Instead of being parallel to the spine and sternum, the heart is positioned ______________ within the ___________. at a 45° with the sternum; middle mediastinum (left of the midline) The heart is enclosed by the ___________ and is situated in the ___________, which contains... pericardium; pericardial cavity; the heart and a small amount of pericardial fluid The broad base of the heart points _________, and the apex, or __________, points _________. craniodorsally; left ventricle; caudoventrally The left side of the heart is called the _________ because... auricular surface; both the right and left auricles can be seen on the left side The right side of the heart is known as the ___________ because... atrial surface; both the right and left atria can be seen on this side What are the two interventricular grooves and where are they located? 1. paraconal interventricular groove- left side, continues from under the left auricle. 2. subsinuosal interventricular groove- right side, continues from under the caudal vena cava Superficial separation of the atria and the ventricles. coronary groove The pericardium is the ___________ of the heart, and it is divided into... fibroserous envelope; an outer fibrous layer and an inner serous layer The serous pericardium has the following layers... 1. parietal layer- fused with the fibrous outer pericardium 2. visceral layer (EPICARDIUM)- directly applied to heart The pericardial cavity is the space between the ___________ and the _____________. parietal and visceral serous pericardium The thick middle layer of the heart wall that is composed of cardiac muscle. myocardium The thin, smooth-surfaced layer lining the inside of the myocardium that is continuous with the lining of the blood vessels. endocardium The myocardium of the ___________ is 3-4 times thicker than the __________. left ventricle; right ventricle The the atria of the heart are the __________. receiving chambers The ventricles of the heart are the __________. ejecting chambers The right chambers of the heart contain ____________; the left chambers of the heart contain ____________. deoxygenated blood (venous); oxygenated blood (arterial) Blood enters the right atrium from... Dorsal intercostal aa. --> azygous v. ---------------> Ventral intercostal aa. --> Internal thoracic v. ----> cranial vena cava + caudal vena cava = SINUS VENARUM ------> RIGHT ATRIUM The coronary sinus (which drains blood from the heart itself) also drains into the sinus venarum Transverse ridge of tissue between the two caval openings inside the right atrium (where the cranial and caudal vena cavas drain into the sinus venarum). Intervenous tubercle Slit-like depression where the fetal foramen ovale existed, allowing blood to pass from the right to left atrium. fossa ovale Why does a fetus need the foramen ovale, but it closes to become the fossa ovale after birth? A fetus is not breathing using its lungs with in utero; therefore, blood can travel directly between the two ventricles without going to the lungs first. Once a neonate breathes on its own, thi opening must close to force blood to travel to the lungs first to pick up oxygen. The fossa ovalis is caudal to the _______ on the _________ of the __________. Intervenous tubercle on the inside of the right atrium Interlacing muscles on the internal surface of the wall of the right auricle. pectinate mm. The smooth-surfaced, thick portion of the heart muscle in the right atrium; shaped like a semi-lunar crest. crista terminalis The crista terminalis is the muscle from which the _________ radiate in both atria; this also associated with the __________ (aka. ____________) IN THE RIGHT ATRIUM. pectinate mm.; sinoatrial node; pacemaker The right ventricle communicates with the right atrium via the ____________. atrioventricular valve The septal cusp of the atrioventricular valve continues to the septal wall of the ventricle by ____________, which are attached to the septal wall by ___________. chordae tendinae; 3-4 papillary muscles The muscular irregularities of the interior of both of the ventricular walls. Trabeculae carneae The right ventricle ejects ________ blood into the _______, which transports the blood to the _________, which subsequently send the blood to the _________. deoxygenated; pulmonary trunk; pulmonary arteries (left and right); lungs The pulmonary trunk is located... between the auricles Muscular strand that that extends across the lumen of the right ventricle from the septal to the parietal walls. trabecula septomarginalis Thin, concave fold of tissue that is present on the cranial part of the left interatrial septal wall; remnant of fetal passageway. valve of foramen ovale The left atrium receives ________ blood from the lung via... oxygenated; 5-6 pulmonary veins The left ventricle ejects blood to the _______. aorta The aortic fibrous ring and the atrioventricular fibrous rings are made up of... right and left fibrous trigones The right and left atrioventricular valves are made up of... septal and parietal cusps The right and left atrioventricular valves are ________ valves. bicuspid/ mitral The aortic valve is made up of... right, left, and septal semilunar valves The semilunar cusps of the aortic valve have _________ in the middle of their free borders. nodules The pulmonary valve is at the junction between the ______ and the _______. right ventricle; pulmonary trunk