CardioVascular System Flashcards
Heart
Contains 4 chambers composed of cardiac muscle that pumps blood through the vasculature.
Vasculature
The vascular system of a part of the body and its arrangement consisting of arteries, capillaries and veins
Right Side of Heart
Pulmonary Circulation:
Accepts deoxygenated blood returning from the body and move it to the lungs by way of the pulmonary arteries to be re-oxygenated
Left Side of Heart
Systemic Circulation:
- Receives oxygenated blood from the lungs by way of the pulmonary veins and forces it to the rest of the body through the aorta.
- More muscular side of the heart
- Maintains blood pressure throughout the entire body
Atria
- Thin walled structures where blood is received from the venae cavae or pulmonary veins
- Contract to push blood into the ventricles
Venae Cavae
Receives deoxygenated blood entering the right side of the heart
Pulmonary Veins
Receives oxygenated blood entering the left side of the heart
Ventricles
Contract to send blood into the lungs and into systemic circulation
Atrioventricular Valves
Separate the atria from the ventricles
Semilunar Valves (Three Leaflets)
Separate ventricles from the vasculature; Allow the pump to create pressure within the ventricles necessary to propel the blood forward within circulation while also preventing back-flow of blood
Tricuspid Valve (Three Leaflets)
Separate right atrium and right ventricle
Mitral or Bicuspid Valve (Two Leaflets)
Separate left atrium and left ventricle
Pulmonary Valve
Separate right ventricle form pulmonary circulation
Aortic Valve
Separates left ventricle from the aorta
Electrical Conduction of the Heart
- Impulse initiation occurs at the SinoAatrial (SA) Node and is then depolarized causing the 2 Atria to contract
- Atrial Systole (Contraction) and Atrial Kick
- Signal reaches the AtrioVentricular (AV) Node where it is delayed to let the ventricles fill with blood
- Signal travels to the Bundle of HIS and its branches embedded in the Inter Ventricular Septum (wall)
- Signal is pushed to the Purkinje Fibers which distributes the signal to the ventribular muscle
Myogenic Activity
Heart can contract without neural input
Atrial Systole
Contraction:
Results in an increase in atrial pressure forcing more blood into the ventricles
Atrial Kick
Additional blood volume accounting for 5-30% of cardiac output
AtrioVentricular (AV) Node
Sits at the junction of the Atria and the Ventricles
Pukinje Fibers
Distribute the electrical signal of the heart to the ventricular muscles
Intercalated Discs
How the ventricular muscles are connected; consists of gap junctions directly connecting the cytoplasm of adjacent cells thereby allowing for coordinated ventricular contraction
Systolic Contraction
- Top # in B.P.
- Higher Pressure
- Ventricular contraction and closure of the AV valve occurs and blood is pumped out of the ventricles
Diastolic Contraction
- Bottom # in B.P
- Lower Pressure
- Heart is relaxed, the semilunar valves are closed and blood from the atria fills the ventricles
Blood Pressure
Systolic Pressure (ventricular contraction)/ Diastolic Pressure (ventricular relaxation)
- Normal is 90 / 60 to 120/80
- Measure of the force per unit area exerted on the wall of the blood vessels
Cardiac Output
Total blood volume pumped by a ventricle per minute
Cardiac Output = Heart Rate (bpm) x Stroke Volume (blood pumped per heart beat)
Order of EKG Diagram:
- P wave (small bump)
- Q (Decreasing point)
- R ( Highest Peak)
- S (Lowest Peak)
- T Wave (Larger bump)
P Wave
Depolarization of atria in response to SA node
PR Interval
Delay of AV node to allow filling of ventricles
QRS Complex
Depolarization of ventricles triggers main pumping contractions
ST Segment
Beginning of ventricular repolarization (should be flat)
T Wave
Ventricular Repolarization
Endothelial Cells
- Line all blood vessels, maintain the vessel by releasing chemicals that aid in vasodilation and vasoconstriction
- Allow WBC to pass through the vessel wall and into the tissue during inflammatory response
- Release chemicals when damaged to form blood clots and repair vessel
Arteries
Part of Vasculature:
