blood pressure

Question 1

What is systolic pressure?

Answer 1

pressure in system when heart contracts- area of high pressure

Question 2

What is diastolic pressure?

Answer 2

pressure when heart relaxed- blood vessel pressure drops

Question 3

What do you measure blood pressure in?

Answer 3

mmHg

Question 4

where do you measure blood pressure in dogs?

Answer 4

Artery, canul

Question 5

How do you measure blood pressure in dogs?

Answer 5

Take a chorotid artery
Put a canula in it and connect to tube which is connected to a column mercury
When the heart contracts it will push blood against the column of mercury- makes the column of mercury go up
When the heart relaxes- the column of mercury goes down

Question 6

How do you measure blood pressure in humans?

Answer 6

using a sphygmomanometer

1. Wrap a cuff around arm
2. Cuff is attached to the bulb/pump
3. Inflate the cuff , putting pressure on the breakel artery, which is a superficial blood vessel in the upper arm
4. apply enough pressure to collapse that artery
5. When you have collapsed that artery- you are above the systolic pressure
6. Release pressure from cuff, until that point where some blood starts to flow= systolic pressure
7. The more air you let out the bag, more and more blood flows through, you are not constricting blood flow or collapsing artery= below diastolic pressure
8. Determine the pressure when blood vessel first starts opening which is systolic pressure, and the pressure when the blood vessel is not collapsed at all= diastolic pressure.

Question 7

What are the sounds of Korotkoff?

Answer 7

the systolic and diastolic pressures correspond to the pressures at which a sound is first heard( systolic) and when it dies away.(diastolic)

Question 8

What does a stethoscope do when you measure blood pressure?

Answer 8

put just below the cuff on breakel artery,
normal blood flow of muscle makes no noise- as it flows smoothly
Decrease pressure in cuff, some blood is starting to flow through, you will hear a soft tapping= systolic pressure
Decrease pressure even more, more and more blood starts to flow, makes a continuous rushing sound, then the sound dies when there is no turbulent blood flow and no constricting vessel which means you are at the Diastolic pressure.

Question 9

How do you determine blood flowing?

Answer 9

Using a stethoscope- from its sounds that it makes

Question 10

How do you write the blood pressure?

Answer 10

systolic/diastolic

Question 11

What is the average blood pressure?

Answer 11

120/80 mmHg in major arteries

e.g. vena cava

Question 12

Why does the measured blood pressure vary?

Answer 12

As its highest and its greatest variation is in the major arteries near the heart such as the aorta and large arteries and then lowers at small arteries and arterioles
However then by the time the blood returns to the heart via the vena cava, the pressure is almost 0(drops) and variation gets less due to being so far from the pump and heart and the elastic nature of veins and blood vessels which will even out the blood flow.

Question 13

How does blood pressure vary?

Answer 13

1. From person to person (inter-individual)
2. With age.
3. Depend on what you are doing or feeling (intra-individual )

Question 14

What is the bp formula?

Answer 14

cardiac output x peripheral resistance

Question 15

What is cardiac output?

Answer 15

force of cardiac contraction

Question 16

What is peripheral resistance?

Answer 16

diameter of blood vessels - of vessels are narrow blood pressure is high

Question 17

What are the 2 main things blood pressure depends on?

Answer 17

• How hard the heart is contracting

- How wide the blood vessels are

Question 18

why is there a rise in bp with age ?

Answer 18

loss of elasticity in blood vessel( arteriosclerosis )resulting in raised peripheral resistance
while cardiac output stays same

Question 19

What is the structure of blood vessels?

Answer 19

Veins- bring blood to the heart
Arteries- take blood from the heart
Capillaries- gas and nutrient exchange

Question 20

What happens when blood pressure increases?

Answer 20

Blood vessels constricting- blood pressure increases

Heart contracts harder- cardiac output increases- blood pressure increases

Question 21

What happens when blood pressure decreases?

Answer 21

Blood vessels dialate- blood pressure down

cardiac output decreases

Question 22

What happens with blood pressure if age increases? Example?

Answer 22

the rise in mean blood pressure with age is the result of a loss of elasticity in the blood vessels (arteriosclerosis), resulting in raised peripheral resistance.

Question 23

What are the mechanisms which regulate arterial blood pressure?

