Chapter 14 Lecture 3, Pages

Blood pressure The pressure, or push of the blood as it flows through the circulatory system It exists in all blood vessels, but higher in the arteries than in the veins

Blood pressure The blood pressure is highest at the aorta (leaves the heart) and lowest at the vena cavas (returns to the heart) This is called the blood pressure gradient *Fig , Pg. 449 It keeps the blood flowing If arterial blood pressure falls, the blood will not circulate (death soon)

Blood pressure The direct cause of blood pressure is the volume of blood in the vessels Bleeding decreases blood pressure strength and rate of heart beat affects the blood pressure

Blood pressure Each time the left ventricle contracts more blood is pushed through the arteries and blood pressure increases When the heart beats faster, more blood is pumped into the arteries increasing blood pressure Strong heartbeat, increase bp Weak heartbeat, decrease bp

Blood pressure How viscous, or thick, the blood is affects blood pressure If fluid moves into the blood after a person suffers from a hemorrhage, the blood gets thinner & blood pressure falls

Blood pressure The blood pressure constantly fluctuates It is higher when the ventricles contract- called systolic pressure It is lower when the ventricles relax, or is between beats- called diastolic pressure

Blood pressure Blood pressure readings are systolic over diastolic Normal blood pressure reading is 120/80 mmHg mmHg means- millimeters of mercury; column of mercury

Hypertension High blood pressure Consistent readings of 140/90 is considered mild hypertension Be aware, change habits, may be on medication

Hypertension Consistent readings of 160/100 is considered severe hypertension See doctor, will be on medication

Hypertension High blood pressure is a major factor in heart disease Increases atherosclerosis, weakens heart, blood vessels may rupture

Hypertension Is called a “silent killer” because there are no symptoms You are a ticking time bomb just waiting to explode!

Very low blood pressure Circulation stops & death Hemorrhage

Blood pressure readings are made by a sphygmomanometer See page 450 for instructions on how to take blood pressure Students will take a blood pressure and have their blood pressure taken during a following lab

Pulse Artery expanding & recoiling Felt where an artery is near the surface of the body & over a bone or other firm base *Don’t use your thumb

Pulse There are 9 pulse points that are easily located *See figure 14-12, page 452

Pulse Is used to detect a heart beat or heart rate

Bleeding Stop bleeding by direct pressure with a cloth if possible (add cloths if soaked, do not take soaked cloth away), elevation, and a pressure point if arterial

Bleeding Pressure points are pulse points Brachial artery for bleeding in the lower arm Femoral artery for bleeding in the leg