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 (anterior 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 (fibrous pericardium + serous pericardium)
what is the fibrous pericardium?
-outermost layer of the pericardium
-dense irregular CT
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 that contains serous fluid for lubrication
-2 parts are: parietal pericardium + visceral pericardium
what is the parietal pericardium?
-made of epithelium and CT
-fuses to the fibrous pericardium to create the pericardial sac
what is the visceral pericardium?
-composed of epithelium and CT
-fused to the heart surface (part of the heart wall)
-also called the epicardium
what is the epicardium?
-outer layer of the heart wall
-simple squamous and CT
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 (contractile)
-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 (in direct contact with blood)
what blood vessels are associated with the right atrium?
-inferior vena cava (blood from body below the heart)
-superior vena cava (blood from body above the heart)
-coronary sinus (blood from the myocardium)
-carry deoxygenated blood into the right atrium
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
-carry oxygenated blood into the left atrium
what are the blood vessels associated with the right ventricle?
-pulmonary trunk (artery)
-divides to form the right and left pulmonary arteries
-carry deoxygenated blood to the lungs
what are the blood vessels associated with the left ventricle?
-aorta (artery)
-carries oxygenated blood to the organ systems
what is the distinguishing feature of the left ventricle?
-thicker myocardium
-pumping blood further distances at a higher pressure compared to the right ventricle
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 cardiac (fibrous) skeleton?
-fibrous CT that separates the atria and the ventricles
-tissue allows for attachment of cardiac muscle
-forms solid rings around the heart valves (aorta + pulmonary trunk) to keep them in place
-provides electrical insulation (prevents simultaneous contraction of the atria and ventricles)
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 (between left atrium and left ventricle)
-2 sheet-like cusps (CT)
-tricuspid valves
-right side (between right atrium and right ventricle)
-3 sheet-like cusps (CT)
what are chordae tendineae?
-connective tissue
-attaches atrioventricular valve cusps to the papillary muscles
-prevents eversion of cusps
what are the papillary muscles?
-projections of the myocardium
-first to contract
what are the two semilunar valves?
-aortic
-separates the left ventricle and the aorta
-pulmonary
-separates the right ventricle and the pulmonary trunk
what are the two types of cardiac muscle cells?
-contractile cells
-conduction system cells
what is the purpose of the contractile cardiac muscle cells?
-form a majority of the myocardium (contractions)
what is the purpose of the specialized cardiac muscle cells? how do they complete this function?
-form the rest of the myocardium
-modified cardiac muscle cells that produce and conduct electrical impulses (DO NOT CONTRACT)
-have many gap junctions to help electrical signals spread quickly
what similarities do cardiac muscle cells have with skeletal muscle cells?
-striated (myofibrils with sarcomeres)
-has sarcoplasmic reticulum and T-tubules (no triads, have a different arrangement)
what differences do cardiac muscle cells have with skeletal muscle cells?
-they are branched (irregular, not parallel)
-uninucleated
-have intercalated discs (region where 2 fibres meet (anchoring junction = lots of proteins)
-contain anchoring and gap junctions
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 as a unit)
how are valves able to open and close?
-in response to pressure changes
-in response to electrical signals
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
where do the atrioventricular (AV) bundle branches go?
-carry the impulse to the apex of the heart
what are purkinje fibers?
-terminal fibers in the ventricles only
-carry signals from the apex upward to all parts of the ventricles (push the blood towards the semilunar valves)
what do the electrical signals of the conduction system spread to?
-the contractile cardiac muscle cells of the myocardium
how would the circulation of blood in the heart be described?
-a closed system (blood is confined to the heart and blood vessels)
-a double circulation with 2 routes (systemic +pulmonary)
what is the path of pulmonary circulation?
-from the right ventricle to the lungs via the pulmonary arteries (deoxy blood)
-oxygen is picked up in the lungs via capillaries
-moves from the lungs to the left atria via pulmonary veins (oxy blood)
what is the path of systemic circulation?
-from the left ventricle to organs via the aorta (oxygenated
-organs take up oxygen via capillaries
-from the organs to the right atrium via the superior and inferior vena cava (deoxygenated)
what are some examples of the subroutes of systemic circulation?
-cerebral (brain)
-hepatic (liver)
-coronary (heart)
-bronchial (respiratory system parts)
what is the path of coronary circulation for oxygenated blood?
-from the left ventricle to the aorta
-branches off to the right and left coronary arteries
-right coronary artery
branches off to the….
-posterior
interventricular artery
and the marginal
artery
-left coronary artery
branches off to the….
