Introduction to PA and Health Flashcards
What is the current PA recommendation from Department of Health?
150 mins per week
What is atherosclerosis?
Pools of lipid accumulating, determined by genetics and lifestyle
The wall of an artery has 3 layers, what are they?
Intima, media, adventitia
What is the inner lining of the intima formed by?
Endothelial cells that provide smooth protective coating between blood and intima layer. Damage to these cells can initiate atherosclerosis.
What is the first stage in plaque initiation?
The vascular endothelium is damaged, exposing underlying CT.
What happens after underlying CT is exposed?
Certain viruses hang around in artery wall. Damage to artery wall means WBC in area will release chemical messengers (causes inflammation).
Why are branch points common sites of atherosclerosis plaque formation?
Because of increased adhesion molecules expressed on the endothelial layer (reduced NO).
This causes more WBC to ‘stick’ to the wall
What do you tend to get in a normal artery which you may not in an infected one?
Laminar flow and production of Nitric Oxide (laminar flow switches on eNOS).
Together these help to reduce adhesion.
When there is damage to a vessel wall, chemokines attract WBC to artery wall. What happens next?
Monocytes can squeeze between gap junctions in endothelial layer, moving into the intima (DIAPEDESIS).
When monocytes are in the intima, what happens next?
Monocytes mature into macrophages, which accumulate lipids and become Foam Cells
How do smooth muscle cells migrate from the media to the intima?
Platelets, endothelial cells, and macrophages release platelet-derived growth factors (PDGF).
How do macrophages turn into foam cells?
By consuming more and more cholesterol (think of it like a pac-man cartoon)
Macrophages release MMPs and ROS, what do these do?
Destabilise a plaque through cellular cytotoxicity and necrotic core formation.
Is cholesterol dangerous?
No. not in its purest form. Cholesterol (oxidsed for example) which is modified IS dangerous.
