Blood Pressure Control

Question 1

Blood Pressure

Answer 1

• Pressure exerted on the walls of blood vessel
• Enables blood to circulate perfuse cells
• 120/80 same amount of blood an pressure mmHg
• Pulmonary 25/8 mmHg

Question 2

Systolic BP

Answer 2

• MAP during heart contraction

Question 3

Diastolic BP

Answer 3

• MAP during heart relax

Question 4

BP

Answer 4

Cardiac Output x Peripheral Resistance

Question 5

Cardiac Output

Answer 5

• Heart Rate x Stroke Volume
• 70ml

Question 6

Autoregulation

Answer 6

• Normal resting redistributing blood as needed by tissue by receptors
• Vasodilation and constriction

Question 7

Autoregulation of perfusion to increase bp

Answer 7

• Cell has surplus oxygen and low metabolic waste
• Moves blood faster stimulate endothelial cell and prostaglandin
• Vasoconstricts precapillary sphincters

Question 8

Autoregulation to decrease BP

Answer 8

• Cell has low level of oxygen and high levels of metabolic waste
• Requires blood to move slowly
• Release nitric oxide stimulate endothelial cell
• Vasodilation occurs

Question 8

Myogenic response

Answer 8

• Stretching of smooth muscle
• Blood flow high stretch and if low then constrict

Question 8

Neural regulation

Answer 8

• Baroreceptors pressure sensor causes aortic arch vagal innovated to the pons in the brainstem vasomotor centre - relax heart
• Carotid artery sense the pressure in walls of aorta connected by glossopharyngeal nerve connected to brainstem

Question 9

Neural regulation

Answer 9

• Low Pressure so decrease firing rate at baroreceptors decrease vagal nerve
• Increase heat rate by increase sympathetic (noradrenaline) therefore increase heat contract + heart rate
• Increase cardiac output

Question 9

Hormonal (RAAS)

Answer 9

• Low blood volume (sodium movement) detected by the kidney’s juxtaglomerular cells
• Stimulate release of renin
• Convert the livers angiotensinogen to angiotensin I then Angiotensin converting enzyme from lungs converts I to II
• Vasoconstrictor peripheral resistance
• Stimulate adrenal cortex to stimulate aldosterone
• Increase sodium reabsorb, water reabsorb

Question 9

Erythropoietin

Answer 9

• Kidney becomes hypoxic trigger epo release
• Stimulate the red bone marrow to produce more erythrocytes
• Erythrocytes increase O2 transport and restore O2 level
• Increase blood viscous decrease blood flow

Question 10

Adrenaline/Nor-adrenaline

Answer 10

• Released by the adrenal medulla Enhance and extend the body’s sympathetic activity
• Increase heart rate

Question 11

Hypotension

Answer 11

• Hypovolemia - low volume blood dehydration

Question 12

Structural dysfunction

Answer 12

• Valve disease
• Ischemia

Question 13

Hypovolemia

Answer 13

• ADH is secreted by
  hypothalamus, transported to the posterior pituitary and stored until nervous stimuli.
• ADH signals kidneys to reabsorb more water
• Prevent the loss of fluids in the urine.
• Increase overall fluid levels
• ADH constricts peripheral vessels.
• Restore blood volume and pressure

Question 14

High blood pressure

Answer 14

• Increase baroreceptors firing which causes increase in vagal activity
• Causes decrease in sympathetic activity which decrease heart rate
• Decrease release of heart contract and heart rate decrease

Question 15

Hormonal high blood pressure

Answer 15

• Detected by juxtaglomerular cells
  -No Production of Renin no conversion or stimulation of adrenal
• Decrease sodium reabsorb
• Remain dilated no constriction

Question 16

ANP (Atrial Natriuretic Peptide)

Answer 16

• Secreted by cells in the atria of the heart B-type ANH
• Antagonist to angiotensin II
• Decrease secretion of Renin aldosterone and ADH
• Decrease blood vol

Question 17

Hypertension

Answer 17

• Sodium homeostasis (renal disease, decrease nephron) stroke vol increase
• Hormone Imbalance increase heart rate
• Peripheral resistance systemic vasoconstriction
• Structural dysfunction - endothelial dysfunction