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)
Components of conduction system
- sinoatrial node
- atrioventricular node
- bundle of HIS
- bundle of his branches
- purkinje fibers
Sinoatrial node
In right atrium at base of superior vena cava, generates impulses the fastest (sets pace)
Atrioventricular node located at..
base of right atrium
Bundle of HIS
electrically connects the atria to the ventricles (referred to as the AV bundle)
Purkinje fibers
supply the signal through each of the ventricles
Adult pulmonary circulation functions to … and systematic circulation functions to …
- deliver and return blood to and from the lung for oxygenation
- deliver and return blood to and from the entire body
Adult pulmonary circulation
- deoxy blood in the right atrium is moved to right ventricle
- right ventricle passes deoxy blood to the lungs via pulmonary arteries
- blood that’s been oxygenated in the lungs returns to left atrium via pulmonary veins
Adult systematic circulation
- left atrium passes oxy blood to the left ventricle
- left ventricle then passes oxy blood to the aorta which sends blood out to body
- oxy blood then arrives at the organs (oxygen is removed from blood by cells which also load carbon D into blood)
- dirty blood rich in carbon D and waste is returned to right atrium via the superior vena cava and inferior vena cava
Subdivision name for brain
cerebral
Subdivision name for liver
hepatic
Subdivision name for heart
coronary
Fetal circulation the fetus gets __, _____, and expels _____ to mothers blood
oxygen; nutrients; wastes
Umbilical vein
carries ox blood from placenta to vena cave
Fetal lung and liver
basically non-functional, 3 shunts to bypass
3 shunts in fetal circulation system
- ductus venosus
- foramen ovale
- ductus arteriosus
Ductus venosus
connects umbilical vein (oxy blood) to inferior vena cava (deoxy blood) to bypass liver, mixed blood enters fetal heart via inferior vena cava
Oxy and deoxy blood mixes in the …
ductus venosus
Foramen ovale
opening located between the right and left atrium and allows blood exchange between them (closes after birth once pressure becomes higher)
Ductus arteriosus
connects pulmonary trunk and aorta
Umbilical arteries
returns mixed blood to placenta
4 parts of blood vessels
- tunica externa
- tunica media
- tunica intima/interna
- lumen
Tunica media
circularly arranged smooth muscle and sheets of elastin (CT)
Tunica externa
outermost layer, loosely arranged collagen fibres. anchors vessel to surrounds fibres. protects and reinforces
Tunica intima/interna
innermost layer of the blood vessel that’s in direct contact with blood flowing in lumen. simple squamous epithelium
Lumen
central area of vessel that contains blood
Types of blood vessels
- arteries
- arterioles
- capillaries
- venules
- veins
2 types of arteries
elastic and muscular
Elastic arteries
contain elastin mainly located in tunica media (but also other layers) aorta
Muscular arteries
contain more smooth muscle, most arteries (coronary artery)
Arterioles
smallest arteries. very muscular vessels that regulate blood flow and pressure
Capillaries are ONLY ..
tunica intima-endothelium and basement membrane
Capillaries
smallest blood vessels, allow exchange of gases, waste and nutrients
Capillaries merge to form…
venules
Venules
smallest veins. two types: small (composed only go tunica intima) and large (composed of very thin tunica intima and tunica externa)
Veins
function to return blood back to the heart. contains valves in order to prevent back flow. large lumen and thin tunica intima (prone to collapse)
Circulatory system includes
- heart
- blood vessels
- blood
- lymphatic system
Circulatory system functions to..
- transport gases, hormones, lymph, nutrients and waste
- protect against disease and fluid loss
Left side of the heart carries ..
oxygenated blood
Right side of the heart carries..
deoxygenated blood
Veins carry blood ..
TO the heart
Arteries carry blood ..
AWAY from the heart
Vessels that enter and exist the heart include ..
- superior and inferior vena cava
- pulmonary veins
- pulmonary arteries
- aorta
Superior and inferior vena cava
deliver blood into the right atrium of heart
Pulmonary veins
return blood that has been deoxygenated on the lungs back to the heart (left atrium)
Pulmonary arteries
take deoxygenated blood from the right ventricle into the lungs to be oxygenated
Aorta
takes oxygenated blood from the left ventricle and delivers it into systemic circulation
Cardiac intercalated disks are..
attacked to one another via desmosomes and gap junctions (keeps cells together and allow exchange of ions and contact in unison)
The bundle branches connect the bundle of ..
HIS to each of the ventricles
Fetal lungs are non functional the blood pressure on the …
right side of the fetal heart is higher than the pressure on the left side (opposite of adult)
Coronary circulation is when oxygenated blood must be..
delivered to the myocardium in order to provide oxygen and nutrients to these cells
From the left ventricle oxygenated blood thats delivered to the aorta will enter into coronary circulation via 2 aortic branches _____ and _____ and the branch into which 4 arteries
- left coronary artery branches into the anterior interventricular artery and circumflex artery
- right coronary artery supplies the right side of the heart and branches into the posterior interventricular artery and the right marginal artery
Anterior Interventricular artery
supplies the interventricular septum and the anterior wall of both ventricles
Circumflex artery
supplies the left atrium and the posterior walls of the left ventricle
Posterior interventricular artery supplies
the posterior ventricular walls
Right marginal artery supplies
the myocardium
Blood flows from the right and left coronary arteries into the …
arterioles then transition into capillaries which supply the myocardium
Capillaries transition into..
venules which transition into cardiac veins
Cardiac veins transition into the..
coronary sinus which drains deoxy blood into the right atrium (sent to the lungs)
Blood vessel arrangement
- From the heart blood flows into arteries
- From the arteries blood flows into arterioles
- From the arterioles blood flows into capillaries
- From the capillaries blood flows into venules
- From the venules blood flow into veins
- From veins blood flows back to the heart
