Peripheral circulation Flashcards
What is peripheral circulation?
Blood vessels that deliver blood flow to and collect it from upper and lower boundaries of the body and contact surfaces
What 2 circulations make up peripheral circulation?
Systemic and pulmonary
What are the functions of peripheral circulation? (4)
Carries the blood, exchange nutrients, waste products and gases with tissues, contribute to regulation of BP, directs blood flow from large arteries towards tissues and from tissues towards large veins
What are conduit vessels?
Artery with lots of elastin - conducting artery - stretches/
.
What is the effect of low O2 on pulmonary circulation?
Reduces flow and re-directs it to to well ventilated areas
What is the effect of low O2 on systemic circulation?
Increase flow to deliver more oxygen to tissues
What is the triple response of Lewis to a stretch on the skin?
1) red reaction - red line (transient local vasodilation)
2) flare - spreading of redness beyond the red line due to axon reflex
3) wheal - swelling in the region of the red line (increase capillary permeability die to histamine release)
Axon reflex causes the spreading of redness beyond the red line in the triple response of Lewis, what is the axon reflex?
Neurone transmission without going through the CNS - causes a local vasodilatory response only tot he cells that the neurones originally stemmed from.
What molecule causes the triple response of Lewis?
Histamine
What type of WBCs release histamine?
Mast cells and basophils
How do smooth muscles contract?
Depolarisation causes the opening of voltage gated Ca2+ channels.
Ca2+ induced Ca2+ release from sarcoplasmic reticulum. Ca2+ binds to calmodulin, tis activates myosin light chain kinase, this phosphorylated myosin and head and stimulates contraction
What is the main molecule do cause endothelial vasodilation?
NO
