Basic Anatomy Of The Heart And Major Vessels Flashcards
What is haematocrit?
Ratio of the volume of rbc to the total volume of blood.
Plasma = 56%
Wbc = 0.5%
Rbc = 44%
Structure of blood vessels
Tunica intima, Tunica media, tunica external / adventitia
Tunica intima
Endothelium and internal elastic lamina (arteries)
Tunica media
Muscle cells and external elastic membrane
Tunica external / adventitious
Collagen and vasa vasorum
Elastic Artery size and example
More than 1cm, aorta
Muscular Artery size and example
Large = 2-10mm, femoral Small = 0.1-2mm, lingual
Arterioles size
10-100um
Large vein size and example
More than 1cm, IVC
Small / medium veins size and example
0.1-10mm facial
Venule size
50-100um
Endothelium Functions
- Selectively permeable barrier (diffusion and transport)
- Provides non-thrombogenic barrier ( no blood clotting but secreting anticoagulants)
- Control of blood blood / resistance (vasoconstriction and vasodilation)
Two categories of capillaries?
Continuous (blood brain barrier)
Fenestrated
Where are the valves in the heart located?
Between the atrium and ventricle and between the left and right ventricles
Valves description
Fibrocollagenous ring, electrically isolates atria from ventricles
Angina pectoris
Decrease in blood flow due to Artery blockage, case anaerobic respiration in cardiac muscle causing a build of lactic acid causing pain
Major features of conduction in cardiac muscle AP
Sinoatrial node, a ventricular node, bundle of His and purkinje fibres
Sympathetic influences of ANS
Sympathetic increases HR and contractility, vasodilation of CA.
Parasympathetic influences of ANS
Decreases HR
Blood problems causes anaemia what is this?
Condition in which there is a deficiency of red blood cells or haemoglobin in the blood, causing weariness
Problems with blood vessels affecting lumen size causes?
Atherosclerosis a disease in the arteries where the deposition of fatty material on their inner walls
What is ischemia and how is it caused?
Ischemia is inadequate blood supply to an organ or part of the body, especially heart muscle. Caused by heart problems or lumen size in blood vessel problems
Heart problems can cause infarction what is this?
Tissue death caused by a reduction / stopping blood flow due to artery blockage, mechanical compression, rupture of vasoconstriction.
Stenosis is caused by valve failure in the heart what is this?
Abnormal narrowing of a passage in the body
