Anatomy Of The Heart And Blood Vessels
Reviewed byDr Jacqueline Payne
The heart is a muscular pump that pushes blood through blood vessels around the body. The heart beats continuously, pumping the equivalent of more than 14,000 litres of blood every day through five main types of blood vessels: arteries, arterioles, capillaries, venules and veins.
The Venous Return Curve
If right atrial pressure were changed in steps over the entire range of possible atrial pressures and venous return were measured at each point, plotting the data set would yield a complete venous return curve, which is presented in . As mentioned earlier, such measurements would have to be made during total blockade of the autonomic nervous system so that circulatory reflexes would be normal. Notice that, at the normal right atrial pressure value , venous return is 100%, which is 5 L/min in man. Venous return falls progressively as right atrial pressure increases, until right atrial pressure reaches 7 mm Hg, the normal value for mean systemic pressure. At that point, venous return is 0 because the pressure gradient for venous return is 0. As right atrial pressure falls below 0, the venous return curve increases at a progressively declining rate until flow reaches a plateau at approximately 4 mm Hg. As discussed above, the reason for the curvilinear nature in this portion of the relationship, termed the transition zone, is the progressive increase in vascular resistance due to the collapse of increasing numbers of veins as right atrial pressure becomes more negative.
The complete venous return curve over the range of right atrial pressure from 8 to 8 mm Hg. Venous return values are for humans.
You May Like: How Does Anemia Cause Heart Failure
Blood Vessels Arteries Capillaries Veins Vena Cava Central Veins
Image 1: Blood Vessels. Arteries carry oxygen rich blood from the left side of the heart to the tissues and organs. After oxygen leaves the blood and moves into the tissues, the level of oxygen in the blood becomes low. The veins carry blood that has a low level of oxygen back to the right side of the heart. Blood from the veins is pumped from the right side of the heart through the blood vessels of the lungs, where new oxygen is picked up. This oxygen rich blood flows from the lungs to the left side of the heart.
Also Check: Does Acid Reflux Cause Heart Palpitations
You May Like: Left Ventricular Systolic Dysfunction Symptoms
What Are Blood Vessels
Blood vessels are channels that carry blood throughout your body. They form a closed loop, like a circuit, that begins and ends at your heart. Together, the heart vessels and blood vessels form your circulatory system. Your body contains about 60,000 miles of blood vessels.
There are three types of blood vessels:
- Arteries carry blood away from your heart.
- Veins carry blood back toward your heart.
- Capillaries, the smallest blood vessels, connect arteries and veins.
Which Vessels Carry Deoxygenated Blood From Different Parts Of The Body To The Heart
Who are the experts?Our certified Educators are real professors, teachers, and scholars who use their academic expertise to tackle your toughest questions. Educators go through a rigorous application process, and every answer they submit is reviewed by our in-house editorial team.
The two basic blood vessels in the human body that are responsible for transporting deoxygenated and oxygenated blood throughout the human body are veins and arteries. Veins take the deoxygenated blood from the body parts back towards the lungs and heart while the arteries take oxygenated blood from the heart…
Recommended Reading: What Causes Left Sided Heart Failure
Ib Dp Biology Topic : Human Physiology : 62 The Blood System Question Bank Hl Paper 1
Which is a valid comparison between arteries and veins?
Answer/Explanation
Which discovery was an indication that the heart pumps blood to the body through arteries?
A. The amount of blood pumped exceeds that of blood producedB. Blood could easily be pushed up a limb vein, but not downC. The observation that there were pores between the right and left atriaD. The heart swelled up when the arteries were tied in an animal experiment
Answer/Explanation
What Is Red Blood And Blue Blood
All blood is red. Hemoglobin, an iron-rich protein in red blood cells, mixes with oxygen to give blood its red color. Blood thats rich in oxygen is known as red blood.
Your veins carry oxygen-poor blood. This is sometimes called blue blood because your veins can look blue underneath the skin. The blood is actually red, but the low oxygen levels give veins a bluish hue.
You May Like: Flonase And Heart Palpitations
What Are The Types Of Blood Vessels
There are three main types of blood vessels:
- Arteries: Arteries are thin, muscular tubes that carry oxygenated blood away from the heart and to every part of your body. The aorta is the bodys largest artery. It starts at the heart and travels up the chest and then down into the stomach . The coronary arteries branch off the aorta, which then branch into smaller arteries as they get farther from your heart.
- Veins: These blood vessels return oxygen-depleted blood to the heart. Veins start small and get larger as they approach your heart. Two central veins deliver blood to your heart. The superior vena cava carries blood from the upper body to the heart. The inferior vena cava brings blood up from the lower body to the heart. Veins in the legs have valves to keep blood from flowing backward.
- Capillaries: These blood vessels connect very small arteries and veins . Capillaries have thin walls that allow oxygen, carbon dioxide, nutrients and waste products to pass into and out of cells.
What Blood Vessel Carries Blood To The Heart
Who are the experts?Our certified Educators are real professors, teachers, and scholars who use their academic expertise to tackle your toughest questions. Educators go through a rigorous application process, and every answer they submit is reviewed by our in-house editorial team.