-anterior
interventricular
artery and the
circumflex artery
-from the arteries moves to the
arterioles and then the capillaries in the myocardium
what is the path of coronary circulation for deoxygenated blood?
-from the capillaries in the myocardium to the venules
-from the venules to the cardiac veins
-from the cardiac veins to a blood vessel called the coronary sinus
-finally goes from the coronary sinus to the right atrium
what is the basis of fetal circulation?
-fetus gets its O2 and nutrients from the mother
-fetus expels wastes to the mother’s blood
-exchange site in the placenta (lungs are not functional)
do the fetus’s blood and mother’s blood supplies mix?
-fetus’s blood and mother’s blood do not mix, but their supplies are close together
what are the differences between fetal and adult circulation?
-fetal circulation contains the umbilical vein
-fetal circulation contains 3 shunts (hole/small passage)
-lungs and liver are non functional in fetal circulation (mothers organs handle their functions)
-only a small amount of blood flow is needed for nourishment and growth
what is the purpose of the umbilical vein?
-carries blood towards the fetal heart
-brings oxygenated blood from the placenta to the vena cava
what are the three shunts in fetal circulation?
-ductus venosus
-ductus arteriosus
-foramen ovale
what is the purpose of the ductus venosus?
-connects the umbilical vein (oxy blood) to the inferior vena cava (deoxy blood)
-allows most of the oxygenated blood from the placenta to bypass the liver
-blood mixes within the inferior vena cava and enters the right atrium
where is mixed blood located in fetal circulation?
-right atrium
-right ventricle
-left atrium
-left ventricle
-pulmonary arteries
-aorta
-umbilical arteries
-foramen ovale
-ductus arteriosus
what is the foramen ovale? what is its purpose?
-hole in the interatrial septum
-allows blood to move from the right to left atrium
-does so to bypass the lungs (not breathing so no gas exchange is occuring)
what is the purpose of the ductus arteriosus?
-connects the pulmonary trunk and the aorta
-does so to bypass the lungs (not breathing so no gas exchange is occuring)
where does mixed blood eventually turn into oxygenated blood?
-placenta
where is deoxygenated blood located in fetal circulation?
-superior vena cava
-inferior vena cava (for a short time
-pulmonary veins
where is oxygenated blood located in fetal circulation?
-umbilical vein
what is the purpose of the umbilical arteries?
-carries blood away from the fetal heart
-returns mixed blood to the placenta
why would we want blood to bypass the lungs and other organs (liver) in fetal circulation?
-these organs in the fetus are non-functional
-they do not need the same amount of blood as a functioning organ would
-only need some blood flow to promote growth and nourishment
what are the 3 general layers of blood vessels? what is the center called?
-tunica externa
-tunica media
-tunica intima/interna
-center is called the lumen (NOT A LAYER)
what is the tunica externa?
-outside layer of blood vessels
-composed of CT
-for protection and reinforcement
-ability to anchor to its surroundings
what is the tunica media?
-middle layer of blood vessels
-composed of smooth muscle
-can constrict to make the lumen smaller
-controls how much blood is flowing to different areas
-composed of elastic fibers (CT)
-allows for flexibility
why would you want to control how much blood is flowing to different parts of the body?
-depending on your activities you will only need a certain amount of blood flow
-ex: running vs sitting watching tv
-depends on your bodies personal needs
what is the tunica intima/interna?
-inner layer of blood vessels
-in direct contact with blood
-composed of simple squamous epithelium
-layer is named the endothelium
-continuous with the endocardium
what is contained in the lumen of blood vessels?
-blood
what type of blood vessel does the general structure not apply to?
-capillaries
what are the 5 types of blood vessels?
-arteries
-arterioles
-capilleries
-venules
-veins
what are arteries?
-blood vessels that carry blood away from the heart
-high pressure
what are the two types of arteries?
-elastic arteries
-muscular arteries
what are elastic arteries?
-composed of elastic CT in all 3 layers
-largest arteries (nearest to the heart)
-ex: aorta
what are muscular arteries?
-composed of LOTS of smooth muscle
-smaller distributing arteries (branched)
-make up most arteries
-ex: coronary artery
what are arterioles?
-smaller arteries
-help regulate blood flow and pressure
what are capillaries?
-smallest blood vessel
-allow for the exchange of gases + nutrients
-contain gaps that allow limited fluid + solutes to leak (exchange with the interstitial fluid) (LIMITED)
what makes capillaries different from the general structure?
