Modules 5 quiz Blood Vessels PDF

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Bl oodVessel s :Chapt er16:355372 Anatomy and physiology:

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The great vessels include the aorta, superior and inferior venae cavae, pulmonary arteries, and pulmonary veins: - The aorta carries oxygenated blood out of the left ventricle to the body. - The pulmonary artery,which leaves the right ventricle and divides almost immediately into right and left branches, carries deoxygenated blood to the lungs. - The superior and inferior venae cavae carry deoxygenated blood from the upper and lower body, respectively, to the right atrium. - The pulmonary veins return oxygenated blood from the lungs to the left atrium. Blood Circulation: Blood flows through two circulatory systems, the pulmonary and the systemic. - Pulmonary circulation routes blood through the lungs, where its oxygenated and returned to the left atrium and ventricle of the heart. - Venous blood arrives at the right atrium via the superior and inferior vena cavae and moves through the tricuspid valve to the right ventricle. - During systole, deoxygenated blood is ejected through the pulmonic valve into the pulmonary artery; it travels through the pulmonary arteries, arterioles, and capillaries until it reaches the alveoli, where gas exchange occurs. - Oxygenated blood of the systemic circulation returns to the heart and enters the systemic circulation through the pulmonary veins into the left atrium and then through the mitral valve into the left ventricle. The left ventricle contracts, forcing a volume of blood with each beat (stroke volume) through the aortic valve into the aorta where it is distributed systemically through the arteries and capillaries. In the capillary bed, oxygen is provided to the tissues of the body; the now-deoxygenated blood is carbon dioxide rich. It passes into the venous system and returns to the heart via the superior and inferior vena cavae and into the right atrium. - The arteries are thicker, have smoother muscle, with less ability to stretch and expand (distension) from internal pressure. Subjected to more pressure than the veins. The veins are more distensible than the arteries. Venous return occurs at a lower pressure than blood flow through the arteries, and veins contain valves to keep blood flowing in one direction. If circulatory volume increases significantly, the veins can expand and act as a repository for the extra volume.

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Arterial Pulse and Pressure - Arterial pulses are the result of ventricular systole, which produces a pressure wave throughout the arterial system (arterial pulse). The arterial blood pressure is the force exerted against the wall of an artery as the bolus of blood exits the heart’s left ventricle with contraction. The pulse is felt as a forceful wave that is smooth and more rapid on the ascending part of the wave; it becomes domed, less steep, and slower on the descending part. Carotid arteries are the most accessible of the arteries closest to the heart, most definitive pulse for evaluation of cardiac function. - Variables that contribute to the characteristics of the pulses:  Volume of blood ejected (stroke volume)  Distensibility of the aorta and large arteries  Obstruction of blood flow  inflammation with narrowing—or PAD)

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Peripheral artery resistance Viscosity of the blood

Jugular Venous Pulse and Pressure The jugular veins, empty directly into the superior vena cava - Reflect activity of the right side of the heart - Level of visibility gives an indication of right atrial pressure. - The external jugular veins are more superficial and more visible bilaterally above the clavicle, close to the insertion of the sternocleidomastoid muscles. The larger internal jugular veins run deep to the sternocleidomastoids, near the carotid arteries, and are less accessible to inspection. The activity of the right side of the heart is transmitted back through the jugular veins as a pulse with five identifiable components—three peaks and two descending slopes Infants - Cutting of the umbilical cord requires the infant to begin breathing. Onset of respiration expands the lungs and carries air to the alveoli. Pulmonary vascular resistance drops. Systemic vascular resistance increases. The ductus arterios closes, usually within the first 12 to 14 hours of life. Once pulmonary vascular resistance is lower than systemic resistance, blood flows into the pulmonary arteries rather than across the interatrial foramen ovale. The interatrial foramen ovale is functionally closed by the shifting pressures between the right and left sides of the heart. Pregnant Patients - Systemic vascular resistance decreases and peripheral vasodilation occurs, results in palmar erythema and spider telangiectasias. - Systolic blood pressure decreases slightly. Decrease in the diastolic pressure. Lowest levels in second trimester and then rise. Remains below blood pressure readings before pregnancy. - Lower blood pressure can be noted when the patient is supine during the third trimester. Secondary to venous compression of the vena cava and impaired venous return. - Lower extremities blood pool in later pregnancy(except in the lateral recumbent position). Result from compression of the pelvic veins and inferior vena cava by the enlarged uterus. This may result in increase dependent edema, varicosities of the legs and vulva, and hemorrhoids. Older Adults - Stiffness and dilation of the aorta, aortic branches, and carotid arteries due to calcification and plaque buildup in the artery walls. - Arterial walls lose elasticity and vasomotor tone, less distensible. Increased peripheral vascular resistance lead to elevated blood pressure (especially systolic).

