Questions

Question 1

Discuss reg of BP including SNS control, RAAS control and mediation via baroreceptors

Answer 1

Change in BP - detected by baroR which stimulate cardiac centre in medulla
SNS activation by a1 receptors causing vasodilation = ↑ in TPR = ↑ BP

Signals sent from brain to heart via b1 receptors to ↑HR contraction = ↑ CO = ↑ BP

BaroR detect ↓ in BP or low renal BF coming into kidneys = SNS stimulates b1 receptors which cause juxtaglomerular apparatus to release renin = renin converts plasma protein angiotensinogen to angiotensin 1
Ag1 converted to Ag2 by ACE which is a very powerful vasoconstrictor = ↑ TPR = ↑ BP

Question 2

Discuss role of ANS in control of smooth muscle

Answer 2

BV: SNS activates a1 receptors in BV wall = vasocon = hypertension

Question 3

Discuss role of ANS in control of glandular secretion

Answer 3

Respiratory tract: PNS = ↑ mucus production = asthma
GI = PNS =↑ acid secretion and after prolonged secretion can lead to stomach ulcers
Eye = PNS stim lacrimal glands = ↑ production and secretion of tears

Question 4

Discuss role of ANS in control of cardiac function

Answer 4

PNS = ↓ HR
SNS = ↑ HR = ↑ BP = angina + hypertension 
BP = CO x TPR 
CO = HR x SV

Question 5

Why are chronic tissue death and destruction associated with smoking

Answer 5

SIPS –> SASP –> pro-inflammatory environment and expression of catabolic phenotype
- causes necrosis
Smoking initiates and maintains inflammatory response

Question 6

Why do people pursed lip breathe

Answer 6

Expel more co2 and ↓ WOB = ↓ dyspnoea

Back pressure inside airways to splint them open, making exit point smaller, pressure keeps the airways open

Question 7

Pathophysiology behind scarring and thickening of airways in people with smoking associated chronic bronchitis

Answer 7

Alveoli lose elastic recoil = ↓ SA = ↓ gas exchange
Bronchial tissue replaced with scar tissue which lose patency
Sputum further narrows the airways, continuation of a wet, warm environment filled with bacteria