04.01H BLOOD VESSELS AND ELECTROCARDIOGRAMS

Mrs. Jessica Romito

SUMMARY, OBJECTIVES, AND STANDARDS

Review module

• 04.01H Blood Vessels and Electrocardiograms
• Compare contrast three major blood vessels
• Learn how to read an electrocardiogram

Review assessment

• 04.01H assignment submission

By the end of this class you will

2. Be able to identify the layers of blood vessels; be able to contrast their structures and functions
3. Understand how an electrocardiogram matches up to the heartbeat function
4. Complete the worksheets from pages 4 and 5
5. Successfully complete assessment submission for 04.01H

STANDARDS�HE.912.C.1.7: Analyze how heredity and family history can impact personal health.�LAFS.1112.RST.1.1: Cite specific textual evidence to support analysis of science and technical texts, attending to important distinctions the author makes and to any gaps or inconsistencies in the account. �LAFS.1112.RST.1.2: Determine the central ideas or conclusions of a text; summarize complex concepts, processes, or information presented in a text by paraphrasing them in simpler but still accurate terms. �SC.912.L.14.34: Describe the composition and physiology of blood, including that of the plasma and the formed elements. �LAFS.1112.RST.3.8: Evaluate the hypotheses, data, analysis, and conclusions in a science or technical text, verifying the data when possible and corroborating or challenging conclusions with other sources of information. LAFS.1112.RST.3.9: Synthesize information from a range of sources (e.g., texts, experiments, simulations) into a coherent understanding of a process, phenomenon, or concept, resolving conflicting information when possible.

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THREE MAIN TYPES OF BLOOD VESSELS

Arteries 🡪 arterioles 🡪 capillaries 🡪 venules 🡪 veins

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Oxygenated blood from the heart to the body tissues in the arteries

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De-oxygenated blood from the body tissues to the heart in the veins

BLOOD VESSELS COMPOSITION

BOTH

The tunica intima is an inner layer of blood vessels. It contains endothelial cells and elastin. The capillaries only contain the endothelial cells of the tunica intima. This allows for rapid exchange of materials.

VEINS

Valves are found within this layer of veins only to prevent blood from flowing backwards

BOTH

Elastin is composed of elastic fibers that allow for artery and vein flexibility.

ARTERIES

Arteries have a larger amount of elastin to withstand the high pressure of blood flow when the heart pumps. Arterioles have less elastin than larger arteries in order to maintain the size of their opening during the slight rise and fall of blood pressure from the pumping of the heart.

BOTH

The tunica media is the middle layer of blood vessels. It is made of smooth muscle responsible for the dilation and constriction of blood vessels to control blood flow.

BOTH

Tunica Externa or Tunica Adventitia is the outermost layer of blood vessels. It is made of connective tissue that provides structural support.

BLOOD VESSEL COMPOSITION -- MICROGRAPHS

ARTERY

VEIN

Artery and Vein 1X

A cross section of a human artery and vein.

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BLOOD VESSEL COMPOSITION -- MICROGRAPHS

Artery and Vein 4X

A magnified cross section of a human artery and vein.

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BLOOD VESSEL COMPOSITION -- MICROGRAPHS

Connective Tissue 10X

A magnified cross section showing the connective tissue found between an artery and vein.

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BLOOD VESSEL COMPOSITION -- MICROGRAPHS

Artery 10X

A magnified cross section showing the connective tissue (outer layer), smooth muscle, and endothelial cells (elastic fiber inner layer) that form the tunics of an artery.

BLOOD VESSEL COMPOSITION -- MICROGRAPHS

Artery 20X

A magnified cross section showing the tunics of a human artery.

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BLOOD VESSEL COMPOSITION -- MICROGRAPHS

Artery 40X

A magnified cross section showing the epithelium lining the inner wall of an artery. This type of epithelium is a single layer of flat cells and is classified as simple squamous epithelium.

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BLOOD VESSEL COMPOSITION -- MICROGRAPHS

Vein 40X

A magnified cross section showing the thinner walls of a vein and cells that line the inside of the vessel.

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THE STRUCTURE OF BLOOD VESSELS

Arteries and veins have the same basic structure with a few notable differences:

1. Arteries have more smooth muscle tissue than veins
2. Arteries appear more round in a cross section than veins
3. Veins have valves which are absent in arteries

Capillaries differ in structure from arteries and veins:

1. They are only one cell thick
2. The walls are composed of a single layer of cells
3. They lack smooth muscle and connective tissue layers

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HOW DOES THE STRUCTURE OF A BLOOD VESSEL AFFECT ITS FUNCTION?

BLOOD VESSELS WORKSHEET from page 5

ELECTROCARDIOGRAMS

SA node: involuntary electrical signal for the atria to contract—60-100 signals per minute

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Sends an action potential

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AV node receives the signal and contracts the ventricles

ELECTROCARDIOGRAMS

• Electrocardiograms (ECGs) record the electrical impulses (action potentials) that move through the heart and cause muscle contractions.
• By placing electrodes on the arms, legs, and the chest wall of a patient, in varying positions, an ECG technician can get a "picture" of the electrical activity of the heart, often referred to as a heart rhythm.

This image shows a P wave, a QRS wave, and a T wave. The P wave is a small oscillation on the graph that happens before the sharp spike of the QRS wave. The T wave is a small oscillation that happens after the QRS wave. (The U wave is the repolarization period.)

ELECTROCARDIOGRAMS

• In an electrocardiogram, each cardiac cycle produces three distinct waves.
• The first wave is the P wave, and it occurs when the top two chambers of the heart, called the atria, depolarize.

ELECTROCARDIOGRAMS

• Recall that
• depolarization creates action potentials,
• which are the electrical impulses that induce muscle contraction.
• Therefore, during the P wave, the atria are contracting, pushing blood into the bottom ventricles of the heart.

ELECTROCARDIOGRAMS

ELECTROCARDIOGRAMS

• The QRS wave represents the depolarization of the bottom chambers of the heart (ventricles),
• which causes the muscles of the ventricles to contract and push blood to the lungs and body.
• The first sound of your heartbeat occurs immediately after the QRS wave,
• when the valves between the atria and ventricles close.

ELECTROCARDIOGRAMS

ELECTROCARDIOGRAMS

• During the T wave, muscles of the ventricles relax as they repolarize.
• The valves of the aorta and pulmonary artery close.
• This creates the second sound of your heartbeat.

ELECTROCARDIOGRAMS

ELECTROCARDIOGRAMS

• In an electrocardiogram, each cardiac cycle produces three distinct waves.
• The first wave is the P wave, and it occurs when the top two chambers of the heart, called the atria, depolarize.

P wave: atria contracting pushing blood into the ventricles

QRS complex: ventricles contracting pushing blood into the lungs and body; FIRST heart sound: valves between atria and ventricles close

T wave: ventricles repolarize; SECOND heart sound: valves of the aorta and pulmonary artery close

ASSIGNMENT 04.01H

• It’s a multiple choice quiz!

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Let’s go to the course to check out where it’s located!

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Contact Information

Mrs. Jessica Romito

Phone Number: +1 (301) 485-9114

(text/call/WhatsApp)

Email: jromito@laurelsprings.com

Mrs. Romito's iClassroom

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LSS Live Academic Help Room

Monday–Friday 8 am to 11 pm Eastern Time�5 am to 8 pm Pacific Time

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