Please enable JavaScript.
Coggle requires JavaScript to display documents.
The Cardiovascular system (Heart (Anatomy (External (Right (Ventricle,…
The Cardiovascular system
Cardiovascular system
Systemic and Pulmonary Circulation
Systemic circuit
Pulmonary Circuit
Circuit able to tolerate high flow , high pressure, High oxygen
Dual pump system supplying two systems
Supplies to both systemic and pulmonary at the same time
Congenital Heart Disease (Ventricular septal defect)
Single ventricle to provide for the both systemic and pulmonary at the same time
Arterial and Venous system
Artery
Histology
Tunica Media
External Elastic Membrane
Thick and dominated by smooth muscle cells
Tunica Intima
Internal Elastic Membrane
Endothelium
Usually Rippled
Due to vessel constriction
Tunica Externa
Collagen and elastic fibres
Types
Elastic Artery
Tunica Media
High density of elastic fibers
Highly resilient to blood pressure
Muscular Artery
Tunica Media
Contains more smooth muscle cells
Arteriole
Tunica externa
Poorly defined
Tunica media
1 - 2 layers of smooth muscle
Vein
Histology
Tunica Media
Thin
Dominated by smooth muscles and collagen fibers
Tunica Intima
Often smooth
Tunica Externa
Elastic fibers
Smooth muscle cells
Collagen
Valves
Internal structures that prevent backflow
Types
Large Veins
Tunica externa
Composed of a mixture of elastic and collagen fibers
Medium sized Veins
Tunica media
Thin
contains little smooth muscle
Tunica Externa
Thick
Longitudinal bundles of collagen and elastic fibers
Venules
Lack tunica media
Differences
Vessel walls
Artery
Tunica media
Contains more smooth muscles and elastic fibers
Vessel Lumen
Artery
Elastic fibers of the walls recoil
Lumen constricts
Vein
Tend to collapse
Flattened and grossly distorted
Vessel Lining
Artery
Endothelial lining cannot contract
endothelium lining folds when artery constricts
Vein
Endothelium lining lacks folds
Heart
Pericardium
Fibrous Pericardium
Retains heart in position
Serous Pericardium
Visceral
Parietal
Pericardial fluid
Anatomy
External
Right
Ventricle
Atrium
Pulmonary veins
Left
Ventricle
Atrium
Pulmonary veins
Superior & inferior Vena Cava
Ascending Aorta
Pulmonary trunk
Internal
Valves
Atrial-Ventricular
Left
Bicuspid
Right
Tri-Cuspid
Pulmonary
Aortic
Interventricular septum
Chordae Tendinae
Tense
Ventricular Systole (Contraction)
Emptying of ventricle
Loose
Ventricular Diastole (Relaxation)
Relaxed and filling blood
Papillary muscles
Connects to the Chordae Tendinae
Coronary arteries
Nourishment of the heart
Myocardial cells
Mitochondria
Oxygen dependant
Oxygen supply of cardiac muscle
Endocardium is poorly permeable to oxygen
Cardiac muscle
Too thick for diffusion of Oxygen
Do not regenerate and are replaced by non-contractile scar tissue
Heart loses strength
Heart failure
arrhythmias or ventricular fibrillation
Treatment
Clot busters
1 more item...
Streptokinase
Tenecteplase
Coronary artery angioplasty/Stenting
1 more item...
Left Coronary Artery
Circumflex
Anterior Interventricular artery
Right Coronary Artery
Right Marginal Branch
Posterior interventricular
Arterial Anatomoses
Linking of the Left and Right coronary arteries
Cardiac Vein
Great Cardiac Vein
Travels alongside anterior interventricular artery
Curves with circumflex
Middle Cardiac Vein
Travels with posterior inter-ventricular artery
Small Cardiac Vein
Drains blood from the side of the heart
Coronary sinus
all veins drains
which opens into the right atrium
Cholesterol
Lipids
High Density Lipoprotein
Low density Lipoprotein
protein that transports cholesterol into cells
Endothelial layer of Blood Vessels
Oxidisation happens in the vessel wall
Inflammation
Development of plaque
Enlargement reduces bloodflow
2 more items...
Plaque causes damage to endothelium
1 more item...
Very Low Density Lipoprotein
Electrical properties of the Heart
Physiology
Membrane potential
Electrical charge across the membrane
At rest
-60Vm
Determinants
Balance of negative and positive charged ions
Na+, Ca+, K+, Cl+
Channel
Protein
Allows ions to pass through
Normally selective to certain specific ions
Voltage Gated channel
Channel
Dependant on the membrane potential
Closed at rest
Depolarisation
Process of Vm moving towards 0
Caused by rapid influx of positive ions
Na+, Ca+
Action potential
Overshoots 0 and becomes positive
Repolarisation
End of action potential
Cell reverts to resting state
Ions move back to original state
Myocardial cells
Auto-active, pace makers
Action potential
Activation of the cell
Propagation
Rapidly within 0.25 sec
Other auto active cells
activated by the propagation of APs originated from the SA node
Pacemaker potential
Drives membrane potential to threshold
Initiates action potential
Nodes
Sinoatrial node
Natural Pacemaker
70 to 80 per minute AP discharge
Internodal pathways
Atrioventricular node
40 to 60 per minute AP discharge
Bundles/ Fibers
AV bundle
20 to 40 per minute AP discharge
Bundle branches
Purkinje fibers
20 to 40 per minute AP discharge
Ion movements
Na+ enters the cell during pacemaker potential until threshold
Ca+ voltage gated channels open increasing the influx of calcium forming the start of the Action potential
Repolarisation of cell membrane, release of K+ through Voltage gated channels, ending the action potential
Hyperpolarise, Outflow of K+ was too great, Na+ is taken it for the next Pacemaker potential
Funny channel
Auto initiation of the Na+ influx
NA-K ATPase
higher K+ in the cell than outside the cell
Membrane potential is negative
More negative ions in the cell than outside the cell
Stimulation of autonomic nerves
Cardiac sympathetic nerves
Increase of Na+ conductance
Increase slope of pacemaker potential
Increase heart rate
Funny channel
Catecholamines
Noradrenaline
Adrenaline
Activate Beta adrenergic receptors in the SA node
Hormonal input
Cardiac vagal nerves
Increase of K+ conductance
Decrease of pacemaker potential
Decrease heart rate
Vagal neurotransmitter
Acetylcholine (ACh)
Activates Muscarinic Cholinergic receptors
Neural input