Class 11.5 (Not On Test 1) Flashcards
Blood Vessel Conditions (What is Turbulence?)
• In body, blood flow is generally laminar.
• Laminar flow is characterized by concentric layers of blood moving in parallel down length of blood vessel. Highest velocity is found in center of vessel. Lowest velocity is found along vessel wall.
• Under conditions of high flow – such as from high blood pressure – laminar flow can be disrupted & become turbulent.
• When this occurs, blood does not flow linearly & smoothly in adjacent layers, but instead flow can be described as chaotic.
• Turbulent flow also occurs in large arteries at branch points, in diseased & narrowed (stenotic or partially
obstructed) arteries, & across stenotic
heart valves.
• Turbulence increases energy (heart action) required to drive blood flow.
What is Thrombosis?
Formation of a blood clot in a blood vessel.
What is a thrombus?
The clot itself is termed a thrombus.
What is the process of Thrombosis?
• Injury, irritation, or surface irregularity in blood vessel wall can be due to variety of causes, e.g., direct trauma, turbulence from high blood pressure, inflammation, infection, smoking, atherosclerosis (fatty deposits called PLAQUES build up between tunica intima & tunica media walls of the arteries and project into the lumen)
• PLATLETS, are always circulating in blood in inactive state, are attracted to abnormal wall section. They “activate” meaning they puff up, leave laminar blood flow & adhere to each other & site. They release chemicals that start clotting cascade.
• As part of process, FIBRIN is formed, protein
that crosslinks with itself to form mesh that
entraps red blood cells to make up thrombus.
_______________ can result in a partial or complete local occlusion of a blood vessel, or they can break off and circulate in the bloodstream.
Thrombi
What is Infarction?
• Infarction is tissue death (necrosis) due loss of its blood supply. Resulting lesion is referred to as an infarct.
• Infarctions are either occlusive (blood vessel is blocked) or hemorrhagic (blood vessel has ruptured.)
• E.g., stroke (cerebrovascular infarction) can be caused by blockage/occlusion (e.g. thrombosis, embolism) or rupture/hemorrhage of cerebral artery.
What is a embolus?
Piece of material traveling in blood vessel that should
not be there. When it reaches vessel whose lumen is too small to let it pass, it occludes vessel, causing an infarction. In this case infarction is referred to as an embolism.
Pieces of thrombus are most common type of embolus. If thrombus breaks loose & travels through bloodstream, it’s often referred to as ________________________. When it blocks a vessel, the result is called ___________________________.
• thromboembolus
• thromboembolism
Emboli can also be made up of a number of other materials, including?
fat globules (e.g. cholesterol from an atherosclerotic plaque, bone marrow from bone fracture); gas bubbles (e.g. air from syringe, or nitrogen bubbles caused by decompression sickness “the bends”); infected materials (e.g., from heart valve infections); cancer (e.g. part of a tumour), foreign substances (e.g. IV drug users injecting talc as a bulking agent with heroin, cocaine, etc.), bone chips from fracture, etc.
What is ARTERITIS?
inflammation of an artery
What is PHLEBITIS?
inflammation of a vein
What is ANGIITIS?
inflammation of blood or lymph vessel (more general term)
What is VASCULITIS?
- same meaning as angiitis
inflammation of blood or lymph vessel (more general term)
Inflammatory Conditions causes?
- Infection
Local: infected wound, abscess, surgery, etc.
Systemic: septicemia (infection circulating in bloodstream), septic embolism - Inflammatory Conditions
Autoimmune diseases (e.g., rheumatoid arthritis, SLE) - Hypersensitivity Reactions
Allergic & hypersensitive reactions to allergen; may be localized or systemic (e.g., Buerger’s Disease, sensitivity reactions to drugs, etc.) - Direct Trauma/Blow
More common in veins because they are closer to
body surface. - Some conditions are idiopathic.
Phlebitis and phlebothrombosis are also fairly common in?
- Post childbirth
- In bedridden individuals or immobilized body parts