Neural cardiovascular control during exercise: influence of sex and ovarian hormones

Hartwich, Doreen (2012). Neural cardiovascular control during exercise: influence of sex and ovarian hormones. University of Birmingham. Ph.D.

Preview

Hartwich_12_PhD.pdf
PDF
Download (1MB)

Abstract

Cardiovascular control during exercise results from three main mechanisms, namely central command (descending neural input), skeletal muscle afferent feedback (metabo - and mechanoreflex) and the arterial baroreflex. The studies outlined in this thesis sought to examine the potential sex- and ovarian hormone influences in neural cardiovascular control during exercise. It was observed that the activation of metabolically sensitive skeletal muscle afferents (i.e. muscle metaboreflex) by partial restriction of blood flow to the exercising skeletal muscle contributes to the exercise tachycardia via a reduction in cardiac baroreflex sensitivity from rest during dynamic exercise. Importantly, the magnitude of this metaboreflex-mediated reduction in cardiac baroreflex responsiveness was not different between men and women during the early and late follicular phases of the ovarian cycle. Baroreflex perturbation during dynamic exercise, by means of hypotensive and hypertensive stimuli to the carotid baroreceptors, revealed that baroreflex control of blood pressure was similarly maintained during exercise in men and women. Finally it was demonstrated that the sympathetic vasoconstriction in the exercising limb is similarly blunted in men and women. Overall, the results of this thesis suggest that there are no differences between men and women in baroreflex function and sympathetic vascular responsiveness during dynamic exercise.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

Supervisor(s):