Anatomy, Embryology, Histology Flashcards
The heart is located in the middle mediastinum and is surrounded by the _
The heart is located in the middle mediastinum and is surrounded by the pericardial sac
The _ represents the right border of the heart
The right atrium represents the right border of the heart
The _ represents the majority of the anterior aspect of the heart and it touches the internal surface of the rib cage
The right ventricle represents the majority of the anterior aspect of the heart and it touches the internal surface of the rib cage
The _ represents the base/ posterior aspect of the heart
The left atrium represents the base/ posterior aspect of the heart
The _ represents the apex of the heart and left boarder
The left ventricle represents the apex of the heart and left boarder
The _ is posterior to the sternal angle
The aortic arch is posterior to the sternal angle
The heart is covered by the body of the sternum and ribs _ through _
The heart is covered by the body of the sternum and ribs 3-6
_ is an large artery that carries deoxygenated blood
Pulmonary trunk is an large artery that carries deoxygenated blood
What are the semilunar valves?
Semilunar valves are located at the entrance to the aorta and the pulmonary trunk
Slender threads called _ attach the free margin of the cusps to the papillary muscles within the ventricles
Slender threads called chordae tendinae attach the free margin of the cusps to the papillary muscles within the ventricles
The papillary muscles and associated cords maintain the _
The papillary muscles and associated cords maintain the closure of the AV valves during ventricular constraction and prevent regurgitation of blood into the atria
The right ventricle/ tricuspid valve has 3 papillary muscles: _ , _ and _
The right ventricle/ tricuspid valve has 3 papillary muscles: anterior , posterior and septal
The left ventricle/ mitral valve has 2 papillary muscles _ and _
The left ventricle/ mitral valve has 2 papillary muscles anterolateral and posteromedial
Each of the semilunar valves is composed of _ which help ensure closure and prevent the regurgitation of blood when they close during ventricular diastole
Each of the semilunar valves is composed of 3 semilunar cusps/ lunule which help ensure closure and prevent the regurgitation of blood when they close during ventricular diastole
The right and left coronary arteries arise from the _
The right and left coronary arteries arise from the aortic sinus which is just above the aortic valve
The coronary arteries are important for _
The coronary arteries are important for vascularizing the myocardium of the heart
The coronary arteries fill with blood during _ stage of the cardiac cycle
The coronary arteries fill with blood during ventricular diastole when the heart muscle is relaxing
The leftcoronary artery divides into two large branches _ and _
The left coronary artery divides into two large branches left anterior descending artery (LAD) and circumflex artery
Another name for the LAD is the _
Another name for the LAD is the anterior interventricular
The LAD is responsible for vascularizing _
The LAD is responsible for vascularizing:
* Anterior 2/3 of the ventricular septum
* Bundle of His
* Anterior aspect/wall of the left ventricle
* Anterolateral papillary muscle (shared with circumflex)
The circumflex artery is responsible for vascularizing _
The circumflex artery is responsible for vascularizing:
* Left atrium
* Anterolateral papillary muscle
* Posterior/ lateral part of the left ventricle vis the left obtuse marginal artery
The circumflex artery gives rise to the _ which vascularizes the posterior/ lateral aspect of the left ventricle
The circumflex artery gives rise to the left obtuse marginal artery which vascularizes the posterior/ lateral aspect of the left ventricle
The _ artery vascularizes the bundle of his
The LAD vascularizes the bundle of his
The right coronary artery divides into 4 major branches:
The right coronary artery divides into 4 major branches:
* SA nodal artery
* Right marginal artery
* Posterior Descending Artery (PDA)
* AV nodal branch
The _ artery (which is a division of _ ) vascularizes the SA node
The SA nodal artery (which is a division of RCA ) vascularizes the SA node
