Anatomy of Bloodflow Through Heart 1 Flashcards
describe the bloodflow through pulmonary and systemic and hepatic portal circulations
- right atrium receives deoxygenated blood from systemic circulation (cranial and caudal vena cava)
- directed to right ventricle (tricuspid valve)
- exits pulmonary trunk –> pulmonary arteries to lungs through the pulmonary valve
- left atrium to the left ventricle (mitral valve) and exit via aorta (aortic valve)
- arterial blood to the head, neck and forelimbs via subclavian and common carotid arteries
- arterial blood to body tissues via descending and abdominal aorta –> hepatic portal system in liver
- venous returns to right atrium via cranial and caudal vena cava
where is the heart within the thorax in left lateral view
between ribs 3-6 at an angle with its base lying cranial and dorsal to the apex which lies caudal and ventral
what is the position of heart in dorsoventral view
lies to the left of midline
apical heart beat
what is the cardiac notch
the region of the heart which is in direct contact with the body wall
the heart is sitting surrounded by mediastinal pleura –> passing over the lateral surfaces of the heart and holding it here between the left and right thorax
where is the heart relative to the mediastinum
within its own serious sac (pericardium) within the middle mediastinum
what are the structures of the middle mediastinum
what structure covers the heart
pericardium
tough structure –> fibrous material (not much flexibility, can cause problems if fluid build up or heart enlarges)
what are the structures of the pericardium
divided into visceral and parietal layers
vsiceral layer –> adherent to surface to heart and reflects over great vessels and then adheres to the fibrious layer that is between the mediastinum
pericardium is filled with fluid –> between parietal and visceral layer (continuous with outersurface of the heart –> epicardium) –> serous fluid fills this gap
what are the layers of the heart
- epicardium (outer)
- myocardium (middle)
- endocardium (inner)
what is the epicardium layer composed of
- superficial layer (visceral pericardium)
- deeper fibroelastic CT
what is the myocardium layer composed of
- cardiac muscle
- endomysium CT
what is the endocardium layer composed of
- endothelium and CT
- purkinje fibres
what type of epithelium is the endocardium
simple squamous epithelium
how is cardiac muscle arranged
in circular and spiral arrangement of cardiac muscle bundles in the myocardium
networks to ensure proper directional flow when they contract and squeeze the blood through the different chambers of the heart
identify the histological features of the cardiac muscle