Cardiopulm Anat/Phys Flashcards
Which node is the primary pacemaker?
SA
Sympathetic innervation of the heart
From sympathetic trunk
Increases HR and contractility
Release of epinephrine/norepinephrine
Parasympathetic innervation of the heart
Vagus
Decreases HR
Release of ACh
Primarily influences SA node
Bainbridge Reflex
Increase in venous return –> stretch receptors in RA –> inhibit parasympathetic activity –> increase HR
Chemoreceptor reflex
Increase in depth and rate of ventilation when receptors sense ppO2 <50 or acidosis
Normal Stroke Volume
60-80 mL
Normal Cardiac Output (rest)
5 L/min (slightly less for women)
Cardiac Output can increase up to ___ during exercise
25 L/min
Normal blood volume
4.5-5.0 L
Plasma
Liquid component of blood
Consists of H2O, electrolytes, proteins
50% of blood volume
RBCs
40% of blood volume
Anemia
Too few RBCs –> fatigue, weakness
Polycythemia
Too many RBCs –> thick blood, increased risk of stroke, heart attack
Atypical ribs
1, 10, 11, 12
Only articulate with one vertebra
Principal muscles of inspiration
Diaphragm, intercostals
Pump handle/ bucket handle
Upper ribs: Pump handle
Lower ribs: Bucket handle
Upper Respiratory Tract
Nasal cavity, pharynx, larynx
Lower Respiratory ract
Trachea through alveoli
Carina
Split in trachea, level of T4
Lingula
Part of left upper lobe, analogous to right middle lobe
Topographic units of the lungs
Bronchopulmonary Segments
10 in right
8 in left
Respiratory unit of the lung
Acinus (contains 3000-4000 alveoli)
Innervation of the Lungs
Sympathetic: Postganglionic fibers innervates smooth muscle of bronchi and pulmonary blood vessels
Parasympathetic: Vagus
What conditions (ppO2/CO2, etc) stimulate increased ventilation?
Increased ppCO2/ Hydrogen ion
Decreased ppO2
Anatomic Dead Space Volume (VD)
Volume that occupies the non-respiratory conducting airways
Expiratory Reserve Volume (ERV)
Amount of air that can still be exhaled after a normal tidal exhalation.
Approx 15% of total lung volume
Functional Residual Capacity (FRC)
Volume of air in the lungs after normal exhalation (ERV + RV)
40% of total lung volume
Inspiratory Capacity (IC)
Maximal volume of air that can be inspired after normal tidal exhalation (TV + IRV)
60% of total lung volume
Inspiratory Reserve Volume (IRV)
Maximal volume of air that can be inspired after a normal tidal volume inspiration.
50% of total lung volume
Minute volume ventilation (VE)
Volume of air expired in one minute
= TV x respiratory rate
Residual volume (RV)
Volume of gas remaining in the lungs at the end of a maximal expiration
25% of total lung volume
Tidal Volume (TV)
10% of total lung volume
Prinzmetal angina (Variant angina)
Occurs due to coronary artery spasm, most often associated with coronary artery disease
Most common type of major birth defect:
Congenital heart defect
S/S of coarctation of the aorta
Infants: palor, sweating, SOB
Older: High blood pressure in arms, lower BP in legs
Tetralogy of Fallot
VSD Pulmonary stenosis Right ventricular hypertrophy Aorta overriding the VSD Cyanotic (R>L shunt)
Most common congenital heart defect in kids with DS
Atrioventricular Canal
Blood flows between all 4 chambers
Usually L>R shunt
