Anatomy of Heart Flashcards
Aorta?
Artery carrying oxygenated blood to the body (pumped by the LEFT side)
Main Arteries branching from arch of aorta (3)
Subclavian Arteries
Common Carotid Arteries
Brachiocephalic Trunk
Pulmonary Arteries?
Receives deoxygenated blood (from RIGHT ventricle) + pumps it to the lungs for gas exchange
How many pulmonary veins? What are they?
(4)
Sup. + Inf. Right Pulmonary Vein
Sup + Inf. Left Pulmonary Vein
Pulmonary Veins?
Receive oxygenated blood from lungs (delivers it to left side of heart)
Sup. Vena Cava
Receives deoxygenated blood from UPPER BODY (above the diaphragm - excluding heart + lungs)
Drains into SUPERIOR part of Right Atrium
Inf. Vena Cava
Receives deoxygenated blood from LOWER BODY (below diaphragm)
Drains into INFERIOR part of Right Atrium
Which veins is the Vena Cava formed from
Superior =Formed by merging of brachiocephalic veins
Inferior = Formed initially in the pelvis (by merging of common iliac veins)
Sulci?
grooves of heart surface (created by chamber divisions)
Coronary sulcus (atrioventricular groove)?
Divides atria from ventricles (runs transversely around heart)
Anterior + posterior interventricular sulci ?
Wall separating the R + L ventricles (run vertically on the respective sides of the heart)
Pericardial Sinuses?
Passageways formed by folds in pericardium around great vessels
Right side circulation
Pulmonary circulation
Left side circulation
Systemic circulation
Blood in R atrium
Deoxygenated blood from sup.+ inf. Vena Cava + coronary veins
right auricle?
(extension of chamber) =muscular pouch acting to increase capacity of atrium
crista terminalis ?
muscular ridge separating two sections of right atrium (due to distinct embryological origin)
Sinus Venarum? (Relation to crista terminalis Blood flow Wall type Derivitive)
Posterior to crista terminalis
Receives blood from sup.+ inf. Vena cava
Smooth walled
Derived from embryonic sinus venosus
Atrium Proper?
(Relation to crista terminalis
Wall type
Derivitive)
Anterior to crista terminalis (includes right auricle)
Derived from primitive atrium
Rough muscular walls (formed by pectinate muscles)
Coronary Sinus?
Blood flow + location
Receives blood from coronary veins
Opens into right atrium between inf. Vena Cava orifice + right atrioventricular orifice
Intra atrial Septum
Solid muscular wall separating left + right atria
Fossa ovalis?
description + function
Oval shaped depression in right atrial septal wall
Allowed shunting of blood to bypass lungs in foetus (closes as newborn takes first breath
Blood in L atrium
Oxygenated blood from 4 pulmonary veins
Left auricle location?
overlaps roof of Pulmonary Trunk
L atrium inflow portion
Location + Blood flow + walls
Posterior
Receives blood from pulmonary veins
Smooth internal structure (derived from pulmonary veins)
L atrium outflow portion
Location + Blood flow + walls
Anterior (includes left auricle)
Lined with pectinate muscles (rough surface)
Derived from embryonic atrium
R ventricle blood
Receives deoxygenated blood from right atrium
Muscular ridge seperating inflow + outflow portion of right ventricle
supraventricular crest
What is trabeculae carnae (found in ventricle inflow portion)
(3 components)
Series of irregular muscular elevations
1) Ridges = attached along whole length on one side (along internal surface of ventricle)
2) Bridges = attach to ventricle at both ends but free in the middle
3) Pillars (papillary muscles) = anchored by base of ventricle - apices attached to fibrous chords (chordea tendae)
Ventricle outflow portion
Location + walls
Superior aspect of ventricle
Smooth walls derived from bulbus cordis
How do Chordae tendae work
Chordae tendae attach to tricuspid valve cusps
By contracting, papillary muscles can pull chordae tendineae to prevent valve prolapse
what are the 2 parts of the intraventricular septum?
Superior membranous part (part of fibrous skeleton)
Inferior muscular part (forms majority of septum)
L ventricle blood flow
Receives oxygenated blood from left atrium
Overview of Conduction in the Heart?
