Cardiovascular System Flashcards
Heart is located in a cavity called ..
mediastinum
Mediastinum
space between lungs within thoracic cavity
Pericardium
double walled sac surrounding heart
3 layers to the pericardium
- fibrous pericardium
- 2 parts of serous pericardium
Fibrous pericardium
outer most layer (dense irregular CT) anchors heart to surrounding tissue like diaphragm and aorta
2 parts of serous pericardium
- parietal pericardium
- visceral pericardium
Parietal pericardium
fused to fibrous pericardium
Pericardial sac
fibrous pericardium and parietal pericardium
Visceral pericardium
(epicardium) fused to heart surface, key part of heart wall
Between pericardial layers =
pericardial cavity w/ serous fluid (for lubrication)
3 parts of heart wall
- epicardium
- myocardium
- endocardium
Epicardium
makes up visceral layer of pericardium. (stratified squamous epithelium and CT)
Myocardium
cardiac muscle (portion that contracts), arranged in spiral/circular bundles, reinforced with CT (fibrous skeleton of heart)
Endocardium
endothelium that lines the inner surface of the heart and all the blood vessels.(simple squamous epithelium and CT)
Endothelium
lines inner surface of heart and ALL blood vessels
The 4 chambers old the heart
- right atrium
- left atrium
- right ventricle
- left ventricle
Right atrium receives deoxygenated blood from the..
- inferior and superior vena cave
- coronary sinus
Left atrium connects to .. and receives oxygenated blood from the..
- 4 pulmonary veins
- lungs
Right ventricle connects to the.. and sends deoxygenated blood to the..
- pulmonary trunk (divides to form 2 pulmonary arteries)
- lungs
Left ventricle connects to the … and sends oxygenated blood to..
- aorta
- rest of the body
Septa
divides chambers of heart
2 septa’s
- interatrial septum
- interventricular septum
Interatrial septum
separates atria
Interventricular septum
separates ventricles (apparent from the outside of the heart as a shallow and often fat-covered groove called the interventricular sulcus)
Fibrous skeleton of heart is..
CT fibres around the muscles of the heart and provides electrical insulation. (prevents stretching of vessels and the valves of heart)
Rings of CT tissue present between atria and ventricles that ..
-Allow the openings of the heart to remain open at all times
-Valves provide the ability to close off certain portions of the heart inhibiting blood flow in certain directions
(The valves are specifically found at the
atrioventricular groove between the atria and ventricles(
2 types of valves
- atrioventricular valves (AV)
- semilunar valves
2 types of AV valves
- bicuspid (mitral) valve
- tricuspid valce
Bicuspid (mitral) valve
divides the left atrium and left ventricle, 2 cusps
Tricuspid valve
divides right atrium and ventricle, 3 cusps (**RI in name for right side)
Chordae tendineae
(collagen CT) attach valve cusps to papillary muscles. (heart strings)
Semilunar valves
3 cusps each (aortic and pulmonary) (chordae tendineae are not used to anchor these)
Aortic valve
separates left ventricle and aorta
Pulmonary valve
separates right ventricle and pulmonary trunk
Cardiac muscle cells form..
BOTH contractile myocardium and conduction system
Similarities to skeletal muscle and cardiac muscle cells
- striated and composed of myofibrils
- composed of thin and thick filaments arranged into sarcomeres
Differences to skeletal muscle and cardiac muscle
- cardiac cells are branched and uninucleated
- cardiac cells are bond by intercalated discs = region where 2 fibres meet
Cardiac muscle cells are specially modified to..
allow them to
conduct an electrical impulse that spreads from cell to cell via gap
junctions (these DONT contract)