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Anatomy
Anatomy exam II Heart
Question | Answer |
---|---|
The _____ is the central portion of the thoracic cavity separating the two pleural cavities. | mediastinum |
What does the mediastinum border anteriorly? | sternum |
What does the mediastinum border posteriorly? | T1-T12 vertebral bodies |
What does the mediastinum border laterally? | mediastinal parts of the parietal pleura |
What does the mediastinum border superiorly? | superior thoracic aperture |
What does the mediastinum border inferiorly? | diaphragm |
The mediastinum is divided into the _____ and ______ mediastinum by a transverse thoracic plane running from the _____ to the intervertebral disc between vertebrae T4-T5 | superior; inferior; sternal angle |
The _____ mediastinum can further be subdivided into the anterior, middle, and posterior mediastinum. | inferior |
The borders of the middle mediastinum are defined by the _____, a cone-shaped sac surrounding the heart and the origins of the great vessels | pericardium |
The _____ is the tough external fibrous layer of the pericardial sac | fibrous pericardium |
The inner _____ pericardium has two layers: the _____ layer, which lines the inner surface of the fibrous pericardium, and the _____ layer (epicardium), which adheres to the heart and forms its outer covering | serous; parietal; visceral |
The potential space between the parietal and visceral layers of serous pericardium is the ______. | pericardial cavity |
The arterial supply to the pericardium is mainly from the _____ arteries, although branches from the _____ arteries and the _____ aorta may also contribute | pericardiacophrenic; musculophrenic; thoracic |
Pericardial innervation comes from the _____ nerves, _____ nerves, and _____ trunks | phrenic; vagus; sympathetic |
Pain sensation is carried by the _____ | phrenic nerves (C3-5) |
The serous pericardium forms reflections around: 1) _____ and _____ and 2) the ______ and the ____ and _______ | the pulmonary trunk and aorta; pulmonary veins and superior and inferior vena cava |
The reflection onto the pulmonary veins forms the _____ | oblique pericardial sinus |
The two reflections form a passage behind the aorta and pulmonary trunk called the _____ | transverse pericardial sinus |
The _____ develops as a result of the _____ that forms in the primordial heart tube | transverse pericardial sinus; cardiac loop |
The _____ is an important landmark for cardiac surgeons | transverse pericardial sinus |
The _____ is directed posteriorly and consists of the left atrium, a portion of the right atrium, and the proximal parts of the great veins | base of the heart |
The _____ is directed anteriorly and to the left and formed by the inferolateral part of the left ventricle. (tip of bottom of left corner) | apex of the heart |
The heart has _____, diaphragmatic, right and left _____ surfaces | anterior; pulmonary |
The _____ is the sharp edge between the anterior and diaphragmatic surfaces | inferior margin |
The _____ separates the anterior and left pulmonary surfaces | obtuse margin |
The heart is divided into four chambers: | right atrium, right ventricle, left atrium, and left ventricle |
When the atria contract, blood is forced into the ventricles. The _____ are open at this point | A-V valves |
When the ventricles contract the _____ are forced shut, and blood is forced to exit via the ____ and _____ | A-V valves; aorta and pulmonary trunk |
The _____ act to prevent valve prolapse | chordae tendineae |
Closure of the _____ produces the first of the two heart sounds (lubb). | A-V valves |
The ___ and ___ valves are open during ventricular contraction so that blood can escape | pulmonary and aortic |
After _____ contraction, the recoil of blood fills the aortic and pulmonary sinuses and forces the valves _____, thereby preventing backflow of blood into the ventricles | ventricular; closed |
Closure of the _____ produces the second heart sound (dupp) | aortic and pulmonary valves |
What are the 4 valves you listen for during auscultation? | aortic; tricuspid; pulmonary; mitral |
The _____ is a collection of dense, fibrous connective tissue that encircles the four cardiac valves | cardiac skeleton |
The four rings of the cardiac skeleton are collectively known as the _____ | annulus fibrosus |
The _____ connects the aortic ring and the left A-V ring | left fibrous trigone |
The _____ connects the aortic ring and the right A-V ring | right fibrous trigone |
The _____ helps to maintain the structural integrity of the valves and provides attachment points for the cusps | cardiac skeleton |
The cardiac skeleton also serves as a dense connective tissue partition that electrically isolates the _____ from the _____ | atria; ventricles |
The heart has its own _____ and does not need input from the nervous system to beat rhythmically | conducting system |
The conducting system consists of specialized _____, NOT neural tissue | myocardial cells |
Input from the nervous system is necessary to change ____ or ____ of contraction. These signals come through the _____ | rate or force; cardiac plexuses |
The _____ initiates an impulse that is rapidly conducted to cardiac muscle fibers in the atria, causing them to contract | SA node |
The impulse is spread by _____, which rapidly transmits the impulse to the _____ | myogenic conduction; AV node |
The signal is distributed from the AV node through the _____ and the right and left bundle branches to the _____ | AV bundle; subendocardial branches |
The subendocardial branchesare also known as _____ | purkinjie fibers |
The ______ arises from the right aortic sinus of the ascending aorta and descends in the _____ between the right atrium and ventricle | right coronary artery; coronary sulcus |
The right coronary artery gives off a ____, which supplies the _____ border of the heart | right marginal branch; right |
In most individuals (~80%), the right coronary artery gives off a _____, which runs in the _____ | posterior interventricular branch; posterior interventricular sulcus |
The _____ arises from the left aortic sinus of the ascending aorta and passes between the pulmonary trunk and left auricle | left coronary artery |
The left coronary artery splits into the _____ branch | anterior interventricular |
The anterior interventricular branch descends obliquely in the ______ and the ______ | anterior interventricular sulcus and the circumflex branch |
What gives rise to the left marginal branch? | the circumflex branch |
Individuals in which the posterior interventricular branch arises from the right coronary artery are said to have a _____ dominant coronary artery | right |
Individuals in which the posterior interventricular branch arises from an enlarged circumflex branch of the left coronary artery are said to have a ____ dominant coronary artery | left |
The _____ is a wide venous channel that runs from left to right in the posterior part of the coronary sulcus | coronary sinus |
The coronary sinus receives the _____ at its left end and the middle and small cardiac veins at its right end | great cardiac vein |
The _____ drains into either the great cardiac vein or directly into the coronary sinus | posterior cardiac vein |
The ____ veins of _____ drain directly into the right atrium | anterior; right ventricle |
If a coronary artery is blocked, it can lead to _____ or a _____ | angina pectoris; MI |
What is angina pectoris? | intermittent chest pain caused by reversible cardiac ischemia |
What is a MI? | heart attack; a localized area of myocardial necrosis induced by local ischemia |
_____ is the most common cause of death in the U.S. (1.2 million myocardial infarctions per year; 0.5 million deaths) | coronary heart disease |
Coronary artery occlusion is usually due to _____ | atherosclerosis |
Treatments for coronary artery blockage include ______ and _______ | coronary artery bypass surgery and angioplasty |
When cardiac cells die during a myocardial infarction, ______ are stimulated | visceral afferent pain fibers |
The brain is unable to distinguish clearly between the _____ and _____ sensory distribution and therefore the pain is interpreted as arising from the _____ regions rather than the ______ organ | visceral and somatic; somatic; visceral |