Exam 4 HEART pt2 Flashcards
Pregnant women have better blood return through the inferior vena cava if they sleep on their____ side. This keeps the heavy fetus and uterus from compressing the inferior vena cava.
left
If the fossa ovalis fails to close immediately after birth, it is called a
patent foramen ovale”, “perforated fossa ovalis”, or an “atrial septal defect”.
consists of the chambers on the left side of the heart (left atrium and left ventricle) and all the named blood vessels that carry blood to the tissues (arteries) and all the named blood vessels that return the blood from the tissues (veins) back to the right atrium of the heart. The tissue capillaries are included.
systemic circulation
consists of the right side of the heart (right atrium and right ventricle), the pulmonary arteries, which convey poorly oxygenated blood to the lungs, and the pulmonary veins, which convey oxygenated blood from the lungs to the left atrium.
pulmonary circulation
is when two or more arteries, or two or more veins, merge to supply the same region.
anastomosis
Some arteries do not form anastomoses; in these so-called _________, there is only one pathway through which blood can reach and organ
end arteries
Often an artery will travel with a corresponding vein, both of which service the same body region
Such vessels are called companion vessels
The tunica intima is composed of endothelium and a subendothelial layer made up of a thin layer of connective tissue. The tunica intima in veins has one-way valves. This is not seen in arteries
The walls of arteries are thicker than the walls of veins because of a thicker tunica media. This enable vasoconstriction and vasodilation in both arteries and veins
The tunica externa is the outermost layer of a blood vessel. It is composed of connective tissue that contains elastic and collagen fibers. Veins have a thicker tunica externa than arteries.
Arteries tend to have more elastic and collagen fibers in all their tunics, which means that arterial walls remain open (patent) and can spring back to shape. In contrast, vein walls tend to collapse if there is no blood in them.
_______________ contain only the tunica intima, but this layer consists of a basement membrane and endothelium only. This allows for easy exchange of materials between the capillary blood and the fluid surrounding the tissue cells
capillaries
perform the most important role of the circulatory system: delivery of oxygen and nutrients and removal of wastes
capillaries
Normal RBCs need to _____________ to slip through capillaries
are the largest arteries. They have elastic fibers throughout all three tunics. This allows these arteries to bulge when the heart ejects blood into them, and then recoil when the heart relaxes. An example is the aorta
elastic arteries
Blood in the arteries is propelled forward during systole of the heart and also continues forward during diastole because of the _____________ of the arterial walls.
elastic recoil
are medium sized vessels, with elastic fibers confined between the tunica media and tunica externa. They have a thick tunica media with multiple layers of smooth muscle, giving them better ability to vasoconstrict or vasodilate. Most of the named arteries are muscular arteries.
muscular arteries
are the smallest arteries. They have fewer layers of smooth muscle in their tunica media. By vasoconstricting or vasodilating the arterioles can increase or decease the arterial blood pressure and also regulate blood flow through the capillaries
arterioles
_______________ is caused by the inheritance of a gene for an abnormal type of hemoglobin called “hemoglobin-S”. This abnormal hemoglobin causes the RBCs to be rigid and take on a sickle shape
Sickle-cell disease
Sickle cells cause blockages (infarcts) and the cells also break, causing anemia (sickle cell anemia)
Every cell in the body is close to a capillary and capillaries are surrounded by
interstitial fluid
___________ are the most common type of capillary. The endothelial cells form a complete, continuous lining and are connected by tight junctions.
Continuous capillaries
_____________ have fenestrations within each endothelial cell and are seen where a great deal of fluid transport occurs between the blood and the tissues (intestines, endocrine glands, and kidneys).
Fenestrated capillaries
have walls that are thinner than arteries, they typically carry deoxygenated blood (except for pulmonary veins), they have lower internal pressure
veins
________ are the smallest veins and drain capillaries. Venules merge to form veins. Eventually these veins merge to form the ____________ which deliver blood to the chambers of the heart.
Venules
great veins
When nearby skeletal muscles contract the blood is propelled forward
skeletal muscle pump
The _________________for blood circulation occurs when we inhale and exhale, which causes alternating pressure changes in the chest.
“respiratory (breathing) pump”
Blood has a tendency to pool in the leg veins when persons are inactive (bedridden). This can lead to
stationary clots (thrombi)
and moving clots (emboli)