Heart Flashcards
Heart
- Double pump system
- Works closely with vascular system (cardiovascular system)
- 300 grams
- 2nd rib - 5th inner costal (between 5 and 6 rib)
- 60% left side
Serous Pericardium
Covering protects heart, decreases friction
- 2 layers
- Parietal (superficial): lines cavity
doubles over on its self and becomes the visceral
- Visceral (deep): lines organ
* Pericardial (serous) fluid in between - 50 mL
- blood can accumulate in this area and inhibit heart contraction
Thoracic Cavity & Mediastinum Cavity
Division of the thoracic cavity (3 chambers):
- 2 pleural chambers (lungs)
- Heart in middle (mediastinum cavity)
Mediastinum Cavity - division of the thoracic cavity
- Heart, thymus gland, portions of the esophagus
- Heart sits in Pericardium sac
Heart Anatomy
Apex: located bear bottom of diaphragm
Base: Posterior part of heart
Heart Layers (heart wall)
- Epicardium (visceral layer)
- most superficial layer - Myocardium (cardia muscle)
- contract -> pushing blood in forward direction
- must contract as unit (all or none) * functional syncytium
- influence pumps (ventricles) - Endocardium
- simple squamous epi
- lines inner aspect of hear and all blood vessels
- most deep
Heart Biological Pumps
Right Ventricle & Left Ventricle
Right Atrium Anatomy
- Auricles: chamber for excess blood
- Pectinate muscles: only in right atrium
- Crista Terminalis: C shaped
- Fossa Ovalis: Door sealed shut between R and L Atrium
- Patent Foramen Ovale (PFO) - Open hole when baby is inside mom. Blood is oxygenated by mom, no need to go to lungs. Goes directly across to Left Atrium
- Pressure changes shuts PFO
- 25% of pop. Fossa Ovalis is not fused shut.
- increased likelihood of stroke
Atrioventricular Valve
Valve located between Atria and Ventricles (2)
Tricuspid Valve: This heart valve is located between the right atrium and the right ventricle. When closed, it allows oxygen-depleted blood returning to the heart from the venae cavae to fill the right atrium. It also prevents the back flow of blood as it is pumped from the right atrium to the right ventricle. When open, it allows blood from the right atrium to flow into the right ventricle.
Mitral Valve (bicuspid) : This heart valve is located between the left atrium and left ventricle. When closed, it allows the left atrium to fill with oxygen-rich blood returning to the heart from the pulmonary veins. It opens to allow blood from the left atrium to fill the left ventricle.
Tri something before you Bi something. Tri (right side) Bi (left side)
Tricuspid Stenosis
Tricuspid stenosis is a narrowing of the tricuspid valve opening that slows blood flow from the right atrium to the right ventricle
- increases work of the heart to get blood where it needs to go
Tricuspid Regurgitation (incompetent valve)
Tricuspid regurgitation is a disorder in which this valve does not close tight enough. This problem causes blood to flow backward into the right upper heart chamber (atrium) when the right lower heart chamber (ventricle) contracts
Ventricles
Two chambers on bottom below atrium.
- Right and Left Ventricle
- Ventricle walls are thicker vs atria -> they work harder
- Left ventricle wall is larger vs Right ventricle wall
- Left ventricle does more work
Ventricle - Carneae Trabeculae
rounded or irregular muscular columns which project from the inner surface of the right and left ventricle of the heart
- ‘cross bars of flesh’
- helps with contraction
Ventricle - Papillary Muscle
- Attached to ligaments (chordae tendineae aka ‘guy wires’)
- Ligaments attach to cusps:
- Tricuspid (3 papillary muscles)
- Bicuspid (2 papillary muscles)
Ventricle - Chordae Tendineae
Aka ‘Guy Wires’ ligaments attached to cusps and papillary muscle
- Tricuspid
- Bicuspid
Help ensure blood moves in the right direction
How Atrioventricular Valves Function
- Blood returning to the heart fills atria, pressing against the AV valves. The increased pressure forces AV valves open.
- As ventricles fill, AV valve flaps hang limply into ventricles.
- Atria contract, forcing additional blood into ventricles
a. AV valves open; atrial pressure greater than ventricular pressure - Ventricles contract forcing blood against AV valve cusps
- AV valve close
- Papillary muscles contract and chordae tendineae tighten, preventing valve flaps from everting into atria.
b. AV valves closed; atrial pressure less than ventricular pressure
Great Vessels
Blood vessels directly attached to the heart itself.
The great vessels is the collective term given to the major arteries and veins that convey blood to and away from the heart
*some have valves, others do not
Great Vessel - Superior Vena Cava (Vein)
- Drains blood from the head, neck and certain aspect of the thorax
- Returns blood to right atrium
- No valves
Great Vessel - Inferior Vena Cava
The inferior vena cava (or IVC) is a large vein that carries the deoxygenated blood from the lower and middle body into the right atrium of the heart. It is formed by the joining of the right and the left common iliac veins, usually at the level of the fifth lumbar vertebra.
-No Valve
Veins vs. Arteries
Veins - always carry blood to the heart
Arteries - always take blood away from the heart
Pulmonary Trunk - Great Vessels
Left & Right Pulmonary Artery
- Both go to their respective lungs
Pulmonary Artery - Great Vessels
Left & Right Pulmonary Artery
- Both go to their respective lungs
A. Semi lunar valves (ensure one way blood flow to prevent regurgitation)
B. Ligamentum Arteriosum (PDA) - path of least resistance for babies in mom.
- skips P. Artery - > Lungs
- P. Artery - > PDA - > Aorta - > Body
- When amniodic fluid is cleared from lungs when baby is born, PDA closes and becomes -> Ligamentum Arteriosum
4 Pulmonary Veins - Great Vessels
All 4 return to Left Atrium
- 2 bring back blood from L lung
- 2 bring back blood from R lung
- No Valves
Aorta - Great Vessels
- Largest Blood Vessel in body
- Left ventricle
- Semi-lunar valves (located in pulmonary trunk)
- Typically always closed. Only open when ventricles contract
Semi-lunar vs Atrioventricular Valve
Function: Ensure blood flow in certain direction
- Atrioventricular Valve - almost always open, closed briefly with ventricles contract
- Semi-lunar - almost always closed, open with ventricles contract
Location:
- Atrioventricular Valve - between atria and ventricle
- Semi-lunar - base of large vessels
Semi-Lunar
Located in ventricles specifically in pulmonary trunk
- typically always closed
As ventricles contract & intraventricular pressure rises, blood is pushed up against semilunar valves, forcing them open
As ventricles relax & intraventricular pressure falls, blood flows back from arteries filling the cusps of the semilunar valves, forcing them to close.
Arch of Aorta - Candy Cane
- Brachiocephalic a -> path divides (2)
2a. To the left -> R. Common Carotid a.
2b. To the right -> R. Subclavian a.
R. Common Carotid a.
R. Common Carotid a.
R. Subclavian a.
R. Subclavian a. R. Axillary a. (armpit) - where subclavian becomes axillary
R. Axillary a. -> R. Brachial a. (bicep) *where we take someones blood pressure
R. Brachial a. (to end of humorous/elbow) -> Brachial artery splits (2) -> R. Radial a. & R. Ulnar a.
R. Radial a. & R. Ulnar a. -> Meet @ hand to form -> R. Palmar Arch
