Cardiovascular System Flashcards
What is the #1 killer in the US?
Cardiovascular disease
What are the components of the CVS?
Heart and blood vessels
What region holds the heart, esophagus, and trachea?
Mediastinum
Where does deoxygenated blood enter the heart?
R side, through SVC and IVC
Name the valve between atrium and ventricle on left and right side of heart
Right: tricuspid Left: bicuspid/mitral/AV
What is hematocrit?
Percentage of RBCs in given volume of blood (determines viscosity)
What are the most abundant WBCs?
Neutrophils
Explain diapedesis
WBCs leave blood vessels by squeezing through simple squamous lining. Monocytes become big macrophages after leaving the blood vessel
How much blood enters and leaves the heart every minute?
About 5.5 liters
What is in plasma?
90% water, then dissolved substances, ions: Na, Ca, H, OH, bicarb, antibodies, clotting factors, enzymes
What is in the buffy coat (between RBCs and plasma)
WBCs and platelets
What do B-lymptocytes do?
Make and secrete antibodies
What do T-lymphocytes do?
Destroy virally-infected cells and cancerous cells if they have signal proteins
Describe the tunica interna
(intima) endotherlium faces lumen of blood vessels
Describe the tunica media
smooth muscle for vasoconstriction and vasodilation, with a layer of epithelial and nervous tissue
Describe the tunica externa
Superficial, mostly CT with a lot of collagen and elastic fibers and nerves and lymphatic vessels. These CTs anchor the blood vessel
What is the radial pulse caused by?
The stretch and recoil of the artery’s tunicas
What’s the aortic reflex?
A fall in blood pressure due to peripheral vasodilation and cardiac inhibition
What’s the carotid sinus reflex?
High blood pressure stimulates baroreceptors, send signals to medulla oblongata, so increases parasympathetic which decreases HR
Describe what happens with an aneurism
A ballooning out of an artery wall where blood has seeped between layers of the tunicas
Describe the 3 ways to get low pressure blood to the heart
- Pressure changes in chest and abdominal cavity during breathing 2. “Milking” action of muscle movement 3. One-way valves
Name 3 circulatory systems
Systemic, pulmonary, coronary
What is the diameter of the aorta?
1 inch/2.5 cm
What does the brachiocephalic trunk branch into?
the brachiocephalic artery, which is divided into the R subclavian artery and the R common carotid artery
What branches to the left off the aorta?
L subclavian artery and L common carotid artery
What is the “lub-dub” sound from?
The closing of valves: lub: tricuspid and bicuspid dub: aortic and pulmonary
What happens during diastole?
Both atria fill with blood
What happens during systole?
Both ventricles contract
What is systolic and diastolic pressure?
Pressure against the walls of the blood vessels during those phases of the cardiac cycle
Define hemostasis
Process to prevent and stop bleeding. First stage of wound healing
What’s step 1 in hemostasis?
Vasoconstriction- smooth muscle in tunica media contracts to reduce blood leaving vessel
What’s step 2 in hemostasis?
Collagen in tunica externa unravels and triggers platelets that originate in red bone marrow to come to the site. When exposed to collagen platelets get “sticky”
What’s step 3 in hemostasis?
Coagulation: clotting factors, RBCs, and platelets form temporary plug/fiber mesh
How is calcium ion involved in hemostasis?
It is a cofactor for clotting factors: a fine balance of calcium in blood is necessary (9-11mg/100mL blood) because you don’t want to clot too fast or for it to take too long
Why are blood calcium levels needed at 9-11mg/100mL blood?
- for nerve impulses to be generated/transmitted 2. For muscular contraction 3. For coagulation to occur in a timely matter
What do blood thinners do?
Stops clotting factors/diminishes formation of clot/plug
What binds calcium to stop clotting when collecting blood in a vial?
citrate/EDTA
What 2 sources control contraction of the heart?
intrinsic: specialized cardiac cells like SA node, AV node, etc and extrinsic: vagus nerve- slows HR down
What is perfusion?
exchange of gas, glucose, amino acids, and waste between tissue cells and capillary beds
