Anatomy Of The Heart

Question 1

Right atrium

Answer 1

▪️forms right border of the heart 
▪️receives blood from SVC, IVC, coronary sinus 
▪️anatomy
-crista terminalis
-pectini muscles 
-fossa ovale
-atrioventricular orifice 
-right auricle

Question 2

Crista terminalis

Answer 2

▪️ridge on the inside between atrium and auricle
▪️runs from SVC to IVC
▪️behind ridge walls are smooth

Question 3

Musculi pectinati

Answer 3

▪️anterior to crista terminalis

▪️roughened walls-bundles of muscular fibres

Question 4

Fossa ovale

Answer 4

▪️marks location of embryonic foramen ovale which allowed blood to bypass the lungs in feral circulation

Question 5

Atrioventricular orifice

Answer 5

▪️communication with atria and ventricle

▪️closed by tricuspid/bicuspid valve

Question 6

Right auricle

Answer 6

▪️ear like muscular pouch

▪️overlaps bottom of aorta

Question 7

Right ventricle

Answer 7

▪️anterior to RA so blood moves horizontally forward 
▪️blood exits through pulmonary trunk 
▪️anatomy 
-tricuspid valve 
-chrodae tendinae
-trabeculae carnae 
-papillary muscles 
-septomarginal trabecula (moderator band)
-conus arteriosus (infundibulum)
-pulmonary valve

Question 8

Tricuspid valve

Answer 8

▪️in atrioventricular orifice
▪️food of endocardium and connective tissue
▪️3 cusps-A,P, septal

Question 9

Chrodae tendinae

Answer 9

▪️tendon-like fibrous cords that connect cusps to papillary muscles

Question 10

Trabeculae carnae

Answer 10

▪️muscular irregular columns on wall of ventricle

▪️collection of TC are papillary muscles

Question 11

Papillary muscles

Answer 11

▪️projects of a collection of trabeculae carnae
▪️R
-anterior (largest), posterior, septal (inconsistent)
▪️L (larger)
-anterior, posterior
▪️attached to chrodae tendinae and prevent cusps from turning inside out due to pressure increase -contract when ventricle contracts

Question 12

Septomarginal trabecula (moderator band)

Answer 12

▪️bridge between lower interventricular septum and base of anterior papillary muscle
▪️carries proportion of cardiac conduction system to anterior wall

Question 13

Left atrium

Answer 13

▪️most of bast of heart 
▪️blood enters from 4 pulmonary veins
▪️mostly smooth walls except for auricle (pectini muscles)
▪️anatomy 
-left auricle 
-valve of feral foramen ovale 
-mitral valve (bicuspid)
- 4x pulmonary veins

Question 14

Valve of fetal foramen ovale

Answer 14

▪️before birth blood moves from R-L
▪️when first breath is taken, pressure changes means that pressure in L is larger than R so blood tries to move back in to R
▪️the valve gets forced to close and prevent this
-takes a while to close, not immediate

Question 15

Left ventricle

Answer 15

▪️anterior to left atrium 
▪️wall is 3x thicker than RV
▪️exits into aorta
▪️forms A, diaphragmatic, left pulmonary and apex surfaces 
▪️anatomy 
-mitral valve 
-papillary muscles
-chordae tendinae
-trabeculae carnae 
-aortic valve

Question 16

Mitral valve

Answer 16

▪️in atrioventricular orifice
▪️food of endocardium and connective tissue
▪️2 cusps-A,P

Question 17

Aortic valve

Answer 17

▪️semilunar valve at entrance of aorta
▪️3 cusps- R, P, L
▪️R and L both have an opening to the R and L coronary arteries
-as blood recoils after ventricular contraction it fills the sinuses, blood is then forced into the arteries

Question 18

Pulmonary valve

Answer 18

▪️semilunar valve at entrance of pulmonary truck
▪️3 cusps- L, R, A
-prevent blood flowing back into ventricle

Question 19

Conus arteriosus (infundibulum)

Answer 19

▪️smooth walled entrance to pulmonary trunk

Question 20

Cardiac skeleton

Answer 20

▪️dense, fibrous tissue in rings which interconnect in a plane between the atria and ventricles
▪️surround AV orifices, aortic orifice and opening of pulmonary trunk
▪️maintains integrity of openings and attachments of cusps
▪️separates muscular wall of A from V therefore isolating V
-AV bundle connects muscles of A and V