The _ artery (which is a division of _ ) vascularizes the right ventricle and apex
The right marginal artery (which is a division of RCA ) vascularizes the right ventricle and apex
The _ artery (which is a division of _ ) vascularizes the AV node
The AV nodal branch (which is a division of RCA ) vascularizes the AV node
The PDA, which comes from the RCA in 85% of individuals vascularizes _
The PDA, which comes from the RCA in 85% of individuals vascularizes posterior 1/3 of the interventricular septum
* Also the posterior aspect of the ventricles
* Posteromedial papillary muscles
The anterolateral papillary muscle has a (dual/ single) blood supply
The anterolateral papillary muscle has a dual blood supply
* Supplied by the LAD and the circumflex
The posteromedial papillary muscle has a (dual/ single) blood supply
The posteromedial papillary muscle has a single blood supply
* Supplied by the PDA
The _ is a large vein that receives most of the venous return from the heart and drains into the right atrium near the IVC
The coronary sinus is a large vein that receives most of the venous return from the heart and drains into the right atrium near the IVC
_ is a vein that accompanies the LAD and dumps into the coronary sinus
Great cardiac vein is a vein that accompanies the LAD and dumps into the coronary sinus
_ is a vein that accompanies the PDA and dumps into the coronary sinus
Middle cardiac vein is a vein that accompanies the PDA and dumps into the coronary sinus
_ is a vein that accompanies the RCA and dumps into the coronary sinus
Small cardiac vein is a vein that accompanies the RCA and dumps into the coronary sinus
Three layers of the heart, superficial to deep
- Epicardium the visceral layer of the pericardium
- Myocardium cardiac muscle cell layer
- Endocardium simple squamous epithelium
The _ is a simple squamous epithelium (endothelium) that lines the lumen of the heart
The endocardium is a simple squamous epithelium (endothelium) that lines the lumen of the heart
The subendocardium is a connective tissue layer beneath the endocardium that contains _
The subendocardium is a connective tissue layer beneath the endocardium that contains veins, nerves, purkinje fibers
The _ is a layer of simple squamous epithelium (mesothelium) on the external surface of heart tissue
The epicardium is a layer of simple squamous epithelium (mesothelium) on the external surface of heart tissue
Beneath the mesothelium is _ tissue that contains nerves, coronary vessels, and adipose tissue
Beneath the mesothelium is fibroelastic tissue that contains nerves, coronary vessels, and adipose tissue
Which layer of the heart wall is seen?
Myocardium
Nuclei in cardiac myocytes will be located _ in the cell and will be _
Nuclei in cardiac myocytes will be located centrally in the cell and will be mononucleated (1-2)
Characterize cardiac myocytes
Cardiac myocytes:
* Blunt-ended (intercalated discs)
* Branched
* Striated
* Involuntary contraction
_ are step-like junctions that form end-to-end attachments between adjacent cardiac muscle cells
Intercalated discs are step-like junctions that form end-to-end attachments between adjacent cardiac muscle cells
The lateral portion of the intercalated disc contains _ and _
The lateral portion of the intercalated disc contains desmosomes and gap junctions
The transverse portion of the intercalated disc contains _
The transverse portion of the intercalated disc contains fasciae adherens, desmosomes, gap junctions
_ are important connections between cardiac myocytes that facilitate ionic coupling and aid in coordinating contraction
Gap junctions are important connections between cardiac myocytes that facilitate ionic coupling and aid in coordinating contraction
A functional contractile unit that spans from Z disc to Z disc is called a _
A functional contractile unit that spans from Z disc to Z disc is called a sarcomere
T tubules invaginate from the sarcolemma at the _
T tubules invaginate from the sarcolemma at the z disc
The sarcoplasmic reticulum is located at the _
The sarcoplasmic reticulum is located at the z disc
A dyad is defined as _ and _
A dyad is defined as 1 sarcoplasmic reticulum and 1 T tubule
* Located at the Z disc
How do the purkinje fibers transfer information to the cardiac myocytes?
