erythrocytes), white blood cells (leukocytes), and platelets (thrombocytes).

Four main blood types

A, B, AB, and O.

Average adult blood volume

Between 8 to 10 pints.

Type and crossmatch

The mandatory testing process performed before a blood transfusion to ensure compatibility between donor and recipient.

Rh factor

An inherited antigen on red blood cells; its presence makes a person Rh-positive, and its absence makes them Rh-negative.

Cholesterol

A product of fat metabolism; total, LDL, and HDL levels are evaluated to assess the risk of a vascular event.

Triglycerides

Fats normally present in the body; high levels are clinically associated with heart disease and atherosclerosis.

Cardiovascular diagnostic tests

Arteriography, cardiac catheterization, stress testing, Doppler ultrasound, echocardiogram, ECG, heart scan, MUGA scan, stress Cardiolite, TEE, venogram, and carotid ultrasound.

Congestive Heart Failure (CHF)

A condition that impacts multiple body systems, specifically the circulatory, respiratory, integumentary, and digestive systems.

Leukemia

A cancer of the blood-forming tissues that involves the circulatory, integumentary, immune, and skeletal systems.

Arteriosclerosis vs. Atherosclerosis

Arteriosclerosis is the general hardening of the arteries; atherosclerosis is the specific buildup of fatty plaque deposits.

Carditis types

Pericarditis (outer sac inflammation), myocarditis (muscle inflammation), and endocarditis (inner lining inflammation).

Anemia

Lack of red blood cells and/or hemoglobin

Aneurysm

A bulging arterial wall that may produce palpitations or tear

Angina

Severe chest pain from a coronary artery spasm

Cardiac arrest

Complete and sudden cessation of heart action

Arrhythmia

Irregular heart rhythm

Arteriosclerosis

Rigid arterial walls; causes hypertension

Atherosclerosis

Fatty deposits on the lining of blood vessels

Athletic heart syndrome

Pounding heartbeats after exercise, enlarged heart, slow pulse

CVA

Confusion, weakness of one side, visual changes, paralysis, personality change

CHF

Congestion of blood in the circulatory system; edema of extremities and lungs

Coronary artery disease

Tightness of chest, substernal chest pain radiating down left arm, nausea and vomiting, perspiration, fainting

Embolus

A circulating foreign substance in a blood vessel

Endocarditis

Vegetative growths or inflammation of inner heart structures

Hypertension

Blood pressure consistently above normal

Hypotension

Consistently low blood pressure

Leukemia

Excessive WBCs, bruising, fatigue, painful lymph nodes

Murmur

A gurgling or swishing sound heard upon auscultation of the heart

MI

Severe, crushing pain radiating through chest to neck and jaw and down left arm; nausea, dyspnea

Myocarditis

Mild chest soreness, fever, dyspnea, palpitations, feeling of pressure

Pericarditis

Sharp, sudden pain at sternum radiating to back of shoulders and arms; decreases when erect or leaning forward

Phlebitis

Localized inflammation of a vein

Sickle cell anemia

Abnormally shaped red blood cells, enlarged liver, pallor, painful crisis periods

Stasis ulcer

Skin breakdown from inadequate circulation

Thrombophlebitis

Inflamed vein lining with thrombus formation, severe pain, fever, chills, and discoloration of involved extremity

Varicosities

Dilated, twisted veins, inefficient valves, leg cramps

Four major parts of the circulatory system

Heart; Blood vessels; Blood; Lymphatic system

Difference between pulmonary and systemic circulation

Pulmonary circulation flows blood from the right ventricle through the right pulmonary artery to the lungs and back to the left atrium. Systemic circulation flows blood from the left ventricle through the rest of the body to the right atrium.

Where the "Lub" heart sound is auscultated

Apex of the heart

Where the "Dub" heart sound is auscultated

Second intercostal space on each side of the sternum

Location and action of the natural pacemaker (SA node)

Located in the right atrium. It initiates the heartbeat; causing both atria to contract and sending impulses to the AV node; bundle of His; and Purkinje fibers to contract the ventricles.

Heart block

Occurs when the impulse from the SA node does not carry over to the AV node. Atria beat at a normal rate while ventricles contract slowly at about 40 beats per minute.

Fibrillation

A life-threatening condition caused by a breakdown of rhythm and contraction strength due to pacemaker malfunction; resulting in an uncoordinated and ineffective heartbeat.

Basic cause of arrhythmia

An area of the heart (known as an ectopic pacemaker) "sparks" and stimulates an abnormal contraction of the myocardium.

Purpose and function of an artificial pacemaker

It generates an electrical impulse through an electrode catheter connected to a battery-powered pulse generator to cause a contraction when the SA node fails.

