Blood Pressure Fresh Cement Definition force blood exerts

Blood Pressure Fresh Cement

Definition: • force blood exerts against inner walls of blood vessels • most commonly. . pressure in arteries supplied by branches of aorta 2/12/2022 2

Cause • produced by heart action 2/12/2022 3

Factors Influencing • Heart Action – Stroke volume: amount of blood the ventricle discharges with each heart beat – Cardiac output: volume of blood per minute pumped by the heart • (calculated by multiplying stroke volume in m. L by heart rate in beats per minute) 2/12/2022 4

Factors Influencing • Blood Volume – definition: sum of formed elements and plasma – varies with age, sex, & body size – approximately 5 L (8% body weight) – blood pressure is directly proportional 2/12/2022 5

Factors Influencing • Peripheral Resistance – definition: resistance to blood flow due to friction between blood and blood vessel walls – Blood pressure must overcome to keep blood flowing 2/12/2022 6

Factors Influencing • Blood Viscosity – definition: tendency for fluid to resist flowing due to internal friction of its molecules – blood cells and plasma proteins increase blood viscosity 2/12/2022 7

• Tool: Measurements – Sphygmomanometer (BP dial / cuff) 2/12/2022 8

Measurements cont’ • Sounds – KOROTKOFF (tapping) – Cause • Systolic pressure: max pressure during contraction • Diastolic pressure: force of blood in arteries during relaxation • Normal Value: 120/80 2/12/2022 9

Control • Mechanisms regulating cardiac output / peripheral resistance • Starling’s Law: the >length of the muscle fibers, the >the force of contraction THUS the more blood that enters the heart, the stronger the ventricular contraction, the greater the stroke volume, the greater the cardiac output 2/12/2022 10

Control • Cardiac center of the medulla oblongata regulates heartbeat 2/12/2022 11

Clinical Focus 2/12/2022 12

Hypertension • definition: high blood pressure (values over 140/90) • Causes: kidney disease, high sodium intake, obesity, psychological stress, and arteriosclerosis 2/12/2022 13

Hypertension • Results: decrease in elasticity of arterial walls • Treatment: exercising regularly, controlling body weight, reducing stress, and limiting sodium intake 2/12/2022 14

Pulse • Definition: alternating expansion and elastic recoiling of arterial wall created when ventricles contract (heart rate) 2/12/2022 15

Heart Sounds • First: low-pitched sound, often described as a “lubb” sound (AV valves closing) • Second: higher-pitched sound, often described as a “dupp” sound (semilunar valves closing) 2/12/2022 16

Heart Sounds • Provide information about normal function of heart which can aid in diagnosing • Abnormal Sounds: (heart murmur) • An incompetent valve produces a gurgling or swishing sound • Stenosed valves produce a rushing sound prior to the first beat 2/12/2022 17

Measurements • Place index and middle fingers at the pulse point. A pulse point is located on an artery that is near surface of skin • Press firmly with flat fingers until you feel the pulse. Count the beats. 2/12/2022 18

Pulse Points 2/12/2022 19

Measurements • Normal Values –Newborns 100 -160 bpm –Child (age 1 -10) 70 -100 bpm –Child – Adults 60 -100 bpm –Well-trained athletes 40 -60 bpm 2/12/2022 20

Pulse Characteristics • Regular / irregular • Strong / weak • Hard / soft 2/12/2022 21

Clinical Focus • Bradycardia • Tachycardia 2/12/2022 22

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