Cardiopulmonary A&P Flashcards
What structures does the right coronary artery supply?
-RT atrium and ventricle
-inferior wall of LT ventricle
-AV and SA node (60% population)
-bundle of his
What structures does the LT coronary artery supply?
-“the widow maker”
-LT anterior descending (LT ventricle, septum, inferior apex)
-LT circumflex (lateral and inferior walls of LT ventricle, SA node)
Name the 5 layers of the heart from outer to inner
fibrous pericardium, parietal pericardium, visceral pericardium (epicardium), myocardium, endocardium
Where is the pericardial cavity?
Between the parietal pericardium and visceral pericardium (epicardium)
What is the serous pericardium composed of?
visceral and parietal pericardium
4 main characteristics/functions of myocardium
-Automaticity: pacemaker cells keep heart moving w/o conscious voluntary control
-Conductivity: gap junctions between myocytes allow them to depolarize as a group
-O2 demand
-Contractility: affected by sympathetic stimulation, hormonal circulation, preload and afterload
What are the 4 main valves? Describe their location
-tricuspid (atrioventricular): RT atrium and RT ventricle
-mitral (atrioventricular): LT atrium and LT ventricle
-pulmonary (semilunar): RT ventricle and pulmonary artery
-aortic (semilunar): LT ventricle and aorta
Describe the blood flow of deoxygenated blood to lungs
deoxygenated blood from vena cava -> RT atrium -> through tricuspid valve -> RT ventricle -> pulmonary valve -> pulmonary artery -> lungs
Describe the blood flow of oxygenated blood
oxygenated blood through pulmonary veins -> LT atrium -> through mitral valve -> LT ventricle -> aortic valve -> aorta -> body
Equation for hemodynamics
CO = HR x SV
CO - cardiac output
HR - heart rate
SV - stroke volume
What is cardiac output? At rest rate?
Amount of blood ejected out of the LT ventricle into the body per minute
at rest, 4-5 L/min
What is stroke volume? Rate?
Amount of blood ejected out of the LT ventricle per beat
SV = end diastolic volume (EDV) - end systolic volume (ESV)
55-100mL/beat
What 3 things affect SV? Briefly describe each
Preload: “EDV”; amount of filling and stretch on cardiac muscle pre-contraction
Afterload: force LT ventricle generates to overcome aortic pressure to open aortic valve (resistance heart contraction pushes against); inversely related to SV
Contractility: force of cardiac contraction in Lt ventricle (affected by sympathetic stimulation and O2 supply)
What is Frank-Starling Law?
-cardiac contractility is dependent on preload
-increased cardiac contractility results in greater stroke volume
the greater the EDV, the greater the stx and volume pumped
What is ejection fraction (EF)? Normal range? Equation? Low EF indicator of what?
Percentage of blood emptied from ventricle during systole; 60-70%
EF = SV/LVEDV
Indicator of cardiomyopathy or heart failure
What influences does sympathetic stimulation (adrenergic) have on heart?
-control in medulla via T1-T4
-SA node, AV, conduction pathways
-increases HR, force of myocardial contraction, O2 demand
-coronary artery vasodilation
What influences does parasympathetic stimulation (cholinergic) have on heart?
-control in medulla via vagus nerve, cardiac plexus
-innervates SA and AV nodes
-slows rate and force of myocardial contraction, less O2 demand
-coronary artery vasoconstriction
Chemoreceptor location and function
found in carotid body; sense CO2, O2, and pH which affect HR and RR (also affect sympathetic and parasympathetic stimulation)
Where are baroreceptors found?
aorta and carotid sinus
What does the circulatory reflex respond to? Describe what happens w/ increased and decreased BP
BP changes
Increased BP - parasympathetic stimulation; decreases rate and force of contraction
Decreased BP - sympathetic stimulation, increased HR and BP, vasoconstriction
What are the 6 ion concentration terms?
hyperkalemia, hypokalemia, hypercalcemia, hypocalcemia, hypermagnesemia, hypomagnesemia
Describe what the 6 ion concentrations are and what they do
hyperkalemia: increased potassium (decrease HR, decrease contractile force, arrhythmias, EKG changes)
hypokalemia: decreased potassium (EKG changes)
hypercalcemia: increased calcium (increased HR and increased contractility)
hypocalcemia: decreased calcium (may cause arrhythmias)
hypermagnesemia: increased magnesium (Ca blocker, arrhythmias or cardiac arrest, hypotension, confusion, lethargy)
hypomagnesemia: decreased magnesium (ventricular arrhythmias, CA vasospasm)
What are the 8 main structures of the electrical system of the heart?
