Chapter 7- The Cardiovascular System Flashcards
3 parts of cardiovascular system
- 4 chambered heart
- blood vessels (arteries, capillaries, and veins)
- blood
general movement of blood
veins –>right side of heart–>lungs–>left side of heart–>recirculated through arteries
pulmonary circulation
right side of heart accepts deoxygenated blood returning from body and moves it tot he lungs by way of pulmonary arteries
systemic circulation
left side of heart receives oxygenated blood from lungs by way of pulmonary veins and forces it out to the body through the aorta
4 chambers of heart
2 atria (thin walls) and 2 ventricles (more muscular. get blood after atria and once they fill the contract to send blood to lungs and systemic circulation)
atrioventricular valves
separate atria from ventricles (LAB RAT)
Left Atrium = Bicuspid
Right Atrium = Tricuspid
semilunar valves
separate ventricles from vasculature, these valves allow the pump to create the pressure within the ventricles necessary to propel the blood for circulation (also prevents backflow) (three leaflets)
tricuspid valve
three leaflets. valve b/w right atrium and right ventricle
mitral or bicuspid valve
two leaflets. valve b/w left atrium and left ventricle
pulmonary valve
valve that separates the right ventricle from the pulmonary circulation
aortic valve
valve that separates left ventricle from aorta
right vs. left heart
R- supporting circulation to lungs
L- systemic circulation (more muscular side)
pathway of electrical conduction for heart
SA (sinoatrial) node –> both atria contract –> AV (atrioventricular) node –> signal delayed for a bit while ventricles fill up –> AV (bundle of His) bundle –> purkinje fibers
location of SA node
small collection of cells located in right atrium (starts electrical impulse of heart)
atrial systole and atrial kick
contraction, results in increase in atrial pressure that forces a little more blood into the ventricles. this additional volume of blood is an atrial kick (accounts for 5-30% of cardiac output)
Purkinje fibers
distribute electrical signal through the ventricular muscle
intercalated discs
connects muscle cells in heart. contain many gap junctions directly connecting the cytoplasm of adjacent cells thereby allowing for coordinated ventricular contraction
vagus nerve
provides parasympathetic signals to slow the heart down
Two phases involved in heartbeat
systole and diastole
systole
ventricular contraction and closure of AV valves occurs and blood is pumped out of ventricles
diastole
heart is relaxed. semilunar valves are closed and blood from atria fills the ventricles
cardiac output
total blood volume pumped by a ventricle in a minute.
CO = (heartrate)(stroke volume) —about 5 L/min
artery
blood away from heart. largest in system is aorta. major arteries: coronary, common carotid, renal. very muscular and elastic (resist flow of blood which is why heart has to be so powerful)
arterioles
smaller, muscular arteries. arteries branch into these, which ultimately lead to capillaries that perfuse the tissue.
venules
smaller venous structures that connect capillaries to larger veins of body.
endothelial cells
lines all of the blood vessels. helps to maintain the vessel by releasing chemicals that aid in vasodilation and vasoconstriction. can allow white blood cells to pass through the vessel wall and into tissues during an inflammatory response. release chemicals when damaged that are necessary in formation of blood clots to repair the vessel and stop bleeding.
what to recognize regarding veins and arteries
same types of cells comprise the different vessels and that arteries have much more smooth muscle than veins
arteries typically carry oxygenated blood. which 2 arteries carry deoxygenated blood?
pulmonary arteries (going to lungs) and umbilical arteries (fetus lungs do not work until birth)
capillaries
vessels w/ 1 endothelial layer and are so small that red blood cells travel in a single file line. thin- to allow for diffusion of gases/ nutrients/ waste/ hormones
what is a bruise?
damaged capillaries that leak blood in a closed space
veins
always carry deoxygenated blood. thin walled, inelastic vessels that transport blood to heart.
veins typically carry deoxygenated blood. which 2 veins carry oxygenated blood?
pulmonary veins and umbilical veins
what causes varicose veins?
when blood tries to move backward the valves will slam shut. distended valves where blood has pooled.
typically blood will pass through how many capillary beds before returning to the heart? exceptions?
