7.1 - Neural Control Of Cv Response To EX

Question 1

What are the MAP equation and the FICK equation??

Answer 1

MAP = Q X TPR

FICK : VO2 = HRxSVxAVO2 difference

Question 2

Discuss the work of Rowell(1986) and how this was refuted by White and Raven (2014)???

Answer 2

Rowell believed that no vagal contribution occurred above 100bpm, but White showed its more linked than that, and at rest contribution is mostly vagal,but at higher intensities vagal tone subsides and increased SNS activity exists.

Question 3

What neural pathways did Basnayate et al(2011) find evidence of??

Answer 3

The insular cortex, anterior cingulate cortex, thalamic regions and the role of the midbrain

Question 4

Discuss the key EPR work from Alam and Smirk (1937)??

Answer 4

Looked particularly at the type 3 and 4 afferents - which are polymodal in nature and increase muscle SNS activity

Cuff ischaemia during exercise raised systolic pressure higher than the control and maintained this higher SBP when exercise stopped.

Question 5

Discuss the key baroreflex reset work from Williamson et al (2005)

Review this work.

Answer 5

During ex the baroreflex is reset.
During high intensity work and a higher heart rate, both the operating and centring point exist at a higher arterial blood pressure .
This gap increases with intensity, as the operating point gets closer to the threshold .

Question 6

What did Williamson (2010) show??

Answer 6

That the exercise pressor reflex modulates central command, with RPE playing a role - see diagram.

Question 7

What is functional sympatholysis (Buckwater and Clifford, 2001)????

Answer 7

The paradox between localised vasodilation (to increase active muscle blood flow) and systematic vasoconstriction (to regulate blood pressure).

Question 8

What did (Seals 2004) suggest?

Answer 8

Does Robin Hood Exists for the lung? - a respiratory metaboreflex that ‘steals’ blood flow from the locomotor muscles
- provided evidence of increased sympathetic vasoconstriction when the respiratory muscles are fatigued (⬆️reflex activating metabolites + ⬆️ group III/IV phrenic afferent discharge)

Question 9

What did Smith et al (2005) show?

Answer 9

⬆️firing from the group III afferent neurones leads to an exaggerated EPR (In turn , organ damage, muscle fatigue and increased PVR)