HTN and Stroke

Question 1

What is mean arterial pressure (MAP)?

Answer 1

It is defined as the average arterial pressure during a single cardiac cycle

Question 2

Formulate MAP:

Answer 2

(2 x diastolic) + systolic ] divided by 3

Question 3

Define Hypertension

Answer 3

a chronic medical condition in which the blood pressure in the arteries is persistently elevated
defining is controversial but often regarded as ≥140/90 mmHg

Question 4

How does HTN affect the body?

Answer 4

Over time high BP will damage the walls of your arteries, they become weak and form an enlargement called an aneurysm, or burst and bleed into the surrounding tissue. Small tears from the weakness can attract calcium and fat to form build up called plaque, which increases and decreases blood flow as the diameter is decreasing. Blood cells can stick to the plaque and form clots, further reducing the BF. Damage to arteries raises BP even more as the heart works harder to get the blood where it needs to go. HTN can eventually cause stroke, heart failure, kidney disease.

Question 5

What is a stroke?

Answer 5

A stroke occurs when blood flow in parts of the brain is blocked. After just a few minutes the starved brain cells begin to die.

Question 6

What is a Thrombotic stroke

Answer 6

A thrombotic stroke occurs when a blood clot (thrombus) forms in one of the arteries that supply blood to your brain. A clot may be caused by fatty deposits (plaque) that build up in arteries and cause reduced blood flow (atherosclerosis) or other artery conditions.

Question 7

What is an Ischaemic stroke?

Answer 7

This is when an artery in the brain narrows or becomes completely blocked, preventing normal blood flow. It could become blocked by a thrombus (blood clot) which forms in an unhealthy artery in the brain. It could also be caused by an embolis, a blood clot that forms elsewhere in the body and travels to the brain.
Ischaemic = starved.

Question 8

What is a hemorrhagic stroke?

Answer 8

Abnormal bleeding disrupts normal blood flow- i.e. a blood vessel bursting and bleeding on the brain and robbing the intended tissue of its nourishment.

Question 9

What is an Embolic stroke?

Answer 9

. An embolic stroke occurs when a blood clot that forms elsewhere in the body (embolus) breaks loose and travels to the brain via the bloodstream. Eventually, the clot lodges in a blood vessel and blocks the flow of blood, causing a stroke

Question 10

What is a Systemic hypoperfusion stroke?

Answer 10

Systemic hypoperfusion (low blood flow) is caused by circulatory failure of the heart, causing stroke.

Question 11

What is an cerebral Venous sinus thrombosis stroke? (CVST)

Answer 11

Cerebral venous sinus thrombosis (CVST) occurs when a blood clot forms in the brain’s venous sinuses. This prevents blood from draining out of the brain. As a result, blood cells may break and leak blood into the brain tissues, forming a hemorrhage.

Question 12

What percentage of strokes are ischaemic?

Answer 12

80%

Question 13

Decussation means?

Answer 13

'’Crossed over’’

Question 14

What three things affect BP?

Answer 14

• Cardiac output- (the amount of blood the ventricles push out of the heart each minute). As cardiac output increases, so does BP.
• Blood volume
• Resistance- anything working against the blood flow through the arteries

Question 15

What contributes to resistance in the arteries?

Answer 15

• Flexibility in the walls of the arteries. (The walls are supposed to expand with every beat to reduce pressure on the walls)
• Artery diameter
• Blood viscosity

Question 16

What is an aneurysm?

Answer 16

An excessive localized swelling of the wall of an artery.

Question 17

Name some assessments for a stroke:

Answer 17

FAST – time of onset vital to outcome and treatment options
• CT scan
• MRI
• Angiography
• ECG
• Chest x-ray
• Blood tests
• Holter monitor
• Cardiac markers
• FBC
• Coagulation studies

Question 18

The Wernicke’s area in the brain is responsible for what?

Answer 18

Language and comprehnsion

Question 19

The Broca’s area in the brain is responsible for what?

Answer 19

Speech control

Question 20

If a client had a stroke on the right side of his brain, what problems would you expect to see?

Answer 20

A stroke on the right side of the brain can cause changes in: (THE LEFT SIDE OF THE BODY)

Paralysis on the left side of the body   
Vision problems   
Quick, inquisitive behavioral style   
Memory loss
Spatial-perceptual deficits
Impulsive behaviour
Impaired time concepts
Impaired judgement

Question 21

If a client had a stroke on the left side of his brain, what problems would you expect to see?

Answer 21

Paralysis on the right side of the body
Speech/language problems (aphasias)
Slow, cautious behavioural style
Memory loss
Aware of deficits, depression, anxiety
Impaired comprehension related to language and mathematics

Question 22

What is systemic vascular resistance?

Answer 22

The force opposing the movement of blood within the blood vessels.

Question 23

What is the principal factor determining vascular resistance?

Answer 23

The radius of the small arteries and arterioles

Question 24

Define elevated serum lipids?

Answer 24

High amounts of fat in blood serum

Question 25

Define blood serum?

Answer 25

the clear yellowish fluid that remains from blood plasma after clotting factors (as fibrinogen and prothrombin) have been removed by clot formation.

Question 26

How much blood needs to flow into the brain per minute?

Answer 26

750ml/min

Question 27

What provides the blood supply to the brain?

Answer 27

The circle of willis, via the internal carotid arteries and vertebral arteries.

Question 28

What is cerebral autoregulation?

Answer 28

It regulates the diameters of cerebral BV in response to changes in pressure so that BF can remain the same.

Question 29

What makes up the blood brain barrier?

Answer 29

Endothelial cells which are connected by tight junctions with an extremely high electrical resistivity. The astrocyte cell surround the endothelial cells, providing biochemical support. (The astrocyte cell is necessary to create the BBB).