Physical exam components: Blood Vessels 1. Palpate the arterial pulses in distal extremities, comparing characteristics bilaterally for: Rate - Rhythm

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Contour Amplitude

2. Auscultate the carotid, abdominal aorta, and the renal, iliac, and femoral arteries for bruits. 3. Withthepatientrecliningata45-degreeangle, inspect for jugular venous pulsations and distention; differentiate jugular and carotid pulse waves, and measure jugular venous pressure. 4. Inspect the extremities for sufficiency of arteries and veins for: -

Color, skin texture, and nail changes Presence of hair Muscular atrophy Edema or swelling Varicose veins

5. Palpate the extremities for: -

Warmth Pulse quality Tenderness along any superficial vein Pitting edema

Sequence of Exam: HPI: Leg Pain or cramps • • • •

Onset, duration, character, location, waking at night with leg pain Skin changes Limping (claudication) Continuous burning in toes, pain in thighs or buttocks, pain over specific location, induced by activity Skin changes: cold skin, pallor, sores, redness or warmth over vein, visible veins, darkened or ischemic skin

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Swollen Ankles     

Onset and duration Related circumstances (recent and long travel, post- operative immobilization, recent travel to high elevations) Associated symptoms (onset of nocturia, increased frequency of urination, increasing shortness of breath) Treatment attempted (including rest, massage, heat, elevation) Medications (heparin, warfarin, diuretics, antihypertensive medications)

PMH: Cardiac surgery or hospitalization for cardiac evaluation or disorder, congenital heart defect, surgical or interventional vascular catheterization procedures

Chronic illness: hypertension and studies to define its cause, bleeding disorder, hyperlipidemia, diabetes, thyroid dysfunction, stroke, vasculitis, thrombosis, transient ischemic attacks, coronary artery disease, atrial fibrillation, other type of dysrhythmia FMH: morbidity and mortality related to cardiovascular system; hypertension, dyslipidemia, diabetes, heart disease, thrombosis, peripheral vascular disease, abdominal aortic aneurysms, ages at time of illness or death Personal and Social History:       

Employment: physical demands; environmental hazards; sources of emotional stress Tobacco Nutritional status; usual diet: proportion of fat, food preferences, history of dieting Weight: loss or gain, amount and rate Exercise Use of alcohol Use of recreational drugs

Infants and Children:     

Hemophilia Sickle cell disease Renal disease Coarctation of the aorta Leg cramps during exercise

Pregnant Patients:  

Blood pressure: prepregnancy levels, elevation during pregnancy; evidence of preeclampsia with associated symptoms and signs Legs: edema, varicosities, pain or discomfort.

Older Adults:     

Leg edema: pattern, frequency, time of day most pronounced Interference with activities of daily living Ability of the patient and family to cope with the condition Claudication: area involved, unilateral or bilateral, distance one can walk before its onset, sensation, length of time required for relief Medications used for relief; efficacy of drugs

Physical Examine and Findings: Palpate arterial pulses in neck and extremities to determine the sufficiency of the entire arterial circulation. (carotid, brachial, radial, femoral, popliteal, pedal, and posterior tibial arteries using distal pads of 2nd and 3rd finger. Thumb may be used if vessels have a tendency to move when probed by fingers. In this setting the thumb is particularly useful in “fixing” the brachial and even the femoral

pulses. Compare characteristics bilaterally and between upper and lower extremities

Palpate firmly but not to occlude the artery. The exception to this is when doing the Allen test to ensure ulnar artery patency before radial artery puncture. Palpate the arterial pulses (most often the radial) to assess the heart rate and rhythm, pulse contour (waveform), amplitude (force), symmetry, and sometimes obstructions to blood flow. The contour of the pulse wave is pliable. Healthy arteries have a smooth, rounded, or dome shape. Pay attention to the ascending portion, the peak, and the descending portion. Variations from the expected findings are described in Fig. 16.9.