Answer 23

• rapid

- longterm

Question 24

What is an example of a fast Nervous mechanism of controlling blood pressure?

Answer 24

Baroreceptors- which respond to an increase in blood pressure

• it relies on nerves
• important

Question 25

What happens when there is a rise in blood pressure?

Answer 25

When blood pressure goes up, our arteries stretch so it activates stretch/baroreceptors
this sends impulses to medulla

Question 26

What are these stretch receptors?

Answer 26

they are free nerve ending which are

stretched when blood vessels dilate

Question 27

What are the 2 ways that the medulla reduces blood pressure?

Answer 27

1. the medulla sends a.p down towards peripheral blood vessels and causes vasodialation, which increases diameter of blood vessels, and blood pressure will fall
2. Via vagus nerve ( which is the parasympathetic stimulation of the heart), decreases cardiac output, blood pressure falls and barorecpetors no longer stimulated.

Question 28

Where are the baroreceptors location?

Answer 28

within our arteries, esp in arch of aorta and carotid body, we have stretch receptors in the walls of the artery.

Question 29

What are the herring’s nerves and what does it show?

Answer 29

comes from the carotid baroreceptors which show they respond to blood pressure
-Show- as you increase blood pressure , the barorecpeotrs fire more a.p
Shows barorecpetors are sensitive to blood pressure
What happens in dogs ?
if the herrings nerve is cut, the baroreceptors are inactivated , therefore the blood pressure control is lost

Question 30

What is the Humoral mechanism?

Answer 30

Long term
relies on the hormones
- THE Renin system responds to a fall in blood pressure.

Question 31

What happens in the renin/angiotensin system?

Answer 31

Blood pressure drops
Kidney senses bp drops
releases renin which acts on a plasma protein
which causes the production of angiotensin 1
-which is converted to angiotensin 2 by an enzyme called angiotensin converting enzyme (ACE)
-a genetic defect which results in too much ACE will raise blood pressure and responsible for peoples high bp - making them susceptible to heart attack
-ACE inhibitor are a possible therapy.
-Angiotenisn 2 -is a vasocontrsiticter (smooth muscles can contract by hormones)
-Blood vessels get smaller and blood pressure rises

Question 32

What is another long term mechanism?

Answer 32

In the kidney called Pressure diuresis

Question 33

What happens in Pressure Diuresis?

Answer 33

Kidney- produces urine so controls body fluid levels
-If the blood pressure rises , it stays high , the kidney produces more urine which lowers plasma volume, blood volume and lowers blood pressure.

Question 34

What is hypertension?

Answer 34

a prolonged period of high blood pressure

Question 35

What is then meant by ‘high blood pressure’ in hypertension?

Answer 35

-As in World Health Organisation- if the systolic pressure above 140 to 160 and diastolic is above 90

Question 36

What is a normal blood pressure?

Answer 36

if systolic pressure below 140

diastolic blood pressure is below 90

Question 37

Systolic is more prone?

Answer 37

it has much more variation, as more things can affect it such as being tired, our activities etc

Question 38

Diastolic is less prone?

Answer 38

less subject to systemic influences and is therefore a more useful guide to blood pressure.

Question 39

What does the american heart association show?

Answer 39

Normal bp- is less than 120 and less than 80
Elevated bp- 120-129 and less than 90
Hypertension- is 130-139 or 80-89
Hypertension stage 2- 140 or higher or 90 or higher

Question 40

What is the classification of systemic hypertension?

Answer 40

In most cases 85% of the causes of hypertension are not known.- This is known as idiopathic, primary or essential hypertension.
15% of hypertension is secondary to some other diseases (usually renal or adrenal in origin)
Hypertension can be chronic (benign), which is characterised by a slow onset (symptomless then sudden), or more dangerously malignant (fast onset)(symptoms occur quick and bp can suddenly shoot up- causing death quick).

Question 41

What are the risk factors for primary hypertension ?

Answer 41

genetic predisposition
stress/emotion
obesity
excessive alcohol (small amounts may be benefical)
sodium( in 50% of cases hypertension is salt resistant)

this is the aetiology of the disease

Question 42

What are the long term effects of hypertension ?

Answer 42

kidney damage
increased bulk of heart leading to angina pectoris
damaged arteries leading to atherosclerosis.