Lecture 9 2/25/14

Question 1

The Heart

Answer 1

Hollow muscular organ, that pumps blood through the circulatory system.

Situated obliquely within the mediastinum and the lowest part is the left 5th lowest intercostal space within the apex.

The wider base is at the top and is the right 2nd intercostal space. 2/3 of the mass of the heart is to the left and 1/3 of the mass is to the right. Located in the front of the trachea and the esophagus.

Question 2

The Heart Produces what?

Answer 2

ANH or ANP

Atrial Natriuretic Hormone or Atrial Natriuretic Peptide

Question 3

Describe the Vessels?

Answer 3

are rigid pipes, so if we increase our fluid volume, we will see a corresponding increase in blood pressure.

Question 4

Pericardium

Answer 4

Loose Fitting Membrane, enclosing the heart

Question 5

3 Functions of the Pericardium

Answer 5

1. It serves to protect the heart.
2. It helps reduce the friction between the heart and non-moveable structure. So any structure that moves in the thoracic cavity, it has a membrane that produces serrous fluid that helps reduce friction between the two moving components.
3. Bind the heart into the proper position to prevent kinking of the great vessels. Restrict range of motion to a certain extent. Pumps and twists a little bit so the pericardium is bound along the top of the base. The base where the vessels enter and exit, they restrict too much range of motion to heart as it is contracting.

Question 6

Layers of the Heart

Answer 6

Outside of the Heart:

Parietal Pericardium

Question 7

Describe Parietal Pericardium

Answer 7

Produce it’s serrous fluid into the space called the Pericardial Cavity or Space.

Black thicker layer, on top of the Parietal Pericardium layer, is called the Fibrous CT layer. Has connective tissue in it. And for the most part it is collagen fiber.

Question 8

What makes up the Pericardial Sac?

Answer 8

made up of parietal pericardium and the fibrous connective tissue layer. So it’s outer fibrous and inner parietal pericardium.

Question 9

Pericardial Sac is bound to what?

Answer 9

Bound to the diaphragm and helps to anchor it.

Question 10

Visceral Pericardium

Answer 10

Adheres to the outside of the heart muscle tissue. Inside layer but outside the heart.

Serrous membrane that comes into contact with the heart, layer that comes into contact on the inside. Same is Epicardium.

Question 11

Why is it called the Epicardium?

Answer 11

Because the visceral pericardium is bound to the muscular layer of the heart muscle tissue. It is truly the outside layer of the heart.

Question 12

Both the layers, Visceral Pericardium and Parietal Pericardium are serrous layers that do what?

Answer 12

producing a fluid, serrous fluid, that help lubricate and reduct friction between those two layers.

Question 13

3 Layers of the Heart

Answer 13

Outer Layer Epidcardium

Middle Layer Mycardium

Inner Layer Endocardium

Question 14

Describe Epicardium

Answer 14

It is the outer layer

Question 15

Mycocardium

Answer 15

Middle Layer

The thickest layer. Muscular layer. Contains cardiac muscle, doesn’t contain skeletal muscle. Cardiac muscle and smooth muscle is different from Skeletal muscle because it is a Functional Syncytium, group of muscle fibers that contract as a unit.

Question 16

Why does Syncytium Happen?

Answer 16

Because of Intercalated Discs. The intercalated discs are gap junctions. Gap junctions conduct electrical impulse, but, they have little portals, or openings between cells, or holes that connect one cell to the next.

Question 17

Endocardium

Answer 17

Is a endothelial layer. Like the epithelium, but it doesn’t come into contact with the outside environment, if it does, it means you’re bleeding.

It is one cell layer thick and it functions to reduce friction and prevent adhesion of blood products to it’s wall.

Lines the inside the chambers of the heart.

Question 18

Explain the Blood Flow

Answer 18

From the Superior Vena Cava, the blood flows into the Right Atrium. From the Right Atrium the blood travels down to the Right Ventricle. Then from the Right Ventricle to the Pulmonary Trunk then to the Lungs.

We receive the blood from the lower part of the body, from the Superior and Inferior Vena Cava, we’ve given off the oxygen because we’re coming back from the body to the heart, so we gotta re-oxygenate the blood, so it’s gotta be sent to the lungs.

Now the blood is oxygenated, the flow goes from the lungs, to the Pulmonary Veins going back to the heart to the Left Atrium, then to the Left Ventricle. From the Left Ventricle, the blood leaves to the Aorta.

Question 19

Two Types of Valves

Answer 19

AV Valves: Atrioventricular Valves. They lie between the atria and the ventricles.

Tricuspid Valve and Bicuspid Valve

Pulmonary Semilunar Valve

Question 20

Tricuspid Valve

Answer 20

Called Tricuspid Vale because it has 3 flaps to that valve

Question 21

Pulmonary Semilunar Valve

Answer 21

Next valve going to the lungs; lung circulation

Question 22

Bicuspid Valve

Answer 22

Blood coming back from the lungs;

It has 2 flaps to that valve. Most common valve for disease, also called Mitral Valve.

Question 23

Describe the difference between Heart Murmur and Heart Arrhythmia

Answer 23

Heart Murmur is abnormal heart sound

Heart Arrhythmia is a abnormal heart beat