cardio anatomy Flashcards
What is pericardiocentesis?
A procedure where fluid is pulled off the pericardium. If fluid is around the heart and stretches the pericardial sac out, the heart doesn’t have room to expand. Usually done in the OR. In extreme conditions and instability, can be done in the ER with US
Pericardial effusions can be caused by what?
CHF, viral illnesses, chirosis, etc
Elevated Jugular venous pressure (JVP) can indicate what?
Can indicate heart issues and pericardial effusion
The mediastinum separates what two cavities?
The pleural cavities and the middle mediastinum houses the heart.
The thymus, trachea, aorta, vena cava all run through the mediastinum
What is the pericardium made of?
Fibrous tissue and serous (parietal and visceral). Parietal lines the pericardium and visceral lines the heart. Sac is anchored to the diaphragm inferiorly and anchored to the sternum anteriorly. The sac limits the overstretching of the heart.
What nerves supply the pericardium?
The phrenic nerve (C3, C4, C5) supplies the pericardium. Referred pain from pericarditis can occur in the shoulders and neck
What is another area of the body with referred pain?
People with gallbladder issues, can come in with shoulder pain
What are the surfaces of the heart?
anterior/sternocostal, inferior/diaphragmatic, L pulmonary, R pulmonary, base, and apex (palpate the PMI at the apex of the heart)
What nerves supply the heart muscle?
The spinal nerves (T2-T4) sensory nerves to the heart and dermatomes. Tissue is dying from ischemia. Radiation of pain down the left arm.
What are the sulci of the heart?
Coronary, anterior interventricular, posterior interventricular. There is fat in the sulci but there are arteries and veins that run in the sulci too
What does the coronary sulcus separate?
Right atria and right ventricle
Explain blood flow through the heart
Describe the right atrium structures
Superior and inferior vena cava, coronary sinus, pectinate, fossa ovalis, auricle (partially reflected). The coronary sinus drains the coronary veins.
The pectinate muscles in the walls of the atrium help with contraction.
What is important about the auricle?
The auricle increases surface area and acts as a blood reservoir to improve contraction. The auricle is typically where blood clots form. The auricle also houses some of the pacemaker cells of the heart.
What is important about the fossa ovalis?
a remnant from the foreman ovale in utero. An echo with a “bubble study”= a patent foramen ovale (PFO) that doesn’t fully close after birth. Looking to see if bubbles travel between the two atria
Define the tricuspid valve
Tricuspid (atrioventricular) valve with chordae tendinea and attach via papillary muscles. R ventricle (trabeculae carneae, conus arteriosus/ Tetralogy of Fallot), pulmonary (semilunar) valve cusps. Pulmonary trunk/ arteries to the lungs (carry deoxygenated blood). No chordae tendena with semilunar valves.
What is the point of the tricuspid valve?
What is the point of the tricuspid valve?
The whole point of the valve is to prevent backflow of blood.
What do trabeculae carnage function for?
to help with contractions. There is no trabeculae by the pulmonary valve called the conus arterosus and it slows the blood down to exit so as not to increase pressure so much. ex: conus arteriosis, so narrowing of blood flow and more turbulent blood flow.
Which ventricle is thicker?
The right ventricle is much thinner and the left ventricle is naturally much thicker because it pumps blood to the whole body.
What is the tetralogy of Fallot?
Tetralogy of Fallot (congenital birth defect)- malposition of structures where the conus arteriosis is narrow and so there is more turbulent blood flow through the pulmonary trunk, causing things like hypoxia
How do the semilunar valves close?
The blood fills them up and sloshes onto them
What is the cardiac skeleton?
It is made up of 4 interconnecting fibrous rings that serve as points of attachment and are held together by trigones.
Describe the structures of the left atrium
Pulmonary veins from the lungs, auricle appendage, valve of foramen ovale (closed). Intraaterial spetum is the smooth portion.
What is left ventricular hypertrophy?
Left ventricular hypertrophy (extra thickening of the muscle) is common in individuals with high blood pressure
Describe the structures of the bicuspid valve
Mitral (bicuspid/atroventricular) valve. L ventricle. Aortic valve (coronary arteries inside SL cusps), aorta (ascending aorta).
What is the likelihood of having certain types of dominant hearts?
R dominant heart in the image
R dominant heart 85%
L Dominant heart 10-15% (the PDA comes off the left coronary artery)
Codominant heart 5-10%
What determines the dominance of the heart?
The PDA (Posterior interventricular branch of right coronary artery)
What does the right coronary artery (RCA) supply?
