a&p ii exam #2

what are the major functions of the cardiovascular system?

transportation, regulation, and protection

what are the substances transported by blood?

oxygen, carbon dioxide, nutrients, hormones, waste, and heat

what does blood regulate?

body temperature, pH, and fluid balance

how does blood protect the body?

it prevents blood loss through hemostasis and defends against pathogens

what are two major components of blood?

plasma and formed elements

what percentage of blood is made of plasma?

55%

what is plasma’s major component?

water

how much water makes up plasma?

90%

what are the three major plasma proteins?

albumin, globulins, fibrinogen

what is the function of the plasma protein: albumin?

maintains osmotic pressure

where is albumin produced?

in the liver

what is the function of the plasma protein: globulins?

transports substances & functions as antibodies

where are alpha & beta globulins produced?

in the liver

where are gamma globulins produced?

by plasma cells

what is the function of the plasma protein: fibrinogen?

enables blood clotting

where are fibrinogens produced?

in the liver

what substances (besides plasma proteins) dissolve in plasma?

electrolytes, nutrients, hormones, dissolved gases, waste products

what are the formed elements of blood?

erythrocytes, leukocytes, platelets

what is the function of erythrocytes?

to transport oxygen and carbon dioxide

what is the function of leukocytes?

protects the body against infections & diseases

what is the function of platelets?

helps stop bleeding by forming platelet plugs & assisting blood clotting

list the five leukocytes from most abundant to least

neutrophils, lymphocytes, monocytes, eosinophils, basophils

where does hematopoiesis occur?

in red bone marrow

what is a hemocytoblast?

a pluripotent stem cell that gives rise to all formed elements of blood

what is erythropoiesis?

the production of red blood cells

which hormone regulates erythropoiesis?

erythropoietin (EPO)

where is erythropoietin (EPO) produced?

in the kidneys

what stimulates erythropoietin’s release?

in response to low blood oxygen

what is a reticulocyte?

an immature red blood cell release from the bone marrow before becoming a mature erythrocyte

what is the role of megakaryocytes?

they produce platelets

what is the function of hemoglobin?

binds + transports oxygen & carries a small amount of carbon dioxide

what is a primary function of a neutrophils (a leukocyte)?

phagocytizes (destroys) bacteria

what is a primary function of lymphocytes (a leukocyte)?

fights specific germs & remember them for next time (adaptive immunity)

what is a primary function of monocytes (a leukocyte)?

turn into macrophages that "eat" germs & dead cells (become macrophages for phagocytosis)

what is a primary function of eosinophils (a leukocyte)?

defends against parasites

what is a primary function of basophils (a leukocyte)?

releases histamine during inflammation

what are the three phases of hemostasis?

vascular spasm, platelet plug formation, & coagulation

what are the steps in platelet plug formation?

platelet adhesion, activation, & aggregation to form a platelet plug

what are the basic steps in coagulation?

prothrombin converts to thrombin, then converts fibrinogen into fibrin to form a stable clot

how do the intrinsic and extrinsic clotting pathways differ?

the intrinsic pathway begins with damage inside the blood vessel, while the extrinsic pathway begins with tissue damage outside the vessel

how are the intrinsic and extrinsic clotting pathways similar?

both lead to fibrin clot formation

what are the ABO and Rh blood group systems?

type A, type B, type AB, type O, Rh+, Rh-

what is the type A blood group?

A antigen, anti-B antibodies

what is the type B blood group?

B antigen, anti-A antibodies

what is the type AB blood group?

A & B antigens, no antibodies

what is the type O blood group?

no A or B antigens, anti-A & anti-B antibodies

what blood type is the universal donor?

O negative

what blood type is the universal recipient?

type AB

what is the Rh+ blood group?

Rh antigen present

what is the Rh- blood group?

