Anatomy of the CVS 1 Flashcards
Basic functions of Arteries, Capillaries and Veins
Arteries - distribute blood from heart
Capillaries - exchange nutrients
Veins - collect and return blood to the heart
Basic function of Lymphatics
Drain excess extracellular fluid from tissues
Where is the cardiovascular system located?
- Heart: middle mediastinum.
- Blood vessels
- Lympahtics
Do the brain and eye have lymphatics?
NO
Does cartilage have blood vessels?
NO
Where are the main structures of the cardiovascular system located?
The middle mediastinum
What are the two main circulations of the CV system?
- Pulmonary circulation: heart-lungs-heart
- Systemic circulation: heart-body-heart
Also hepatic portal circulation: Lymphatic system.
What are the great vessels of the heart?
- 2 L&R pulmonary veins
- Aorta: ascending, aortic arch, descending
- Superior vena cava
- Right pulmonary artery
- Left pulmonary artery
- Pulmonary trunk
- Inferior vena cava
Between which vertebrae does the heart lie?
T5-8
-In recumbent position
Where is the apex located?
Left ventricle: 5th left intercostal space in the midclavicular line
Where is the left atrium located?
LA=base
- It is wholly posterior, lies in front of the oesophagus.
How is the heart positioning different in children?
Higher in children and lies more horizontal
What is Dextrocardia with situs inversus?
Dextrocardia with Situs Inversus is a rare heart condition characterised by abnormal positioning of the heart.
- In this condition, the tip of the heart (apex) is positioned on the right side of the chest. - Additionally, the position of the heart chambers as well as the visceral organs such as the liver and spleen is reversed (situs inversus).
What is a useful landmark for the heart?
T4 sternal angle
What anatomical relations are anterior to the heart?
- Sternum & costal cartilages 4-7
- Anterior edges lungs and pleurae
- Thymic remnants
What anatomical relations are posterior to the heart?
- Oesophagus
- Descending aorta
- Thoracic vertebrae 5-8
What anatomical relations are lateral to the heart?
- Lungs
- Phrenic nerve
What anatomical relations are inferior to the heart?
Central tendon of diaphragm
What are the main structures of the heart?
- Layers of heart wall
- Chambers
- Heart valves
- Cardiac skeleton
- Coronary arteries
- Cardiac veins
- Pericardium
- Innervation
What are the 3 main layers of the heart wall?
- Endocardium (innermost):
epithelium + basement membrane + connective tissue - Myocardium (middle): cardiac muscle
- Epicardium (outermost):
connective tissue + basement membrane + epithelium
Features of Endocardium
- Lines heart chambers
- Simple squamous epithelium sitting on the basement membrane
- Sits on connective tissue
- Forms valves
Features of Myocardium
- Thick middle layer of heart wall
- Cardiac muscle (myocytes): branching fibres
- Striated muscle, lots of mitochondria, single-central nucleus
- Rich capillary bed
- Muscle bundles in different planes to close down chamber lumen
- Myocytes connected by intercalated discs
Features of Epicardium
- Outer layer of heart wall
- Simple squamous epithelium + BM + connective tissue
- Epithelium = visceral layer of serous pericardium
- Epicardium contains main branches of coronary arteries
- May be fatty
What are the chambers of the heart?
- Right atrium
- Right ventricle
- Left atrium
- Left ventricle
Direction of blood flow is controlled by valves
What are the different borders of the heart?
- Superior border
- Right border
- Left border
- Inferior border
Features of heart valves
- Control direction of blood flow
- Cusps: thin structures derived from endocardium
- Work passively
- Chordae tendineae and papillary muscle prevent valve failure
Clinically important problems with heart valves
- Abnormalities( imcompetence= widening, stenosis= narrowing)
- Infection (bacterial endocarditis)
What are the 4 valves of the heart?
- Pulmonary valve
- Aortic valve
- Mitral valve
- Tricuspid valve
Which valves are the atrioventricular valves?
Tricuspid and Mitral
-Control blood flow from the atria to the ventricles.
What do the aortic valve and pulmonary valve control (semilunar valves)?
Control blood flow out of the ventricles
What is the mitral valve known as?
The bicuspid valve
How many cusps do the semilunar valves (aortic and pulmonary valves) have?
3 cusps
Structural support of Fibrous cardiac skeleton
- Atrioventricular septum
- Roots of great vessels
- Anchorage for valves
- Myocytes/capillary network
Fibrous cardiac skeleton electrical insulation
- Atria from ventricles
- Myocardium from great vessels
Features of coronary arteries
- Right and left
- At systole openings in aortic sinuses shielded by aortic valve cusps
- At diastole elastic recoil of aorta closes aortic valve and blood enters arteries
- Located in epicardium
- At diastole myocardium relaxing and blood can flow into capillaries
- Occlusion (Blockage) = bad news – heart attack!
- Must know main branches.
What holds the heart in place?
- It “Hangs” by great vessels within fibrous pericardium
- Dense connective tissue bag
- Attachments: Central tendon of diaphragm, Sternum, Roots of great vessels.
- Lined by serous pericardium
Features of serous pericardium
- Epithelium
- Secretes pericardial fluid – lubricant
- Visceral layer
Bound to heart (=epicardium) - Parietal layer
Bound to fibrous pericardium - Visceral and parietal layers continuous:
gives closed bag - Allows freedom of movement during cardiac cycle