The pulmonary valve consists of... 3 semilunar cusps (right, left, and intermediate) The sinoatrial node is at the ___________, the semilunar muscular crest at the opening of the right auricle. crista terminalis The atrioventricular node is ___________ to the ___________ of the right atrioventricular valve. craniodorsal; septal cusp The purpose of trabecula septomarginalis is.... provides a shortcut for a bundle of the conducting tissue (atrioventricular bundles), ensuring a simultaneous contraction of all parts of the right ventricle. The only structure to pass through the lumen of the right ventricle (same in left ventricle). trabecula septomarginalis with enclosed atrioventricular bundles with conducting fibers Ligaments that go from the pericardium to the sternum and diaphragm, respectively. sternopericardial ligament; phrenicopericardial ligament The aorta comes out of the ________. left ventricle Th ascending aorta has what branches? right and left coronary arteries The aortic arch has what branches directly from it (not including ascending and descending aorta)? brachiocephalic trunk; left subclavian artery The brachiocephalic trunk has what branches? right and left common carotid aa.; right subclavian a. The right and left common carotid aa. supply... the head, face, and brain The right and left subclavian aa. supply the... neck, thoracic limb, and cranial portion of the thoracic wall The right and left subclavian aa. have what branches on their respective sides of the body? vertebral a., costocervical trunk, internal thoracic a., superficial cervical a. The vertebral a. ascends in the ________ of the ________ after branching from the _________. transverse foramina; 1st-6th cervical vertebrae; subclavian a. The costocervical trunk supplies the... first 3 intercostal spaces, muscles at the base of the neck, and muscles dorsal to the first few thoracic vertebrae The costocervical trunk has what branches? deep cervical a., dorsal scapular a. The internal thoracic a. supplies the... ventral structures of the intercostal spaces The superficial cervical a. supplies the... base of the neck and scapular region The descending aorta has what branches? dorsal intercostal aa., bronchoesophageal a. The left coronary a. comes out of the ___________ under the ______. ascending aorta; left auricle The left coronary artery has what branches? paraconal interventricular branch; circumflex branch The circumflex branch of the left coronary artery curves around the ________. coronary groove The right coronary artery comes from under the ______ and runs.... right auricle; down the right side of the heart The great cardiac (coronary vein) arises at the _______ and runs in the ________. apex of the heart; paraconal interventricular groove The great cardiac (coronary) vein runs in the _________ and empties into the _______, which drains into the _______. paraconal interventricular groove; coronary sinus; right atrium The azygous vein has what branches? dorsal intercostal veins The cranial vena cava has what branches? costocervical vv., internal thoracic v., right and left brachiocephalic vv. The right and left brachiocephalic vv. have what branches on their respective sides of the body? subclavian vv., internal jugular vv., external jugular vv. The connective tissue between the pulmonary artery and aorta that closes by one week of age; remnant of fetal communication between these arteries before breathing outside the body. ligamentum arteriosum The ligamentum arteriosum is a fetal remnant of the _______; failure to close this structure after birth can result in.... ductus arteriosus; patent ductus arteriosus What are the parts of the central nervous system? brain and spinal cord What are the parts of the peripheral nervous system? cranial nerves and spinal nerves What are the parts of the autonomic nervous system? sympathetic and parasympathetic divisions The sympathetic division of the autonomic nervous system is the __________ division; the parasympathetic division is the _________ division. thoracolumbar; craniosacral The sympathetic division of the autonomic nervous system functions in... fight or flight (norepinephrine) The neurotransmitter of the sympathetic division of the autonomic nervous system is __________ and its purpose is... norepinephrine; associated with conditions of stress What are the 6 parts of the sympathetic division of the autonomic nervous system? sympathetic trunk and ganglion, cervicothoracic ganglion, vertebral nerve, middle cervical ganglion, ansa subclavia, cardiac nerves The neurotransmitter of the parasympathetic division of the autonomic nervous system is _______ and its purpose is... acetylcholine; associated with normal homeostatic activity The parasympathetic division of the autonomic NS is associated with _________. anatomic structures What 4 cranial nerves are associated with the parasympathetic division of the autonomic nervous system? CN III, VII, IX, X What are the 3 parts of the parasympathetic division of the autonomic nervous system? vagus nerves (left and right), recurrent laryngeal nerve, vagosympathetic trunk The vagus nerve of the ___________ of the autonomic nervous system splits into... parasympathetic division; dorsal and ventral vagal trunks (on each, the right and left sides) The vagosympathetic trunk is from the __________ to the ___________. cranial to middle cervical ganglia