Heart Flashcards
right side of the heart
recieves oxygen poor blood from the body and then pumps this blood to the lungs to pick up oxygen and dispel carbon dioxide
left side of the heart
recieves oxygenated blood and nutrients from the lungs and pumps it through the body.
pulminary circut
veins and arteries that carry blood to and from the lungs
systemic circut
viens and arteries that carry blood to and from the heart to the rest of the body tissues (not lungs)
what are the two recieving chambers of the heart?
the right atrium- recieves deoxygenated blood from the systemic circut (venae cavae)
the left atrium- recieves oxygenated blood from the pulminary circut. (pulminary veins)
what are the pmping mechanisms of the heart
right atrium- pumps blood to the lungs for oxygenation
left atrium- pumps blood (with oxygen) to the rest of the body tissues.
what are the types of vessels associate with the heart and what are their functions?
Capillary beds- where exchange takes place
Veins- delivers from the capillary beds back to the heart (or another set of capillary beds-portal veins) majority are deoxygenated blood.
Arteries- from heart to capillary beds, most are oxygenated and part of the systemic circut.
describe the hepatic portal system
nutrients from the stomach and intestines diffuse through gut wall and enter a capillary bed. this capillary bed leads to the hepatic portal vein, this blood is rich with nutrients but poor in oxygen.
The hepatic portal vein carries these nutrients(and toxins) to the second capillary bed and liver. Nutrients and toxins enter hepatocytes and blood flow continues to the vena cava and into the heart/lungs for reoxygenation.
where is the heart located?
pericardinal cavity, within the mediastum
pericaridum
tripple layered sac that encloses the heart:
- fibrous pericaridum is the outermost layer and made of dense connective tissue. It is fused to the diaphram (inferiorly) and is fused to the vessles entering/leaving the heart (superiorly).
- serous pericardium ( viseral and parietal layers with serous cavity between them) parietal layer is connected to the inside of the fibrous pericardium. the viseral layer is the epicaridum, which lies on the heart and is considered part of the heart wall.
cardiac tompanade
compression of the heart due to excess fluid in the pericardial cavity
describe the four main vessels of the pulmonary and systemic circut and their functions.
aorta- carries oxygenated blood from the heart to the capillary beds
pulmonary veins- carry oxygenated blood to the heart
vena cavae- carries deoygenated blood from the capillary beds to the heart
pulmonary arteries- carries deoygenated blood from the heart to the lungs.
if you are cupids arrow traveling through the skin to the heart wall what layers do you touch? (skip skin)
fibrous pericardium- parietal pericardium- serous fluid-visceral pericardium (epicardium)-myocardium-endocardium
be blood flowing through the pulmonary and systemic loop, start and end in the capillary beds. include vessels, valves, organs.
capillary beds arterioles arteries SVC, IVC and CS right artium- tricuspid valve- right ventricle- pulmonary semilunar valve- pulminary trunk lungs (through pulminary arteries) heart- four pulmonary veins- left atrium -mithral valve -left ventricle- aortic semilunar valve -aorta veins -venules capillary beds.
describe the ‘lub,dub’ sounds of the heart.
lub- both atrioventicular are closing and atrium are contracting
dub-both semilunar valves closing and ventricles begin relaxing.
describe the heart valves and their function.
to prevent backflow of blood.
Right Antrioventicular (AV)- tricuspid valve
Left Atrioventicular (LV)-mitral valve
they are held in place by the cordeae tendonae.
Semilunar Valves
Aortic-left ventricle and aorta
Pumonary-btwn right ventricle and pulmonary trunk
cells of the conducting system
are specialized cardiac muscle cells that generate their own electrical signal in repetition
Decscribe the sequence of conduction through the heart
Sinoatrial SA node- pacemaker of the crew, fastest!
AV node
bundle of HIS, AV bundle
Bundle branches
Purkinje fibers (cardiac muscle cells ‘fibers’)
what is the composition of blood?
plasma, erythrocytes (red blood cells), Leukocytes (white blood cells), platelets (cell fragments for clot formation)
structure of the blood vessel wall
tunica intima (simple squamous epithelium), tunica media (cicular smooth muscle and elastin), tunica externa (mosley collegen fibers)
arteries in general
experiance higher pressure because they are leaving the heart
- have thicker walls in tunica media (muscle)
- more elastic
types of arteries
elastic- largest in diameter, thick wall rich in elastin. This very elastic vessel smooths out the pressure fluctuations
Muscular arteries- most named, abundant in body, thicer i the tunia media, regulates blood pressure and distribution , ex-during digestion.
Arterioles- smallest, connects to the capillary beds, not much connective tissue.
capillary structure
very thin wall facilitates diffusion (only the tunica intima) single file line of blood cells, large surface area for diffusion, many branches.
how do capillaries control blood flow to tissues?
precapillary sphincters close when tissues is inactive. this mechanism allows blood to connect through a meta-arteriole (thoughughfare) within the capillary bed.
types of capillaries
continuous capillaries- many tight junctions between endothelial cells. least “leaky”
tightest in the brain but also exist in other organs, tight but not completely, select molecules still move through intercellular shaft.
Fenestrated capillaries- lots of holes, easy and rapid diffusion, located in enodcyrine glands, kidney, intestines and synovial membranes
Discontinuous-has fenestrations and very few tight junctions, intracellular shafts are large. located in bone marrow, spleen and liver.
Veins in general
low pressure vessels. have thinner walls and a larger lumen, holds up to 605 of the bodies blood (reservoirs), are collapsible contain valves to prevent back flow of blood. slow because of pressure, skeletal muscle and inner valves help with veinous return to heart.
Types of veins
veins, veinules and portal veins.
describe portal veins
like all portal systems the hepatic portal vein conects two capillary beds between the stomach and small intestines and the liver, then reenters through the inferior vena cava.