Pathway of blood through the body (tracing)

Superior/inferior vena cava -> right atrium -> tricuspid valve -> right ventricle -> semilunar valve -> pulmonary arteries -> lung arterioles/capillaries -> venules -> pulmonary veins -> left atrium -> bicuspid valve -> left ventricle -> semilunar valve -> aorta -> body arterioles/capillaries -> venules/veins -> back to vena cava.

Source and destination of portal circulation

Comes from single organs (stomach; pancreas; large/small intestines; spleen) and goes to the liver to be processed by liver cells.

Five things transported by blood through the body

Oxygen; Nutrients; Cell waste; Hormones; Minerals

What is plasma?

A straw-colored liquid that makes up over half the volume of blood.

What are some things that can be found circulating in plasma? (List 1-6)

Water, Calcium, Sodium, Potassium, Phosphorus, Bicarbonates.

What are some things that can be found circulating in plasma? (List 7-12)

Amino acids, Vitamins, Hormones, Enzymes, Glucose, Fatty acids.

What are some things that can be found circulating in plasma? (List 13-17)

Oxygen, Carbon dioxide, Fibrinogen, Serum albumin, Serum globulin.

What is the function of red blood cells?

They have hemoglobin, which carries oxygen to cells.

What is the function of white blood cells?

They destroy bacteria within tissue fluid, consume toxic substances, and provide immunity.

What is the function of platelets?

To clot blood.

Why is blood typed and crossmatched before being given to a patient?

To ensure compatibility. Agglutinin and agglutinogens must be different to prevent agglutination (clotting) and possible death.

Why is the Rh factor important in a transfusion?

If an Rh-negative person receives Rh-positive blood, their body produces antibodies. A second exposure will cause serious, reactive complications.

Why is the Rh factor important in pregnancy?

An Rh-negative mother with an Rh-positive baby may develop antibodies. In subsequent pregnancies, these antibodies can destroy the baby's RBCs, causing profound anemia.

What is the purpose of an Arteriograph?

Injecting dye to indicate the status of blood flow, malformed vessels, aneurysm, or hemorrhage.

What is the purpose of Cardiac catheterization?

To visualize by fluoroscope the internal heart structure and activity and to visualize the coronary arteries.

What is the purpose of Doppler ultrasonography?

To evaluate major blood vessels to determine deep vein thrombosis, peripheral aneurysms, and occluded carotid arteries.

What is the purpose of an Echocardiograph?

To evaluate cardiac function and structure, and to detect defects by means of sound waves.

What is the purpose of an Electrocardiogram (ECG/EKG)?

To identify heart rhythm, electrolyte imbalance, and conduction.

What is the purpose of a Holter monitor?

To detect irregularly occurring symptoms or evaluate the status of a recovering cardiac patient.

What is the purpose of a Venogram?

Detects the condition of deep veins of the legs, especially deep vein thrombosis.

What is the purpose of a MUGA scan?

To determine the condition of the myocardium.

Arteries

Structure: Have elastic fibers in their walls to expand and recoil to produce a pulse. Function: Carry oxygenated blood away from the heart.

Arterioles

Structure: Same as arteries, only smaller. Function: Carry blood from artery to capillary.

Capillaries

Structure: One-cell-thick walls, microscopic blood vessels. Function: Exchange of oxygen and carbon dioxide with the cells; permit WBCs to leave to attack bacteria and allow plasma to leave to add to the tissue fluid.

Venules

Structure: Small veins. Function: Carry blood from capillary to vein.

Veins

Structure: Have thinner walls than arteries and lack an elastic layer; have valves to assist the return flow of blood. Function: Carry deoxygenated blood back to the heart.

What does a peak flow meter measure? How do you record it?

peak expiratory flow (PEF), or how quickly a patient can force air out of their lungs in L/min

• common to monitor asthma

• helps to identify worsening airway obstruction before symptoms cecome severe

How to Perform a Peak Flow Measurement

Correct technique is essential for obtaining a useful peak flow value. Because the test is highly effort dependent, the respiratory therapist or clinician must explain and demonstrate the maneuver clearly.

The basic steps include:

1. Set the peak flow meter to zero.

2. Have the patient sit or stand upright.

3. Instruct the patient to take the deepest breath possible.

4. Have the patient place the mouthpiece in the mouth with the tongue out of the way.

5. Make sure the lips form a tight seal around the mouthpiece.

6. Instruct the patient to blow out as hard and fast as possible.

7. Record the value.

8. Repeat the maneuver until three acceptable efforts are obtained.

9. Record the highest value.

The patient does not need to exhale completely for several seconds. Peak flow focuses on the fastest burst of air at the beginning of expiration, not the total amount of air exhaled.

What does a pulse oximeter measure? How do you record it?

arterial oxygen saturation (SpO2) and pulse rate (PR)

• normal is 95% or higher