1, but there are three portal systems where it will pass through two capillary beds in series before returning to heart. (hepatic, hypophyseal, and renal)
hepatic portal system
blood leaving capillary beds in walls of gut passes through the hepatic portal vein before reaching the capillary beds in the liver
hypophyseal portal system
blood leaving capillary beds in hypothalamus travels to a capillary bed in the anterior pituitary to allow for paracrine secretion of releasing hormones
renal portal system
blood leaving the glomerulus travels through an efferent arteriole before surrounding the nephron in a capillary network called the vasa recta.
where does a capillary carry blood?
from arterioles to venules
2 components of blood
- 55% plasma (water, nutrients, salt, gas, hormones, proteins)
- 45% cells (erythrocytes, leukocytes, platelets)
formation of blood cells
hematopoietic stem cells (originate in bone marrow)
erythrocyte
red blood cells. designed with about 250 molecules of hemoglobin in order to carry about 1 billion molecules of Oxygen per cell. typically live for 120 days until recyceld for parts.
shape and reason for red blood cell shape
biconcave. smaller and more surface area to allow for greater gas exchange
what happens when red blood cells mature?
they lose their nuclei, mitochondria, and other membrane bound organelles to make more space for hemoglobin
why is it a good thing that mature red blood cells dont have mitochondria?
so it doesn’t metabolize the oxygen its carrying. thus red blood cells rely on glycolysis to generate ATP
hematocrit
measurement of how much of the blood sample consists of red blood cells (normal is between 36-53%, higher for males)
normal hemoglobin levels
between 12 and 17.5 (higher for males)
leukocytes
white blood cells. less than 1% of total blood volume in healthy person.
2 categories of leukocytes
- granulocytes (neutrophils, eosinophils, and basophils)
2. agranulocytes (lymphocytes and monocytes)
granulocytes (granular leukocytes)
contain cytoplasmic granules that are visible by microscopy. involved in inflammatory reactions, allergies, pus formation, and destruction of bacteria and parasites
agranulocytes
do not contain granules released through exocytosis, like granulocytes.
lymphocytes
primary responder against infection. specific immune response, they learn from experience and are prepared to mount a fast response upon repeated exposure to familiar pathogens. bodys targeted fight against particular pathogens (ex: viruses, bacteria)
B-cells
lymphocytes that mature in spleen/lymph nodes. responsible for antibody generation
T-cells
lymphocytes that mature in thymus and kill virally infected cells and activate other immune cells
monocytes
phagocytize foreign matter (ex: bacteria)
macrophages
monocytes that leave bloodstream and enter an organ (ex: microglia in CNS, Langerhans cells in skin, osteoclasts in bone)
Thrombocytes
platelets. cell fragments or shards released from cells in bone marrow known as megakaryocytes. assist in blood clotting.
hematopoiesis
production of blood cells and platelets. triggered by a number of hormones, growth factors, and cytokines
erythropoietin
secreted by the kidney and stimulates mainly red blood cell development
thrombopoietin
secreted by the liver and kidney and stimulates mainly platelet development
antigens
on surface of red blood cells. any specific target (usually protein) to which the immune system can react. (ex: ABO and Rh factor)
ABO system
A and B are codominant and O(i) is recessive (4 blood types: A, B, AB, O)
universal blood donor
O blood, will not cause ABO-hemolysis in any recipient. can only receive O blood.
universal recipient
receive from all blood types
during blood transfusions, what is actually being transfused?
red blood cells ONLY. no plasma.
If you have A, B, AB, or O blood… what type of antigens do you produce?
you produce the SAME antigens as the type of blood that you have. (no O antigens, people with O blood have no antigens)
If you have A, B, AB, or O blood… what type of antibodies do you produce?
anit-(what you dont have), people with AB blood produce no antibodies.
