Module 6: Cardiovascular Flashcards
- fibroserousmembrane that covers the heart and beginning of its great vessels; closed sac
- functions:
a. restrict excessive movement of the heart
b. serve as a lubricated container
pericardium
Two Layers of Pericardium
A. Fibrous Pericardium
B. Serous Pericardium
*Visceral Layer
*Parietal Layer
- fibrous part; tough external layer
- stabilizes the heart and prevents it from overdilating
- fuses superiorly with tunica adventitia of the great vessels and pretracheallayer of deep cervical fascia attached to the posterior part of the sternum by the STERNOPERICARDIAL
LIGAMENT - bound posteriorly by loose connective tissue to structures in the posterior mediastinum
FIBROUS PERICARDIUM
The continuity of the fibrous pericardium with the central tendon of the diaphragm constitutes the __
pericardiacophrenic ligament
- composed mainly of mesotheliumthat lines the internal surface of the fibrous pericardium and external surface of the heart
- has 2 layers:
A. Parietal Layer
B. Visceral Layer
SEROUS PERICARDIUM
- serous membrane that lines the internal surface
of the fibrous pericardium - this layer is reflected onto the heart at the great vessels (pulmonary trunk, aorta, SVC and IVC) and becomes the visceral layer
PARIETAL LAYER OF SEROUS PERICARDIUM
- layer reflected by the parietal layer to the heart
at the great vessels - makes up the epicardium
- continuous with parietal layer:
*where the aorta and pulmonary trunk leave the heart
*where the SVC, IVC and pulmonary veins enter the heart
VISCERAL LAYER OF SEROUS PERICARDIUM
- potential space between the parietal and visceral
layers of serous pericardium contains a thin film of fluid - enabling the heart to move and beat in a frictionless
environment - 30-50 ml.of thin, clear fluid in pericardial sac
PERICARDIAL CAVITY
- a finger can be passed through the transverse
pericardial sinus posterior to the aorta and pulmonary trunk and anterior to the SVC and superior to the atria of the heart - important when performing coronary artery bypass
grafting
TRANSVERSE SINUS
- pocket-like recess in the pericardial cavity posterior
to the base of the heart - bounded laterally by the pericardial reflections surrounding the pulmonary veins and IVC; posteriorly by the pericardium
- blind sac (cul-de-sac)
OBLIQUE SINUS
PERICARDIUM: ARTERIAL SUPPLY
- pericardiacophrenic artery (main supply)
- musculophrenic artery
- bronchial, esophageal artery
- superior phrenic artery
- coronary artery (visceral layer of serous pericardium only)
PERICARDIUM: VENOUS DRAINAGE
- pericardiacophrenic vein
* which drains to the brachiocephalic vein
PERICARDIUM: NERVE SUPPLY
PHRENIC NERVE (primary source of sensory fibers) supplies the:
a. fibrous pericardium
b. parietal layer of the serous pericardium
SYMPATHETIC TRUNKS AND VAGUS NERVE supply the:
a. visceral layer of the serous pericardium
* the function of the vagus is uncertain; the sympathetic trunks are vasomotor
- inflammation of the pericardium
- roughened pericardium
- (+) chest pain
- (+) pericardial friction rub
- (+) pericardial effusion
PERICARDITIS
- heart compression secondary to stab or gunshot wounds
- extensive pericardial effusion does not allow full expansion of the heart limiting the amt. of blood the heart can receive, reducing cardiac output
(+) pericardial effusion
(+) hemopericardium
(+) pneumopericardium
CARDIAC TAMPONADE
- drainage of fluid from pericardial cavity
- wide bore needle inserted to left 5thor 6th ICS near the sternum
- cardiac tamponade relief
PERICARDIOCENTESIS
How big is the heart?
The normal heart weighs averages:
250-300 grams in females
300-350 grams in males
HOW DOES THE HEART WORK?
