Notes

Pericardium – it is the membrane that surrounds and covers the heart. It has an inner and outer membrane and in-between is a fluid that reduces the friction when the heart is beating.


LECTURE NOTES
PART I. THE HEART
Heart - It is a muscle that pumps blood and keeps it circulating throughout the body.

ANATOMY (PARTS) OF THE HEART:
Pericardium – it is the membrane that surrounds and covers the heart. It has an inner and outer membrane and in-between is a fluid that reduces the friction when the heart is beating.


Figure 1. Pericardium and Pericardial fluid



Figure 2. Anatomy of the Heart


Four Chambers of the Heart
The two upper chambers are called auricles or atria (singular: atrium). Heart has left and right atrium.
Structure: Thin-muscular walls
Function: Force blood into the lower chamber which does not need high pressure.
The two lower chambers are called ventricles. The heart has left and right ventricles.
Structure: Thick-muscular walls
Function: Lower right ventricle pumps blood from the heart to the lungs.
Lower left ventricle pumps blood from the heart to the whole body.

Median septum - Muscular wall in the middle of the right and left side of the heart.
It prevents the mixing of oxygenated and deoxygenated blood.

Four Valves of the Heart (All valves control the one-way flow of the blood. They prevent backflow of blood.)
Tricuspid valve
Structure: Valve composed of three flaps between the right atrium and right ventricle.
Function: Controls the flow of the blood from the right atrium to the right ventricle.
Pulmonary Valve
Structure: Valve found between the right ventricle and the pulmonary artery
Function: Control the flow of the blood from the right ventricle to the pulmonary artery attached to each lung.
Bicuspid valve or Mitral valve
Structure: Valve composed of two flaps between the left atrium and left ventricle.
Function: Controls the flow of blood from the left atrium to the left ventricle.
Aortic Valve
Structure: Valve found between the left ventricle and the aorta
Function: Control the flow of blood from the left ventricle to the aorta.

Blood vessels associated with the heart.
Superior or Anterior vena cava
Structure: a large vein attached to the upper right atrium.
Function: Where the deoxygenated blood coming from the head, neck and arms enter the heart.
Inferior or Posterior vena cava
Structure: a large vein attached to the lower part of the right atrium.
Function: Where the deoxygenated blood coming from the lower part of the body enters the heart.
Pulmonary artery
Structure: a large artery attached to the right ventricle.
Function: Where the deoxygenated blood from the right ventricle enters the lungs
Pulmonary veins
Structure: a large vein attached to the upper part of the left atrium.
Function: Where the oxygenated blood coming from the lungs enter the heart.
Aorta
Structure: a large artery attached to the left ventricle.
Function: Where the oxygenated blood coming from the left ventricle passes through and leaves the heart to be distributed to the different parts of the body.

PART II. COORDINATED FUNCTIONS OF THE RESPIRATORY AND CIRCULATORY SYSTEM

Figure 3. Pathway of Blood

HUMAN BLOOD CIRCULATION

Two types of Circulation:
Pulmonary Circulation – Deoxygenated Blood flows from the heart, then to the lungs. Oxygenated blood flows from the lungs back to the heart again before it is pumped back into the systemic circulation.

Systemic Circulation – Blood flows around the body. Oxygenated blood leaves the heart and is distributed by the arteries to all parts of the body except the lungs. Deoxygenated blood leaves the parts of the body through the veins and goes back to the heart.

Mechanism of Blood Flow in the Heart

Figure 4. Mechanism of Blood flow

PART III. CORONARY DISEASE

Coronary is an artery that lies on the outside of the heart and carries blood to the muscle in the walls of the heart. When the artery is blocked, and blood cannot flow in it, a heart attack can happen.

Heart attack is when a blood flow in a part of the heart is completely blocked which causes that part to not receive the oxygen and nutrients it needs. That region or part of the heart dies which is fatal and causes heart attack or cardiac arrest.

Factors that may contribute to the occurrence of cardiac arrest
Unhealthy diet rich in cholesterol and fats
Chronic stress
Smoking and excessive alcohol drinking
Lack of physical activities
Hereditary

Preventive Measures
Having a balanced and proper diet. Consuming plant fats as a substitute for animal fats as they do not stick on the wall of the arteries.
Having proper stress management.
Avoiding cigarette smoke and drinking excessive alcohol because it has a negative effect on the heart and the lungs.
Regular and physical exercise to have a long-term beneficial effect.




ANSWER KEY
Answer Key to Activity #1 Coordinated Functions
Path of Deoxygenated Blood:
Superior Vena Cava (upper) and Inferior vena cava (lower)
Right atrium contracts; tricuspid valve opens
Right ventricle contracts; pulmonary valve opens
Pulmonary artery to the lungs

Path of Oxygenated Blood:
Pulmonary veins to the heart
Left atrium contracts, mitral valve opens
Left ventricle contracts; Aortic valve opens
Aorta to the different parts of the body