Originates at the opening of the semilunar valve and passes anteriorly in the coronary sulcus. And goes kind of towards this inferior margin of the heart. It has several branches, the right marginal branch which runs anteriorly onto the heart and then it goes past and serves the posterior interventricular branch. It also gives off the sino-atrial node branch and as they branch, this supplies the SA node. So in total there are 3 branches of the right coronary artery. Supplies the R atrium and ventricle, SA and AV nodes, the interatrial septum, a portion of the L atrium, the posterior inferior one-third of the interventricular septum and a posterior of the posterior part of the L ventricle
What is the electrical activity of the flow of blood?
When the tissue is damaged we can see changes in these areas on an EKG. Chemical electrical activity through calcium
Describe the anterior venous drainage part of the heart
Anterior Interventricular vein becomes the great cardiac veins travel posteriorly → cardiac/coronary sinus
Right marginal becomes small cardiac → cardiac/coronary sinus
Describe the posterior venous drainage part of the heart
The posterior small, middle, cardiac veins → cardiac/coronary sinus
Describe the movement of electrical signals throughout the heart
SA node (intrinsic pacemaker of the heart, located at the junction of SVC and R atrium) → atrioventricular node (intrinsic pacemaker of the heart, near coronary sinus within atrioventricular septum) → atrioventricular bundle (travels along the interventricular septum and turns into the L and R bundle branches) → Purkinje fibers (spreads the impulse down to the bottom of the heart)
What is the cardiac complex?
Cardiac plexus→ branches of the vagus nerve (parasympathetic) and sympathetic trunk
Vagus will either increase or decrease contractility.
What are the cardiac baroreceptors?
They sense arterial stretch and regulate blood pressure= activation and send signals to the medulla, which tells the heart to speed up or slow down, increase/decrease contractility
Aortic arch (CN X)
Carotid sinus (CN IX)
What is orthostatic hypotension and how does the body prevent it?
Usually due to dehyration. Baroreceptors help prevent this and help our body response to stress or blood loss. Arterial dilation in response to a sense in too much stress.When blood pressure is too low there isn’t a lot of stretch. It is a condition where blood pressure drops significantly when a person stands up from a sitting or lying position. Gravity drops their blood pressure too fast. Parkinson’s disease is a neurological issue
What are the 3 layers of the heart wall?
Epicardium, Myocardium, Endocardium
What is the epicardium?
visceral layer of pericardium
What is the myocardium?
circular or spinal bundles of contractile cardiac muscle cells
What is the endocardium?
innermost layer, is continuous with endothelial lining of blood vessels has more smooth muscle
What are intercalated discs?
Are connecting junctions between cardiac cells that contain: desmosomes and gap junctions. Allow the heart to be a functional syncytium, a single coordinate unit or “function in synchrony”
What are desmosomes?
that hold cells together, and prevent cells from separating during contraction
What are gap junctions?
allow ions to pass from cell to cell, electrically couple adjacent cells. Allow the calcium to flow in and help the heart contract.
What are the borders of the heart?
base, apex, anterior surface, right border, left border, posterior surface
What is the direction of blood flow through the heart?
IVC + SVC –> right atrium (the chamber most medial) –> right ventricle (most anterior) –> deoxygenated blood heads through the pulmonary trunk to the lungs –> pulmonary veins –> left atrium (most posterior) –> left ventricle –> aorta
What features differentiate a right, left, and codominant heart? What features make a heart left dominant?
If the PDA branches off the right or left coronary artery. If the PDA were to branch off both, the heart would be codominant
What is the name of the branch of the left anterior descending artery?
diagonal branch
What is the crista terminalis?
muscular ridge that separate the pectinate muscles from the smoother part of the right atrium
What neural contribution/control does the vagus nerve have on the heart?
the superior and inferior cervical cardiac nerves innervate the cardiac plexus and the heart. These general visceral efferent, or parasympathetic fibers, are associated w/ slowing the heart rate. The thoracic cardiac branches to the cardiac plexuses are also parasympathetic and slow the heart rate.
sensory, motor, parasympathetic
When reading about each of the associated nerve branches, record the contribution of sympathetic functions. What happens during sympathetic innervation?
increase HR, increase impulse conduction, dilation of coronary arteries, force of contraction
What is the pulmonary fibrous ring?
prevents over disstension of the right AV valve, provides a direct attachment for cardiac muscle. The collagen of the fibrous ringhelps to separate electrical activities between the chambers by insulating the propagation of electrical impulses during a heartbeat. Pulmonary regurgitations
what is the left fibrous ring?
prevents over disstension of the left AV valve, provides a direct attachment for cardiac muscle. The collagen of the fibrous ringhelps to separate electrical activities between the chambers by insulating the propagation of electrical impulses during a heartbeat. mitral regurgitations
What is the right fibrous ring?
