Anatomy: Cardiovascular System Flashcards
Heart
pumps to keep blood flowing
Vessels
Highway system
Capillaries
loading and unloading docks
Heart Chambers
2 chambers for receiving blood.
2 chambers for pumping
Two circuit systems for the heart:
Pulmonary
Systemic
Pulmonary Circuit:
Heart-lungs, gas exchange, lungs- heart
What do the veins do?
return blood to the heart
De-oxygenated blood
Blood poor
What do arteries do?
Take blood away from the heart
oxygenated blood
Oxygen-rich blood
Where does the systematic travel?
To and from the rest of the body.
Where does the heart sit?
in the thoracic cavity within the pericardium (around the heart)
What is the pericardial sac? And what is within it?
Serous membrane.
Very strong connective tissue
Both visceral and parietal pericardium is within it.
Parietal
layer of the heart that is stuck to the wall of the pericardial cavity
Visceral
layer of the heart stuck to the surface of the heart
CANNOT SCRAPE AWAY
Why is there lubricating fluid produced between the layers of the heart?
To reduce friction around the constantly moving heart.
What are the three layers of the heart wall?
Epicardium(AKA visceral pericardium) Outer surface
Endocardium- innermost layer. Think slick surface for blood to flow past.
Myocardium- middle layer. Thick and heavy on left side, thinner on right.
What are cardiocytes?
cardiac muscle cells
What are the characteristics of the cardiac muscle tissue?
Striations, one nucleus, connected by intercalated discs (specialized cell juncts)
Have a high concentration of myoglobin and many mitochondria
What are atrias?
Entry ways
What are auricles?
Ears for expansion.
Each atria has one
What is the purpose of the coronary circulatory system?
Used to feed the heart because it needs nourishment, too.
Where do veins and arteries of the circulatory system attach?
at the base, which is the top of the heart
Where is the apex of the heart?
Lies slightly left of the midline at the bottom of the heart.
What are the three ways that blood enters the right atrium?
The superior and inferior vena cava, and the coronary sinus
What are valves?
Fold of fibrous tissue that help prevent backflow of blood.
Semilunar and cuspid valves
Where does the right atrium receive blood from?
Systematic circulatory system
Where does the coronary sinus return the blood to?
The right atrium from the coronary veins
What forces blood through the pulmonary semilunar valve into the pulmonary trunk and to lungs?
Contraction of the right ventricle
Where does gas exchange occur in the pulmonary circuit?
The pulmonary capillaries around the alveoli in lungs
Where does the pulmonary circuit begin and end?
Begins- R. ventricle
Ends- L atrium
Where does the systemic circuit begin and end?
Begin- left ventricle
End- right atrium
What does the systemic circuit do?
Supplies the rest of the capillary bed in the body.
Why is the wall of the right side of the heart thinner than the left side?
Proximity of lungs
Contraction forces and pressure
What does the coronary circulatory system do?
Nourishes/feeds the heart cells
Where does the right coronary artery supply blood to? and where is it located?
Right atrium, SA (sinoatrial) and AV (atrioventricular) nodes, and portions of both ventricles
Originates at the base of the aorta.
where does the Left coronary artery supply blood to?
Left ventricle, left atrium, interventricular septum
Where does the circumflex artery branch off of?
The left coronary artery
What do arteries of the coronary system show?
Anastomosis
What is anastomosis?
Interconnectedness that insures constant blood supply to the heart.
There are multiple routes to get blood from any part of the body
this allows the heart muscle to never go without blood.
What is autohythmicity?
cells that contract without external stimuli
they are well coordinated and efficient
Sinoatrial and Atrioventricular Nodes:
Impulse begins at SA node (located in wall of R. atrium near entrance of superior vena cava)
Cells of SA node are connected to AV node
AV node found on floor of R. atrium
AV node passes impulse to the ventricles
Action potential travels along the AV bundle, into the Left and Right bundle that branches in the interventricular septum, then along Purkinje cells to each cell of the ventricles
What does systole mean?
contraction
What does diastole mean?
Relaxation/filling
What causes the “lubb-dupp” heart sound?
lubb- closing of AV valves
Dupp- closing of semilunar valves
3 layers of arteries and veins
tunica interna
tunica media
tunica externa
Tunica interna:
inner layer of the a and v.
includes the endothelium and basement membrane
In arteries- there is also internal elastic membrane in this layer.
Tunica media:
middle layer.
contains concentric rings of smooth muscles; responsible for vasoconstriction and vasodilation
Tunica externa:
outer layer
Stabilizes and anchors the blood vessels
Composed of collagen fibers and some elastic fibers.
What are some differences between arteries and veins?
wall of Arteries are generally thicker than veins
when not opposed by blood pressure, arteries contract, appearing smaller in diameter than associated veins
3 types of arteries:
elastic arteries
muscular arteries
arterioles
Elastic arteries:
large arteries that take blood from the heart
walls are not as thick proportionally as other arteries
Extremely resilient
Muscular arteries:
distribute blood to skeletal muscles and internal organs
Large amount of smooth muscle
Arterioles:
small muscular arteries
Capillaries:
blood vessels that allow exchange of fluids and gases
Blood flow is slow; surface of walls modified to allow for a diffusion surface.
Veins:
collect blood from capillary beds and tissues and returns it to the heart.
Categorized by diameter:
Venules
medium-sized veins
large veins
Venules:
smallest vessels
Lack a tunica media
Medium- sized veins
Few fibers of smooth muscle in them.
Have all the tunicas but tunica media is thin
Large veins:
all three layers of tunica are present.
Naming of vessels:
names refer to the part of the body where the vessels lie, or the organ that they supply.
left and right are important
usually veins lie parallel to arteries (exception- neck and extremities)
arteries are deep to the veins
vessels visible on anterior surface of arm are veins; they help in temperature maintenance.
Hepatic portal system:
Subdivision of systemic venous circulation
Composed entirely of veins and are found in the liver.
Where do all digestive organs drain their blood? and what happens there?
drain into the liver, except the liver
The blood is cleansed and detoxified
Alcohol consumption in the hepatic portal system:
excessive quantities results in intoxication
Intoxicated state lost after liver breaks down alcohol.
What is cirrhosis?
Destruction of liver tissue
fetal circulation- life in utero:
Different blood pathways.
Umbilical arteries take fetal blood to the placenta to be cleansed and pick up oxygen and nutrients.
Umbilical vein brings nutrient-rich oxygenated blood back to the fetus.
what is a problem with fetal circulation?
what is the solution?
There is no gas exchange in the fetal lungs
2 adaptations to fetal heart prevent large volume of blood flow through pulmonary circuit.
What are the two adaptations to the fetal heart?
foramen ovale- between the two atria
ductus arteriosus- between the aortic arch and the pulmonary trunk.
What happens to the ductus arteriosus at birth?
Fetus takes a breath an expands lungs and pulmonary vessels, and shuts the DA.
What is the remnants to the ductus arteriosus?
ligamentum artiosum
How is the fossa ovalis formed?
the foramen ovale is shut by a valvular flap at birth leaving a slight depression in the adult heart (fossa ovalis)
What does the inhalation of nicotine result in?
vasoconstriction of arterioles
What does nicotine stimulate the secretion of and what does it do?
epinephrine
a heart stimulant and thus increases cardiac output
this leads to a raised BP and increase strain on the heart.
