Lipids/ cardiovascular pathophysiology & Pathophysiology of thyroid glands Flashcards
What other disorders of the body are affected by vascular disease?
- Stroke- Strokes are caused by blocked BV in the brain
2.Angina- caused by restricted blood supply to the heart Muscle
- Coronary heart disease- BV to heart , reducing the blood supply to heart muscle
4.Heart failure- Heart cannot pump properly and supply to the body
5.Rheumatic heart disease - Damage to the heart from rheumatic fever
- Birth heart defects- Defects heart structures existing at birth
- Deep vein thrombosis- Blood clots formed in the leg veins which move to the heart and lungs
Epidemiology of Vascular Disease?
-Worldwide effected
- Low social economic
Risk factors of CVD
Non-modifiable factors:
1. Age
2.Gender
3. Race & Ethnicity
4. Genetic factors
Modifiable factors:
1. High BP
2. Smoking
3. Obesity
4. High blood cholesterol
5. Diabetes
6. Physical inactivity
What is the old and new concept of the Atherogenesis?
Old= Healthy -> Subclinical- Small plague (Lipid deposit)-> Symptomatic- Plague takes over the whole shape (Mths- Days)
New= Healthy -> Arterial wall bulges outward with the deposition of the collateral deposits -> Endothelial cells are disrupted causing activation of platelets, platelet puck the endothelial lining and case formation of blood clot and thrombus
What is the information about cholesterol?
Structural component (30%) of Cell membranes.
Precursor for steroid hormone synthesis.
Structural component of lipoproteins
What is the information about LDL cholesterol?
- Strongly associated with atherosclerosis and CHD events
– 10% increase results in an approximate 20% increase in CHD risk
– Most of the cholesterol in plasma is found in LDL particles
– Smaller denser LDL are more atherogenic than larger, less dense particles
– Risk associated with LDL-C is increased by other risk factors such as Low serum [HDL-C] Smoking Hypertension & Diabetes
LDL Receptor Structure
*Best characterised lipoprotein receptor
- Membrane bound
- 5 major domains
- Internalises LDL into cell
- Recognises apoE & apo-B100
- Binds:
VLDL, IDL, Chylomicron remnants & LDL
HDL cholesterol?
- HDL has a protective effect for risk of atherosclerosis and CHD
- Epidemiological studies show the lower the HDL level, the higher the risk for atherosclerosis and CHD
- HDL tends to be low when triglycerides are high
- HDL is lowered by smoking, obesity and physical inactivity
- ApoA-I is the major apolipoprotein in HDL and an elevatedapoA-I is linked to reduced CVD risk
Key info on Triglycerides?
1.May be associated with increased risk of CHD event
- Link with increased CHD risk is complex
- May be direct effect of smaller TG-rich lipoproteins and/or
- May be related to: low HDL concentrations, hyperinsulinaemia/insulin resistance, hypertension and abdominal obesity
What are lipoproteins?
- Molecular complexes that consist of lipids and proteins.
- They function as transport vehicles for lipids in blood plasma
- Lipoproteins deliver the lipid components (cholesterol andtriglyceride etc.) to various tissues for use.
Structure of lipoproteins
Phospholipid
triglyceride
free cholesterol9i
Info about Apolipoproteins
- The protein composition differs from one lipoproteinclass to another
- Activate enzymes involved in lipid metabolism (LCAT,LPL)
3.Maintain structural integrity of lipid/protein complex 4. Delivery of lipids to cells via recognition of cell surface receptors
What are the different types Apolipoproteins?
apoA-I- HDL structural protein;
apoA-II-HL activation
apoA-IV - Tg metabolism; LCAT activator; diet response
What are the two thyroid hormones and why are they important?
Thyroxine (T4) and triiodothyronine (T3)
* For normal growth and development and have many effects on metabolic processes
- Effect on metabolism to stimulate the basal metabolic rate
Key information about Thyrotropin-releasing hormone (TRH)?
*3 amino acid peptide hormone
* glu-his-pro
* Reference range 24 – 138 pg/mL
* Half-life 4 – 5 minutes
* Receptors embedded in anterior pituitary cell membranes
* Binding of hormone = activates of G protein-phospholipase C - Ca2+-protein kinase-phosphorylated protein cascade
