Cardiovascular System Flashcards
How do lymphatic vessels help the cardiovascular system?
Lymphatic vessels help by collecting excess fluid surrounding tissues and returning it to the cardiovascular system.
Primary function of the Cardiovascular System
Service cells of the body, bringing nutrients to cells and helping to remove waste.
Three Major Components of the Cardiovascular System
Heart
Veins
Arteries
Four Functions of the Cardiovascular System
Generates blood pressure and moves blood
Transport blood
Exchange of nutrients and wastes at the capillaries
Regulates blood flow as needed by the body
Parts of the Closed Circuit Pathway of the Cardiovascular System
Heart -> Arteries -> Arterioles -> Capillaries -> Venules -> Veins
-> Heart again
Arteries
Carry blood away from the heart
3 Layers in the wall of an artery
Thin inner epithelium
Thick smooth muscle layer
Outer connective tissue
Arterioles
Small arteries that regulate blood pressure
Capillaries
Microscopic vessels between arterioles and venules. They form beds of vessels where exchange with body cells (nutrients out, waste materials in) occur, and have a combined large surface area.
Precapillary Sphincters
Control blood flow through a capillary bed. They can shut down a blood capillary, and blood then flows through the shunt (direct pass from arteriole to venular). If closed, blood moves to an area where gas exchange is needed. This might happen if it’s cold outside - directs blood towards center of body instead of extremities.
Veins
Carry blood toward heart. If they carry blood against gravity, they have valves to keep blood flowing toward heart.
Venules
Small veins that receive blood from the capillaries.
3 layers of Venules and Vein walls
Thin inner epithelium
Smooth muscle layer (less than arteries)
Outer connective tissue (less than arteries)
Overall, thinner than arteries, allowing for greater expansion
Heart
Large, muscular organ consisting of mostly cardiac muscle tissue. It runs the cardiovascular system.
Myocardium
The cardiac muscle tissue in the heart.
Cardiac Muscle Fibers
Branched, uninucleated, striated muscle fibers. Tightly joined by intercalated disks.
Intercalated Disks
Disks that hold the cardiac muscle fibers together very tightly so that there is no “leakage” of fluids such as blood.
Pericardium
Sac that surrounds the heart.
The right and left sides of the heart are separated by what?
The septum
Atria
The chambers in the upper half of the heart
Ventricles
The chambers in the lower half of the heart
2 sets of valves in the heart
Atrioventrical
Semilunar
Purpose of heart valves?
Heart valves keep blood flowing in one direction
Atrioventricular Valves are between what?
The atria and the ventricles.
The Left Atrioventricular valve is what?
Bicuspid
The right atrioventricular valve is what?
Tricuspid
Superior Vena Cava
Primary vein returning to the heart from the top of the body.
Inferior Vena Cava
Primary vein returning to the heart from the bottom of the body.