- suction and pressure pump
- propels blood to all parts of the body
- complex framework of dense collagen forming:
- 4 fibrous rings
- right and left fibrous trigone
- membranous parts of interatrial, interventricular septa
- keeps the orifices of the AV and semilunar valves patent
- provides attachment for the leaflets and cusps
- provides attachment for the myocardium
- forms an electrical insulator
FIBROUS SKELETON
- formed by the inferolateral part of the left ventricle
- lies posterior to the left 5th ICS; approx. 9 cm from the median plane
- motionless throughout the cardiac cycle
- apex beat
APEX OF THE HEART
- opposite the apex
- posterior aspect of the heart
- formed mainly by the left atrium and partially by the right atrium
- faces posteriorly toward the bodies of vertebrae T6-T9
- extends superiorly to the bifurcation of the pulmonary trunk and inferiorly to the coronary sulcus
- receives the pulmonary veins, SVC and IVC
BASE OF THE HEART
FOUR SURFACES OF THE HEART
- STERNOCOSTAL SURFACE (Anterior)
- formed mainly by the right ventricle - DIAPHRAGMATIC SURFACE (Inferior)
- formed mainly by the left ventricle,partly by the right ventricle
- related to the central tendon of diaphragm - RIGHT PULMONARY SURFACE
- formed mainly by the right atrium - LEFT PULMONARY SURFACE
- formed mainly by the left ventricle
- forms the cardiac impression of the left lung
FOUR BORDERS OF THE HEART
- RIGHT BORDER - formed by the right atrium extending between the SVC and IVC
- INFERIOR BORDER - formed mainly by the right ventricle and slightly by the left ventricle
- LEFT BORDER - formed mainly by the left ventricle and slightly by the left auricle
- SUPERIOR BORDER - formed by the right and left atria and auricles
- ascending aorta and pulmonary trunk emerge from this border and the SVC enters its right side
- forms the inferior boundary of the transverse pericardial sinus
LAYERS OF THE HEART
- ENDOCARDIUM - thin internal layer lining membrane of the heart and its valves
- MYOCARDIUM - thick middle layer composed of cardiac muscle
- EPICARDIUM - thin external layer (mesothelium)formed by the visceral layer of the serous pericardium
- receiving chamber
- are demarcated from the ventricles by the coronary sulcusor atrioventriculargroove
atria
- Forms the right border of the heart
- Receives venous blood from the: SVC, IV and Coronary Sinus
Right Atrium
(Right Atrium)
- ear-like conical muscular pouch
- increases the capacity of the atrium; add on room
RIGHT AURICLE
(Right Atrium)
- forms the muscular anterior wall
- resemble teeth of a comb
PECTINATE MUSCLES
(Right Atrium)
- smooth, thin-walled, posterior part where the SVC, IVC and coronary sinus open up
SINUS VENARUM
(Right Atrium)
- vertical ridge separating the smooth and rough parts of the atrium
- its equivalent externally is the Sulcus Terminalis (Terminal Groove)
CRISTA TERMINALIS
(Right Atrium)
- short venous trunk bet. the right AV orifice and IVC orifice
receives most of the cardiac veins
OPENING OF CORONARY SINUS
(Right Atrium)
- separates the right from the left atria
- contains the Fossa Ovalis which is a remnant of the Foramen Ovale
INTERATRIAL SEPTUM
- incomplete closure of the foramen ovale
- left to right shunt causing enlargement of the right atrium and ventricle and dilatation of the pulmonary
- trunk surgical repair
ATRIAL SEPTAL DEFECT
(Right Atrium)
- the opening where poorly oxygenated blood from the
right atrium is discharged into the right ventricle
RIGHT ATRIOVENTRICULAR ORIFICE
(Right Ventricle)
- guards the right AV orifice
- the valve is made of 3 cusps: ANTERIOR CUSP, POSTERIOR CUSP, SEPTAL CUSP
- tendinous cords are attached to the free edges of the cusps
TRICUSPID VALVE
(Right Ventricle)
- conical muscular projections attached to the ventricular wall and connected to the cusps of the tricuspid valve via the Chordae Tendinae
- 3 __ in the right ventricle: anterior, posterior, septal
PAPILLARY MUSCLES
(Right Ventricle)
- irregular muscular elevations
- give the ventricular wall a sponge-like appearance
- composed of three types
a. Papillary Muscles
b. Moderator Band
c. Prominent Ridges
TRABECULAE CARNAE
(Right Ventricle)
- also known as septomarginal trabecula
- muscular bundle from the inferior part of the IVS to the base of the anterior papillary muscle
- carries part of the right branch of the AV bundle to the anterior papillary muscle
MODERATOR BAND
(Right Ventricle)
- made up of muscular and membranous parts
- partition between the right and left ventricle
INTERVENTRICULAR SEPTUM
- incomplete closure of the ventricular septum
- most common site is the membranous part
- size of defect is 1-25mm.
