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Cardiovascular Gissel Hernandez p. 5 - Coggle Diagram
Cardiovascular
Gissel Hernandez
p. 5
Major components and functions of blood
Regulation:
Maintain body temp by absorbing, distributing heat
Maintain normal pH using buffers; alkaline reserve of bicarbonate ions
Transport:
Deliver O2 and nutrients to body
Transport metabolic wastes to lungs and kidneys for elimination
Transport hormones from endocrine organs to target organs
Protections:
Preventing blood loss: plasma proteins and platelets in blood initiate clot formation
Preventing infection
Immunity carried in blood: antibodies, complement proteins, white blood cells
Composition of blood:
Blood is only fluid tissue in body
Type of connective tissue, matrix is nonliving fluid called plasma, cells are living blood cells called formed elements, cells are suspended in plasma
Formed elements:
Erythrocytes (red blood cells, RBCs)
Leukocytes (white blood cells, WBCs) only formed in element that is complete cell with nuclei and organelles
Platelets
Leukocytosis: Increase in production of WBC, normal response to infection
Leukocytes grouped into major categories:
Granulocytes: contain visible cytoplasmic granules (neutrophils, eosinophils, basophils)
Agranulocytes: do not contain visible cytoplasmic granules (lymphocytes, monocytes)
Mnemonic to remember decreasing abundance in blood: Never let monkeys eat bananas (neutrophils, lymphocytes, monocytes, eosinphils, basophils)
Erythrocytes: dedicated to respiratory gas transport, hemoglobin binds reversibly with oxygen
Platelets: fragments of larger megakaryocyte
Involved in blood clotting process
Function: form temporary platelet plug that helps seal breaks in blood vessels
Platelet formation is regulated by thrombopoietin
Anatomy of the Heart
Coronary sulcus (atrioventricular groove)
Anterior interventricular sulcus
Anterior position of interventricular spetum
Posterior interventricular sulcus
Four chambers
two superior atria
two inferior ventricles
Interatrial septum: separates atria
Interventricular septum: separates ventricles
Right and left atrium, receiving chambers
right and left ventricle, pumping chambers
Atria: the receiving chambers
-small, thin-walled chambers; contribute little to propulsion of blood
Auricles: appendages that increase atrial volume
Right atrium: receives deoxygenated blood from body
Three veins empty into right atrium
Superior vena cava: returns blood from body regions above the diaphragm
Inferior vena cava: returns blood from body regions below the diaphragm
Coronary Sinus: returns blood from coronary veins
Left atrium: receives oxygenated blood from lungs
Ventricles: discharging chambers, make up most volume of heart
Right ventricle: most of anterior surface (pumps blood into pulmonary trunk)
Left ventricle: posteroinferior surface (pumps blood into aorta, largest artery in body)
Trabeculae carneae: irregular ridges of muscle on ventricular walls
Papillary muscles: project into ventricular cavity
Heart Vales: Ensure unidirectional (one way) blood flow through heart- prevents back flow of blood
Open and close in response to pressure changes
Two major types of valves
Atrioventricular valves located between atria and ventricles
Semilunar valves located between ventricles and major arteries
Atrioventricular (AV) Valves:
Two atrioventricular (AV) valves prevent back flow into atria when ventricles contract
Tricuspid valve (right AV valve): made up of three cusps and lies between left atria and ventricle
Chordae tendineae: anchor cusps of AV valves to papillary muscles that function to
Semilunar (SL) Valves
Two semilunar (SL) valves prevent back flow from major arteries back into ventricles
Open and close in response to pressure changes
Each valve consists of three cusps that roughly resemble a half moon
Pulmonary semilunar valve: located between right ventricle and pulmonary trunk
Aortic semilunar valve: located between left ventricle and aorta
Layers of the heart
Epicardium: visceral layer of serous pericardium
Myocardium: circular or spiral bundles of contractile cardiac muscle cells
Endocardium: innermost layer; is continuous with endothelial lining of blood vessels
Lines chamber heart
Major functions of
the cardiovascular system
Receiving Chambers of Heart:
Right atrium: receives blood returning from systemic circuit
Left atrium: receives blood returning from pulmonary circuit
Pumping Chambers of Heart
Right ventricle: pumps blood through pulmonary circuit
Left ventricle: pumps blood through systemic circuit
Heart is transport system consisting of two side-by-side pumps
Right side receives oxygen- poor blood from tissues
Pumps blood to lungs to get rid of CO2 pick up O2, via pulmonary circuit
Left side receives oxygenated blood from lungs
Pumps blood to body tissues via systemic circuit
Location:
In mediastinum between second rib and fifth intercostal space
Base (posterior surface) leans toward right shoulder
Apex points toward left hip
