Peripheral vascular physiology

Basis of vasoconstriction

  • Appreciation of the role of G-protein mediated changes in intracellular calcium levels
  • Implications of calcium-channel blocking drugs upon vasoconstriction
  • Note: detailed knowledge of the vasoactive enzyme pathways is NOT required
  • Its role as a source of vasoactive mediators
  • Stimuli to endothelial secretion

Overview of the structure of the microcirculation

  • Terminal arterioles, capillaries, lymphatic capillaries, postcapillary venules and venules
  • Transcapillary exchange
  • Movement of lipophilic and hydrophilic substances
  • Role of tight junctions, glycocalyx and pores in determining selective passage

Filtration

  • Role of interstitial oncotic pressure and capillary hydrostatic pressure
  • Physiological basis of the net filtration of water within a capillary bed
  • Clinical effects of poor endothelial quality, low oncotic pressure and high venous pressure
  • Role of lymphatics
  • Range of pressures within which autoregulation occurs
  • Basis of the myogenic regulatory response and the effects of local vasodilatory factors
  • Role of potassium, carbon dioxide and adenosine in metabolic hyperaemia
  • Effects of inflammatory mediators in altering microcirculatory dynamics (dilation)

Pulmonary flow

  • Special arteriolar response to hypoxia (constriction) and its basis

Cutaneous flow

  • Role of arteriovenous anastomoses in thermoregulation
  • Contributory factors to enhanced local blood flow
  • Coronary metabolic hyperaemia as the basis of high oxygen extraction

Brain circulation

Skeletal muscle flow

  • Capillary recruitment via metabolic hyperaemia
  • Role of skeletal muscle beds in generating total peripheral resistance