Purkinje fibers communicate with cardiac myocytes through gap junctions and connect via desmosomes and fasciae adherens but not through intercalated discs
Purkinje fibers can be found in _ layer of the heart
Purkinje fibers can be found in a subendocardial location
Three layers of arteries superficial to deep
- Tunica adventita connective tissue
External elastic lamina
- Tunica media smooth muscle, elastic fibers
Internal elastic lamina
- Tunica intima endothelium
Large arteries like the aorta will have lots of elastic fibers in the _ layer
Large arteries like the aorta will have lots of elastic fibers in the tunica media
* We will see fenestrated membranes which are thick, concentric sheaths of elastic membrane in the wall
In large elastic, conducting arteries, we will find small vessels called _ that vascularize the artery tissue itself
In large elastic, conducting arteries, we will find small vessels called vasa vasorum that vascularize the artery tissue itself
Describe the components of a muscular artery
Muscular arteries:
* These are smaller than elastic arteries and they distribute blood to various organs
* Have a thick layer of SM cells, internal elastic lamina, usually an external elastic lamina layer too
* Contains vasa vasorum
The vessels that are largely responsible for regulating blood pressure are the _
The vessels that are largely responsible for regulating blood pressure are the arterioles
* They are the terminal arterial vessels
* They are our smallest arteries
* Tunica media consists of only 1-2 layers of smooth muscle
Fenestrated capillary
(Continuous/ fenestrated/ sinusoid) capillaries have a discontinuous basal laminae
Sinusoid capillaries have a discontinuous basal laminae
Both _ and _ capillaries contain fenestrations
Both fenestrated and sinusoid capillaries contain fenestrations
Where do we find continuous, fenestrated, and sinusoid capillaries?
Continuous: muscle, nerve, lungs, BBB
Fenestrated: endocrine glands, intestine, pancreas, renal glomerulus
Sinusoid: liver, spleen, bone marrow, lymph
_ cells convert inactive angiotensin I to angiotensin II (especially in the lung)
Endothelial cells convert inactive angiotensin I to angiotensin II (especially in the lung)
_ cells release relaxing factor nitric oxide and contraction factor endothelin 1
Endothelial cells release relaxing factor nitric oxide and contraction factor endothelin 1
Endothelial cells also release _ to initiate blood coagulation
Endothelial cells also release tissue factor to initiate blood coagulation
Other roles that endothelial cells play
- Deactivate substances like bradykinin, serotonin, thrombin, NE, prostaglandins
- Breakdown lipoproteins –> TGs, cholesterol
_ is a substance released by endothelial cells that acts as a potent vasodilator and inhibitor of intravascular platelet aggregation
Prostacyclin is a substance released by endothelial cells that acts as a potent vasodilator and inhibitor of intravascular platelet aggregation
List the layers of veins from superficial to deep
- Tunica adventita
- Tunica media
- Tunica intima
The thickest and most prominent layer in veins is _
The thickest and most prominent layer in veins is tunica adventita
Veins that contain valves can be found in _ layer
Veins that contain valves can be found in tunica intima
(Artery/ Vein) will appear rounder
Artery will appear rounder
(Artery/ Vein) will have a thicker wall
Artery will have a thicker wall
The tunica media in (artery/ vein) will have more smooth muscle
The tunica media in artery will have more smooth muscle
The lumen of (artery/ vein) will be larger
The lumen of vein will be larger
Lymphatic vessel with valve
The fetal heart begins as a tube and it starts to circulate blood unidirectionally during week _ of development
The fetal heart begins as a tube and it starts to circulate blood unidirectionally during week 5 of development
Name the five regions of the primitive heart tube
- Truncus arteriosus
- Bulbus cordis
- Primitive ventricle
- Primitive atrium
- Sinus venosus
The truncus arteriosus turns into the _ and _
The truncus arteriosus turns into the ascending aorta and pulmonary trunk
The bulbus cordis turns into the _
The bulbus cordis turns into the right ventricle
The primitive ventricle turns into the _
The primitive ventricle turns into the left ventricle
The primitive atrium turns into the _
The primitive atrium turns into the right and left atria
The sinus venosus turns into the _
The sinus venosus turns into the coronary sinus, posterior right atrium
The common cardinal veins become the _
The common cardinal veins become the superior vena cavae
The umbilical vein becomes the _
The umbilical vein becomes the ligamentum teres hepatis
