Flashcards in Anatomy of the heart Deck (22):
What is the anatomical terminology when describing the body?
1. Superior (upwards) vs. Inferior (downwards)
2. Anterior (front) vs. Posterior (back)
3. Lateral (towards the outside) vs. Medial (towards the middle of the body)
4. Proximal (closer to) vs. Distal (further away)
What are the 3 planes of the body?
1. Coronal (frontal) - divides anterior and posterior
2. Transverse/axial (horizontal) - divides superior and inferior
3. Median (sagittal)
Sub groups: Parasagittal ( to the right of the sagittal ), produces unequal halves of the body
Midsaggittal: produces equal halves
Where is the heart located and what does it contain?
- The heart is located in the centre-left of thorax in a space called the mediastinum
- It is a muscular organ that sits inside a protective sac (pericardium) that is sealed around the great vessels and has two layers
What are the two layers of the pericardium?
1. Fibrous membrane:
provides protection and structural support
2. Serous membranes:
secretory layers which provide lubrication between heart and fibrous membrane
secretes serous fluid
what are the 4 layers of the pericardium?
0. Heart chamber
1. Endocardium: one-cell thick layer which is the interface between heart and blood.
2. Myocardium - thick layer of cardiac muscle cells, thicker in left
3. Visceral layer of serous pericardium - the epicardium: a layer of serous tissue between the myocardium and pericardial space. Also known as the epicardium.
4. Parietal Pericardium - a layer of serous tissue lining the fibrous pericardium and facing the pericardial space
5. Fibrous Pericardium - connective tissue to protect the heart and hold its position
what are the main vessels of the heart?
Aorta: ascending aorta + aortic arch.
The aortic arch starts and ends at the level of the sternal angle
superior vena cava
inferior vena cava
pulmonary trunk: bifurcates and goes to the 2 lungs by branching into right and left to go to both lungs.
What is the difference between the superior and inferior vena cava?
If blood is coming back from head/arms = superior vena cava
If blood is coming back from rest of the body = inferior vena cava
What are the 4 types of valves in the heart?
Valves on the RIGHT side of the heart:
1. Tricuspid valve (3 cusps)
4. Pulmonary valve (3 cusps)
Valve on the Left side of the heart:.
2. Aortic valve (3 cusps)
3. Mitral valve (2 cusps with one cusp being larger than the other)
What is the structure of the walls of blood vessels?
- protection and structure
- fixing to other structures nearby
- Includes most of the smooth muscle as well as elastic and collagen
- Vascular endothelium
- Basement supporting matrix
What is the structure and function of the artery?
Circular vessels - carry high pressure so need to expand equally
- Also known as conduit vessels
- Carry blood from one location to another
What is the function of the arteriole?What is the function of the capillary?
- Also known as resistance vessels
- They control flow into the copious numbers of capillary beds
- Also known as exchange vessels
- Responsible for gas exchange, absorption and secretion
What is the structure of the veins and venules?
- More distortable
- Have valves to maintain directional flow as blood flows at low pressure
Veins sometimes called capacitance vessels because they contain the majority of blood at any given time
What does the blood for coronary circulation arise from?
Blood arises just superior of aortic valve (not pulmonary valve to ensure the blood is oxygen rich)
What are the main arteries involved in coronary circulation?
Right coronary artery branches:
1. Atrial branch
Sinu-atrial nodal branch
2. Marginal branch
3. Posterior interventricular branch (posterior descending artery PAD)
Left coronary artery branches:
1. Anterior interventricular branch (left anterior descending LAD)
2 diagonal branches
- Right conus artery (not one of the 3 main ones and strictly speaking only 3 vessels)
- Sometimes arises from right coronary artery
What veins are included in coronary circulation?
Coronary sinus = it is located posterior and drains into the bottom of the right atrium so it can then travel to the lungs to be re-oxygenated
- Coronary veins drain into the coronary sinus and into the right atrium
What are the 3 branches of the aortic arch?
1. Brachiocephalic trunk (arm-head trunk)
- splits into two vessels: vessel going to arm and vessel going to right side of head.
-bifurcates into the Right subclavian artery and the right common carotid artery, the left come directly off the aortic arch.
2. Left common carotid artery
3. Left Subclavian Artery
what veins form the superior vena cava?
The Right internal jugular vein and the right subclavian vein join together to form the Right Brachiocephalic Vein
•The Left internal jugular vein and the Left subclavian vein join together to form the Left Brachiocephalic Vein
•Both brachiocephalic veins join together the form the Superior Vena Cava
When do abdominal branches start?
Below the diaphragm
what are the functions of the percardium?
-Defines the borders of the middle mediastinum
-The fibrous layer prevents the heart overfilling and sudden dilation (i.e during exercise) as it does not stretch
-The pericardial fluid allows the 2 serous layers (visceral and parietal) to move against each other without friction as well as a shock absorber
-Acts as a barrier to infection
-Keeps the heart stable and within the thoracic cavity by ligaments (sternopericardial and pericardiophrenic)
What happens if the pericardial cavity fills with blood? What is this called?
CARDIAC TAMPONADE – where the pericardial cavity fills with excess fluid (normally blood) called a pericardial effusion and compresses the heart thereby restricting its movements(beating) and is fatal
Solution is to use a LARGE needle to remove the fluid by entering at the left of the xiphisternum and aim towards the left shoulder – PERICARDIOCENTESIS
what are the sinuses of the rpercardium>
Reflection of the serous pericardium onto the pulmonary veins
Reflection of the serous pericardium that separates the arteries and veins
Superior to the L.A