-only contain an endothelium layer with a basement membrane (tunica intima)
what is the composition of venules? what is their purpose?
-contain a tunica intima with thin tunica media and thin tunica externa layers
-to collect blood from the capillaries
what are veins?
-bring blood back to the heart
-contain valves that prevent backflow of blood
-contain a large lumen
-thin tunica media layer (less smooth muscle)
-more connective tissue (greater stretching capacity)
how does the veins having less smooth muscle affect them?
-can cause them to collapse
what are the main characteristics of blood?
-connective tissue
-higher viscosity than water
-pH of 7.35-7.45
-4-6 liters of blood in an adult
why is blood more viscous than water?
-blood contains cells
what is blood composed of?
-plasma (matrix) (fluid portion with solutes) (majority)
-formed elements (cellular portion)
what is plasma?
-matrix of blood
-blood minus the formed elements
-composed of 90% water
-composed of 8% proteins
-composed of 2% other solutes
what is the most abundant plasma protein?
-albumin
what are the formed elements in the blood?
-red blood cells
-white blood cells
-platelets
what are red blood cells?
-also called erythrocytes
-most abundant cell type in the body
-biconcave disc shape
-anucleate (no nucleus or other organelles) once mature
-bind to and transport most of the oxygen in the blood
what is the significance of the shape of red blood cells?
-concave in the center to increase surface area
what is the hematocrit
-the percentage of red blood cells in blood volume
-around 45%
how long do red blood cells live? where are they destroyed?
-120 days (short lived)
-destroyed in the liver + spleen (recycled)
what are the components of red blood cells?
-hemoglobin (iron pigment protein)
-four globin chains (protein)
-four iron containing heme groups (red pigment)
-1 iron per heme
-site of reversible oxygen binding
what is the function of heme?
-attaches and transports O2
what is the function of globin?
-attaches and transports CO2
what are white blood cells?
-also called leukocytes
-varied life span (days-years)
-defend against disease
what are the two types of white blood cells?
-granulocytes (visible protein granules)
-agranulocytes (lack visible protein granules)
what are the 3 types of granulocytes?
-neutrophils (60%)
-eosinophils (3%)
-basophils (1%)
what is the function of neutrophils?
-phagocytic (engulf + digest invaders)
-kill bacteria
what is the function of eosinophils?
-attack blood parasites
what is the function of basophils?
-release histamine to increase inflammation
-release heparin to decrease local clotting during immune responses
what is the point of releasing heparin to decrease local clotting?
-allows for more white blood cells to get to the site of injury
-clotting would block the site
what are agranulocytes? what types are there?
-lymphocytes (35%)
-monocytes (5%)
what are the two types of lymphocytes?
-t lymphocytes
-b lymphocytes
what is the function of t lymphocytes?
-kill infected and diseased cells directly
-activate an immune response
-kill a tumor or virus
what is the function of b lymphocytes?
-become plasma cells
-release antibodies to circulate within plasma
-mark foreign substances for destruction
what are platelets?
-fragments of cells called megakaryocytes
-involved in clotting
-life span of 10 days if they are not used for clotting
-do not have a lot of organelles
what is hemopoiesis/ hematopoiesis?
-the formation of blood cells
-all blood cells come indirectly from hemocytoblast (stem cells) cells in red bone marrow
what are stem cells?
-cells that can form many different types of cells
where is red bone marrow found in the adult body?
-axial skeleton
-pelvic + pectoral girdles
-proximal ends of humerus and femur
how does the coronary sinus reach the right atrium?
-through a hole in the right atrium
what happens to the shunts within the fetal circulation?
-close following birth
what are the main proteins found within plasma?
-albumins
-fibrinogen
-globulin
-protein based hormones and enzymes
what are albumins for?
-carry substances like hormones, enzymes, and medicines throughout the body
-helps control tissue water balance
what is fibrinogen for?
-clot formation
what is globulin for?
-defence
-antibodies
-detect and bind foreign invaders (bacteria + viruses)
what other solutes are found in blood?
-nutrients
-vitamins
-wastes
-electrolytes
-oxygen + carbon dioxide
what is the function of lymphocytes? where are they typically found?
-immunity
-resist disease
-within lymphatic tissues
what is the function of monocytes?
-enter tissue and enlarge to become macrophages (big eater) (phagocytic)
what is an atrial septal defect?
-a hole in the interatrial septum
-commonly occurs due to incomplete closure of the foramen ovale
what is atherosclerosis?
-build up of fat deposits in the tunica intima
-leads to a narrowing/blockage of arteries
