Heart

Which of the following is the correct conduction pathway through the heart? a. SA node-ventricular muscel-AV node-His bundle-bundle branches-Purkinje fibers-atrial muscle b. SA node-atrial muscle-AV node-bundle branches-His bundle-purkinje fibers-vetricular muscle c. SA node-atrial muscle-AV node-His bundle-bundle branches-Purkinje fibers-ventricular muscle d. SA node-purkinje fibers-AV node- His bundle- bundle branches-atrial muscle-ventricular muscle

C.

Middle mediastinum

Contains the pericardium and the heart and the immediately adjacent parts of the great arteries, phrenic nerves, main bronchi, and other structures in the root of the lungs GREATEST CLINICAL IMPORTANCE

Posterior interventricular branch

Is another branch of the right coronary artery It supplies blood to both ventricles, and then anastomoses with the circumflex artery from the left coronary artery

what is the oblique vein a remnant of

The embryonic left superior vena cava

Right marginal vein

ascends along the right margin of the heart and joins the small cardiac vein in the coronary sinus, or opens directly into the right atrium

Which of the following does NOT empty directly into the right atrium? a. azygous vein b. inferior vena cava c. superior vena cava d. coronary sinus

azygous vein

The left atrium and left ventricle receive their major arterial supply from which artery a. anterior interventricular branch of the left coronary artery b. circumflex branch of the left coronary artery c. marginal branch of the right coronary artery d. posterior interventricular branch of the right coronary artery

b. circumflex branch of the left coronary artery

A patient with a with a "heart valve problem" comes into the the dental clinic for periodontal therapy. She says that her old periodontist always gave her antibiotics before treatment, and insisting that the dentist hear the problem, she places the stethoscope in the left fifth intercostal space medial to the nipple line. Which heart valve is best heard over the apex of the heart a. Tricuspid valve b. mitral valve c. pulmonary valve d. aortic valve

b. mitral valve (bicuspid valve)

What does small cardiac vein receive

blood from the back of the right atrium and ventricle

How does electrical impulse reach AV node

by way of three internodal bundles. The AV node then initiates a signal that is conducted through the ventricular myocardium by way of the atrioventricular bundle (bundle of HIS) and purkinje fibers

The conducting system of the heart is all _________ fibers and NOT _________

cardiac muscle NERVES

What happens if there is resistance to pulmonary blood flow in the lungs

causes a strain on the right ventricle and results in ventricular hypertrophy

Anterior cardiac veins

comprise three or four small vessels which collect blood from the front of the right ventricle and open into the right atrium

Smallest cardiac veins (thesbian veins)

consist of a number of minute veins which arise in the muscular wall of the heart; the majority open into the atria but a few end in the ventricles

When viewed from the back (posterior view) the most obvious structure lying in the coronary sulcus is the

coronary sinus

When do coronary arteries receive most of their blood flow

during diastole or ventricular relaxation when the left ventricle is filing with blood

Sinus rhythm

every P wave is followed by a QRS complex, the R-R interval is regular, and the P-R interval is less than 0.2 seconds

Fast sinus rhythm

faster than 100 beats a minute also called SINUS TACHYCARDIA

The apex of the heart is located at the level of a. third left intercostal space b. fourth left intercostal space c. Fifth left intercostal space d. Sixth left intercostal space

fifth left intercostal space

What allows blood to pass from the right atrium to the left atrium, bypassing the nonfunctional fetal lungs while the fetus obtains oxygen from the placenta

foramen ovale

what is the permanently closed formaen ovale in adults called

fossa ovalis

Where do the coronary arteries arise

from the ascending aorta immediately above the aortic valve. Their major branches are distributed over the surface of the heart lying within subepicardial connective tissue

Where does the ductus arteriosus shunt blood

from the left pulmonary artery to the aorta just beyond the origin of the artery to the left subclavian artery

where does the right atrium receive blood, and what type of blood is it receiving

from the systemic circuit via the superior and inferior venae cavae as well as the coronary sinus deoxygenated blood

Internal or endocardium layer

homologous with the tunica intima of blood vessels. Lines the surface of the heart chambers with SIMPLE SQUAMOUS ENDOTHELIUM and underlying loose connective tissue containing small blood vessels

Myocardium layer

homologous with the tunica media of blood vessels. Forms the bulk of the heart mass and consists predominantly of cardiac muscle cells arranged in a spiral configuration. This spiral arrangement allows the heart to "wring" the blood from the ventricles toward the aortic and pulmonary semilunar valves

The oblique vein ends

in the coronary sinus near its left extremity; this vein is continuous above with the ligament of the left vena cava

