Blood Pressure Dino Magou New Jersey Institute of Technology Materials Science and Engineering Biomedical Engineering

Friday night?

Vital Signs Physiological measurements taken to quickly understand a patient’s basic body functions There are four basic vital signs – Temperature – Pulse – Blood Pressure – Respiratory rate

Blood Pressure Pressure that circulating blood creates against the walls of blood vessels Usually taken inside the elbow at the brachial artery Blood pressure is reported in mmHg Blood pressure readings can be used to diagnose health problems

Stethoscope and Sphygmomanometer Used to measure blood pressure Operator listens to patient’s pulse while tightening the BP cuff When pulse can no longer be heard, pressure is released – Pressure is recorded

Diastolic and Systolic Pumping Resting

MAP MAP - Mean Arterial Pressure – Mean = Average Used to describe the average blood pressure in a person Not a simple average – Time the heart rests (diastole) is 2 times longer than the time the heart pumps (systole) Normal MAP is ~ 60 mmHg

How does MAP relate to a person’s physiologic condition? Paramedics monitor MAP closely in patients who have suffered from sever blood loss Low MAP means not enough blood to vital organs Lack of blood affects supply of O 2 – Commonly called Ischemia Ischemia leads to permanent organ damage/failure

How does caffeine affect your BP? Before coffeeAfter 3 cups of coffee

Experiment 1: Blood pressure and Temperature Take normal blood pressure Take blood pressure while having hand in bath of ice for 15 seconds Compare both blood pressures What do you think will happen?

Why did that happen? The cold caused discomfort, maybe even pain Symptoms like discomfort activate the sympathetic nervous system – “Fight or flight” response Zebra grazing grass Heart rate is increased by constraining blood vessels – This increases systolic, diastolic and MAP

Blood Supply Your body needs constant pressure to supply: – Muscles with enough O 2 to function – Effectively remove waste products (eg. CO 2 ) Remember: Mean arterial pressure can be used to diagnose how much blood is effectively getting to your organs How should exercise affect blood pressure?

Experiment 2: Blood Pressure and Exercise Take normal blood pressure Take blood pressure after having run in place for 2 minutes Compare both blood pressures What should we see?

What did your body do? During exercise your muscles need more blood to function properly – Blood delivers O 2, and removes CO 2 In order to get that extra blood to your muscles, your heart pump faster (higher pulse) and actually increases the amount of blood per pump – This increases systolic pressure – Diastolic pressure should decrease or remain the same

Me at the gym… Before runAfter 1 mile run

Why is BP important to you? What happens to your heart Heart enlarges and weakens High pressure can damage delicate organs – eg. Eye High risk of heart attack and stroke Permanent damage  – Loss of limbs and or basic functions How to keep it healthy Don’t smoke Maintain healthy weight Exercise REGULARLY Keep healthy diet – Avoid excessive sodium, fat and cholesterol

Age and BP

Recap Blood Pressure – how hard your heart works – Systolic (pumping) – Diastolic (resting) Diet and exercise affect your Blood Pressure – Caffeine, fatty and greasy foods Temperature and environmental stimulus affects BP – “Fight or flight” response