Question 21

Right coronary artery

Answer 21

▪️arises from aorta and runs between PT and right auricle
▪️descends vertically in coronary sulcus (AV groove)
▪️gives off:
- marginal branch- runs along inferior border
-posterior interventricular branch-posteriorly
-R PI is 80-90% dominant
▪️it may anastomose with the left artery

Question 22

Left coronary artery

Answer 22

▪️arises from aorta
▪️asses between PT and left auricle
▪️larger than right
▪️divides when it reaches coronary sulcus into
-anterior interventricular branch-runs toward apex then goes posterior at inferior border
-circumflex branch- turns left and runs in sulcus posteriorly and gives off marginal branch and PI branch (20% dominant)

Question 23

Areas supplied by coronary artery

Answer 23

▪️RCA
-RA
-most of RV
-diaphragmatic part of LV
- posterior 1/3 of interventricular septum 
-60% of SAN
▪️LCA
-LA
-most of LV
-partially RV
-anterior 2/3 of interventricular septum 
-40% SAN 
-AVN and bundle

Question 24

Venous drainage of the heart

Answer 24

▪️coronary sinus receives blood from

• anterior cardiac veins- small part anterior of RV
• small cardiac vein
• great cardiac vein
• middle cardiac vein
• left marginal vein
• left post ventricular vein

Question 25

Pericardium

Answer 25

▪️fibro-serous sac that encloses hear and roots of great vessels
-restricts excessive movements of heart 
▪️fibrous pericardium attached 
-below to central tendon of diaphragm 
-to adventitia of great vessel 
-to sternum by sternopercardial ligaments 
▪️serous pericardium 
-visceral (epicardium)
-parietal 
-pericardial cavity with lubricant

Question 26

What can go wrong with pericardium?

Answer 26

▪️pericardial effusion 
-build up of fluid in pericardial cavity 
-heart is compressed and effective 
▪️pericarditis 
-inflammation of pericardium

Question 27

Wave of excitation movement

Answer 27

▪️SAN depolarises and sends a wave of excitation which causes the atria to contract together
▪️this stimulates the AVN (opening of coronary sinus in the AV septum)
▪️AVN sends this wave down the AV bundle which splits off into L and R
-R continues to apex of RV down the septomarginal trabecula to anterior papillary muscle, it then continues as the purkinje fibres which goes up and around the apex
-L passes to the left side of IV septum into LV which then divides in to PF going up and around the apex

Question 28

Cardiac plexus

Answer 28

▪️mixture of PNS and SNS
▪️deep
-between aortic arch and carina of trachea
▪️superficial
-inferior to aortic arch and superior to pulmonary trunk

Question 29

Aortic dissection

Answer 29

▪️wall of aorta slits vertically creating a false channel
▪️common between tunica intima and tunica media
▪️dissection in ascending aorta can lead to less blood getting to brain and coronary arteries therefore may lead to myocardial infarction or stroke
▪️dissection in abdominal aorta can lead to ischaemia to kidneys

Question 30

Transposition of the great arteries

Answer 30

▪️aorta and pulmonary arteries switch places
▪️oxygenated blood keeps returning to lungs
▪️deoxygenated blood cycles body- not enough oxygen to tissues
▪️atria septal or ventricular septal defects allows mix of oxygenated and deoxygenated can prolong survival
▪️also a patent ductus arteriosus mixes blood

Question 31

Types of blood vessels

Answer 31

▪️resistance
-arterioles and small arteries
▪️capacitance (storage areas)
-venues and small veins

Question 32

Blood vessel must…

Answer 32

▪️withstand changes in pressure

▪️be flexible enough to move with underlying tissues and organs

Question 33

Arteries

Answer 33

▪️elastic, muscular, resistance
▪️elasticity of aorta helps smooth out fluctuations in BP and allow for efficient gas exchange
▪️tunica intima- inside layer, grows with age, arteriosclerosis
▪️tunica media- thickest layer, smooth muscle, elastin
▪️tunica adventitia- thin connective tissue (prevent from stretching beyond threshold)
-vasa vasorum- artery too thick for gas exchange

Question 34

Skeletal muscle pumps

Answer 34

▪️valve in veins prevent backflow of blood
▪️contacting muscles compress veins (between valves) forcing the blood towards the heart
▪️not as smooth as arteries