Rh antigen absent

what can incompatible blood transfusions cause?

agglutination and hemolysis

where is the heart location within the thoracic cavity?

in the mediastinum, between the lungs, posterior to the sternum, superior to the diaphragm

what are the four chambers of the heart?

right atrium, right ventricle, left atrium, left ventricle

what are the major internal structures of the heart?

chambers, septa, valves, papillary muscle, chordae tendineae, venous & arterial openings

what is the function of the chambers in the heart (major internal structure)?

receives and pumps blood

what is the function of the septa in the heart (major internal structure)?

separates right and left sides

what is the function of the valves in the heart (major internal structure)?

prevents backflow

what is the function of the papillary muscles in the heart (major internal structure)?

holds the chordae tendineae in place

what is the function of the chordae tendineae in the heart (major internal structure)?

prevents AV valve prolapse

what is the function of the venous & arterial openings in the heart (major internal structure)?

allows blood to enter and leave the heart

what are the two atrioventricular (AV) valves?

tricuspid and mitral valves

where are the atrioventricular (AV) valves located?

between atria & ventricles

what are the atrioventricular (AV) valves supported by?

chordae tendineae & papillary muscles

what are the two semilunar valves?

pulmonary and aortic valves

where are the semilunar valves located?

at the ventricular exits

what is the difference between atrioventricular valves vs. semilunar valves?

AV valves have chordae tendineae; semilunar valves don’t

what are the layers of the pericardium?

fibrous pericardium, parietal layer of serous pericardium, pericardial cavity, visceral layer of serous pericardium (epicardium)

where the pericardial cavity located?

between parietal and visceral layers

what is the function of the pericardium?

protects the heart, anchors it in place, & reduces friction during beating

what is the myocardium?

cardiac muscle tissue

why are intercalated discs important?

they connect cardiac muscle cells & allow coordinated contractions

what is the function of the endocardium?

lines the heart chambers & valves, & provides a smooth surface for blood flow

what veins drain blood from the myocardium?

cardiac veins that empty into the coronary sinus, which drains into the right atrium

what are the phases of a cardiac contractile cell action potential?

depolarization, plateau phase, & repolarization

why is the plateau phase important in cardiac muscle?

prolongs contraction & prevents tetanus: allowing the heart to pump effectively

what is the difference between a cardiac muscle & a skeletal muscle contraction?

cardiac muscle: contracts involuntarily, has intercalated discs & automaticity, cannot undergo tetanus

skeletal muscle: contracts voluntarily, requires motor neuron stimulation

what are the major blood vessels that enter and leave the heart?

superior & inferior vena cava, pulmonary trunk & arteries, pulmonary veins, aorta

which major blood vessels carry oxygen-rich blood?

pulmonary veins and aorta

which major blood vessels carry oxygen-poor blood?

superior/inferior vena cava, pulmonary trunk & arteries

what is the pathway of blood through the heart?

superior/inferior vena cava → right atrium → tricuspid valve → right ventricle → pulmonary semilunar valve → pulmonary trunk → pulmonary arteries → lungs → pulmonary veins → left atrium → mitral valve → left ventricle → aortic semilunar valve → aorta

what factors produce one-way blood flow through the heart?

pressure differences, opening & closing of valves, coordinated contraction of the myocardium

why is the heart considered a double pump?

the right side pumps blood to the lungs (pulmonary circuit), while the left side pumps blood to the body

what are the parts of the cardiac conduction system in order?

SA node → AV node → AV bundle (Bundle of His) → Right and left bundle branches → Purkinje fibers

how does the cardiac conduction system produce efficient pumping?

it coordinates atrial contraction before ventricular contraction

how does the autonomic nervous system regulate cardiac function?

sympathetic stimulation increases heart rate and contractility; parasympathetic stimulation decreases heart rate

what is a cardiac cycle?

one complete heartbeat

what is a systole?

heart contraction

what is a diastole?

heart relaxation

what are the four phases of the cardiac cycle?

ventricular filling, isovolumetric contraction, ventricular ejection, isovolumetric relaxation

how is atrial systole related to ventricular filling?

strial contraction completes ventricular filling before ventricular systole

during which phase are the AV valves open?

ventricular filling

during which phase are the semilunar valves open?

ventricular ejection

during which phases are the AV & semilunar valves closed?

ventricular filling, isovolumetric contraction, ventricular ejection, isovolumetric relaxation

what causes the first and second heart sounds?

S1 ("lub"): closure of AV valves

S2 ("dub"): closure of semilunar valves

what is systolic blood pressure?

pressure during ventricular contraction

what is diastolic blood pressure?

pressure during ventricular relaxation

what is cardiac output?

the volume of blood pumped by one ventricle each minute

how is cardiac output measured?

liters per minute (L/min)

what is the equation for cardiac output?

cardiac output = heart rate × stroke volume (CO = HR × SV).

how do heart rate and stroke volume affect cardiac output?

increasing either HR or SV increases cardiac output, while decreasing either lowers cardiac output