Ph.D. from Oregon State University
Educator since 2017
Our heart acts as a pump to circulate the blood to different parts of our body. Blood vessels carry oxygen poor blood to heart, from where it is sent to the lungs to get fresh oxygen supply. Oxygen rich blood is sent back to heart and from there it is…
Don’t Miss: Flonase Chest Pain
What Does The Circulatory System Do
The circulatory system is made up of blood vessels that carry blood away from and towards the heart. Arteries carry blood away from the heart and veins carry blood back to the heart.
The circulatory system carries oxygen, nutrients, and to cells, and removes waste products, like carbon dioxide. These roadways travel in one direction only, to keep things going where they should.
What Are The Coronary Arteries
Like all organs, your heart is made of tissue that requires a supply of oxygen and nutrients. Although its chambers are full of blood, the heart receives no nourishment from this blood. The heart receives its own supply of blood from a network of arteries, called the coronary arteries.
Two major coronary arteries branch off from the aorta near the point where the aorta and the left ventricle meet:
- Right coronary artery supplies the right atrium and right ventricle with blood. It branches into the posterior descending artery, which supplies the bottom portion of the left ventricle and back of the septum with blood.
- Left main coronary artery branches into the circumflex artery and the left anterior descending artery. The circumflex artery supplies blood to the left atrium, as well as the side and back of the left ventricle. The left anterior descending artery supplies the front and bottom of the left ventricle and the front of the septum with blood.
These arteries and their branches supply all parts of the heart muscle with blood.
When the coronary arteries narrow to the point that blood flow to the heart muscle is limited , a network of tiny blood vessels in the heart that arent usually open may enlarge and become active. This allows blood to flow around the blocked artery to the heart muscle, protecting the heart tissue from injury.
Don’t Miss: Why Do Av Nodal Cells Not Determine The Heart Rate
Problems Of The Heart And Circulatory System
Problems with the cardiovascular system are common more than 64 million Americans have some type of cardiac problem. But cardiovascular problems dont just affect older people many heart and circulatory system problems affect children and teens, too.
Heart and circulatory problems are grouped into two categories: congenital and acquired .
Congenital heart defects. These abnormalities in the hearts structure are present at birth. Approximately 8 out of every 1,000 newborns have congenital heart defects ranging from mild to severe. These defects occur while the fetus is developing in the mothers uterus and its not usually known why they occur. Some congenital heart defects are caused by genetic disorders, but most are not. What all congenital heart defects have in common, however, is that they involve abnormal or incomplete development of the heart.
A common sign of a congenital heart defect is a heart murmur an abnormal sound thats heard when listening to the heart. Usually a heart murmur is detected by a doctor whos listening to the heart with a stethoscope during a routine exam. Murmurs are very common in children and can be innocent murmurs found in an otherwise healthy heart. Other murmurs can be caused by congenital heart defects or other heart conditions.
A blood test can measure if someones cholesterol is too high. A childs total cholesterol level is borderline if its 170 to 199 mg/dL, and its considered high if its above 200 mg/dL.
Where Are The Heart And Blood Vessels Found
The heart is a fist-sized organ which lies within the chest behind the breastbone . The heart sits on the main muscle of breathing , which is found beneath the lungs. The heart is considered to have two sides the right side and the left side.
The heart has four chambers an atrium and a ventricle on each side. The atria are both supplied by large blood vessels that bring blood to the heart . Atria have special valves that open into the ventricles. The ventricles also have valves but, in this case, they open into blood vessels. The walls of the heart chambers are made mainly of special heart muscle. The different sections of the heart have to squeeze in the correct order for the heart to pump blood efficiently with each heartbeat.
Also Check: What Heart Chamber Pushes Blood Through The Aortic Semilunar Valve
Heart Anatomy: By The Numbers
1. Superior vena cava: Receives blood from the upper body delivers blood into the right atrium.
2. Inferior vena cava: Receives blood from the lower extremities, pelvis and abdomen, and delivers blood into the right atrium.
3. Right atrium: Receives blood returning to the heart from the superior and inferior vena cava transmits blood to the right ventricle, which pumps blood to the lungs for oxygenation.
4. Tricuspid valve: Allows blood to pass from the right atrium to the right ventricle prevents blood from flowing back into the right atrium as the heart pumps .
5. Right ventricle: Receives blood from the right atrium pumps blood into the pulmonary artery.
6. Pulmonary valve: Allows blood to pass into the pulmonary arteries prevents blood from flowing back into the right ventricle.
7. Pulmonary arteries: Carry oxygen-depleted blood from the heart to the lungs.
8. Pulmonary veins: Deliver oxygen-rich blood from the lungs to the left atrium of the heart.
9. Left atrium: Receives blood returning to the heart from the pulmonary veins.
10. Mitral valve: Allows blood to flow into the left ventricle prevents blood from flowing back into the left atrium.
11. Left ventricle: Receives oxygen-rich blood from the left atrium and pumps blood into the aorta.
12. Aortic valve: Allows blood to pass from the left ventricle to the aorta prevents backflow of blood into the left ventricle.