prevents over disstension of the right AV valve, provides a direct attachment for cardiac muscle. The collagen of the fibrous ringhelps to separate electrical activities between the chambers by insulating the propagation of electrical impulses during a heartbeat. tricuspid regurgitations
What is the aortic fibrous ring?
prevents over disstension of the right aortic valve, provides a direct attachment for cardiac muscle. The collagen of the fibrous ringhelps to separate electrical activities between the chambers by insulating the propagation of electrical impulses during a heartbeat. aortic regurgitations
What is the location and function of anterior interventricular vein ?
within the anterior interventricular sulcus near the apex of the heart. drains the inferior portion of the left ventricle.
What is the location and function of the right marginal vein?
arises along the right ventricle at the inferior border, the junction between the anterior (sternocostal) and inferior (diaphragmatic) surfaces. Adrians the right atrium and right ventricle
What is the location and function of great cardiac vein?
superiorly within the anterior interventricular sulcus then with the coronary sulcus to the coronary sinus. drains left side of the heart
What is the location and function of small cardiac vein?
follows the course of the right marginal artery and crosses deep to the right coronary artery as it travles to the coronary sinus. drains the posterior portion of the right atrium and ventricle
What is the location and function of posterior cardiac vein?
drains the left atria
What is the location and function of left marginal vein?
lateral aspect of the left ventricle. drains the left ventricle
What is the location and function of middle cardiac vein?
courses superiorly within the posterior interventricular groove and drains into the coronary sinus. drains the inferior diaphragmatic surface of the heart.
What is the location and function of coronary sinus vein?
posterior interventricular region. delivers deoxygenated blood form the myocardium to the right atrium.
What is the location and function of SA node of the right coronary artery?
junction of the crista terminalis in the upper wall of the right atrium and openingof the SVC
What is the location and function of right marginal branch of the right coronary artery?
courses inferiorly towards the apex of the heart. supplies the right ventricle
What is the location and function of posterior interventricular branch (PDA) with diagonal branches of the left coronary artery?
descends within the anterior interventricular grooveand is accompanied by the great cardiac vein. usually reaches the apex to the posterior (inferior) aspect of the heart
supplies parts of the left and right ventricle and anterior 2/3of the interventricular septum
What is the location and function of circumflex branch of the left coronary artery?
courses superiorly on the left atrium. supplies to the left atrium
What is the location and function of left marginal of the left coronary artery?
circumflex branch of the coronary artery. supplies the left ventricle
the apex of the lies at what?
5th intercostal space at the midclavicular line of the left thorax
What is part of the parietal pericardium?
the pericardial sac
at what location are the visceral and parietal layers of the serous pericardium?
base of the heart surrounding the great vessels
the electical connection pathwya between the atria and ventricles is the?
bundle of His
What is the endocardium?
one cell layer thin of endothelium and some underlying connective tissue in varying thicknesses. more developed in the atria than the ventricles. Simple squamous epithelium/ elongated or flattened nuclei. It is the special name given to the epithelial lining of blood vessels
The p wave on an EKG represents?
depolarization of the atria
What is the epicardium?
What is the myocardium?
main and thickest layer. tunica media of the artery. a big band of darkly staining cardiac muscle cells. sectioned in various orientations. stain with hemtoxin and eosin. individual cells are irregular in size and shape, because they branch. myofibrils are readily apparent as cells pecking the cells cytoplasm. ribbon shaped. nuclei large and located in the middle of the cell. other nuclei line the connective tissue between. most of these in RBC and fibroblasts to make intertissue and support for the cardiac muscle. capillaries interspersed throughout.
what are the trabeculae?
allows for coordination of rhythm and the heart beat
what are papillary muscles?
extend off the walls of the heart to attach chordinae tendonae
what are the pectinate muscles?
only in the atria and plays a large role in fetal development
what are cardiac interfasicles or bundles?
provide a pathway for arterioles and venuoles
What structure separates the base from the diaphragmatic surface?
coronary sinus
what sits immediately posterior to the base of the heart?
esophagus
the anterior surface is made up of?
right atrium, right ventricle, left ventricle
the left pulmonary surface is made up of?
left ventricle
the right pulmonary surface is made up of?
right atrium
encircling the heart on both sides and separating the atria from the ventricles is what structure?
coronary sulcus
anterior inteventricular sulcus
runs down the anterior of the heart separating the two ventricles, containing the great cardiac vein and anterior interventricular artery
posterior interventricular sulcus
runs on the diaphragmatic surface and contains the middle cardiac vein and posterior interventricular artery