**Clinical Pearl: Carotid Palpation When palpating the carotid arteries, never palpate both sides simultaneously. Excessive carotid sinus massage can cause slowing of the pulse and a drop-in blood pressure and compromise blood flow to the brain, leading to syncope. If you have difficulty feeling the pulse, rotate the patient’s head to the side being examined to relax the sternocleidomastoid muscle. Compare each wave crest with the next to detect cyclic differences. The amplitude of the pulse is described on a scale of 0 to 4: 4 Bounding, aneurysmal 3 Full, increased 2 Expected, 1 Diminished, barely palpable 0 Absent, not palpable. Determine the regularity of the pulse. If it is irregular, determine whether there is a consistent pattern. -

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An irregular heart rate that occurs in a repeated pattern may indicate sinus arrhythmia, a cyclic variation of the heart rate characterized by an increasing rate on inspiration and decreasing rate on expiration. A patternless, unpredictable, irregular rate may indicate heart disease or an impaired conduction system such as atrial fibrillation. If you note an irregular rate, record the beats per minute and compare it with the rate heard when auscultating the heart.

Note the strength of the pulse. Lack of symmetry (in pulse contour or strength) between the left and right extremities suggests impaired circulation. Compare the strength of the upper extremity pulses with those of the lower extremities and the left with the right. Ordinarily, the femoral is as strong as or stronger than the radial pulse. If the femoral pulsation is absent or diminished, proximal obstruction

should be suspected, which may be due to such conditions as coarctation of the aorta, atherosclerotic peripheral arterial disease, or vasculitis. Auscultation Auscultate over an artery for a bruit if you are following the radiation of murmurs first noted during the cardiac examination or looking for evidence of local obstruction. These sounds are usually low pitched and relatively hard to hear. Place the bell of the stethoscope directly over the artery. Sites to auscultate for a bruit are over the carotid, subclavian, abdominal aorta, renal, iliac, and femoral arteries. When listening over the carotid vessels, ask the patient to suspend his or her breathing for a few heartbeats so that respiratory sounds will not interfere with auscultation (Fig. 16.10). Sounds heard over the neck include venous hums and carotid bruits (Box 16.2).

Assessment for Peripheral Arterial Disease Reduced circulation to the tissues will lead to signs and symptoms that are related to the following: site, degree of narrowing, ability of collateral channels to compensate, rapidity with which the problem develops. The first symptom is claudication. This pain can be characterized as a dull ache with accompanying muscle fatigue and cramps. It usually appears during sustained exercise and relieved with rest, recurring with the same amount of activity. The site of pain is distal to the narrowing. After determining the distinguishing characteristics of the pain, note the following: -

Pulses (strong, weak or possibly absent) Possible systolic bruits over the arteries that may extend through diastole Loss of expected body warmth in the affected area Localized pallor and cyanosis Collapsed superficial veins, with delay in venous filling Thin, atrophied skin; muscle atrophy

Perform the following steps to judge the degree of narrowing and the potential severity of the arterial insufficiency:

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Have the patient lie supine Elevate the extremity Note the degree of blanching Have the patient sit on the edge of the bed or examining table to lower the extremity. Note the time for maximal return of color once the elevated extremity is lowered. Slight pallor on elevation and a return to full color as soon as the leg becomes dependent are the expected findings. A delay of many seconds or even minutes before the extremity regains full color indicates arterial insufficiency. When return to full color takes as long as 2 minutes, the problem is severe. A measurement of the capillary refill time provides another method of assessing severity (Box 16.3).

General guideline for assessment of possible causes of pain: PAIN LOCATION PROBABLE OBSTRUCTED ARTERY Calf Superficial femoral artery Thigh Common femoral artery or external iliac artery Buttock Common iliac artery or distal aorta (erectile dysfunction may accompany stenosis of distal aorta) If the pain is constant, the narrowing is critical and probably acute; if it is excruciating, a major artery has probably been severely compromise Peripheral Veins Jugular Venous Pressure Careful measurement of the jugular venous pressure (JVP) is important. The simplest, most reproducible, and reliable method requires two pocket rulers at least 15 cm long.

