Cardiovascular System

Question 1

order of excitation during cardiac impulse

Answer 1

SA node ~> initiation, r atrium, depolarization and 2 atria contract simultaneously causing atrial kick into ventricles
AV node ~> sits at junction of the atria and ventricles, signal delayed
Bundle of His ~> interventricular septum
Purkinje fibers ~> distributes signal through ventricles

Question 2

Cardiac output formula

Answer 2

CO = HR x SV

Question 3

muscle cells connected by…

Answer 3

• intercalated discs
• contain gap junctions directly connecting cytoplasm of adjacent cells allowing for coordinated ventricular contraction

Question 4

electrocardiogram

Answer 4

know the cardiac cycle

Question 5

artery

Answer 5

• moves blood away from heart
• most carry oxy blood (only pulm and umbilical arteries contain deoxy blood)
• highly muscular and elastic, creating tremendous resistance to flow
• arterioles branch off into capillaries

Question 6

capillary

Answer 6

• single endothelial cell layer
• easy diffusion no muscle

Question 7

veins

Answer 7

• thin walled
• inelastic, transport blood to the heart
• carry deoxy blood except for pulm and umbilical veins
• stretch to accommodate larger quantities of blood

Question 8

how does the cardiac output of either side of the heart compare to the other

Answer 8

identical

Question 9

valves…

Answer 9

prevent back flow in veins

Question 10

how do skeletal muscles help in circulation?

Answer 10

• squeeze veins as muscles contract squeezing blood upwards

Question 11

deep vein thrombosis (DVT)

Answer 11

• may become dislodged and travel through right side of the heart and to the lungs causing pulmonary embolus

Question 12

after leaving the aorta, how does blood travel back to the r atrium?

Answer 12

aorta ~> arteries ~> arterioles ~> capillaries ~> venules ~> veins ~> vena cavae ~> r atrium

Question 13

how are portal systems unique?

Answer 13

blood passes through 2 capillary beds instead of one

Question 14

hepatic portal system

Answer 14

• blood leaving capillary beds in the walls of the gut passes through the hepatic portal vein before reaching the capillary beds in the liver

Question 15

hypophyseal portal system

Answer 15

• blood leaving the capillary beds in the hypothalamus travels to a capillary bed in the ant pituitary to allow for paracrine secretion of releasing hormones

Question 16

renal portal system

Answer 16

• blood leaving glomerulus travels through an efferent arteriole before surrounding the nephron in a capillary network called the vasa recta

Question 17

blood comp

Answer 17

~55% plasma (water, protein, hormone, salt, gases)
~1% WBCs and platelets
~45% RBCs

Question 18

RBCs

Answer 18

• lack nuclei, unable to divide
• live ~120 days in bloodstream before cells in liver and spleen phagocytize and recycle them

Question 19

normal hemoglobin amount

Answer 19

13.5-17.5 g/dL male
12.0-16.0 g/dL female

Question 20

hematocrit

Answer 20

41-53% male
36-46% female

Question 21

granular leukocytes

Answer 21

• neutrophils
• eosinophils
• basophils
  inflammation, allergies, pus, bacteria destruction

Question 22

agranulocytes

Answer 22

• lymphocytes: specific immune response, primary responders in infection, B cells mature in bone marrow and T cells mature in thymus
• monocytes: phagocytes, called macrophages upon leaving the bloodstream, every bodily system has a unique name

Question 23

B cell

Answer 23

antibody generation

Question 24

T cells

Answer 24

kill vitally infected cells and activate specific immune cells

Question 25

hematopoiesis

Answer 25

page #273

Question 26

erythroblastosis fetalis

Answer 26

upon first pregnancy of a different Rh sign baby, antibodies are formed but it’s the end of the pregnancy by that point

it becomes a threat to the second pregnancy as antibodies can cross the placenta

medicine prevents this

ABO antigens are a class of IgM do we aren’t concerned about them crossing placenta like an anti-Rh IgG

Question 27

Ohm’s Law for circulation

Answer 27

ΔP = CO x TPR
ΔP: pressure differential across circulation
CO: cardiac output
TPR: toral vascular resistance (the longer a blood vessel is and the smaller the cross sectional area the more resistance

Question 28

greatest to least blood pressure blood vessels

Answer 28

aorta ~> arteries ~> arterioles ~> capillaries ~> venules ~> veins ~> vena cavae

Question 29

opening capillary beds will…

Answer 29

dec vascular resistance bc capillary beds are all parallel to one another aside from portal systems

Question 30

explain how oxygen-heme binding causes shifts

Answer 30

• when an oxygen binds to heme causes the hemoglobin to become relaxed, and thus affinity for oxygen inc
• loss of an oxygen dec affinity
• cooperative binding, s-shaped sigmoidal curve

Question 31

carbonic anhydride

Answer 31

catalyzes both side of the rxn

CO2 + water <~CA~> carbonic acid <~> H+ + bicarb

Question 32

starling forces

Answer 32

• hydrostatic pressure vs oncotic pressure
• hydrostatic pressure pushes fluid out of the arteriolar end of a capillary bed
• oncotic pressure draws it back in at the venule end

Question 33

carbs and aa…

Answer 33

are absorbed into the capillaries of the small intestine and enter circulation via the hepatic portal system

Question 34

fats…

Answer 34

• absorbed into lacteals in the small intestine, bypassing the hepatic portal circulation via the thoracic duct
• when released from intestinal cells, fats are packaged into lipoproteins which are water-soluble

Question 35

wastes enter bloodstream by…

Answer 35

traveling down their respective concentration gradients from the tissues to the capillaries

blood eventually travels to the kidneys where waste either secreted or filtered

Question 36

peptide hormones

Answer 36

cell surface receptors

Question 37

steroid hormones

Answer 37

• diffuse into the cell to activate intracellular or intranuclear receptors

Question 38

most lymph returned to circulatory system via…

Answer 38

thoracic duct

Question 39

clotting

Answer 39

1) endothelial blood vessel damage reveals collagen and tissue factor
2) platelets clump together in response
3) coagulation factors released by the liver activate prothrombin into thrombin by thromboplastin
4) thrombin converts fibrinogen to fibrin which actually forms the mesh clot
5) clot broken down by plasmin