Rh factor
surface protein on red blood cells. either Rh+ (present D allele) or Rh- (absent D allele)
Rh+ –> autosomal dominant
erythroblastosis fetalis
mother is Rh- and fetus is Rh+ she will become sensitized to Rh factor and her immune system will make antibodies against it. if she chooses to have a second child and its also Rh+ then the mothers antibodies will attack the fetus blood and kill the fetus.
which cell types in blood do not contain nuclei?
erythrocytes and platelets
hypertension
high blood pressure (may result in damage to blood vessel/ organ system)
sphygmomanometer
measure the gauge pressure in the systemic circulation. ratio of systolic/diastolic = ventricular contraction/ ventricular relaxation
normal blood pressure
between 90/60 and 120/80
largest drop in blood pressure
across arterioles to the capillaries. necessary b/c capillaries are thin-walled and unable to withstand the pressure of the arterial side of the vasculature
how can ohms law (V=IR) be applied to the cardiovascular system?
pressure differential = (cardiac output)(total peripheral resistance)
what acts like resistors in a circuit?
arterioles and capillaries because resistance is based on resistivity, length, cross-sectional area
baroreceptors
in walls of vasculature. specialized neurons that detect changes in the mechanical forces on the walls of the vessel. (ex: if blood pressure is too low they will stimulate sympathetic nervous system for vasoconstriction so bp will increase)
atrial natriuretic peptide (ANP)
if bp is too high. specialized atrial cells secrete this hormone. it aids in loss of salt within the nephron acting as a natural diuretic with loss of fluid.
where does gas and solute exchange occur between blood and tissues?
capillaries and it moves with concentration gradients
binding of oxygen to the heme group
oxidation-reduction reaction
healthy oxygen saturation
above 97%
in lungs, where does the oxygen diffuse?
alveolar capillaries
cooperative binding
as O is added or removed from heme group it continuously gets easier to do it. (sigmoidal curve)
how CO2 enters the circulatory system to leave the body?
partially through heme (it has a lower affinity for CO2), but mainly through the blood plasma as the bicarbonate ion (HCO3-)
carbonic anhydrase
catalyzes the combination reaction between CO2 and water to form carbonic acid (H2CO3)
Bohr effect
hemoglobins binding affinity is inversely related to both to acidity and to the concentration of carbon dioxide
what does a left shift in the oxyhemoglobin curve mean?
higher affinity (like fetal hemoglobin)
what does a right shift in the oxyhemoglobin curve mean?
lower affinity
hydrostatic pressure
force per unit area that blood exerts against the vessel walls. (pushes fluid out and is dependent on blood pressure)
oncotic pressure (osmotic pressure)
drawing fluid into the vessels and is dependent on the number of particles dissolved in the plasma
starling forces
balance of opposing forces. essential for maintaining the proper fluid volumes and solute concentrations inside and outside the vasculature.
edema
accumulation of excess fluid in the interstitium
what happens if the lymph nodes are blocked so lymphatic fluid cannot empty though the thoracic duct?
edema
clots
cagulation factors (proteins released by liver) and platelets and prevent/minimize blood loss
endpoint of coagulation cascade
activation of prothrombin to form thrombin and thromboplastin which can then convert fibrinogen into fibrin
what breaks down a clot?
plasmin which is generated from plasminogen.
cause of right shift of oxyhemoglobin dissociation curve?
increased CO2, increased H+, decreased pH, increased temp
cause of left shift of oxyhemoglobin dissociation curve?
decrease CO2, decreased H+, increased pH, decreased temp
exposure of which subendothelial compounds start coagulation cascade? what stabilizes the clot?
exposure on collagen and tissue factor. fibrin stabilizes the clot.
pericardium
sac that protects heart
more acidic blood does what to the hemoglobins affinity for O2
decreases as bloods pH decreases
what happens when you lose albumin into the urine
albumin = plasma protein, so this would decrease the oncotic pressure in the capillaries
