UNIT 2: heart Flashcards
where is the heart located?
middle mediastinum - behind sternum/ between 2nd and 6th ribs and between T5-8/ directly above diaphragm
where can you find the apex of the heart?
posterior to 5th intercostal space- left midclavicular line
where is the base of the heart?
posterior towards T6 to T9 (predominantly left atrium)
What are the four surfaces of the heart?
- anterior/ sternocostal - RV
- diaphragmatic/ inferior - LV
- left pulmonary - LV
- right pulmonary - RA
what are the four borders of the heart?
- superior
- inferior
- left
- right
what is the loose fitting sac around the heart called and what is it made of?
pericardium - double walled fibroserous membrane
what is the serous pericardium split into?
visceral / parietal
what does the parietal pericardium form?
epicardium - thin external layer
what is the function of the pericardium?
- fixation of heart
- prevents overfilling
- lubrication
- protection from infection
how are the pericardial sinuses formed? what are the two sinuses and where are they found?
embryological folding of primordial heart
- transverse: separates the heart’s arterial outflow - posterior to aorta and pulmonary trunk - can pass a finger through (surgeons use this for cardiac surgery/ clamps)
- oblique: blind recess partly covering the SVC/IVC/pulmonary veins
which veins/arteries supply the pericardium?
- pericardiophrenic artery - main supply (branch of internal thoracic artery)/ other arteries: musculophrenic/ bronchial/ esophageal/ superior phrenic/ coronary
- pericardiophrenic veins and azygos veins
what are the other two external layers of heart?
- myocardium = cardiac muscle
- endocardium = internal layer of endothelium/ sub-endothelial connective tissue
where does the right atrium receive blood from?
venous blood from SVC/IVC
what is an auricle?
atrial appendage - muscular pouch that increases capacity of atrium on anteromedial portion
(represents primordial atrium)
how is the interior of the right atrium split?
atrium proper - anterior to cristae terminalis - rough muscular wall due to pectinate muscles
sinus venarum - posterior to cristae terminalis - smooth walls - incorporates sinus venosus
from which veins does the sinus venarum receive blood from?
SVC/ IVC/ coronary sinus
where is the fossa ovalis found?
interatrial septum - remnant of oval foramen (foetus - bypass lung)
where is the sulcus terminalis found on right atrium?
external surface -terminal groove
what is the name of upper region of the right ventricle?
describe its feature
conus arteriosus
smooth wall/ cone shaped
what is the name of the ridged muscular wall separating the outflow part from inflow part of right ventricle?
supraventricular crest
what is the name of the partition between the right and left ventricle? describe its two parts
interventricular septum
- upper: membranous part - thin - continuous with fibrous skeleton of heart
- lower: muscular part - thick due to high blood pressure produced by LV
what is the name of the irregular muscular elevations in ventricles?
trabecular carneae
what is the name of the moderator band which carries the right branches of the AV bundle and what does this facilitate?
septomarginal trabecula
- allows co-ordinated contraction of anterior papillary muscle
what forms the tricuspid valve?
three cusps: anterior/ posterior/ septal which are controlled by contraction of papillary muscles connected by chordae tendinae
