Cardiac Anatomy and Physiology Flashcards
Where is the Heart found?
Thoracic cavity.
The Heart sits ______ to the Vertebral Column
Anteriorly
The Heart sits ______ to the diaphram
Superior
Which intercostal space does the Apex of the Heart lie?
5th Intercostal space (also lies along mid clavicle line)
Which intercostal space does the base of the Heart lie?
2nd / 3rd Intercostal space
What is the name of the Sac that surrounds the heart?
Pericardium
The Pericardium’s function is….
To protect heart from frictions with surrounding organs
The two layers of the Pericardium is called…
Fibrous pericardium and epicardium
Which Veins supply right aria with deoxygenated blood?
Superior and Inferior vena cava.
Which Artery carries oxygenated blood away from left ventricle ?
Aorta.
What are the 4 Chambers of the Heart?
- Right Atrium
- Right Ventricle
- Left Atrium
- Left Ventricle
Which artery carries deoxygenated blood away from Right Ventricle?
Pulmonary Artery
The Pulmonary Artery delivers _______ blood to the __________
- Deoxygenated
- Lungs
________ Blood is delivered back to the _____ Atrium by the _____________
- Oxygenated
- Left
- Pulmonary vein
Where does the right ventricle pump blood too?
The Lungs and close organs.
Where does the left ventricle pump blood too?
The rest of body.
What valves are on the Right side of heart?
- Tricuspid Valve
- Pulmonary Semilunar Valve
What valves are on Left side of heart?
- Bicuspid Valve / Mitral
- Aortic Semilunar Valve
What is function of Coronary Arteries?
Vessels on surface of heart to supply heart with blood.
What is the function of Coronary Veins?
Carries deoxygenated blood from myocardium and empties them into right atria / ventricle
What is the function of Coronary Sinus?
Draining of deoxygenated blood from heart muscles back into right atria.
What is a difference in structure of Right Ventricle and Left Ventricle?
Left Ventricle has thicker ventricle walls.
The ________ divides the left and right sides of the heart…
Septum
Valves are tethered in place by _________ _________
Chordae tendineae.
What is the function of Chordae Tendineae?
- Attach AV valves to the walls of the ventricles.
- Prevent valves prolapsing - blood back backflow
What are the muscle layers of the Heart?
- Epicardium (outer layer)
- Myocardium (mid layer)
- Endocardium (inner layer)
What fatty tissue surrounds the Heart?
Adipose Tissue.
The Heart is __________
Myogenic
- initiates own electrochemical impulse
Heart beat is caused by…..
Excitable tissue (automaticity) and action potentials
The Refractory period is……
250ms
When does the Refractory period occur?
At AV (tricuspid) valve
How is the impulse conducted?
Down the inter ventricular septum and out bundle of HIS
What stimulates contractibility of both ventricles?
Purkijie Fibres
The refractory period when another AP cannot be stimulated is called…..
Absolute Refractory Period
The refractory period when another AP can be stimulated is called…..
Relative Refractory Period
What happens during P stage?
Sinoatrial node depolarises and atria contract
P-Q stage?
Time taken for signal to reach Atrioventricular node from SA node
Q stage?
Depolarisation of Inter ventricular Septum?
R stage?
Depolarisation of Bible of HIS
QRS stage?
Depolarisation of both Ventricles
Q - T stage?
Time of ventricular contraction and relaxation.
(Systole and Diastole)
T stage?
Ventricular repolarisation immediately before relaxation.
Systole is when….
Ventricles contract
Diastole is when….
Ventricles relax
What happens in Early Systole?
- Volume in ventricle is at max
- Pressure is higher than in atria
- Ventricles beginning to contract
- QRS wave in ECG
- Bicuspid valve shut
- Aortic semilunar valve open
What happens in Systole?
- Blood pushed out through Aortic Semilunar valve into Aorta
- Vol of blood falls in ventricles
What happens in Late Diastole?
- Aortic pressure higher than ventricular pressure
- Semilunar valve closed
- AV valves open from atrial systole
- Ventricular pressure begins to rise
What happens in early Diastole?
- Rapid pressure in relaxing ventricles, less than in atria.
- Semilunar valve closes
- Bicuspid valve shut
- Volume in ventricle at a minimum.
What makes the ‘sub’ sound?
Closing of semilunar valve
What makes the ‘dub’ sound?
Bicuspid valve
Equation for Cardiac Output…
Cardiac Output = Heart Rate x Stroke Volume
- HR = num of beats per min
- SV = vol of blood pumped out by a ventricle each beat
Which Nerves control Heart Rate?
- Vegas nerve - parasympathetic activation, +ve, bradycardia
- Sympathetic neve - sympathetic activation, -ve, tachycardia
A feature of capillaries is they are ____ layer thick…
One
What is the function of capillaries?
Gaseous exchange
Blood pressure is the interaction between….
The heart and vessels
Types and Functions of Blood Vessels…. (5)
- Artery - elastic and muscular
- Arterioles - Smooth muscle, local control of blood
- Capillaries - used for gaseous exchange
- Venules - recieve blood from capillaries, permeable.
- Veins - Large volume, low pressure, store blood.
Types of Capillaries (3)
- Continuous
- Fenestrate
- Sinusoidal
What is a Continuous Capillary?
- Tight endothelia lining
- Forms blood brain barrier
- Found in skeleton muscle and brain
What is a Fenestrate Capillary?
- Less intact endothelia lining
- Permit high range of exchange due to ‘leakiness’
- Found in kidney and intestine
What is Sinusoidal Capillary?
- Incomplete endothelial lining
- Exchange of large molecules and cells
- Max opportunity to modify blood
- Found in liver and bone marrow
