Anatomy of the CVS 1 Flashcards
What tissues lack blood vessels?
Cartilage and The epidermis both receive a nutrient supply by diffusion from the blood supply of underlying tissues
What is a portal system?
Two sets of capillaries connected by a portal vein which isn’t part of the normal path of circulation.
What is the hepatic portal circulation?
The hepatic portal vein connects the capillaries of the digestive tract with those of the liver.
What forms the right border of the heart?
The Right atrium and a little the right ventricle
What chambers make up the left border of the heart?
The left ventricle. Also known as the apex of the heart.
What makes up the anterior border of the heart?
The right atrium, left ventricle and right ventricle. (the right ventricle is about 1/2 the border)
What makes the posterior border of the heart?
The left atrium. Also known as the base
What chambers form the inferior border of the heart?
Mainly the right ventricle with the left contributing near the apex.
What do we call the veins & arteries that supply the heart itself with blood?
Coronary Arteries
Cardiac Veins
Into what vessels do the cardiac veins drain?
First the Coronary Sinus then into the right atrium
What is contained in the anterior mediastinum?
Thymus gland or remnants
Fat
Ligaments
What plane separates the superior & inferior mediastinum and what level is it at?
The thoracic plane at T4.
It passes through the sternal angle.
Where on the surface is the apex of the heart?
The 5th left intercostal space in the mid-clavicular line.
What is situs inversus?
A congenital condition where pretty much everything internally has been inverted around the middle axis to the other side.
People are usually asymptomatic but it can be very confusing.
Whats the difference in the heart with a child?
A child’s is higher and more horizontal
What structures are considered lateral to the heart?
The lungs and phrenic nerves
What structures are found posterior to the heart>
The oesophagus
Descending aorta
Thoracic Vertebrae T5-T8
What structures are anterior to the heart?
The anterior edges of the lung/pleurae
Thymic remnants
The sternum
Costal cartilages 4-7
What are the layers of the heart wall & what surrounds it?
Innermost - Endocardium
Middle - Myocardium (cardiac muscle)
Outermost - Epicardium (Visceral Pericardium)
All surrounded by a pericardial cavity and serous parietal pericardium. Around that is a fibrous pericardium.
What makes up the endocardium?
A layer of squamous epithelium on a basement membrane with some connective tissue.
What makes up the epicardium?
Connective tissue + a basement membrane with simple squamous epithelium on it.
The epithelium of the epicardium is also the serous visceral pericardium.
What layer of the heart wall forms the valves?
The endocardium (also lines the heart chambers)
What connects the myocytes in the myocardium?
Intercalated Discs.
Which are made of gap junctions (electrical communication) & desmosomes (binding myocytes together)
What do intercalated discs allow?
The cardiac muscle to act as a functional syncytium. All contracting simultaneously and as one.
How does cardiac muscle appear in histology?
Faintly Striated
Branching
Mononucleated
Connected by intercalated discs
Which section of the heart wall can put on fat?
The epicardium
What are cusps and how many are in each valve?
thin structures derived from the endocaridum that make up the valves.
All the valves have 3 cusps (tricuspid) except the mitral which has 2 (bicuspid), L atrium to L ventricle.
What do chordae tendinae and papillary muscle do?
They prevent the valves from turning inside out and failing and to function.
What is incompetance and stenosis of a heart valve?
Incompetence is widening of the valve
Stenosis is narrowing of the valve
What do we call an infection of the heart valves?
Bacterial Endocarditis
What are the 4 valves?
R Atrium -> R ventricle = Tricuspid Valve
R Ventricle -> Pulmonary Trunk = Pulmonary Valve
L Atrium -> L ventricle = Mitral or Bicuspid Valve
L Ventricle -> Aorta = Aortic Valve
What do we call the aortic and pulmonary valve?
Semilunar valves
What do we call the tricuspid and mitral valves?
Atrioventricular Valves
What happens when a valve has stenosis?
It narrows and the chamber must generate a greater pressure to force blood out resulting in hypertrophy and eventually cardiac failure.
What happens to an incompetent valve?
It cant close properly so there is some regurgitation of blood and the chamber must work harder. again leading to hypertrophy and cardiac failure.
What are the 2 functions of connective tissue in the heart? and what is it also known as?
Structural support in the form of the:
- Atrioventricular septum
- roots and anchorage of great vessels
- supports myocytes and capillaries.
Electrical insulation:
- Separates atria from ventricles to prevent simultaneously contraction.
- Separates myocardium from great vessels so the vessels don’t contract.
Its also known as the Cardiac Skeleton.
Why does blood only enter the coronary arteries during distole?
During systole:
- The aortic valve is open
- the cusps block the openings in the aorta to the aortic sinuses
During Diastole:
- The valve shuts
- The aortic sinuses are exposes and blood flows in from the aorta.
Why does blood only enter the heart’s capillaries during distole?
Because during systole the heart is contracted cutting off the capillaries.
In what layer of the heart are its coronary arteries found?
In or on the epicardium
What happens when theres occlusion (blockage) of a coronary artery?
Heart Attack
What are the attachments of the heart?
It sits in a dense connective tissue bag called the fibrous pericardium.
Its attached to the Sternum, Central Tendon of the diaphragm and hangs from the roots of the great vessels.
what is the function of pericardial fluid within the serous membrane?
It acts as a lubicant
To what are the serous membranes bound to?
The parietal layer is bound to the fibrous pericardium
The Visceral Layer is bound to the heart as part of the epicardium
What is the function of the serous pericardium?
To allow freedom of movement to the heart during the cardiac cycle.