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Place the patient in the supine position using a bed or examining table with an adjustable back support. Use a light to supply tangential illumination across the right side of the patient’s neck to accentuate the appearance of the jugular venous pulsations. When the supine patient is initially placed flat, note the engorgement of the jugular veins. Gradually raise the head of the bed until the jugular venous pulsations become evident between the angle of the jaw and the clavicle. Palpating the carotid pulse helps identify the venous pulsations and distinguish them from the carotid pulsations. The jugular pulse can only be visualized; it cannot be palpated. Several conditions may make the JVP examination more difficult: (1) severe right heart failure, tricuspid insufficiency, constrictive pericarditis, and cardiac tamponade may each cause extreme elevation of the JVP so that it is not apparent until the patient is sitting upright; (2) severe volume depletion makes the JVP difficult to detect even when the patient is flat; and (3) in extreme obesity, overlying adipose tissue obscures the jugular venous pulsations. Place a ruler with its tip at the midaxillary line (the position of the heart within the chest) at the level of the nipple and extended vertically. Place the second ruler at the level of the meniscus of the JVP, extended horizontally to where it intersects the vertical ruler. The vertical distance above the level of the heart is noted as the mean JVP in centimeters of water. A value of less than 9 cm H2O is the expected value. Maneuvers useful for confirming the JVP measurement include hepatojugular reflux and evaluation of the venous engorgement of the hands Hepatojugular Reflux: To assess the hepatojugular reflux maneuver, use your hand to apply firm pressure for 10 seconds to the abdomen in the midepigastric region and instruct the patient to breathe regularly. Observe the neck for an elevation of at least 3 to 4 cm in JVP that lasts beyond a few seconds. The JVP equilibrates to its true level after removal of the abdominal hand pressure. If the JVP is not obvious with this maneuver, the pressure is either much higher or much lower. Repeat the maneuver with the patient more supine if you suspect the pressure to be lower. Position the patient more upright if you suspect the JVP to be higher Evaluation of Hand Veins: Used as an “auxiliary manometer” of the right heart pressure when the patient does not have thrombosis or arteriovenous fistula in that arm or superior vena cava syndrome. With the patient semirecumbent, place the hand on the examination table or mattress. Palpate the hand veins, which should be engorged, to make sure they are compressible. Slowly raise the hand until the hand veins collapse. Use a ruler to note the vertical distance between the midaxillary line at the nipple level (level of the heart) and the level of collapse of the hand veins. Confirm this level by lowering the hand slowly until the veins distend again and raise it back until they once again collapse. This distance should be identical to the mean JVP. The hand vein measurement is particularly helpful to evaluate severe right heart failure when the pressure may be 20 to 30 cm H2O or with volume depletion.

Assessment for Venous Obstruction and Insufficiency An acute obstruction may result from injury, external compression, or thrombosis. In the affected area, constant pain occurs simultaneously with the following: Swelling and tenderness over the muscles, engorgement of superficial veins, erythema and/or cyanosis. - Inspect the extremities for signs of venous insufficiency

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Examine the patient in both the standing and supine positions, particularly in the case of a suspected chronic venous occlusion. Ultrasound studies can confirm the presence of venous occlusion.

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Thrombosis. Note any redness, thickening, and tenderness along a superficial vein, suggesting thrombophlebitis of a superficial vein. Suspect a deep vein thrombosis if swelling, pain, and tenderness occur over a vein. It cannot be confirmed on physical examination alone and requires diagnostic imaging.

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Edema. Inspect the extremities for edema, manifested as a change in the usual contour of the leg. Press your index finger over the bony prominence of the tibia or medial malleolus for several seconds. A depression that does not rapidly refill and resume its original contour indicates orthostatic (pitting) edema, not usually accompanied by thickening or pigmentation of the overlying skin. Right-sided heart failure leads to an increased fluid volume. Severity is characterized by grading 1+ thru 4+. 1+ Slight pitting, no visible distortion, disappears rapidly, 2+ A somewhat deeper pit than in 1+, but again no readily detectable distortion; disappears in 10– 15 seconds, 3+ Noticeably deep pit that may last more than a minute; dependent extremity looks fuller and swollen, 4+ Very d...