- Move blood AWAY from the heart to the lungs and other parts of the body
- Containing OXYGENATED blood
***Pulmonary and Umbilical arteries contain deoxygenated blood
Aorta
- Largest artery in the body
- The main artery of the body, supplying oxygenated blood to the circulatory system
Arterioles
Part of Vasculature:
- Smaller muscular arteries that are elastic; creating tremendous resistance to the flow of blood
- Elastic recoil from walls maintains high B.P. and forces Blood Forward
Capillaries
Part of Vasculature:
- Small vessels that RBC’s pass through single file
- Allows easy diffusion of gases (O2, CO2), nutrients (Glucose) and wastes (Ammonia, Urea, etc…)
- Interface for communication of circulatory system with tissues
- Allows endocrine signals to reach target tissues
Bruise
When capillaries are damaged, blood can leave them and enter the interstitial space; In a close space this creates a bruise
Venules
Part of Vasculature:
- Where the capillaries join together; Which then join to form veins
Connects Capillaries with veins
Veins
Part of Vasculature:
- Thin walled, inelastic vessels that transport blood to the heart
- Contain DEOXYGENATED blood
- Smaller amount of smooth muscles means there less recoil and can accommodate larger quantities of blood
***Pulmonary and Umbilical Veins contain oxygenated blood
Skeletal Muscles
Surrounds the veins, squeezing and contracting to force blood upward against gravity
Blood Flow Path Through the Heart
- Deoxygenated blood enters the Right Atrium
- Tricuspid Valve
- Right Ventricle
- Contraction
- Pulmonary Valve
- Pulmonary Artery
- Lungs (blood becomes oxygenated)
- Pulmonary Veins
- Oxygenated blood enters the Left Atrium
- Mitral Valve
- Left Ventricle
- Contraction
- Aortic Valve
- Aorta
- Arteries
- Arterioles
- Capillaries (where gas and nutrient exchange occur)
- Venules
- Veins
- Venae Cavae
Then back to the top^
Superior Vena Cava (SVC)
Blood returns from the body to the heart for portions of the body ABOVE the heart
Inferior Vena Cava (IVC)
Blood returns from the body to the RIGHT side of the heart for the body BELOW the heart
Hepatic Portal System
Blood leaving the capillary beds in the walls of the gut passes through the hepatic portal vein before reaching the capillary beds in the liver
Hypophyseal Portal System
Blood leaving the capillary beds in the hypothalamic travels to a capillary bed in the anterior pituitary to allow for paracrine secretion or release of hormones
Renal Portal System
Blood leaving the glomerulus (Capillaries at the end of the kidney) travels through an efferent arteriole before surrounding the nephron in a capillary network called the Vasa Recta
Composition of Blood
- 55% Plasma
- 45% Cells
- <1% Blood
Plasma
Liquid portion of the blood; Aqueous mixture of nutrients, salts, respiratory gases, hormones and blood proteins
Erthyrocytes (Red Blood Cells - RBCs)
- Specialized cell designed for O2 transport
- Biconcave (indented on both sides) to travel through capillaries and increase cell surface for gas exchange
- Have NO nuclei, mitochondria or membrane bound organelles (cannot use the O2 it carries)
- Rely entirely on Glycolysis for ATP
- Unable to divide
Leukocytes (White Blood Cells - WBCs)
Defenders against pathogens, foreign cells, cancer and materials not recognized as “self”
Granulocytes
Lymphocytes / White Blood Cell:
Neutrophils, Eosinophils and Basophils
- Contain cytoplasmic granules
- Contain toxic compounds to invading microbes
Lymphocytes
Lymphocytes / White Blood Cell:
- Specific immune response against viruses and bacteria
- Agranular
- Primary responders to infection
- Long term memory bank of pathogen recognition
B-Cells
Lymphocytes / White Blood Cell:
- Mature in spleen or lymph nodes
- Responsible for antibodies
T-Cells
Lymphocytes / White Blood Cell:
- Mature in thymus
- Kill virally infected cells and activate other immune cells
Monocytes
Lymphocytes / White Blood Cell:
- Agranular
- Phagocytize foreign matter like bacteria
Macrophage
Lymphocytes / White Blood Cell:
When monocytes leave the blood stream and enter an organ
Microglia
Lymphocytes / White Blood Cell:
Macrophage in the nervous system
Langerhan Cell