The _ are four swellings of the heart tube at the junction of the atrium and ventricle –> important to both atrial and ventricular septation; they form atria septa and AV valves
The endocardial cushions are four swellings of the heart tube at the junction of the atrium and ventricle –> important to both atrial and ventricular septation; they form atria septa and AV valves
Endocardial cushions are composed of several cells types including _ embryological cells
Endocardial cushions are composed of several cells types including neural crest cells
The _ is an important hole that allows placental (oxygenated) blood to travel from the _ –> _ and bypass the fetal lungs
The foramen ovale is an important hole that allows placental (oxygenated) blood to travel from the RA –> LA and bypass the fetal lungs
Steps of atrial septation
- Foramen primum
- Septum primum
- Foramen secundum
- Septum secundum
Once the fetus is born, the pulmonary vascular resistance will _ ; the left atrial pressure will _ and the right atrial pressure will _
Once the fetus is born, the pulmonary vascular resistance will drop ; the left atrial pressure will increase and the right atrial pressure will decrease –> shuts the patent foramen ovale
The _ portion of the interventricular septum begins on the floor of the primitive ventricles and grows upward; the _ portion begins from the endocardial cushions
The muscular portion of the interventricular septum begins on the floor of the primitive ventricles and grows upward; the membranous portion begins from the endocardial cushions
The truncus arteriosus joins the _ and _ in a common outflow
The truncus arteriosus joins the developing pulmonary trunk and ascending aorta in a common outflow
The aorticopulmonary septum must first form as a _ as the truncus arteriosus gives rise to the pulmonary arteries and aorta
The aorticopulmonary septum must first form as a spiral as the truncus arteriosus gives rise to the pulmonary arteries and aorta
In the fetus, the lungs are filled with amniotic fluid rather than air; so the fetal oxygen source is the _
In the fetus, the lungs are filled with amniotic fluid rather than air; so the fetal oxygen source is the placenta
We have three fetal blood vessels _ and three fetal shunts _ that disappear after birth
We have three fetal blood vessels: umbilical vein and umbilical arteries (2) and three fetal shunts ductus venosus, foramen ovale, ductus arteriosus that disappear after birth
The placenta is designed such that maternal blood surrounds fetal vessels transporting nutrients and removing waste; it does this without _
The placenta is designed such that maternal blood surrounds fetal vessels transporting nutrients and removing waste; it does this without mixing maternal and fetal blood
The umbilical vein carries (oxygenated/ deoxygenated) blood from the _ to _
The umbilical vein carries oxygenated blood from the placenta to liver to go to the RA
Once the umbilical vein carries oxygenated blood from placenta –> liver, we reach our first shunt, _ which bypasses the liver into the _
Once the umbilical vein carries oxygenated blood from placenta –> liver, we reach our first shunt, ductus venosus which bypasses the liver into the inferior vena cava –> RA
The foramen ovale is our second shunt which allows us to bypass the _ and pump blood from _ to _
The foramen ovale is our second shunt which allows us to bypass the lungs and pump blood from RA to LA, LV, aorta
The diversion of blood through the foramen ovale is called the _ shunt
The diversion of blood through the foramen ovale is called the right-to-left shunt
Ductus arteriosus is a connection point between the _ and _ to “bypass the lungs” which have high pulmonary vascular resistance
Ductus arteriosus is a connection point between the pulmonary artery and aorta to “bypass the lungs” which have high pulmonary vascular resistance
* This creates a mixing of deoxygenated blood and oxygenated blood in the descending organs that is then carried to the organs
An increase in left heart pressure after birth helps to close the patent ductus arteriosus; in addition _ also helps it to close
An increase in left heart pressure after birth helps to close the patent ductus arteriosus; in addition decreased prostaglandin E2 also helps it to close
* Additionally the lung releases bradykinin
* All of these help to constrict the walls of the ductus arteriosus
Prostaglandin E1 and E2 is produced by the _ and _ to keep the ductus arteriosus open
Prostaglandin E1 and E2 is produced by the placenta and ductus to keep the ductus arteriosus open
Upon closure of the ductus venosus, the liver is now perfused and the remnant is the _
Upon closure of the ductus venosus, the liver is now perfused and the remnant is the ligamentum venosum