1) Excitation signal (action potential) created by SA node
2) Wave of excitation spreads across atria (causing contraction)
3) Signal delayed when it reaches AV node
4) Conducted into Bundle of His (down the intra ventricular septum)
5) Spread waves of impulses along ventricles (Bundle of His + purkinje fibres) causing them to contract
SA node location
upper wall of right atrium
sympathetic n.s on SA node
increase firing rate of S.A node (+ heart rate)
parasympathetic n.s on SA node
decreases firing rate of S.A node (+ heart rate)
AV node location
Within atrioventricular septum (near opening to coronary sinus)
Bundle of His (what does it do + where)
Transmits electrical signal from AV node → purkinje fibres in ventricles
Descends down membranous part of interventricular septum
Divides into R+L bundle branches (depending on the ventricle)
Purkinje fibre adaptations (2)
Abundant with glycogen + extensive gap junctions
Purkinje fibre (what do they do?)
Rapidly transmit cardiac action potentials from AV bundle to ventricular myocardium (causes ventricular systole)
Innermost layer of heart wall
Endocardium
loose connective tissue + simple squamous epithelial tissue
Subendocardial Layer (heart wall)
Joins endocardium + myocardium
= loose fibrous tissue (contains vessels + nerves)
Contains purkinje fibres
Myocardium?
Cardiac muscle (involuntary striated muscle) Responsible for contractions of heart
Subepicardial Layer?
between myocardium + epicardium
Epicardium
Outermost layer of heart = formed by visceral layer of pericardium
= connective tissue + fat
Connective tissue secrets small amount of lubricating fluid into pericardial cavity
Lined by simple squamous epithelial cells
Fibrous Pericardium (+ function)
Continuous with central tendon of diaphragm
Made of tough connective tissue (relatively non-distensible)
Rigid structure = prevents overfilling of the heart
serous pericardium
2 layers (Outer parietal layer + Inner visceral layer) Both single sheet of epithelial cell = mesothelium
Pericardium Functions (4)
1) Fixes heart in the mediastinum (limits motion)
Possible as its attached to diaphragm, sternum + outer layer of great vessels
2) Prevents overfilling
3) Lubrication (reduces friction generated from heart against thoracic cavity)
4) Protection from infection (physical barrier from other organs more prone to infection)
AV valves
tricuspid (R) , mitral (L)
SL valves
aortic (L), pulmonary (R)
Tricuspid properties
RIGHT atrium + ventricle (right AV orifice)
3 cusps (anterior, septal, posterior)
Base of each cusp anchored to fibrous ring surrounding orifice
Mitral Properties
LEFT atrium + ventricle (left AV orifice) 2 cusps (anterior + posterior) - attached to fibrous ring
how are AV valves supported?
Supported by attachment to chordae tendae + papillary muscles (preventing prolapse)
3 papillary muscles = right interior surface
2 papillary muscles = left interior surface
When are AV valves closed
start of ventricular systole
When are SL valves closed?
start of ventricular diastole
Pulmonary valve properties
RIght ventricle + pulmonary trunk (pulmonary orifice) 3 cusps ( right, left, anterior) after position in foetus before the heart rotates
Aortic valve properties
Left ventricle + aorta (aortic orifice) 3 cusps (right, left, posterior) - from position in foetus L+R aortic sinuses = mark origin of R+L coronary arteries
Aortic sinuses?
As blood recoils during ventricular diastole blood flows back into aortic sinuses
Enters coronary arteries to supply the myocardium
Lunule?
Free superior edge of cusp leaflet = thickened
Nodule?
Where cusp leaflet is widest (at midline)
How do SL valves close?
At beginning of ventricular diastole blood flows backwards, pushing leaflet together + closing the valves)
2 Main coronary arteries
Left + right coronary arteries (arise from left + right aortic sinuses)
Venous Drainage
small trabituaries –> larger veins draining into coronary sinus (in the coronary sulcus of posterior surface)
5 main tributaries
Great Cardiac Vein
Small Cardiac Vein
Middle Cardiac Vein
Left Marginal Vein
Left Posterior Ventricular Vein
