Topic 12: Cardiovascular System Flashcards
what does the cardiovascular system contain?
-heart
-blood vessels
-blood (connective tissue)
what is the purpose of the cardiovascular system?
-transport gases, nutrients, hormones, wastes, and heat throughout the body
-offers protection (immune function) against disease and fluid loss (clotting to prevent bleeding after injury)
where is the heart located?
-cavity called the mediastinum (compartment of your chest cavity)
-a space between the
lungs within the thoracic
cavity (chest cavity
what is the coverings of the heart called?
-pericardium
what is the pericardium?
-double-walled sac surrounding the heart
-made of 3 layers
what is the fibrous pericardium?
-outermost layer of the pericardium
-dense irregular CT
(collagen fibres)
what is the purpose of the fibrous pericardium being composed of dense irregular CT?
-gives strength in all directions
-to prevent overstretching
what is the fibrous pericardium’s other main function?
-anchors itself to surrounding structures
-EX: diaphragm, larger
vessels (aorta, vena cava,
etc)
what is the serous pericardium?
-forms 2 layers which creates the pericardial cavity in between
-2 parts are:
-parietal pericardium
-visceral pericardium
what is the parietal pericardium?
-made of epithelium and CT
-fuses to the fibrous pericardium
what does the fibrous pericardium and the parietal pericardium create?
-the pericardial sac
what is the visceral pericardium?
-composed of stratified squamous epithelium and CT
-very smooth and thin
-fused to the heart surface
what is the visceral pericardium also called?
-epicardium
-since it fuses to the heart surface it is part of the heart wall
what are the 3 layers of the heart wall and their location?
-epicardium (outside)
-myocardium (middle)
-endocardium (inside)
what is the function of the myocardium? how would the pattern of the muscle tissue help?
-acts as a pump
-multiple layers going in multiple directions allows for stronger pumping action
what is the myocardium?
-middle layer of the heart wall
-made of cardiac muscle
-arranged in a
spiral/circular pattern
-reinforced with CT
what is the endocardium?
-inside layer of the heart wall
-composed of simple squamous epithelium and CT
what is the name of the epithelium in the endocardium and what is its purpose?
-endothelium
-lines the inner surface of the heart and ALL blood vessels
-minimizes surface friction for the blood passing through the heart by acting as a free surface
what blood vessels are associated with the right atrium?
-inferior and superior vena cava
-coronary sinus
what is the location of the coronary sinus? posterior or anterior?
-posterior
what are the blood vessels associated with the left atrium?
-4 pulmonary veins
-2 coming from the left
-2 coming from the right
what are the blood vessels associated with the right ventricle?
-pulmonary trunk
-divides to form the right and left pulmonary arteries
what are the blood vessels associated with the left ventricle?
-aorta
what is the distinguishing feature of the left ventricle?
-thicker myocardium
-pumping blood further distances at a higher pressure compared to the right ventricle
-still pumping equal amounts of blood
what divides the chambers of the heart?
-septa
-interatrial septum
-interventricular septum
what does the interatrial septum seperate?
-the atria
what does the interventricular septum separate? what is it deep to?
-the ventricles
-deep to the interventricular sulcus
- shallow groove filled
with fat and blood
vessels
what is the fibrous skeleton?
-CT fibers that surround the muscle fibers
-4 dense CT rings that
surround the valves of
the heart
what is the purpose of the CT rings?
-allows for the valves to open and close when needed
-provides electrical insulation
-prevents simultaneous
contraction of the
chambers
what are the two types of valves in the heart?
-atrioventricular valves
-semilunar valves
what are the two atrioventricular valves?
-bicuspid (mitral) valve
-left side
-2 cusps
-tricuspid valves
-right side
-3 cusps
what are chordae tendineae?
-connective tissue
-attaches atrioventricular valve cusps to the papillary muscles
what are the papillary muscles?
-projections of the myocardium
what are the two semilunar valves?
-aortic
-separates the left
ventricle and the aorta
-pulmonary
-separates the right
ventricle and the
pulmonary trunk (leads
to pulmonary arteries)
what do cardiac muscle cells form?
-contractile myocardium
-normal cells
-a conduction system
-modified/special cells
what is the purpose of the normal cardiac muscle cells?
-create contractions for pumping blood throughout the heart
what is the purpose of the specialized cardiac muscle cells?
-generate and conduct electrical signals
-mainly to open specific valves/parts of the heart (ex: opening the right atrium)
what similarities do cardiac muscle cells have with skeletal muscle cells?
-striated (myofibrils with sarcomeres)
-has sarcoplasmic reticulum and T-tubules
what differences do cardiac muscle cells have with skeletal muscle cells?
-they are branched (irregular, not parallel)
-uninucleated
-have intercalated discs
from which pressures does blood like to move?
-high to low
-higher pressure in the atria to the lower pressure ventricles
what junctions do intercalated discs contain?
-anchoring junctions
-so they don’t fall apart
-gap junctions
-allows them to work
together as a unit (when
one contracts, the
adjacent ones will also
contract)
how are valves able to open and close?
-in response to pressure changes
-in response to electrical signals
what are intercalated discs?
-they connect cardiac muscle fibers together
-thickenings of the sarcolemma (membrane)
what is the conduction system made of?
-modified cardiac muscle cells that produce and conduct electrical impulses
what are the parts of the conduction system?
-sinoatrial (SA) node
-atrioventricular (AV) node
-atrioventricular bundle (bundle of his)
-atrioventricular (AV) bundle branches
-purkinje fibers
what is the sinoatrial (SA) node and where is it located?
-generates the fastest impulse
-sets the pace of the entire system
-located in the right atrium at the base of the superior vena cava
-signals to the contractile myocardium
where is the atrioventricular (AV) node located?
-base of the right atrium
-inferior to the sinoatrial (SA) node
what is the atrioventricular bundle (bundle of his) and where is it located?
-superior part of the interventricular septum
-acts as the electrical connection between the atria and the ventricles