Anatomy Unit 5 - the heart and fetal circulation

what are the major components of the cardiovascular system?

heart, blood vessels, blood

what is the cardiovascular systems major function?

transportation of nurtients and oxygen, waste products, and hormones

how is the heart positioned in the body?

slightly to the left with the apex pointing towards the left hip

what are the two circuits? where do they go and why?

pulmonary circuit, to the lungs to become oxygenated; systemic circuit, to the entire body for transportation

what does the right side of the heart do?

receives deoxygenated blood from the body and pumps it to the lungs

what does the left side of the heart do?

receives oxygenated blood from the lungs and pumps it to the body

what is a vein?

a vessel that carries blood to the heart

what is an artery?

a vessel that carries blood away from the heart

what are the chambers of the heart?

right atrium, right ventricle, left atrium, left ventricle

what are the auricles of the heart?

extensions of the atria

where does the right atrium receive blood from?

superior vena cava, inferior vena cava, coronary sinus

what does the right ventricle pump blood into?

pulmonary trunk which splits into right and left pulmonary arteries

where does the left atrium receive blood from?

two right pulmonary veins and two left pulmonary veins

what does the left ventricle pump blood into?

aorta; ascending aorta, arch of aorta, descending aorta

what does oxygenated blood travel in?

arteries and veins

3 multiple choice options

what prevents back flow in the chambers?

valves

what valve prevents back flow into the right atria?

tricuspid

what valve prevents back flow into the left atria?

bicuspid or mitral

what valve prevents back flow into the right ventricle?

pulmonary semilunar

what valve prevents back flow into the left ventricle?

aortic semilunar

what causes valves to open and close?

pressure

what is systole?

ventricles contract

when does the "lub" sound happen?

systole

what causes the "lub" sound?

tricuspic and bicuspid valves close

what is diastole?

ventricles relax

when does the "dub" sound happen?

diastole

what causes the "dub" sound?

semilunar valves closing

what are the layers of the heart from superficial to deep?

epicardium, myocardium, endocardium

which part of the heart is the thickest?

left ventricle

when does maximum blood flow to the myocardium occur?

diastole

why is there limited blood flow in coronary circulation during systole?

coronary arteries are compressed and the entrances are partially blocked by the cusps of the aortic semilunar valve

what artery is most likely to be the issue in heart attacks?

anterior interventricular artery

what vein is paired with the right marginal artery?

small cardiac vein

what vein is paired with the anterior interventricular artery?

great cardiac vein

what vein is paired with the posterior interventricular artery?

middle cardiac vein

what is the intrinsic conduction system?

sets the basic rhythm of the beating heart

what are the steps of the intrinsic conduction system?

1. sinoatrial node (pacemaker)

2. atrioventricular node

3. atrioventricular bindle (Bundle of His)

4. bundle branches

5. Purkinje fibers

what does a fetus need from its mothers circulation?

oxygen, nutrients, removal of waste

what is the placenta?

an organ that allows the maternal and fetal blood to communicate

how many umbilical veins are there? what do they do?

one; brings oxygen and nutrients to the fetal heart

how many umbilical arteries are there? what do they do?

two; take deoxygenated blood away from the fetal heart

where does the umbilical vein pass through?

the primitive liver to the inferior vena cava

what does the umbilical regress into?

ligamentum teres (round ligament of the liver)

what is foramen ovale in a fetus?

a hole between the right an left atrium to bypass the lungs

does blood still flow to the lungs in a fetus?

yes, only a small amount to nourish the tissue

what does foramen ovale become after birth?

fossa ovalis

what is the ductus arteriosus in a fetus?

vessel connecting the left pulmonary artery to the aorta

what does the ductus arteriosus become after birth?

ligamentum arteriosum