P: revision questions Flashcards
the size of which blood vessel is important in determining peripheral vascular resistance?
tone of ARTERIOLES
why is systolic blood pressure higher than diastolic?
as systolic pressure needs to be high enough to propel blood to the tissues, where as diastolic is just minimum resting pressue when heart relaxes to
what are the normal mechanisms that regulate blood pressure to keep it within normal range?
Baroreceptors** in carotid sinuses & aortic arch: stimulated when BP rises, inhibited when BP lowers
- > brain
- > RAS** = Renin Angiotension System
- > vasodialation/constriction, increase or decrease CO
- > Atrial Natriuretic Peptide**
- > homeostasis returned
what does systemic hypertension normally present as?
when BP is persistently higher than 140/90
what can secondary hypertension result from?
Can arise from any condition that influences BP regulation
- renal: sodium excretion, fluid retention
- endocrine: response of arterioles to sympathetic stimulation - over production of cortisul, aldosterone of ACTH
- renal artery stenosis: decrease B supply to kidney => renin => angiotension II => vasoconstriction => increase BP
risk factors of hypertension?
enviro/lifestyle:
- abdominal obesity
- insulin resistance/type 2 diabetes
- inactivity
- alco
principle mechanisms of cell injury?
1) reduced ATP
2) mitochondiral damage
3) influx Ca
4) increased Reactive Oxygen Species
5) loss of membrane integrity
6) DNA damage, protein misfolding
igG?
Vaccination
forms antibody-antigen complex(binds to antigen) which leads to it being phagocytosed, they have good memory, secondary large response
igM?
first response expressed by B cells, same response/magnitude errytime
igE
allergies - hay fever, ASTHMA
immunity to parasite infections
Hypersensitivity 1!
igA?
secreted across mucus membranes
igD?
expressed on naive B cells
hypersensitivity 1 is mediated by?
igE mediated
igE bind to mast cells
involved in anaphylactic reactions eg. asthma
hypersensitivity 2 mediated by?
igG mediated
- cytotoxic
antibodies produced by the normal immune response bind to antigens on a patients own cells
hypersensitivity 3 mediated by?
immune complex mediated
- damaging inflammation
hypersensitivity 4 mediated by?
cell mediated
how can chronic hypertension affect blood vessels?
atherosclerosis
hyaline arteriolsclerosis
benign nephrosclerosis
-> basically thickening of wall due to deposition of plasma proteins/extracellular matrix production, smooth muscle atrophy, scarring