Lymphocytes / White Blood Cell:
Macrophage in the skin
Osteoclasts
Lymphocytes / White Blood Cell:
Macrophage in the bone
Thrombocytes
Platelets:
Cell fragments and shards released from cells in bone marrow; Function in blood clotting
Hematopoiesis
Production of blood cells and platelets triggered by hormones, growth factors and cytokinesis
Erythropoietin
Secreted by kidney to stimulate RBC development
Thrombopoietin
Secreted by the liver and kidney to stimulate platelet development
Clots
Composed of coagulation factors (proteins) and platelets to minimize blood loss
Coagulation
- Coagulation factors and platelets come into contact with tissue factor (exposed collagen) initiate cascade
- Ends with Activation of Prothrombin to form Thrombin by Thromboplastin
- Thrombin convers Fibrinogen to Fibrin
Fibrin
Net-like structure capturing RBC and platelets forming a stable clot over the area
Scab
Clot that forms on a surface vessel that has been cut
Plasmin
Generated from Plasminogen; Breaks down blots
Antigen
Any specific target (usually a protein) to which the immune system can react; Found on the surface of RBCs
Universal Recipient of Blood
AB blood type; No antigen is foreign so no adverse reaction upon transfusion
Universal Donor of Blood
O blood type; Blood will not cause ABO-related hemolysis in recipient
Rh Factor
Surface protein on RBC
+ = Have the allele
- = Lack the allele
Erythroblastosis Fetalis
In subsequent pregnancies when mom is Rh- but the baby is Rh+ the maternal anti-Rh antibodies (made during first pregnancy) can cross the placenta and attack the fetal blood cells resulting in destruction of the fetal cells
Sphygmomanometer
Measure blood pressure
Baroreceptors
Specialized neurons that detect changes in the mechanical forces on the wall of the vessels
Hemoglobin
- A protein composed of 4 cooperative subunits; Each containing a prosthetic heme group that binds to an oxygen molecule
- When oxygen binds to heme it induces a confrontational shift in the shape from taut to relaxed increasing hemoglobin affinity for oxygen
Cooperative Binding
A form of allosteric regulation when hemoglobin binds one oxygen it increases the affinity for more oxygen
Carbon Dioxide (CO2)
Non-polar gas with low solubility in aqueous plasma; it can be carried by hemoglobin BUT most exists in the blood as the bicarbonate ion HCO3
Bicarbonate Buffer System
CO2 (g) + H2O (l) H2CO3 (aq) H+ (aq) + HCO3- (aq)
*Links respiratory and renal systems (kidney can excrete bicarbonate)
Carbonic Anhydrase
Enzyme in RBC that catalyzes the combination reaction between CO2 and H2O to form H2CO3 (a weak acid) which is able to dissociate
Renal Tubular Acidosis Type I
Kidney is unable to excrete acid efficiently leading to a build up of protons (H+) in the blood
Metabolic Acidosis
Excess CO2 is formed; to compensate respiratory rate is increased to exhale more
Carbohydrates and Amino Acids
Absorbed in the capillaries of the small intestine and enter systemic circulation via the hepatic portal system
- Fats are absorbed into Lacteals in the small intestine and enter systemic circulation via the thoracic duct
Wastes
CO2, Urea, NH3
Travel down their [ ] gradients from the tissues to the capillaries; Eventually reaching the kidneys where they are filtered or secreted for elimination from the body
Hydrostatic Pressure
Force per unit area that blood exters against the vessel walls; Generated by the contraction of the heart and the elasticity of the arteries
Osmotic Pressure
“Sucking” pressure generated by solutes as they attempt to draw water into the bloodstream
Oncotic Pressure
“Sucking” pressure attributable to plasma proteins
Pressure at Arteriole
Hydrostatic Pressure (push fluid out) > Oncotic Pressure (draw fluid in) = Net Efflux of water from circulation
Pressure at Venule
Oncotic Pressure (draw fluid in) > Hydrostatic Pressure (push fluid out) = Net Influx of water back into circulation
Starling Forces
Balance of the opposing forces; Essential to maintaining proper fluid volumes and [solutes] insides and outside the vasculature.
Edema
Accumulation of excess fluid in the interstilum (cells surrounding the blood vessels)