Middle cardiac vein ends

in the coronary sinus near its right extremity

Where does the coronary sinus lie and open

in the posterior part of the coronary sulcus (ATRIOVENTRICULAR GROOVE) and opens in the right atrium between the opening of the inferior vena cava and the right atrioventriucluar orfice, it's opening is guarded by a semilunar valve (THEBESIAN VALVE)

Sympathetic stimulation will have which direct effect on the heart a. decreased automaticity b. AV block c. Increased vagal response d. bradycardia e. increased stroke volume

increased stroke volume

What effect does sympathetic nerves at SA node have

increases heart rate. The effect on the muscle is an increase in rise of pressure within the ventricle, thus increasing stroke volume

What is larger the inferior or superior vena cava

inferior

Where does the great cardiac vein open

into the left extremity of the coronary sinus

where does the small cardiac vein open

into the right extremity of the coronary sinus

Anterior interventriucalar artery (left anterior or descending artery)

is a branch of the left coronary artery and accompanies the great cardiac vein

Fossa ovalis

is a depression in the right atrium of the heart, the remnant of a thin fibrous sheet that covered the foramen ovale during fetal development

AV node

is an area of specialized tissue between the atria and the ventricles of the heart, specifically in the posterioinferior region of the interatrial septum near the opening of the coronary sinus Conducts the normal electrical impulse from the atria to the ventricles

Left ventricle

is larger and thicker than right ventricle and pumps blood through all other vessels of the body

Myocarditis

is the inflammation of the muscular layer of the heart (myocardium)

What is a remnatn of the ductus arteriosus in the fetus

ligamentum arteriosum

Sinuatrial node location and function

located at the junction of the superior vena cava and the right auricle it is the most rapidly depolarizing cardiac muscle tissue of the heart (this is way its refereed to as the "pacemaker"

What does the left coronary artery supply

major part of the heart including the left atrium, left ventricle, and ventricular septum

Myocardium

muscle tissue of the heart it forms the middle layer between the outer epicardium and inner endocardium striated muscle

A worker in the meat-processing industry comes down with an illness presenting with symptoms of fever, headache, and sore throat. A few days later, he feels chest pain and has pink, frothy sputum. His physician states that the worker has a viral infection caused by coxsackie B. This patient has inflammation of which layer of the heart a. epicardium b. myocardium c. endocardium d. pericardium

myocardium

Where does the AV bundle of HIS leave

near the lower part of the interatrial septum and splits over the upper part of the interventriuclar septum into a left and right bundle branch

Does the heart require external influences in order to beat

no the conduction system stimulates the heart to beat independently

Where does the inferior vena cava open and where is it returning blood

opens into the lower part of the right atrium and it returns blood from the lower half of the body

What is the effect of the vagus nerve on the SA node

opposite of sympathetics!!!! It decreases heart rate The vagus nerve also decreases the excitability of the junctional tissue around the AV node, and this results in slower transmission Note: strong vagal stimulation here may produce an AV block

Where do sympathetic fibers go

pass into the cardiac plexus and from there to the SA node and the cardiac muscle

Right ventricle

pumps blood to the lungs

Coronary Sinus

receives most of the venous blood from the heart and empties into the right atrium

Where does the left atrium receive blood and what type of blood is it

receives oxygenated blood from the lungs

What vein frequently opens inot the right atrium and is therefore sometimes regarded as belonging to the anterior cardiac veins

right marginal vein

Where do the sympathetic fibers arise from

segements T2-T4 of the spinal cord and are distributed through the middle cervical and cervico-thoracic (or stellate ganglia) and first four ganglia of the thoracic sympathetic chain

What artery supplies the SA node

sinoatrial nodal artery

Slow sinus rhythm

slower than 60 beats per minute SINUS BRADYCARDIA

Coronary Sinus tributaries

small cardiac vein middle cardiac vein great cardiac vein

Right coronary artery arises from

the anterior aortic sinus of the ascending aorta and runs forward between the pulmonary trunk and the right auricle.

Where do ventricles receive blood from

the atria

Where does the left coronary artery arise from

the left posterior aortic sinus of the ascending aorta and passes forward between the pulmonary trunk and the left auricle

What is the small vein that arises along the left side of the left atrium just beneath the lower left pulmonary artery

the oblique vein

What does the rate of discharge of the SA node set

the rhythm of the entire heart

How many valves of the heart are there and what is there function

there are 4 valves of the heart that are designed to allow one-way flow only of blood. Their function is to PREVENT BACKFLOW into the releasing chamber

Where does the blood travel after entering the right atrium

to the right ventricle via the right AV valve. The right ventricle then pumps blood into the pulmonary circuit via the pulmonary semilunar valve, which allows blood to flow into the pulmonary arteries.