- left to right shunt
- large shunt may lead to pulmonary hypertension resulting to cardiac failure
- 50% of small muscular VSDs close spontaneously
VENTRICULAR SEPTAL DEFECT
(Right Ventricle)
- separates the ridged muscular wall of the inflow part from the smooth wall of the outflow part
- deflects the incoming flow into the main cavity of the ventricle and the outgoing flow into the conus arteriosus toward the pulmonary orifice
SUPRAVENTRICULAR CREST
(Right Ventricle)
- arterial cone which leads into the pulmonary trunk
CONUS ARTERIOSUS (Infundibulum)
(Right Ventricle)
- guards the pulmonary orifice
- located at the level of the 3rd costal cartilage
- consists of 3 semilunar cusps: anterior cusp, right cusp, left cusp
PULMONARY VALVE
- approx. 5 cm. long and 3 cm. wide
- divides into right and left pulmonary arteries
- conduct poorly oxygenated blood to the lungs for oxygenation
PULMONARY TRUNK
- forms most of the base or posterior surface of the heart
- slightly thicker wall than the right atrium
LEFT ATRIUM
(Left Atrium)
- two superior and two inferior pulmonary veins entering the smooth posterior wall
PULMONARY VEINS
(Left Atrium)
- forms the superior part of the left border of the heart
- smaller muscular auricle containing pectinate muscles
LEFT AURICLE
(Left Atrium)
- smaller pectinate muscles larger smooth walled part
PECTINATE MUSCLES
(Left Atrium)
- semilunar depression in the interatrial septum
- the surrounding ridge is the valve of the oval fossa
FLOOR OF FOSSA OVALIS
(Left Ventricle)
- opening through which the left atrium discharges the oxygenated blood into the left ventricle
- surrounded by the mitral valve
LEFT ATRIOVENTRICULAR ORIFICE
- benign neoplasm or tumor
- 90% located in atrium
- size is from 1 cm. to 10 cm. can present as a hard globular mass or a soft gelatinous appearance
- (+) fever and malaise
- surgical removal is curative
MYXOMA
- forms the apex of the heart, nearly all its left surface and
border and most of the diaphragmatic surface - performs more work than the right ventricle because of the higher arterial pressure in the systemic circulation
- walls are two to three times thick
- has a longer and narrower conical cavity than the right
LEFTVENTRICLE
(Left Ventricle)
- located posterior to the sternum at the level of the 4th costal cartilage
- resembles a bishop’s miter
- anterior and posterior cusps
- papillary muscles and their tendinous cords support the mitral valve,
- allowing the cusps to resist the pressure developed during contractions (pumping) of the left ventricle.
- The cords become taut just before and during systole, preventing the cusps from being forced into the left atrium
MITRAL VALVE
- ballooning of mitral valve leaflets (floppy) which extends back into the left atrium during systole
- leaflets are enlarged, thick and rubbery
MITRAL VALVE PROLAPSE/INSUFFICIENCY
(Left Ventricle)
- larger than those of the right ventricle
- *note: no moderator band on the left ventricle
PAPILLARY MUSCLES (anterior and posterior)
(Left Ventricle)
- finer; more numerous
TRABECULA CARNAE
(Left Ventricle)
- smooth-walled supero-anterior outflow part that leads to the aortic valve and aortic orifice
AORTIC VESTIBULE
(Left Ventricle)
- blood leaves the left ventricle through the aortic orifice located at the upper right and posterior part
AORTIC ORIFICE
(Left Ventricle)
- located posterior to the left side of the sternum at the level of the 3rd ICS
- no tendinous cords
- semilunar cusps:
1. right cusp
2. left cusp
3. posterior cusp
AORTIC VALVE