13. Aorta: Distributes blood throughout the body from the heart.
Do Arteries Always Carry Oxygenated Blood
For the most part, yes. The exceptions are pulmonary arteries and veins. Pulmonary arteries carry deoxygenated blood to the lungs. Pulmonary veins return the oxygenated blood to the heart.
A note from Cleveland Clinic
Your circulatory system plays a critical role in keeping you alive. Blood vessels carry blood to the lungs for oxygen. Then your heart pumps oxygen-rich blood through arteries to the rest of the body. Your veins help your body get rid of waste products. Conditions like high blood pressure, high cholesterol and atherosclerosis can affect the health of your circulatory system. If you have one of these conditions, talk to your healthcare provider about steps you can take to protect your cardiovascular health.
Last reviewed by a Cleveland Clinic medical professional on 09/21/2021.
References
Recommended Reading: Can This 10 Second Trick Prevent Your Heart Attack
How Does Blood Flow Through Your Lungs
Once blood travels through the pulmonic valve, it enters your lungs. This is called the pulmonary circulation. From your pulmonic valve, blood travels to the pulmonary arteries and eventually to tiny capillary vessels in the lungs.
Here, oxygen travels from the tiny air sacs in the lungs, through the walls of the capillaries, into the blood. At the same time, carbon dioxide, a waste product of metabolism, passes from the blood into the air sacs. Carbon dioxide leaves the body when you exhale. Once the blood is oxygenated, it travels back to the left atrium through the pulmonary veins.
Classification & Structure Of Blood Vessels
Blood vessels are the channels or conduits through which blood is distributed to body tissues. The vessels make up two closed systems of tubes that begin and end at the heart. One system, the pulmonary vessels, transports blood from the right ventricle to the lungs and back to the left atrium. The other system, the systemic vessels, carries blood from the left ventricle to the tissues in all parts of the body and then returns the blood to the right atrium. Based on their structure and function, blood vessels are classified as either arteries, capillaries, or veins.
Don’t Miss: Can Ibs Cause Palpitations
Biology Of The Blood Vessels
, MD, Michigan Medicine at the University of Michigan
The heart and blood vessels constitute the cardiovascular system. The blood circulating in this system delivers oxygen and nutrients to the tissues of the body and removes waste products from the tissues.
The blood vessels consist of
-
Arteries
All blood is carried in these vessels.
What Does The Heart Do
The heart is a pump, usually beating about 60 to 100 times per minute. With each heartbeat, the heart sends blood throughout our bodies, carrying oxygen to every cell. After delivering the oxygen, the blood returns to the heart. The heart then sends the blood to the lungs to pick up more oxygen. This cycle repeats over and over again.
Read Also: Does Ibs Cause Heart Palpitations
The Constant Pumping Of The Heart Maintains Blood Pressure And Supply Throughout The Body
The blood moving through the circulatory system puts pressure on the walls of the blood vessels. Blood pressure results from the blood flow force generated by the pumping heart and the resistance of the blood vessel walls. When the heart contracts, it pumps blood out through the arteries. The blood pushes against the vessel walls and flows faster under this high pressure. When the ventricles relax, the vessel walls push back against the decreased force. Blood flow slows down under this low pressure.
You May Like: Can Too Much Vitamin D Cause Heart Palpitations
Outside View Of The Back Of The Heart
Coronary veins -take oxygen-poor blood that has already been used by muscles of the heart and returns it to the right atrium.
Circumflex artery supplies blood to the left atrium and the side and back of the left ventricle.
Left coronary artery divides into two branches .
Left anterior descending artery supplies blood to the front and bottom of the left ventricle and the front of the septum.
Pulmonary veins -bring oxygen-rich blood back to the heart from the lungs.
Right coronary artery supplies blood to the right atrium, right ventricle, bottom portion of the left ventricle and back of the septum.
Don’t Miss: Does Acid Reflux Cause Heart Palpitations
How Does The Circulatory System Work
Your circulatory system functions with the help of blood vessels that include arteries, veins and capillaries. These blood vessels work with your heart and lungs to continuously circulate blood through your body. Heres how:
What Are The Different Types Of Arteries
There are three types of arteries. Each type is composed of three coats: outer, middle, and inner.
- Elastic arteries are also called conducting arteries or conduit arteries. They have a thick middle layer so they can stretch in response to each pulse of the heart.
- Muscular arteries are medium-sized. They draw blood from elastic arteries and branch into resistance vessels. These vessels include small arteries and arterioles.
- Arterioles are the smallest division of arteries that transport blood away from the heart. They direct blood into the capillary networks.
There are four types of veins:
- Deep veins are located within muscle tissue. They have a corresponding artery nearby.
- Superficial veins are closer to the skins surface. They dont have corresponding arteries.
- Pulmonary veins transport blood thats been filled with oxygen by the lungs to the heart. Each lung has two sets of pulmonary veins, a right and left one.
- Systemic veins are located throughout the body from the legs up to the neck, including the arms and trunk. They transport deoxygenated blood back to the heart.
Use this interactive 3-D diagram to explore an artery.
Use this interactive 3-D diagram to explore a vein.
Recommended Reading: What Are The Early Signs Of Congestive Heart Failure