Blood Pressure Flashcards
What is blood pressure ?
The pressure of the blood in the circulatory system, related to contraction of the heart and muscles that surround the blood vessels
Where is blood pressure measured?
In the systemic circulation
How is blood pressure measured?
A cuff is inflated around a relaxed patients arm, stopping the flow of blood through the artery.
The cuff is then slowly relaxed and blood pressure is measured
What is systolic pressure ?
When the ventricles are pumping with enough force to overcome the pressure exerted by the cuff
What is normal systolic pressure?
120 mmHg (male) 110 mmHg (female)
What does average systolic pressure increase with?
Age, so 100 + age is a safe maximum
What is diastolic pressure?
When the pressure of the blood is sufficient to keep arteries open, even when the ventricles relax
What does the disappearance of a beat when the pressure is decreasing in the cuff indicate?
A steady flow of blood (diastolic pressure)
What is normal diastolic pressure?
80 mmHg (male) 70 mmHg (female)
When is hypertension diagnosed?
When the diastolic pressure is >10 mmHg above normal
What is the equation for blood pressure?
BP = CO x PR
What is the equation for CO?
CO = HR x SV
How do the kidneys maintain blood pressure?
They regulate BP by removing excess water (and salt) from the body. The higher the BP, the more water is forced out in the nephrons. This reduces the volume of Lymph and lowers the blood pressure
What is a characteristic of the blood when regulated by the kidneys?
Lowering the BP makes the blood thicker and more likely to clot
What is the level of CO2 in the blood monitored by?
The carotid artery and the aorta
Where are impulses sent to in the nervous system?
Impulses are either sent down the accelerator nerve (sympathetic nervous system) or the vagus nerve (parasympathetic nervous system)
What effect does the accelerator nerve have in heart rate?
Speeds it up
What effect does the vagus nerve have on heart rate?
Slows it down
What do both nerves lead to ?
SA node
What effect would stimulating the sympathetic nervous system innervation have on BP?
The accelerator nerve would increase HR, therefore increasing CO and thus increasing BP
What effect would stimulating the parasympathetic nervous system innervation have on BP?
The vagus nerve would decrease HR, therefore decreasing CO and this decrease BP
What do the stretch receptors in the heart do ?
They stretch the walls of the heart when more blood is returned due to exercising and the heart responds to this by beating faster and harder
How is radial pulse measured?
Arm should be beside the body with the forearm horizontal and palm down. Place fingers around or under the wrist, supporting it. Fingers should lie down under the radial border.
Count the number of pulses in a 20 or 30 second period and record the pulse rate / min
How is carotid pulse measured?
Place fingertips between the sternocleidomastoid muscle and the larynx. With 2 or 3 fingers, gently press the region until you locate a pulse. Determine HR by counting the number of pulses / min
How is brachial pulse measured?
Located on the inside of the upper arm near the elbow. Turn your right palm up with the arm slightly bent at the elbow. Rest your arm on a flat surface. Place 2 fingers on the inner third of the elbow crease. Press firmly for approx 20 secs