What does the great cardiac vein receive

tributaries from the left atrium and both ventricles: one, the left marginal vein is of considerable size and ascends along the left margin of the heart

What wave represents ventricular repolarization

T wave

The order of blood flow through the heart

1. Entering the right atrium are the coronary sinus and the superior and inferior venae cavae carrying deoxygenated blood from the systemic circuit 2. Upon contraction of the right atrium, blood passes through the right AV valve to the right ventricle 3. Upon contraction of the right ventricle, blood leaves to pass to the right and left lungs via pulmonary arteries 4. Blood gases are exchanged in the lung, and oxygenated blood returns via pulmonary veins to the left atrium 5. Upon contraction of the left atrium, blood passes through the left AV valve to the left ventricle 6. Upon contraction of the left ventricle, oxygenated blood passes through the aortic valve to the systemic circuit via the aorta and its branches

The apex of the heart is formed by the tip of the left ventricle and is located at the level of the

5th left intercostal space

What is the spontaneous depolarization rate of SA node

60 to 100 times per minute, causing the atria to contract

Which of the following arteries accompanies the great cardiac vein a. circumflex artery b. anterior interventricular artery c. posterior interventricular artery d. right marginal artery

Anterior interventricular artery

What artery is most often involved in coronary occlusions and is often the one that is bypassed in bypass cardiac surgery

Anterior interventricular artery (typically provides the most blood to conducting tissue)

What is an important branch the right coronary artery gives off

Anterior right atrial branch (this then gives off the sinoatrial nodal artery)

What divides the two atriums of the heart

Atrial septum

Pressure of atriums before birth and after birth

Before Birth: R is high and L is low After Birth: R is low and L is high

Where does blood travel after it enters the left atrium

Blood flows through the left AV valve in to the left ventricle. From the left ventricle, blood passes through the aortic valve and enters the arch of the aorta, which will deliver blood to the body's systemic circuits

What parts of the autonomic nervous system are involved in the control of the heart

Both parasympathetic and sympathetic

What causes shortness of breath and pulmonary edema

If the pressure in the veins of the lungs increases causing fluid accumulation in the lung

Which of the following describes the function of the ductus arteriosus in the fetus? a. it shunts blood from the aorta to the pulmonary artery b. it shunts blood from the pulmonary artery to the aorta c. it shunts blood from the right atrium to the left atrium d. it shunts blood from the umbilical vein to the inferior vena cava

It shunts blood from the pulmonary artery to the aorta

What is larger the right or left coronary artery?

Left

What artery supplies the right ventricle

Marginal branch of the right coronary artery (located in the coronary sulcus)

What wave represents atrial deploraization

P wave

What wave represents impulse between SA and AV node (AV conduction)

PR

The major sensory nerve to the parietal pericardium is from branches of the

Phrenic nerve (C3-C5)

During VENTRICULAR SYSTOLE the ventricles of the heart contract and the _______ and _______ valves open to allow blood to be pumped into the pulmonary and general circulatory systems, respectively, while the other valves are closed

Pulmonary and Aortic

Most veins carry deoxygenated blood from the tissues back to the heart what are the only TWO EXCEPTIONS

Pulmonary and umbilical veins (both carry oxygenated blood)

What wave represents ventricular depolarization

QRS

What wave represents the ejection of blood

QT

The _____ node is in the wall of the ______ atrium, near the enterance of the superior vena cava

SA right

electrical impulse of the heart is initiated by the

Sinoatrial (SA) node (pacemaker) and spreads to the rest of the right atrial myocardium directly, to the left atrial myocardium by way of a bundle of interatrial conducting fibers

What provides parasympathetic control of the heart

Vagus nerve

What divides the two ventricles of the heart

Ventricular septum

What is fatigue caused by

When the left side of the heart is not able to pump as much blood forward causing less oxygen to be received by the remainder of the body

Posterior (descending artery) intervenricular artery

a branch of the right coronary artery, and accompanies the middle cardiac vein

What cardiac veins do not end in the coronary sinus

anterior cardiac veins smallest cardiac veins

What does the left coronary artery branch into once it enters the atrioventricular groove

anterior interventricular branch and the circumflex branch

Pericardium layer

is the set of membranes around the heart (its actually composed of three layers of membranes). The innermost is the visceral pericardium, the middle is the parietal pericardium, and the outer one is the extra one, called the fibrous pericardium. The visceral and pareital are rather thin and delicate. The outer one, the fibrous pericardium is tough

What happens to the foramen ovale after birth

it is intially closed by the septum primum (valve of the ovale) as pressure in the left atrium exceeds that in the right atrium. Eventually the foramen ovale becomes permanently closed with fibrous connective tissue and becomes the fossa ovalis in adults

Where does the superior vena cava open and where is it returning blood

it opens into the upper part of the right atrium and it returns blood from the upper half of the body

What has larger and thicker walls the atria or the ventricles

ventricles

Patent ductus arteriosus

when the ductus does not close (closes mostly after 24 hours after birth)