lecture 8 - Blood Pressure Control and Tissue Perfusion

Question 1

Most common results of high bp

Answer 1

62% stroke, 49% of heart disease

Question 2

high bp can also cause

Answer 2

intracerebral haemorrhage

Question 3

left ventricular failure can causEʔ

Answer 3

pulmonary oedema

Question 4

What are the consequences of uncontrolled hypertensionʔ

Answer 4

Strokeː haemorrhage/ischaemia
lv hypertrophy, diastolic dysfunction, atrial fibrillation, heart failure
hastened atherosclerosis
vascular diseasesː coronary, peripheral arterial
retinopathy
renal failure

Question 5

Evidence for Salt increasing Blood pressure

Answer 5

All defects result in decreased ability of the kidney to excrete sodium

Question 6

Alcohol consumption

Answer 6

causes high hp

70%reduction in alcohol - reduce by 3.4/2.1 mmhg

Question 7

ischaemic heart disease and stroke deaths increase withʔ

Answer 7

increase in BP and increase in age

Question 8

how do mechanoreceptors respond to an increase in BP

Answer 8

Mechanoreceptors respong to stretch, excites baroreceptors

Question 9

Aortic nerve

Answer 9

Vagus (10th)

Question 10

Carotid sinus

Answer 10

glossopharyngeal (9th)

Question 11

Where do baroreceptors afferents projectʔ

Answer 11

9th and 10th cranial nerves in the cardiovascular centre

Question 12

What does an increase in afferent input result in

Answer 12

increase in parasympathetic and decrease in sympathetic effects on the heart

Question 13

Where is the cardiovascular centre of the heart locatedʔ

Answer 13

in the medulla oblongata of the brainstem

region - nucleus tractus solitarius

Question 14

What is orthostatic (postural) hypotensionʔ

Answer 14

gravitational venous pooling of blood to lower extremities. happens from when you stand up from lying down
there is an increase in dependent venous blood pooling
decrease in pulse pressure and mean arterial pressure

Question 15

Where are baroreceptors locatedʔ

Answer 15

Aortic arch and carotid sinus

Question 16

What increases heart rate and contracility

Answer 16

norepinephrine and norepinephrine

Question 17

Which hormone causes vasoconstriction

Answer 17

angtiotensin 2

Question 18

Which hormones cause vasodilation

Answer 18

Atrial natriuretic peptide
Epinephrine
nitric oxide

Question 19

What causes an increase in blood volume

Answer 19

Aldosterone and ADh acts on the collecting ducts of the kidneys and increases water reabsoprtions and an increase in volume - increase in BP

Question 20

what causes a decrease in blood volume

Answer 20

atrial natriuretic peptide

Question 21

Capillariesː Anatomy and histology

Answer 21

single layer of endothelial cells.
dimensions - 5-10 micrometers
cns - very tight
liver and bone marrow - large clefts between cells

Question 22

What are the types of capillariesʔ

Answer 22

Continuous capillaries,
fenestrated capillaries
Discontinuous capillaries

Question 23

locations of continuous capillarieS

Answer 23

Fat muscle, nervous system

Question 24

locations of fenestrated capillaries

Answer 24

intestinal villi
endocrine glands
kidney glomeruli

Question 25

locations of discontinuous capillaries

Answer 25

liver, bone marrow and spleen

Question 26

Startling's law of the capillaries

Answer 26

Starling's hypothesis states that the fluid movement due to filtration across the wall of a capillary is dependent on the balance between the hydrostatic pressure gradient and the oncotic pressure gradient across the capillary.

Question 27

What is oedema

Answer 27

An increase in volume of the interstitial fluid above normal due to increase in venous back pressure on capillaries

Question 28

right heart failure leads to

Answer 28

systemic oedema

Question 29

left heart failure leads to

Answer 29

pulmonary oedema