Structural, functional differences between blood vessel types
Vascular system consists of two main circulations:
– Pulmonary circulation: short loop that runs from heart to lungs and back to heart
– Systemic circulation: long loop to all parts of body and back to heart
▪ Heart pumps blood out to system via single systemic artery, the aorta
▪ Blood returning to heart is delivered via terminal systemic veins, superior and
inferior vena cava, as well as coronary sinus
• Important differences between systemic arteries and veins:
– Arteries run deep, whereas veins are both deep and superficial
▪ Arteries run deep only, but veins run deep or superficial
– Deep veins share same name with corresponding artery
– Superficial veins do not correspond to names of any arteries
• Blood vessels: delivery system of dynamic structures that begins and ends at heart
– Work with lymphatic system to circulate fluids
• Arteries: carry blood away from heart; oxygenated except for pulmonary circulation and
umbilical vessels of fetus
• Capillaries: direct contact with tissue cells; directly serve cellular needs
• Veins: carry blood toward heart; deoxygenated except for pulmonary circulation and
umbilical vessels of fetus
• All vessels consist of a lumen, central blood-containing space, surrounded by a wall
• Walls of all vessels, except capillaries, have three layers, or tunics:
Tunica intima
Tunica media
Tunica externa
• Capillaries
– Endothelium with sparse basal lamina
Blood flow through heart and body
Right side of heart:
Superior vena cava, inferior vena cava, coronary sinus
right atrium
tricuspid valve
right ventricle
pulmonary semilunar valve
pulmonary trunk
pulmonary arteries
lungs
Left side of heart
four pulmonary veins
left atrium
mitral valve
left ventricle
aortic semilunar valve
aorta
system circulation
Cardiac Cycle and ECG
.
• Sinoatrial (SA) node
– Pacemaker of heart in right atrial wall
– Generates impulses about 75×/minute (sinus rhythm)
– Impulse spreads across atria, and to AV node
• Atrioventricular (AV) node
– In inferior interatrial septum
• Atrioventricular (AV) bundle (bundle of His)
– In superior interventricular septum
– Only electrical connection between atria and ventricles
• Right and left bundle branches
– Two pathways in interventricular septum
– Carry impulses toward apex of heart
• Subendocardial conducting network
▪ Also referred to as Purkinje fibers
– Complete pathway through interventricular septum into apex and ventricular walls
.
• Electrocardiograph can detect electrical currents generated by heart
• Electrocardiogram (ECG or EKG) is a graphic recording of electrical activity
– Composite of all action potentials at given time; not a tracing of a single AP
– Electrodes are placed at various points on body to measure voltage differences
▪ 12 lead ECG is most typical
• Main features:
– P wave: depolarization of SA node and atria
– QRS complex: ventricular depolarization and atrial repolarization
– T wave: ventricular repolarization
– P-R interval: beginning of atrial excitation to beginning of ventricular excitation
– S-T segment: entire ventricular myocardium depolarized
– Q-T interval: beginning of ventricular depolarization through ventricular
repolarization
ABO, Rh blood types
– ABO blood groups
▪ Based on presence or absence of two agglutinogens (A and B) on surface of
RBCs
▪ Blood may contain preformed anti-A or anti-B antibodies (agglutinins)
Table 17.4 ABO Blood Groups.
Vital Signs (BP and Pulse)
• Systolic pressure: pressure exerted in aorta during ventricular contraction
– Left ventricle pumps blood into aorta, imparting kinetic energy that stretches aorta
– Averages 120 mm Hg in normal adult
• Diastolic pressure: lowest level of aortic pressure when heart is at rest
• Pulse: throbbing of arteries due to difference in pulse pressures, which can be felt under
skin
• Clinical monitoring of circulatory efficiency
– Vital signs: pulse and blood pressure, along with respiratory rate and body
temperature
– Taking a pulse
▪ Radial pulse (taken at the wrist): most routinely used, but there are other
clinically important pulse points
▪ Pressure points: areas where arteries are close to body surface
– Can be compressed to stop blood flow in event of hemorrhaging
• Blood pressure (BP): force per unit area exerted on wall of blood vessel by blood
– Expressed in mm Hg
– Measured as systemic arterial BP in large arteries near heart
• Transient elevations in BP occur during changes in posture, physical exertion, emotional
upset, fever
• Age, sex, weight, race, mood, and posture may also cause BP to vary
Disorders of Cardiovascular System
Congential Heart Disease: Issue with heart structure and/ or function present from birth
Endocarditis and Myocarditis: Inflammation of the heart
Cerebrovascular Accident: Blood flow to portion of the brain is interrupted (stroke)
Peripheral Artery Disease (PAD): Arteries narrow and reduce blood flow to extremeties
Myocardial infraction:
blood flow to part of the heart is blocked (heart attack)