SA and AV node, internodal tracts, Bachmann’s bundle, Bundle of His, RT bundle, LT bundle, Purkinje fibers
What is systole?
Period of contraction while the heart pumps blood into circulation
What is diastole?
Period of relaxation as the chambers fill with blood
What are the 4 phases of the cardiac cycle?
Phase 1: filling period
Phase 2: isovolumic contraction
Phase 3: ejection
Phase 4: isovolumetric ventricular relaxation
How many lobes does each lung have?
RT: 3
LT: 2
What are the 8 segments of the lungs?
Apical, anterior, superior, medial, lateral, inferior, anterior basal, posterior
What makes up the pleurae of the lungs? Functions?
-visceral (innermost) and parietal (outermost) pleurae, pleural cavity, pleural fluid
-cushions and lubricates lungs during expansion and retraction
What innervates the parietal pleura? What sensations do they sense?
-phrenic and intercostal nerves
-pain, temp, and touch
What is the purpose of pleural fluid? What happens if there’s no pleural fluid?
-creates surface tension to keep lungs in place and allows lungs to expand
-pneumothorax
Muscles of inspiration
Accessory: SCM, scalenes
Principal: external intercostals, diaphragm
Muscles/structures of expiration for quiet and active breathing
Quiet: passive recoil from lungs and rib cage
Active: internal intercostals, rectus abdominus, external and internal oblique, TA
Describe the role of each inspiratory muscle
-SCM: elevates the sternum
-scalenes: elevate upper ribs
-external intercostals: elevate rib cage
-diaphragm: elevates the lower ribs
Describe the role of each muscle involved with expiration
-internal intercostals: depresses ribs
-abdominals: depresses lower ribs, compresses abdominal contents and pushes diaphragm upward
Describe what happens to the diaphragm during inspiration and expiration
Inspiration: it contracts
Expiration: it relaxes
What types of pressure does breathing depend on?
Atmospheric, intra-alveolar, intrapleural
Describe the difference between the surface tension of the alveoli and within the pleural cavity
Alveoli: elasticity of the lungs and surface tension of the alveoli create an inward pull
Pleural cavity: surface tension within cavity creates an outward pull
Describe the difference between the surface tension of the alveoli and within the pleural cavity
Alveoli: elasticity of the lungs and surface tension of the alveoli create an inward pull
Pleural cavity: surface tension within cavity creates an outward pull
What parts of the brain primarily control breathing?
Medulla and pons
Describe the affects of CO2, pH levels, and chemoreceptors with respiration
CO2 increases -> pH decreases -> stimulates respiratory centers in medulla to contract diaphragm and external intercostals -> increases rate and depth of respiration
CO2 decreases -> pH increases -> causes respiratory centers to lower rate and depth of respiration
What molecules make up hemoglobin (Hgb)?
4 iron (hemes) and 4 protein (globins)
What are the various forms of Hgb in blood?
Oxyhemoglobin: Hgb carrying O2
Doxyhemoglobin: Hgb that released O2 to peripheral tissue
Carboxyhemglobin: Hgb bound to CO instead of O2 (abnormal)
What % of O2 is transported to the periphery? Where is the rest transported?
98% periphery, 2% plasma
What is SaO2? How is it calculated? What’s it called when measured w/ a pulse oximeter?
Blood gas analysis
Oxyhemoglobin/total hemoglobin
SpO2
What determines the O2 carrying capacity of the body? Women rate? Men rate?
Concentration of Hgb
Women: 12-16 g/dL
Men: 13-16 g/dL
What condition occurs if someone’s Hgb concentration is lower than normal?
Anemia
Where does gas exchange occur?
Respiratory zone, bottom of the lungs since there is smaller more abundant alveoli
What is the goal for gas exchange?
Ventilation (V) to be matched to perfusion (Q)
What do areas of the lungs with greater perfusion act as? What are areas with greater ventilation considered?
Shunts, dead space
What do areas of the lungs with greater perfusion act as? What are areas with greater ventilation considered?
Shunts, dead space
