Cardiovascular System Flashcards
What are the intercalated discs of the cardiac muscle made up of? What does each part do?
Gap Junctions: allow for quick communication b/w cells for a coordinated contraction
Fascia Adherens: tension is distributed b/w cells
What is the job of the arteries?
Carry blood away from the heart
What is the job of the veins?
Carry blood towards the heart
What are the steps of the pulmonary circuit? What is its job?
Right atrium –> Right ventricle –> Pulmonary trunk –> pulmonary arteries —> lungs –> pulmonary veins –> left atrium; allows blood to pick up oxygen; Route b/w heart and lungs
What are the steps of the systemic circuit? What is its job?
Left ventricle –> aorta –> cells of body –> veins –> right atrium; brings oxygen to cells; route b/w heart and body tissues
What is the pericardium? What are the different layers?
Serous membranes that surround the heart; Outer layer = fibrous pericardium, Inner layers= serous pericardium
What does the tough, fibrous pericardium do? What is it made of?
Anchors heart, prevents overfilling; dense IR CT
What are the different layers of the serous pericardium?
Visceral pericardium= flush to the heart
Parietal pericardium
What is the pericardial cavity filled with?
Pericardial fluid that reduces friction b/w contracting heart and outer wall of pericardial sac
What are the 4 chambers of the heart?
Right atrium, Right ventricle, Left atrium, Left ventricle
What are the chordae tendineae? What are they made of?
“heart strings”, dense regular CT, ensure that blood goes in one direction
Why is the left ventricular myocardium is thicker than the right?
Needs to be stronger to pump blood to whole body
What are the 2 atrioventricular valves? What do they do?
Tricuspid (right) & Bicuspid (left); Keep blood flowing in one direction
What is the semilunar valve? Where are they located?
Prevent blood from flowing backwards towards ventricles; Pulmonary semilunar = b/w right ventricle & pulmonary trunk, Aortic semilunar = b/w left ventricle and aorta
What is the fibrous skeleton?
Barrier b/w atria and ventricles that prevents an electrical impulse from passing
What is the cardiac conduction system?
Nodes and bundles in cardiac muscle conduct electrical impulses through the heart
What is the Sinoatrial node? Where is it?
In right atrium; initiates electrical impulse, stimulates atria via internodal pathway stimulated AV node
What are the broad steps of the cardiac cycle?
Atrial Diastole (muscle relaxing), Atrial Systole (contraction), Ventricular Systole (contraction), Ventricular Diastole (relax)
What supplies blood to the heart?
Right coronary artery & left coronary artery
What do the cardiac veins do?
Drain blood to coronary sinus –> empties into right atrium
What is atherosclerosis?
Buildup of plaque in arteries causing narrowing, making blood flow more difficult
What is a myocardial infarction?
heart attack; result of blood not reaching cardiac muscle tissue
What are the layers of blood vessels? What makes up each?
Tunica Intima (Simle squamous), Tunica media (smooth muscle), Tunica Externa (loose areolar CT)
What is the vasa vasorum?
Some large vessels have their own blood supply
How do arterial walls compare to veins?
They are thicker and stronger because they are under high pressure
What is the function of elastic arteries? Where are they found?
The ability to expand and recoil helps smooth out pressure surges. Found right off the ventricles
How do muscular arteries differ from elastic arteries?
Less elastin and more smooth muscle
Characteristics & Functions of Arterioles
Are branches of muscular arteries; Constrict and dilate quickly to regulate blood flow; Large arterioles (3 tunics), Small arterioles (2 tunics)
What are capillaries? What are they made of?
Very thin blood vessels that allow for exchange of components, made of only a single layer of tunica intima (simple squamous) and basement membrane
What are precapillary sphincters?
Smooth muscle that constrict or get wider to regulate blood flow
What happens when precapillary sphincters are open? Closed?
Precapillary Sphincters open –> blood fills capillary beds
Precapillary Sphincters closed –> blood passes through capillary bed via a channel- tissue supplied by this capillary bed are bypassed
What are the different types of the capillaries?
Continuos, fenestrated, sinusoidal
Characteristics & Functions of Continuous Capillaries
Tight junctions decr. permeability; Intercellular clefts allow small molecules to pass; have pericytes; most common, found in skeltal muscles, skin, and nervous system
Characteristics & Functions of Fenestrated Capillaries
High rate of molecular exchange between tissue and blood; have pores through endothelial cells called fenestrations (“windows”)
Characteristics & Functions of Sinusoid Capillaries
Special fenestrated capillary; most permeable; large intercellular clefts, incomplete basement membrane, few tight junctions
What is the blood brain barrier made of? Why?
Continuous capillaries have low permeability so that few things can get through
A red blood cell leaving the heart and traveling to the small intestine would travel through how many capillary beds before returning to the heart?
Two
What does a venule do?
Drain capillaries
What are the valves in veins made of? What do they do?
Folds of tunica intima; keep blood moving forward under low pressure
What causes a varicose veins?
Incompetent valves in veins –> blood pools, stretching veins and causing misshapen vessels
What are arterial and vein anastomoses?
Provide alternative pathways for blood to reach a given body region
What are the 2 parts of blood pressure?
Systolic: arterial pressure when left ventricle contracts
Diastolic: arterial pressure when left ventricle relaxes
What are the 3 main classes of blood cells?
Erythrocytes, Leukocytes, Platelets
What is the shape of red blood cells?
Biconcave
What is erythropoiesis? What is needed?
Production of RBCs from stem cells in red bone marrow; Iron needed to produce new cells
What type of antigens would Type A blood have? Type B? Type AB? Type O?
A: A antigens
B: B antigens
AB: A & B antigens
O: neither A or B antigens
What type of antibodies would Type A blood have? Type B? Type AB? Type O?
A: anti-B
B: anti-A
AB: None
O: anti-A & anti-B
What is the Rh factor? When does it become a problem?
Rh is a protein that is either present (+) or absent (-) on RBC. Rh antibodies are able to pass through the placenta and attack a fetus. Becomes a problem when cells from Rh+ fetus enter woman’s bloodstream
