the circulatory system unit 8

What is the size of an adult heart?

A man's closed fist

Aortic Valve

Allows blood to flow from the left ventricle to the aorta and prevents blood from flowing back into the ventricle.

Pulmonary Valve

Allows blood to flow from the right ventricle to the pulmonary arteries and prevents blood from flowing back into the ventricle.

Pulmonary Arteries

Arteries that transport oxygen poor blood from the right ventricle to the lungs.1 artery goes to the right lung & 1 artery goes to the left lung.

left atrium

Atria = plural) The left upper chamber which receives oxygen-rich blood from the lungs through the pulmonary vein.

What is the name of the node above the right ventricle?

Atrioventricular node (AV node) It causes the contraction of the muscle of the ventricles.

Which blood vessel is the most numerous in the body?

Capillaries

Tricuspid Valve

Controls the flow of blood from the right atrium to the right ventricle, preventing blood from flowing backwards.

What is the sinoatrial node (SA node)?

Initiates the contraction (rhythm of the heartbeat) of the muscles of the atria. Aka - pacemaker of the heart

What is the function of the heart?

It pumps the blood that supplies the body with oxygen, nutrients, and removes waste.

aorta

Large artery through which oxygen-rich blood passes from the left ventricle to the rest of the body.

What part of the development of an embryo does the development of the circulatory system happen?

Long before any other major organ system, early in the fourth week following fertilization. The baby's heartbeat can be heard between 8 - 10 weeks.

What is the role of the cardiovascular system?

Maintaining homeostasis by transporting vital nutrients to the tissues of the body and removing waste products.

What type of tissue is the heart made of?

Muscle tissue

Superior and Inferior Vena Cava

Oxygen-poor blood enters the right atrium through these two large veins. Superior brings blood from the upper body. Inferior brings blood from the lower body.

map of the human heart:

Oxygen-poor blood flows from the body (through the superior & inferior vena cava) into the right atrium Oxygen-poor blood flows to the right ventricle (through the tricuspid valve) The right ventricle pumps blood to the lungs, through the pulmonary artery, where blood releases waste and picks up oxygen. Oxygen-rich blood returns to the heart (from the lungs) through the pulmonary vein and enters the left atrium. Oxygen-rich blood flows from the left atrium (through the mitral/bicuspid valve) into the left ventricle The left ventricle pumps oxygen-rich blood through the aortic valve to the aorta then the rest of the body.

What is the name of the membrane surrounding the heart?

Pericardial sac (aka pericardium) Peri - means "around" Cardi or cardio - means "heart"

Define pressure.

Pressure is a measure of the force that the blood exerts against the vessel walls as it moves the blood through the vessels.

What are the two closed systems of blood vessels?

Pulmonary Circulation : Between the heart & lungs The pulmonary vessels transport blood from the right ventricle to the lungs and back to the left atrium. Systemic Circulation Between the heart & body The systemic vessels carry blood from the left ventricle to the tissues in all parts of the body and then returns the blood to the right atrium.

Right Ventricle

The right lower chamber distributes oxygen-poor blood to the lungs through the pulmonary artery.

Right Atrium

The right upper chamber that receives oxygen-poor blood from the body through the vena cavas

How do the atria differ from the ventricles?

The two atria are thin-walled chambers that receive blood from the veins. The two ventricles are thick-walled chambers that forcefully pump blood out of the heart through arteries.

What is the function of the valves of the heart?

To keep the blood flowing forward and not flowing backwards.

The heart works as two pumps, one on the right and one on the left, working simultaneously (True or False).

True

Pulmonary Veins

Veins that bring oxygen rich blood from the lungs to the left atrium. 1 vein comes from the right lung and 1 vein comes from the left lung.

How many liters of blood does an adult heart pump per minute?

about 5 liters

The walls of ... are the thickest, the walls of ... are thinner, and the walls of .. are the thinnest.

arteries/veins/capillaries

Arteries branch into smaller and smaller vessels, what are these smaller vessels called?

arterioles

What is the function of the arteries?

carry blood away from the heart

What is the function of the veins?

carry blood to the heart

Where in the body is heart rate controlled?

in the brain

What are the 4 chambers of the heart?

right atrium right ventricle left atrium left ventricle

How is blood pressure recorded? So, if you have a blood pressure of 120/80, what is your systolic pressure?

systolic pressure over the diastolic pressure 120 = systolic pressure

What are the functions of blood?

transporting oxygen from the lungs to body tissue and carbon dioxide from body tissue to the lungs. transporting nourishment from digestion and hormones from glands throughout the body. transporting disease-fighting substances to the tissue and waste to the kidneys.

Veins branch into smaller and smaller vessels, what are these vessels called?

venules

left ventricle

The left lower chamber which distributes oxygen-rich blood to the rest of the body through the aorta.

What is the function of the capillaries?

The exchange of materials (oxygen, carbon dioxide, etc.) between the blood and tissue cells.

Myocardium

"Myo" = means muscle "Cardi" = means heart It is the middle layer of muscle of the heart

Mitral valve

(also known as the bicuspid valve) Controls the flow of blood from the left atrium to the left ventricle, preventing blood from flowing backwards.

What 3 parts does it consist of?

The heart (muscle & connective tissue) blood vessels (arteries, arterioles, veins, venules, and capillaries) blood

Septum

Separates the right side and left side of the heart. Prevents oxygen-rich and oxygen-poor blood from mixing.

Coronary Arteries

Surround the heart itself and supplies oxygen rich blood to the heart muscle from the aorta.

What are the 2 phases of the cardiac cycle?

Systole is the contraction of the ventricles (pumping blood out of heart) Diastole is the relaxation of the ventricles (filling up with blood).

Why do the veins in arms and legs have valves?

The blood in the veins of your arms and legs are being pumped back to the heart against gravity. The valves prevent the back flow of blood in response to the pull of gravity.

What is the cardiovascular system also known as?

The circulatory system