Cutaneous Vasculature and Thermoregulation

A presentation on cutaneous vasculature and thermoregulation.

1. CUTANEOUS VASCULATURE And Thermoregulation 14.08.20 Dr. Jerriton Final Yr PG

2. OVERVIEW

3. INTRODUCTION The skin blood flow is normally 250 to 300 mL/min but can vary from nearly zero in cold to as much as 6 to 8 L/min. The skin vascular system is unique in that it is organized into 3 functionally distinct vascular segments: the loops within the tips of the papillae, the SVP, and the DVP. It serves several functions other than blood supply. It is implicated in several skin diseases.

4. 1. DEVELOPMENT

5. ANGIOGENESIS

6. ANGIOGENESIS CONTROL

7. 2. ARCHITECTURE

8. A single vascular loop extends into the dermal papilla of the hair follicle, while a mesh of blood vessels surrounds the anagen hair follicle (CD31 IHC stain)

9. 3. ULTRASTRUCTURE

10. WEIBEL PALADE BODIES ET cell specific elongated rod-shaped storage granules in the cytoplasm Released by exocytosis in response to vascular perturbation Role in inflammation, hemostasis, regulation of vascular tone and angiogenesis

11. CONTENTS OF WPB

12. 4. FUNCTIONS

13. 4. FUNCTIONS

14. THERMOREGULATION Thermoregulation is the ability of an organism to maintain a core body temperature, which is 37° C (98°F) within an optimal physiological range. Thermoneutral zone (TNZ) is the range of ambient temperatures where the body can maintain its core temperature solely through regulating dry heat loss, i.e., skin blood flow TNZ for a naked resting human = 26°C to 36°C

15. THERMOREGULATION Non-Glabrous Skin Glabrous Skin Reflex thermoregulation by the sympathetic nervous system Cold Hot Sympathetic system Vasoconstriction Para-sympathetic system + Neurotransmitter release Vasodilatation

16. THERMOREGULATION Non-Glabrous Skin Glabrous Skin Reflex thermoregulation by the sympathetic nervous system Cold Hot Sympathetic system Vasoconstriction Para-sympathetic system + Neurotransmitter release Vasodilatation AV anastomoses (Glomus body)

17. THERMOREGULATION Non-Glabrous Skin Glabrous Skin Reflex thermoregulation by the sympathetic nervous system Cold Hot Sympathetic system Vasoconstriction Para-sympathetic system + Neurotransmitter release Vasodilatation AV anastomoses (Glomus body) Cold Hot

18. THERMOREGULATION

19. 5. DISEASES

20. POST-MENOPAUSAL HOT FLUSH Disorder of thermoregulation Rapid and exaggerated heat dissipation response Triggered by small elevations in core body temperature (d/t estrogen depletion) acting within a greatly reduced thermoneutral zone Estrogen replacement acts by reducing core body temperature

21. RAYNAUD’S DISEASE Pathological thermoregulatory reflex Exaggerated vasospastic response to cold or emotion Increased sympathetic vasoconstrictive activity, which results in increased blood flow through AV anastomosis

22. REFERENCES Rook’s Textbook of Dermatology Fitzpatrick’s Dermatology Bolognia’s Dermatology